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Stachowska-Pietka J, Poleszczuk J, Flessner MF, Lindholm B, Waniewski J. Alterations of peritoneal transport characteristics in dialysis patients with ultrafiltration failure: tissue and capillary components. Nephrol Dial Transplant 2020; 34:864-870. [PMID: 30403818 DOI: 10.1093/ndt/gfy313] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Ultrafiltration failure (UFF) in peritoneal dialysis (PD) patients is due to altered peritoneal transport properties leading to reduced capacity to remove excess water. Here, with the aim to establish the role of local alterations of the two major transport barriers, peritoneal tissue and capillary wall, we investigate changes in overall peritoneal transport characteristics in UFF patients in relation to corresponding local alterations of peritoneal tissue and capillary wall transport properties. METHODS Six-hour dwell studies using 3.86% glucose solutions and radioisotopically labelled serum albumin added to dialysate as a volume marker were analysed in 31 continuous ambulatory PD patients, 20 with normal ultrafiltration (NUF) and 11 with UFF. For each patient, the physiologically based parameters were evaluated for both transport barriers using the spatially distributed approach based on the individual intraperitoneal profiles of volume and concentrations of glucose, sodium, urea and creatinine. RESULTS UFF patients as compared with NUF patients had increased solute diffusivity in both barriers, peritoneal tissue and capillary wall, decreased tissue hydraulic conductivity and increased local lymphatic absorption and functional decrease in the fraction of the ultra-small pores. This resulted in altered distribution of fluid and solutes in the peritoneal tissue, and decreased penetration depths of fluid and solutes into the tissue in UFF patients. CONCLUSIONS Mathematical modelling using a spatially distributed approach for the description of clinical data suggests that alterations both in the capillary wall and in the tissue barrier contribute to UFF through their effect on transport and distribution of solutes and fluid within the tissue.
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Affiliation(s)
- Joanna Stachowska-Pietka
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Jan Poleszczuk
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | | | - Bengt Lindholm
- Divisions of Baxter Novum and Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Jacek Waniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
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Abstract
Objective The present study aimed to develop an animal model of chronic peritoneal exposure that directly links transport with the tissue involved. Methods Daily, rats were intraperitoneally infused through subcutaneous ports with 20 mL of these solutions: isotonic Krebs (K), K + 2.5% mannitol (M), K + 2.5% N-acetylglucosamine (NAG). Controls included catheter-only (CC) and age-control rats (AC). After 2 months, each rat was anesthetized and a plastic chamber was affixed to the abdominal wall serosa to isolate a portion of the peritoneum for transport studies. In the first 90 minutes, a hypertonic solution (approximately 500 mosm/kg) containing 14C-mannitol was placed in chamber. The volume and 14C concentration were measured to determine the rate of osmotic flux (flow/Areachamber) into the chamber and the flux of mannitol from the chamber to the tissue. At 90 minutes, fluorescein isothiocyanate conjugate (FITC)–albumin was given intravenously. The rate of appearance of that substance in the chamber was measured over a period of 180 minutes and divided by Areachamber to determine the average flux. After the rat was humanely killed, the tissue under the chamber was collected for analysis of its hyaluronan concentration ([HA]). Results All data are given as mean ± standard error: Group Osmotic (μL/cm2) Flux per hour Mannitol (/cm2) Albumin (/cm2) [HA] (μg/g dry) AC 69.9±14.0 0.043±0.004 0.0114±0.0012 1247±136 CC 65.5±8.0 0.040±0.013 0.0105±0.0027 1360±157 K 47.0±11.5 0.067±0.015 0.0116±0.0027 1134±160 M 101±20 0.044±0.017 0.0300±0.0120 1146±157 NAG 72.6±11.4 0.052±0.006 0.0188±0.0144 1240±157 Conclusions In the present pilot study, no significant correlations were observed, but the number of animals in each group was small ( n = 3 – 4). Nevertheless, the results demonstrate the ability of the chamber technique to determine transperitoneal transport of water, small solutes, and protein, and to link those values directly to the structure of the tissue lying below the chamber. Thus, chronic treatment can be directly correlated with peritoneal structure and transport function.
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Zakaria ER, Lofthouse J, Flessner MF. Hydrostatic and Osmotic Pressures Modulate Partitioning of Tissue Water in Abdominal Muscle during Dialysis. Perit Dial Int 2020. [DOI: 10.1177/089686089901902s34] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objectives To investigate the effect of simultaneous exposure of anterior abdominal muscle (AAM) to changes in intraperitoneal hydrostatic pressure (Pip) and to osmolality of peritoneal fluid on total tissue water (TTW) and on the pattern of distribution of TTW in the AAM. Design A pilot study of single 60-min dwells in anesthetized Sprague-Oawley (SO) rats, dialyzed with either isotonic (290 mOsm/kg) or hypertonic (510 mOsm/kg) dialysis solutions at nominal Pi of 0 mmHg or 6 mmHg. Measurements TTW (from dry-weight-to-wet -weight ratios) can be divided into the extracellular volume [0ec’ from quantitative autoradiography (QAR) with 14C-mannitol] and intracellular volume (0ic = TTW -0ec). 0ec = 0if + 0iv’ where 0if = interstitial volume and 0iv = vascular volume [from QAR with 1311-immunoglobulin G (lgG)]. All measured parameters are standardized to tissue dry weight and expressed as mean ± standard error. Results Regardless of the osmolality of the dialysis solution, elevation of PiP to 6 mmHg results in tissue expansion, primarily in 0if’ which is doubled to 1.71 ± 0.11 mUg dry weight and 1.60 ± 0.17 mUg dry weight with isotonic and hypertonic dialysis, respectively, as compared to controls (0.64 ± 0.04 mUg dry weight). The local 0iv was not affected by Pip or osmolality of the bathing solution. The overall 0iv is 0.046 ± 0.006 mUg dry weight. A two-way analysis of variance (ANOVA) to access the effect of osmolality and Pip on 0ic demonstrated no significant change in 0ic (F = 1.2, p > 0.1) as calculated for controls (3.13 ± 0.19 mUg dry weight), after isotonic dialysis (3.13 ± 0.20 mUg dry weight), or after hypertonic dialysis (2.77 ± 0.30 mUg dry weight). Conclusion Elevation of Pip to 6 mmHg significantly increased TTW and expanded the tissue. Tissue expansion is primarily in interstitium (0if, which is doubled from control value regardless of dialysis fluid osmolality.
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Affiliation(s)
- El Rasheid Zakaria
- Nephrology Unit, Department of Medicine, University of Rochester Medical Center, Rochester, New York, U.S.A
| | - Joanne Lofthouse
- Nephrology Unit, Department of Medicine, University of Rochester Medical Center, Rochester, New York, U.S.A
| | - Michael F. Flessner
- Nephrology Unit, Department of Medicine, University of Rochester Medical Center, Rochester, New York, U.S.A
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Abstract
Objective We investigated the assumption that blood flow to the microvessels underlying the peritoneum does not limit solute or water exchange between the blood and the dialysis fluid. Design Small plastic chambers were affixed to the serosal side of the liver, cecum, stomach, and abdominal wall of anesthetized rats. Solutions that contained labeled solutes or that were made hypertonic were placed into the chambers, which restricted the area of transfer across the tissue to the base of the chamber and which permitted calculation of mass or water transfer rates on the basis of area. The local blood flow was monitored continuously with a laser Doppler flowmeter during three periods of observation: control, after 50% -70% reduction of the blood flow, and postmortem. Results Urea transfer across all serosa, except for the liver, showed no difference in mean mass transfer coefficient (cm/min) between control (0.0038 0.0046) and after 70% flow reduction (0.0037 -0.0040), but demonstrated a significant decrease with blood flow equal to zero (0.0020). These tissues demonstrated small but insignificant decreases in osmotic water flow into the chamber (0.7 -0.9 μL/min/cm2 under control conditions versus 0.4 -0.7 μL/min/cm2 with reduced blood flow). The liver demonstrated limitations in water and solute transport with a 70% decrease in blood flow. Conclusion Because the liver makes up a small part of the peritoneal area, we conclude that large drops in blood flow do not limit overall solute or water transfer across the peritoneum during dialysis, and therefore acute peritoneal dialysis may be an appropriate modality for ICU patients in shock and renal failure.
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Affiliation(s)
- Michael F. Flessner
- Nephrology Unit, Department of Medicine, University of Rochester Medical Center; Rochester; New York, U.S.A
| | - Joanne Lofthouse
- Nephrology Unit, Department of Medicine, University of Rochester Medical Center; Rochester; New York, U.S.A
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Abstract
Transperitoneal transport is a complicated process that includes diffusion and convection across the walls of blood microvessels into tissue interstitium, transport through the interstitium, and final passage across the peritoneum to the dialysis solution in the cavity. The purpose of this paper is to briefly review the normal physiology of this process and then to summarize the events that occur in response to inflammation within the cavity. These events begin with stimulation of macrophages, which in turn secrete cytokines. The cytokines stimulate mesothelial cells and fibroblasts in the tissue to synthesize and secrete other mediators. Those mediators initiate the complex events through which leukocytes migrate from blood vessel lumens through the interstitium and into the cavity. Much of the available data is from model in vitro systems, and therefore in vivo events must be deduced or hypothesized.
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Abstract
Recent advances in the study of the microcirculation have demonstrated the critical role of the endothelial glycocalyx in transcapillary transport from the plasma to the tissue interstitium. Since the capillary wall represents the initial resistance to solute transfer from the plasma through the tissue to the dialysate, the glycocalyx is potentially of major importance to peritoneal dialysis. Inadvertently removed in early histological studies, this thin, delicate layer of glycosaminoglycans and proteoglycans is now recognized as a primary barrier in transendothelial solute and water transport. Subperitoneal endothelia are exposed to inflammation, angiogenesis, and hyperglycemia, which have been shown to affect the layer by increasing permeability. This entity permits new hypotheses concerning the factors that influence the transport characteristics of peritoneal dialysis patients and provides new avenues of basic research into the fundamental mechanisms of alteration of the peritoneal barrier.
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Affiliation(s)
- Michael F. Flessner
- Division of Nephrology, University of Mississippi Medical Center, Jackson, Mississippi, USA
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Choi J, Credit K, Henderson K, Deverkadra R, Vanpelt HM, He Z, Flessner MF. Antibiotic Prophylaxis in an Animal Model of Chronic Peritoneal Exposure. Perit Dial Int 2020. [DOI: 10.1177/089686080602600222] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Objectives Acute infection in an animal model of chronic peritoneal dialysis (PD) induces structural changes in the peritoneum and alters functional characteristics of transport. These changes may compromise observations of the chronic effects of dialysis solutions. To test the hypothesis that antibiotics would prevent acute infection without affecting transport and structural properties, we characterized the frequency of infection in our rat model of PD and examined whether the inclusion of antibiotics in the dialysis solution altered the transport and structural properties of the peritoneum. Design Female Sprague–Dawley rats were aseptically injected daily under gas anesthesia with 30 – 40 mL of a sterile solution for 2 months via a peritoneal catheter tunneled to a subcutaneous port. Solutions used were Krebs–Ringer bicarbonate (KRB) alone, KRB with antibiotics (cefazolin 200 mg/L and gentamicin 2 mg/L), KRB with 4% glucose, and KRB with both glucose and antibiotics. After 2 months, osmotic filtration and solute transport were assessed in each animal and peritoneal fluid was collected for bacterial culture. Angiogenesis was evaluated by quantitative image analysis of tissue sections stained with CD31. Tissue content of collagen, hyaluronic acid, and sulfated glycosaminoglycan was determined. Results Technique survival (successful PD for 2 months) and infection rate were comparable among all treated groups. There were no differences between the groups in transport properties. Structural changes were comparable between groups, with or without antibiotics. Conclusions Addition of antibiotics to the dialysis solution did not affect the transport characteristics of the peritoneum or the pathologic reaction of the tissue to the PD solution.
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Affiliation(s)
- Jaehwa Choi
- Department of Medicine University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Kimberly Credit
- Department of Medicine University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Karla Henderson
- Department of Medicine University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Ravi Deverkadra
- Department of Medicine University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Heather M. Vanpelt
- Department of Medicine University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Zhi He
- Department of Pathology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Michael F. Flessner
- Department of Medicine University of Mississippi Medical Center, Jackson, Mississippi, USA
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Raphael KL, Isakova T, Ix JH, Raj DS, Wolf M, Fried LF, Gassman JJ, Kendrick C, Larive B, Flessner MF, Mendley SR, Hostetter TH, Block GA, Li P, Middleton JP, Sprague SM, Wesson DE, Cheung AK. A Randomized Trial Comparing the Safety, Adherence, and Pharmacodynamics Profiles of Two Doses of Sodium Bicarbonate in CKD: the BASE Pilot Trial. J Am Soc Nephrol 2019; 31:161-174. [PMID: 31848294 DOI: 10.1681/asn.2019030287] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 09/06/2019] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Oral sodium bicarbonate (NaHCO3) may preserve kidney function in CKD, even if initiated when serum bicarbonate concentration is normal. Adequately powered trials testing this hypothesis have not been conducted, partly because the best dose for testing is unknown. METHODS This multicenter pilot trial assessed the safety, tolerability, adherence, and pharmacodynamics of two doses of NaHCO3 over 28 weeks in adults with eGFR 20-44 or 45-59 ml/min per 1.73 m2 with urinary albumin/creatinine (ACR) ≥50 mg/g and serum bicarbonate 20-28 meq/L. We randomly assigned 194 participants from ten clinical sites to receive higher-dose (HD-NaHCO3; 0.8 meq/kg of lean body wt per day; n=90) or lower-dose (LD-NaHCO3; 0.5 meq/kg of lean body wt per day; n=52) NaHCO3 or matching placebo (n=52). The dose was adjusted depending on side effects. The prescribed dose at week 28 was the primary outcome; a dose was considered acceptable for a full-scale trial if ≥67% of participants were on full-dose and ≥80% were on ≥25% of the per-protocol dose. RESULTS Mean±SD baseline eGFR was 36±9 ml/min per 1.73 m2, serum bicarbonate was 24±2 meq/L, and median (IQR) ACR was 181 (25-745) mg/g. Both doses were well tolerated without significant changes in BP, weight, or serum potassium. The proportions of adverse events and hospitalizations were similar across the groups. Consequently, 87% in HD-NaHCO3, 96% in LD-NaHCO3, and 87% in placebo were on full dose at week 28; and 91% in HD-NaHCO3, 98% in LD-NaHCO3, and 92% in placebo were on ≥25% of the per-protocol dose. Mean urinary ammonium excretion was 25% lower and serum bicarbonate concentration was 1.3 meq/L higher in HD-NaHCO3 compared with LD-NaHCO3 at week 28. However, mean ACR increased by 12% in the lower-dose group and 30% in the higher-dose group. CONCLUSIONS Both NaHCO3 doses were well tolerated over 28 weeks with no significant difference in adverse events or hospitalization compared with placebo. The higher dose lowered urinary ammonium excretion and increased serum bicarbonate more than the lower dose but was associated with a greater increase in ACR. The higher 0.8 meq/kg of lean body wt per day dose of NaHCO3 may be a reasonable choice for future trials.
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Affiliation(s)
- Kalani L Raphael
- Department of Internal Medicine, University of Utah Health and Renal Section, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah;
| | - Tamara Isakova
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Joachim H Ix
- Department of Medicine, University of California San Diego and Renal Section, Veterans Affairs San Diego Healthcare System, San Diego, California
| | - Dominic S Raj
- Division of Renal Diseases and Hypertension, Department of Medicine, George Washington University School of Medicine, Washington, DC
| | - Myles Wolf
- Division of Nephrology, Department of Medicine, Duke Clinical Research Institute, Duke University, Durham, North Carolina
| | - Linda F Fried
- Department of Medicine, University of Pittsburgh and Renal Section, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, Pennsylvania
| | - Jennifer J Gassman
- Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Cynthia Kendrick
- Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Brett Larive
- Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Michael F Flessner
- Division of Kidney, Urologic, and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Susan R Mendley
- Division of Kidney, Urologic, and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | | | | | - Ping Li
- Renal Section, Veterans Affairs Washington, DC Health Care System, Washington, DC
| | - John P Middleton
- Division of Nephrology, Department of Medicine, Duke Clinical Research Institute, Duke University, Durham, North Carolina
| | - Stuart M Sprague
- Department of Medicine, Northshore University Health System, University of Chicago, Evanston, Illinois; and
| | - Donald E Wesson
- Health and Wellness Center, Baylor Scott & White Health, Dallas, Texas
| | - Alfred K Cheung
- Department of Internal Medicine, University of Utah Health and Renal Section, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
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Ix JH, Isakova T, Larive B, Raphael KL, Raj DS, Cheung AK, Sprague SM, Fried LF, Gassman JJ, Middleton JP, Flessner MF, Block GA, Wolf M. Effects of Nicotinamide and Lanthanum Carbonate on Serum Phosphate and Fibroblast Growth Factor-23 in CKD: The COMBINE Trial. J Am Soc Nephrol 2019; 30:1096-1108. [PMID: 31085679 DOI: 10.1681/asn.2018101058] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 03/11/2019] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Higher serum phosphate and fibroblast growth factor-23 (FGF23) levels may be modifiable to prevent cardiovascular disease in CKD. Short-term studies have reported modest efficacy in phosphate and FGF23 reduction with intestinal phosphate binders in CKD. METHODS To investigate effects of lanthanum carbonate (LC; a phosphate binder) and/or nicotinamide (NAM; an inhibitor of active intestinal phosphate transport) on serum phosphate and FGF23 in stage 3b/4 CKD, we conducted a randomized trial among individuals with eGFR 20-45 ml/min per 1.73 m2 to NAM (750 mg twice daily) plus LC (1000 mg thrice daily), NAM plus LC placebo, LC plus NAM placebo, or double placebo for 12 months. Dual primary end points were change from baseline in serum phosphate and intact FGF23 concentrations. RESULTS Mean eGFR for the 205 participants was 32ml/min per 1.73 m2. At baseline, serum phosphate was 3.7 mg/dl and median FGF23 was 99 pg/ml (10th, 90th percentiles: 59, 205). Mean rates of change in phosphate increased slightly over 12 months in all groups and did not differ significantly across arms. Similarly, percent changes in FGF23 per 12 months increased for all arms except LC plus placebo, and did not differ significantly across arms. Gastrointestinal symptoms limited adherence. Adverse events rates were similar across arms. CONCLUSIONS LC and/or NAM treatment did not significantly lower serum phosphate or FGF23 in stage 3b/4 CKD over 12 months. Although these agents appeared safe, intestinal symptoms limited adherence. Reducing phosphate and FGF23 in nondialysis CKD will require new approaches.
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Affiliation(s)
- Joachim H Ix
- Division of Nephrology-Hypertension, Department of Medicine and .,Nephrology Section, Veterans Affairs San Diego Healthcare System, La Jolla, California.,Division of Preventive Medicine, Department of Family Medicine and Public Health, University of California San Diego, San Diego, California
| | - Tamara Isakova
- Division of Nephrology and Hypertension.,Department of Medicine, and.,Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Brett Larive
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio
| | - Kalani L Raphael
- Salt Lake City Veterans Affairs Healthcare System and.,Division of Nephrology and Hypertension, University of Utah Health, Salt Lake City, Utah
| | - Dominic S Raj
- Division of Renal Diseases and Hypertension, George Washington University, Washington, DC
| | - Alfred K Cheung
- Salt Lake City Veterans Affairs Healthcare System and.,Division of Nephrology and Hypertension, University of Utah Health, Salt Lake City, Utah
| | - Stuart M Sprague
- Division of Nephrology, Department of Medicine, NorthShore University Health System-University of Chicago, Pritzker School of Medicine, Evanston, Illinois
| | - Linda F Fried
- Renal Section.,Veterans Affairs Pittsburgh Healthcare System, and.,University of Pittsburgh School of Medicine and University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania
| | - Jennifer J Gassman
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio
| | - John P Middleton
- Division of Nephrology.,Department of Medicine, and.,Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina
| | - Michael F Flessner
- Division of Kidney, Urologic, and Hematologic Disorders, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland; and
| | | | - Myles Wolf
- Division of Nephrology.,Department of Medicine, and.,Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina
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Brosnahan GM, Abebe KZ, Moore CG, Bae KT, Braun WE, Chapman AB, Flessner MF, Harris PC, Hogan MC, Perrone RD, Rahbari-Oskoui FF, Steinman TI, Torres VE, The Halt Pkd Investigators. Determinants of Progression in Early Autosomal Dominant Polycystic Kidney Disease: Is it Blood Pressure or Renin-Angiotensin-Aldosterone-System Blockade? Curr Hypertens Rev 2019; 14:39-47. [PMID: 29564978 PMCID: PMC6063360 DOI: 10.2174/1573402114666180322110209] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 03/02/2018] [Accepted: 03/05/2018] [Indexed: 12/17/2022]
Abstract
Background The HALT PKD trial in early autosomal dominant polycystic kidney disease (ADPKD) showed that intensive control of systolic blood pressure to 95-110 mmHg was associated with a 14% slower rate of kidney volume growth compared to standard control. It is unclear whether this result was due to greater blockade of the renin-angiotensin-aldosterone system (RAAS) by allowing the use of higher drug doses in the low blood pressure arm, or due to the lower blood pressure per se. Methods In this secondary analysis of HALT PKD Study A, we categorized participants into high and low dose groups based on the median daily equivalent dose of RAAS blocking drugs used after the initial dose titration period. Using linear mixed models, we compared the percent change in total kidney volume and the slope of estimated glomerular filtration rate (eGFR) between the 2 groups. We also assessed the effects of time-varying dose and time-varying blood pressure parameters on these outcomes. Results Subjects in the high dose group (n=252) did not experience a slower increase in total kidney volume than those in the low-dose (n=225) group, after adjustment for age, sex, genotype, and BP arm. The chronic slope of eGFR decline was similar in the 2 groups. Higher time-varying systolic blood pressure was associated with a steeper decline in eGFR. Conclusion ADPKD progression (as detected by eGFR decline and TKV increase) was ameliorated by intense blood pressure control as opposed to pharmacologic intensity of RAAS blockade.
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Affiliation(s)
| | - Kaleab Z Abebe
- University of Pittsburgh, Pittsburgh, Pennsylvania, PA, United States
| | - Charity G Moore
- University of Pittsburgh, Pittsburgh, Pennsylvania, PA, United States
| | - Kyongtae T Bae
- University of Pittsburgh, Pittsburgh, Pennsylvania, PA, United States
| | | | | | | | | | - Marie C Hogan
- Mayo Clinic, Rochester, Minnesota, MN, United States
| | | | | | - Theodore I Steinman
- Beth Israel Deaconess Medical Center, Boston, Massachusetts, MA, United States
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11
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Brosnahan GM, Abebe KZ, Rahbari-Oskoui FF, Patterson CG, Bae KT, Schrier RW, Braun WE, Chapman AB, Flessner MF, Harris PC, Perrone RD, Steinman TI, Torres VE. Effect of Statin Therapy on the Progression of Autosomal Dominant Polycystic Kidney Disease. A Secondary Analysis of the HALT PKD Trials. Curr Hypertens Rev 2019; 13:109-120. [PMID: 28460625 DOI: 10.2174/1573402113666170427142815] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/30/2017] [Accepted: 04/18/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Autosomal dominant polycystic kidney disease (ADPKD) commonly results in end-stage renal disease (ESRD), yet a long-term treatment that is well tolerated is still lacking. In a small randomized trial in children and adolescents pravastatin administration for 3 years was associated with reduced renal cyst growth, but no large trial has tested the effect of statins in adults. METHODS We performed a post-hoc analysis of the HALT PKD trials to compare outcomes of participants who never used statins with those who used statin for at least 3 years. Because statins were not randomly allocated, we used propensity score models with inverse probability of treatment weighting to account for imbalances between the groups. For subjects in Study A (preserved renal function, n=438) relevant outcomes were percent change in total kidney and liver volume and the rate of decline in estimated glomerular filtration rate (eGFR); for those in Study B (reduced renal function, n=352) we compared time to the composite endpoint of death, ESRD or 50% decline in eGFR. Follow-up was 5-8 years. RESULTS There was no difference in any outcome between the 2 groups. However, limitations of this analysis are the small number of statin users in Study A, different statin drugs and doses used, non-randomized allocation and advanced disease stage in Study B. CONCLUSION Although this post-hoc analysis of the HALT PKD trials does not demonstrate a benefit of statin therapy, conclusions remain preliminary. A larger randomized trial in young people with ADPKD is necessary to answer the question whether statins can slow renal cyst growth and preserve kidney function.
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Affiliation(s)
| | - Kaleab Z Abebe
- University of Pittsburgh, Pittsburgh, Pennsylvania PA. United States
| | | | | | - Kyongtae T Bae
- University of Pittsburgh, Pittsburgh, Pennsylvania PA. United States
| | | | | | | | | | | | | | - Theodore I Steinman
- Beth Israel Deaconess Medical Center, Boston, Massachusetts MA. United States
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12
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Mariani LH, Bomback AS, Canetta PA, Flessner MF, Helmuth M, Hladunewich MA, Hogan JJ, Kiryluk K, Nachman PH, Nast CC, Rheault MN, Rizk DV, Trachtman H, Wenderfer SE, Bowers C, Hill-Callahan P, Marasa M, Poulton CJ, Revell A, Vento S, Barisoni L, Cattran D, D'Agati V, Jennette JC, Klein JB, Laurin LP, Twombley K, Falk RJ, Gharavi AG, Gillespie BW, Gipson DS, Greenbaum LA, Holzman LB, Kretzler M, Robinson B, Smoyer WE, Guay-Woodford LM. CureGN Study Rationale, Design, and Methods: Establishing a Large Prospective Observational Study of Glomerular Disease. Am J Kidney Dis 2018; 73:218-229. [PMID: 30420158 PMCID: PMC6348011 DOI: 10.1053/j.ajkd.2018.07.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/31/2018] [Indexed: 01/01/2023]
Abstract
RATIONALE & OBJECTIVES Glomerular diseases, including minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and immunoglobulin A (IgA) nephropathy, share clinical presentations, yet result from multiple biological mechanisms. Challenges to identifying underlying mechanisms, biomarkers, and new therapies include the rarity of each diagnosis and slow progression, often requiring decades to measure the effectiveness of interventions to prevent end-stage kidney disease (ESKD) or death. STUDY DESIGN Multicenter prospective cohort study. SETTING & PARTICIPANTS Cure Glomerulonephropathy (CureGN) will enroll 2,400 children and adults with minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy (including IgA vasculitis) and a first diagnostic kidney biopsy within 5 years. Patients with ESKD and those with secondary causes of glomerular disease are excluded. EXPOSURES Clinical data, including medical history, medications, family history, and patient-reported outcomes, are obtained, along with a digital archive of kidney biopsy images and blood and urine specimens at study visits aligned with clinical care 1 to 4 times per year. OUTCOMES Patients are followed up for changes in estimated glomerular filtration rate, disease activity, ESKD, and death and for nonrenal complications of disease and treatment, including infection, malignancy, cardiovascular, and thromboembolic events. ANALYTICAL APPROACH The study design supports multiple longitudinal analyses leveraging the diverse data domains of CureGN and its ancillary program. At 2,400 patients and an average of 2 years' initial follow-up, CureGN has 80% power to detect an HR of 1.4 to 1.9 for proteinuria remission and a mean difference of 2.1 to 3.0mL/min/1.73m2 in estimated glomerular filtration rate per year. LIMITATIONS Current follow-up can only detect large differences in ESKD and death outcomes. CONCLUSIONS Study infrastructure will support a broad range of scientific approaches to identify mechanistically distinct subgroups, identify accurate biomarkers of disease activity and progression, delineate disease-specific treatment targets, and inform future therapeutic trials. CureGN is expected to be among the largest prospective studies of children and adults with glomerular disease, with a broad goal to lessen disease burden and improve outcomes.
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Affiliation(s)
- Laura H Mariani
- Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI; Arbor Research Collaborative for Health, Ann Arbor, MI.
| | - Andrew S Bomback
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Pietro A Canetta
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, MD
| | | | - Michelle A Hladunewich
- Division of Nephrology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Jonathan J Hogan
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Krzysztof Kiryluk
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Patrick H Nachman
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Minnesota, Minneapolis, MN
| | - Cynthia C Nast
- Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Michelle N Rheault
- Division of Nephrology, Department of Pediatrics, University of Minnesota Masonic Children's Hospital, Minneapolis, MN
| | - Dana V Rizk
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Howard Trachtman
- Division of Nephrology, Department of Pediatrics, New York University Langone Medical Center, New York, NY
| | - Scott E Wenderfer
- Renal Section, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX
| | - Corinna Bowers
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH
| | | | - Maddalena Marasa
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Caroline J Poulton
- Division of Nephrology and Hypertension, Kidney Center, Department of Medicine, University of North Carolina, Chapel Hill, NC
| | - Adelaide Revell
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH
| | - Suzanne Vento
- Division of Nephrology, Department of Pediatrics, New York University Langone Medical Center, New York, NY
| | | | - Dan Cattran
- Division of Nephrology, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Vivette D'Agati
- Department of Pathology, Columbia University Medical Center, New York, NY
| | - J Charles Jennette
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC
| | - Jon B Klein
- Department of Medicine, The University of Louisville School of Medicine, and Robley Rex VA Medical Center, Louisville, KY
| | | | - Katherine Twombley
- Pediatric Nephrology, Medical University of South Carolina, Charleston, SC
| | - Ronald J Falk
- Division of Nephrology and Hypertension, Kidney Center, Department of Medicine, University of North Carolina, Chapel Hill, NC
| | - Ali G Gharavi
- Division of Nephrology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Brenda W Gillespie
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI
| | - Debbie S Gipson
- Division of Nephrology, Department of Pediatrics, University of Michigan, Ann Arbor, MI
| | | | - Lawrence B Holzman
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Matthias Kretzler
- Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI
| | - Bruce Robinson
- Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI; Arbor Research Collaborative for Health, Ann Arbor, MI
| | - William E Smoyer
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University, Columbus, OH
| | - Lisa M Guay-Woodford
- Center for Translational Science, Children's National Health System, Washington, DC
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Irazabal MV, Abebe KZ, Bae KT, Perrone RD, Chapman AB, Schrier RW, Yu AS, Braun WE, Steinman TI, Harris PC, Flessner MF, Torres VE. Prognostic enrichment design in clinical trials for autosomal dominant polycystic kidney disease: the HALT-PKD clinical trial. Nephrol Dial Transplant 2018; 32:1857-1865. [PMID: 27484667 DOI: 10.1093/ndt/gfw294] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/15/2016] [Indexed: 12/26/2022] Open
Abstract
Background Patients with mild autosomal dominant polycystic kidney disease (ADPKD) are less likely to be informative in randomized clinical trials (RCTs). We previously developed an imaging classification of ADPKD (typical diffuse cyst distribution Class 1A-E and atypical cyst distribution Class 2) for prognostic enrichment design in RCTs. We investigated whether using this classification would have increased the power to detect a beneficial treatment effect of rigorous blood pressure (BP) control on HALT-PKD participants with early disease (Study A). Methods Post hoc analysis of the early disease HALT-PKD study, an RCT that studied the effect of rigorous versus standard BP control on rates of total kidney volume (TKV) increase and estimated glomerular filtration rate (eGFR) decline in ADPKD patients with eGFR >60 mL/min/1.73 m2. Results Five hundred and fifty-one patients were classified by two observers (98.2% agreement) into Class 1A (6.2%), 1B (20.3%), 1C (34.1%), 1D (22.1%), 1E (11.8%) and 2 (5.4%). The TKV increase and eGFR decline became steeper from Class 1A through 1E. Rigorous BP control had been shown to be associated with slower TKV increase, without a significant overall effect on the rate of eGFR decline (faster in the first 4 months and marginally slower thereafter). Merging Classes 1A and 2 (lowest severity), 1B and 1C (intermediate severity) and 1D and 1E (highest severity) detected stronger beneficial effects on TKV increase and eGFR decline in Class 1D and E with a smaller number of patients. Conclusions Strategies for prognostic enrichment, such as image classification, should be used in the design of RCTs for ADPKD to increase their power and reduce their cost.
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Affiliation(s)
- María V Irazabal
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Kaleab Z Abebe
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Kyongtae Ty Bae
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | | | | | - Alan S Yu
- Kansas University Medical Center, Kansas City, KS, USA
| | | | | | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | | | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
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14
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Mwasongwe SE, Fülöp T, Katz R, Musani SK, Sims M, Correa A, Flessner MF, Young BA. Relation of uric acid level to rapid kidney function decline and development of kidney disease: The Jackson Heart Study. J Clin Hypertens (Greenwich) 2018; 20:775-783. [PMID: 29450959 PMCID: PMC6022371 DOI: 10.1111/jch.13239] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/08/2018] [Accepted: 01/12/2018] [Indexed: 01/13/2023]
Abstract
Whether elevated uric acid (UA) is an independent risk factor for chronic kidney disease (CKD) is not well established. The authors evaluated the relationship of UA with rapid kidney function decline (RKFD) and incident CKD among 3702 African Americans (AAs) in the Jackson Heart Study with serum UA levels measured at baseline exam (2000-2004). RKFD was defined as ≥ 30% eGFR loss and incident CKD as development of eGFR < 60 mL/min/1.73 m2 with a ≥ 25% decline in eGFR between baseline and exam 3 (2009-2013). RKFD and CKD were found in 11.4% and 7.5% of the participants, respectively. In a fully adjusted model, the odds of RKFD (OR, 1.8; 95% CI, 1.25-2.49) and incident CKD (OR, 2.00; 95% CI, 1.31-3.06) were significantly higher among participants in the top UA quartile vs bottom quartile. In the JHS, elevated UA was significantly associated with RKFD and incident CKD.
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Affiliation(s)
| | - Tibor Fülöp
- Department of MedicineDivision of NephrologyMedical University of South CarolinaCharlestonSCUSA
- Medical ServicesRalph H. Johnson VA Medical CenterCharlestonSCUSA
| | - Ronit Katz
- Division of NephrologyKidney Research InstituteUniversity of WashingtonSeattleWAUSA
| | - Solomon K. Musani
- Jackson Heart StudyUniversity of Mississippi Medical CenterJacksonMSUSA
| | - Mario Sims
- Jackson Heart StudyUniversity of Mississippi Medical CenterJacksonMSUSA
| | - Adolfo Correa
- Jackson Heart StudyUniversity of Mississippi Medical CenterJacksonMSUSA
| | | | - Bessie A. Young
- Division of NephrologyKidney Research InstituteUniversity of WashingtonSeattleWAUSA
- Veterans Affairs Puget Sound Health Care CenterSeattleWAUSA
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15
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Yu ASL, Shen C, Landsittel DP, Harris PC, Torres VE, Mrug M, Bae KT, Grantham JJ, Rahbari-Oskoui FF, Flessner MF, Bennett WM, Chapman AB. Baseline total kidney volume and the rate of kidney growth are associated with chronic kidney disease progression in Autosomal Dominant Polycystic Kidney Disease. Kidney Int 2018; 93:691-699. [PMID: 29290310 PMCID: PMC5826779 DOI: 10.1016/j.kint.2017.09.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 09/23/2017] [Accepted: 09/28/2017] [Indexed: 01/04/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive enlargement of kidney cysts leading to chronic kidney disease (CKD) and end-stage renal disease (ESRD). Identification of an early biomarker that can predict progression of CKD is urgently needed. In an earlier Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) study (a prospective, multicenter, observational analysis of 241 patients with ADPKD initiated in 2000), baseline height-adjusted total kidney volume (htTKV) was shown to be associated with development of CKD stage 3 after eight years of follow-up. Here we conducted an extended study and found that in a multivariable logistic regression model, baseline htTKV was shown to be a strong, independent predictor for the development of CKD after a median follow-up of 13 years. The odds ratio of reaching each CKD stage per 100 mL/m increment in htTKV was 1.38 (95% confidence interval 1.19-1.60) for stage 3, 1.42 (1.23-1.64) for stage 4, and 1.35 (1.18-1.55) for stage 5 or ESRD. Baseline htTKV was also associated with relative decreases in the glomerular filtration rate of 30%, and 57% or more. Moreover, the rate of change in htTKV was negatively correlated with the slope of the glomerular filtration rate. While ADPKD genotype was also associated with CKD outcomes, it was not an independent prognostic factor after adjusting for htTKV. Thus, baseline total kidney volume and the rate of kidney growth are strongly associated with the development of advanced stages of CKD. These findings support the use of total kidney volume as a prognostic and potentially monitoring biomarker in ADPKD.
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MESH Headings
- Adolescent
- Adult
- Disease Progression
- Female
- Glomerular Filtration Rate
- Humans
- Kidney/diagnostic imaging
- Kidney/growth & development
- Kidney/pathology
- Kidney Failure, Chronic/diagnosis
- Kidney Failure, Chronic/etiology
- Kidney Failure, Chronic/physiopathology
- Magnetic Resonance Imaging
- Male
- Middle Aged
- Organ Size
- Polycystic Kidney, Autosomal Dominant/complications
- Polycystic Kidney, Autosomal Dominant/diagnostic imaging
- Polycystic Kidney, Autosomal Dominant/pathology
- Polycystic Kidney, Autosomal Dominant/physiopathology
- Predictive Value of Tests
- Prognosis
- Prospective Studies
- Renal Insufficiency, Chronic/diagnosis
- Renal Insufficiency, Chronic/etiology
- Renal Insufficiency, Chronic/physiopathology
- Risk Factors
- Time Factors
- United States
- Young Adult
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Affiliation(s)
- Alan S L Yu
- Division of Nephrology and Hypertension and the Kidney Institute, University of Kansas, Medical Center, Kansas City, Kansas, USA.
| | - Chengli Shen
- Department of Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Douglas P Landsittel
- Department of Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Michal Mrug
- Division of Nephrology, University of Alabama and the Department of Veterans Affairs Medical Center, Birmingham, Alabama, USA
| | - Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jared J Grantham
- Division of Nephrology and Hypertension and the Kidney Institute, University of Kansas, Medical Center, Kansas City, Kansas, USA
| | | | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Arlene B Chapman
- Department of Internal Medicine, Emory University School of Medicine, Atlanta, Georgia, USA; Section of Nephrology, University of Chicago School of Medicine, Chicago, Illinois, USA
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16
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Dad T, Abebe KZ, Bae KT, Comer D, Torres VE, Czarnecki PG, Schrier RW, Steinman TI, Moore CG, Chapman AB, Kaya D, Tao C, Braun WE, Winklhofer FT, Brosnahan G, Hogan MC, Miskulin DC, Rahbari Oskoui F, Flessner MF, Perrone RD. Longitudinal Assessment of Left Ventricular Mass in Autosomal Dominant Polycystic Kidney Disease. Kidney Int Rep 2018; 3:619-624. [PMID: 29854969 PMCID: PMC5976807 DOI: 10.1016/j.ekir.2017.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 12/18/2017] [Accepted: 12/23/2017] [Indexed: 12/02/2022] Open
Abstract
Introduction The high burden of cardiovascular morbidity and mortality in autosomal dominant polycystic kidney disease (ADPKD) is related to development of hypertension and left ventricular hypertrophy. Blood pressure reduction has been shown to reduce left ventricular mass in ADPKD; however, moderators and predictors of response to lower blood pressure are unknown. Methods This was a post hoc cohort analysis of HALT PKD study A, a randomized placebo controlled trial examining the effect of low blood pressure and single versus dual renin−angiotensin blockade in early ADPKD. Participants were hypertensive ADPKD patients 15 to 49 years of age with estimated glomerular filtration rate (eGFR) > 60 ml/min per 1.73 m2 across 7 centers in the United States. Predictors included age, sex, baseline eGFR, systolic blood pressure, total kidney volume, serum potassium, and urine sodium, potassium, albumin, and aldosterone. Outcome was left ventricular mass index (LVMI) measured using 1.5-T magnetic resonance imaging at months 0, 24, 48, and 60. Results Reduction in LVMI was associated with higher baseline systolic blood pressure and larger kidney volume regardless of blood pressure control group assignment (P < 0.001 for both). Male sex and baseline eGFR were associated with a positive annual slope in LVMI (P < 0.001 and P = 0.07, respectively). Conclusion Characteristics associated with higher risk of progression in ADPKD, including higher systolic blood pressure, larger kidney volume, and lower eGFR are associated with improvement in LVMI with intensive blood pressure control, whereas male sex is associated with a smaller slope of reduction in LVMI.
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Affiliation(s)
- Taimur Dad
- Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, Massachusetts, USA
| | - Kaleab Z Abebe
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - K Ty Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Diane Comer
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter G Czarnecki
- Division of Renal Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Robert W Schrier
- Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado, USA
| | - Theodore I Steinman
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Department of Medicine, Brigham and Womens' Hospital, Boston, Massachusetts, USA
| | - Charity G Moore
- Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA
| | - Arlene B Chapman
- Department of Medicine, Biological Sciences Department, University of Chicago, Chicago, Illinois, USA
| | - Diana Kaya
- Department of Oncologic Neuroradiology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Cheng Tao
- Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - William E Braun
- Department of Nephrology, Cleveland Clinic, Cleveland, Ohio, USA
| | - Franz T Winklhofer
- Division of Nephrology, Department of Internal Medicine, Kansas University Medical Center, Kansas City, Kansas, USA
| | - Godela Brosnahan
- Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado, USA
| | - Marie C Hogan
- Division of Nephrology, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Dana C Miskulin
- Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, Massachusetts, USA
| | - Frederic Rahbari Oskoui
- Department of Medicine, Renal Division, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Ronald D Perrone
- Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, Massachusetts, USA
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17
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Brosnahan GM, Abebe KZ, Moore CG, Rahbari-Oskoui FF, Bae KT, Grantham JJ, Schrier RW, Braun WE, Chapman AB, Flessner MF, Harris PC, Hogan MC, Perrone RD, Miskulin DC, Steinman TI, Torres VE. Patterns of Kidney Function Decline in Autosomal Dominant Polycystic Kidney Disease: A Post Hoc Analysis From the HALT-PKD Trials. Am J Kidney Dis 2018; 71:666-676. [PMID: 29306517 DOI: 10.1053/j.ajkd.2017.10.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 10/22/2017] [Indexed: 12/16/2022]
Abstract
BACKGROUND Previous clinical studies of autosomal dominant polycystic kidney disease (ADPKD) reported that loss of kidney function usually follows a steep and relentless course. A detailed examination of individual patterns of decline in estimated glomerular filtration rate (eGFR) has not been performed. STUDY DESIGN Longitudinal post hoc analysis of data collected during the Halt Progression of Polycystic Kidney Disease (HALT-PKD) trials. SETTING & PARTICIPANTS 494 HALT-PKD Study A participants (younger; preserved eGFR) and 435 Study B participants (older; reduced eGFR) who had more than 3 years of follow-up and 7 or more eGFR assessments. MEASUREMENTS Longitudinal eGFR assessments using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation. PREDICTORS Demographic, clinical, laboratory, and imaging features of participants. OUTCOMES Probability of linear and nonlinear decline patterns or of stable eGFR calculated for each participant from a Bayesian model of individual eGFR trajectories. RESULTS Most (62.5% in Study A and 81% in Study B) participants had a linear decline in eGFR during up to 8 years of follow-up. A proportion (22% in Study A and 13% in Study B) of progressors had a nonlinear pattern. 15.5% of participants in Study A and 6% in Study B had a prolonged (≥4.5 years) period of stable eGFRs. These individuals (Study A) had significantly smaller total kidney volumes, higher renal blood flows, lower urinary albumin excretion, and lower body mass index at baseline and study end. In Study B, participants with reduced but stable eGFRs were older than the progressors. Two-thirds of nonprogressors in both studies had PKD1 mutations, with enrichment for weak nontruncating mutations. LIMITATIONS Relatively short follow-up of a clinical trial population. CONCLUSIONS Although many individuals with ADPKD have a linear decline in eGFR, prolonged intervals of stable GFRs occur in a substantial fraction. Lower body mass index was associated with more stable kidney function in early ADPKD.
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18
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Braun WE, Abebe KZ, Brosnahan G, Patterson CG, Chapman AB, Harris PC, Hogan MC, Perrone RD, Torres VE, Miskulin DC, Steinman TI, Winklhofer FT, Rahbari-Oskoui FF, Czarnecki PG, Bae KT, Grantham JJ, Flessner MF, Schrier RW. ADPKD Progression in Patients With No Apparent Family History and No Mutation Detected by Sanger Sequencing. Am J Kidney Dis 2017; 71:294-296. [PMID: 29203126 DOI: 10.1053/j.ajkd.2017.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/07/2017] [Indexed: 12/22/2022]
Affiliation(s)
- William E Braun
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio.
| | - Kaleab Z Abebe
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | - Charity G Patterson
- University of Pittsburgh School of Health and Rehabilitation Sciences, Pittsburgh, Pennsylvania
| | | | | | - Marie C Hogan
- Mayo Clinic College of Medicine, Rochester, Minnesota
| | | | | | | | | | | | | | | | - Kyongtae T Bae
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Shen C, Landsittel D, Irazabal MV, Yu ASL, Chapman AB, Mrug M, Grantham JJ, Bae KT, Bennett WM, Flessner MF, Torres VE. Performance of the CKD-EPI Equation to Estimate GFR in a Longitudinal Study of Autosomal Dominant Polycystic Kidney Disease. Am J Kidney Dis 2016; 69:482-484. [PMID: 28027795 DOI: 10.1053/j.ajkd.2016.10.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 10/08/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Chengli Shen
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | | | - Alan S L Yu
- Kansas University Medical Center, Kansas City, Kansas
| | | | | | | | - Kyongtae T Bae
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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20
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Flessner MF. Pharmacokinetic problems in peritoneal drug administration: an update after 20 years. Pleura Peritoneum 2016; 1:183-191. [PMID: 30911622 DOI: 10.1515/pp-2016-0022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/29/2016] [Indexed: 12/14/2022] Open
Abstract
Intraperitoneal chemotherapy has demonstrated significant pharmacologic and clinical advantage over traditional intravenous administration for cancers that are restricted to the peritoneal cavity. The combination of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) has become the standard technique used to fight ovarian and gastrointestinal cancers in many centers. However, challenges remain for HIPEC to contact the entire peritoneal surface, penetrate the tumor tissue, and transport to the lymphatics and other metastatic sites. New innovations in delivery technique, such as heated aerosol, and in delivery molecules, such as microparticles, nanoparticles, nanogels, and tumor-penetrating peptides are being tested in animal models and will likely soon be in human trials. Improvements in overall care, such as the recent clinical trial of an oral agent for maintenance therapy in ovarian carcinoma, will continue in this field for the next 20 years.
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Torres VE, Abebe KZ, Schrier RW, Perrone RD, Chapman AB, Yu AS, Braun WE, Steinman TI, Brosnahan G, Hogan MC, Rahbari FF, Grantham JJ, Bae KT, Moore CG, Flessner MF. Dietary salt restriction is beneficial to the management of autosomal dominant polycystic kidney disease. Kidney Int 2016; 91:493-500. [PMID: 27993381 DOI: 10.1016/j.kint.2016.10.018] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 10/10/2016] [Accepted: 10/13/2016] [Indexed: 02/07/2023]
Abstract
The CRISP study of polycystic kidney disease (PKD) found that urinary sodium excretion associated with the rate of total kidney volume increase. Whether sodium restriction slows the progression of Autosomal Dominant PKD (ADPKD) is not known. To evaluate this we conducted a post hoc analysis of the HALT-PKD clinical trials of renin-angiotensin blockade in patients with ADPKD. Linear mixed models examined whether dietary sodium affected rates of total kidney volume or change in estimated glomerular filtration rate (eGFR) in patients with an eGFR over 60 ml/min/1.73 m2 (Study A) or the risk for a composite endpoint of 50% reduction in eGFR, end-stage renal disease or death, or the rate of eGFR decline in patients with an eGFR 25-60 ml/min/1.73 m2 (Study B) all in patients initiated on an under100 mEq sodium diet. During the trial urinary sodium excretion significantly declined by an average of 0.25 and 0.41 mEq/24 hour per month in studies A and B, respectively. In Study A, averaged and time varying urinary sodium excretions were significantly associated with kidney growth (0.43%/year and 0.09%/year, respectively, for each 18 mEq urinary sodium excretion). Averaged urinary sodium excretion was not significantly associated with faster eGFR decline (-0.07 ml/min/1.73m2/year for each 18 mEq urinary sodium excretion). In Study B, the averaged but not time-varying urinary sodium excretion significantly associated with increased risk for the composite endpoint (hazard ratio 1.08 for each 18 mEq urinary sodium excretion) and a significantly faster eGFR decline (-0.09 ml/min/1.73m2/year for each mEq 18 mEq urinary sodium excretion). Thus, sodium restriction is beneficial in the management of ADPKD.
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Affiliation(s)
| | - Kaleab Z Abebe
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Robert W Schrier
- University of Colorado Health Sciences Center, Denver, Colorado, USA
| | | | | | - Alan S Yu
- Kansas University Medical Center, Kansas City, Kansas, USA
| | | | | | - Godela Brosnahan
- University of Colorado Health Sciences Center, Denver, Colorado, USA
| | - Marie C Hogan
- Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | | | | | - Kyongtae T Bae
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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22
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Abstract
Nephrology has conducted few high-quality clinical trials, and the trials that have been conducted have not resulted in the approval of new treatments for primary or inflammatory glomerular diseases. There are overarching process issues that affect the conduct of all clinical trials, but there are also some specialty-specific issues. Within nephrology, primary glomerular diseases are rare, making adequate recruitment for meaningful trials difficult. Nephrologists need better ways, beyond histopathology, to phenotype patients with glomerular diseases and stratify the risk for progression to ESRD. Rigorous trial design is needed for the testing of new therapies, where most patients with glomerular diseases are offered the opportunity to enroll in a clinical trial if standard therapies have failed or are lacking. Training programs to develop a core group of kidney specialists with expertise in the design and implementation of clinical trials are also needed. Registries of patients with glomerular disease and observational studies can aid in the ability to determine realistic estimates of disease prevalence and inform trial design through a better understanding of the natural history of disease. Some proposed changes to the Common Rule, the federal regulations governing the ethical conduct of research involving humans, and the emerging use of electronic health records may facilitate the efficiency of initiating multicenter clinical trials. Collaborations among academia, government scientific and regulatory agencies, industry, foundations, and patient advocacy groups can accelerate therapeutic development for these complex diseases.
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Affiliation(s)
- Marva M Moxey-Mims
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
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23
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Kim Y, Bae SK, Cheng T, Tao C, Ge Y, Chapman AB, Torres VE, Yu ASL, Mrug M, Bennett WM, Flessner MF, Landsittel DP, Bae KT. Automated segmentation of liver and liver cysts from bounded abdominal MR images in patients with autosomal dominant polycystic kidney disease. Phys Med Biol 2016; 61:7864-7880. [PMID: 27779124 DOI: 10.1088/0031-9155/61/22/7864] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Liver and liver cyst volume measurements are important quantitative imaging biomarkers for assessment of disease progression in autosomal dominant polycystic kidney disease (ADPKD) and polycystic liver disease (PLD). To date, no study has presented automated segmentation and volumetric computation of liver and liver cysts in these populations. In this paper, we proposed an automated segmentation framework for liver and liver cysts from bounded abdominal MR images in patients with ADPKD. To model the shape and variations in ADPKD livers, the spatial prior probability map (SPPM) of liver location and the tissue prior probability maps (TPPMs) of liver parenchymal tissue intensity and cyst morphology were generated. Formulated within a three-dimensional level set framework, the TPPMs successfully captured liver parenchymal tissues and cysts, while the SPPM globally constrained the initial surfaces of the liver into the desired boundary. Liver cysts were extracted by combined operations of the TPPMs, thresholding, and false positive reduction based on spatial prior knowledge of kidney cysts and distance map. With cross-validation for the liver segmentation, the agreement between the radiology expert and the proposed method was 84% for shape congruence and 91% for volume measurement assessed by the intra-class correlation coefficient (ICC). For the liver cyst segmentation, the agreement between the reference method and the proposed method was ICC = 0.91 for cyst volumes and ICC = 0.94 for % cyst-to-liver volume.
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Affiliation(s)
- Youngwoo Kim
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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24
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Dember LM, Archdeacon P, Krishnan M, Lacson E, Ling SM, Roy-Chaudhury P, Smith KA, Flessner MF. Pragmatic Trials in Maintenance Dialysis: Perspectives from the Kidney Health Initiative. J Am Soc Nephrol 2016; 27:2955-2963. [PMID: 27401689 PMCID: PMC5042681 DOI: 10.1681/asn.2016030340] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Pragmatic clinical trials are conducted under the real-world conditions of clinical care delivery. As a result, these trials yield findings that are highly generalizable to the nonresearch setting, identify interventions that are readily translatable into clinical practice, and cost less than trials that require extensive research infrastructures. Maintenance dialysis is a setting especially well suited for pragmatic trials because of inherently frequent and predictable patient encounters, highly granular and uniform data collection, use of electronic data systems, and delivery of care by a small number of provider organizations to approximately 90% of patients nationally. Recognizing the potential for pragmatic trials to generate much needed evidence to guide the care of patients receiving maintenance dialysis, the Kidney Health Initiative assembled a group of individuals with relevant expertise from academia, industry, and government to provide the nephrology community with information about the design and conduct of such trials, with a specific focus on the dialysis setting. Here, we review this information, and where applicable, use experience from the ongoing Time to Reduce Mortality in End Stage Renal Disease Trial, a large cluster-randomized, pragmatic trial evaluating hemodialysis session duration, to illustrate challenges and solutions to operational, ethical, and regulatory issues.
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Affiliation(s)
- Laura M Dember
- Renal, Electrolyte and Hypertension Division and Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;
| | - Patrick Archdeacon
- Office of Medical Policy and Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland
| | | | - Eduardo Lacson
- Nephrology Division, Tufts Medical Center and Tufts University School of Medicine, Boston, Massachusetts
| | - Shari M Ling
- Center for Clinical Standards and Quality, Centers for Medicare and Medicaid Services, Baltimore, Maryland
| | - Prabir Roy-Chaudhury
- Division of Nephrology, The University of Arizona College of Medicine and Southern Arizona Veterans Administration Health Care System, Tucson, Arizona
| | - Kimberly A Smith
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland
| | - Michael F Flessner
- Division of Kidney, Urology, and Hematology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
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25
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Kramer HJ, Stilp AM, Laurie CC, Reiner AP, Lash J, Daviglus ML, Rosas SE, Ricardo AC, Tayo BO, Flessner MF, Kerr KF, Peralta C, Durazo-Arvizu R, Conomos M, Thornton T, Rotter J, Taylor KD, Cai J, Eckfeldt J, Chen H, Papanicolau G, Franceschini N. African Ancestry-Specific Alleles and Kidney Disease Risk in Hispanics/Latinos. J Am Soc Nephrol 2016; 28:915-922. [PMID: 27650483 DOI: 10.1681/asn.2016030357] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 07/26/2016] [Indexed: 12/15/2022] Open
Abstract
African ancestry alleles may contribute to CKD among Hispanics/Latinos, but whether associations differ by Hispanic/Latino background remains unknown. We examined the association of CKD measures with African ancestry-specific APOL1 alleles that were directly genotyped and sickle cell trait (hemoglobin subunit β gene [HBB] variant) on the basis of imputation in 12,226 adult Hispanics/Latinos grouped according to Caribbean or Mainland background. We also performed an unbiased genome-wide association scan of urine albumin-to-creatinine ratios. Overall, 41.4% of participants were male, 44.6% of participants had a Caribbean background, and the mean age of all participants was 46.1 years. The Caribbean background group, compared with the Mainland background group, had a higher frequency of two APOL1 alleles (1.0% versus 0.1%) and the HBB variant (2.0% versus 0.7%). In the Caribbean background group, presence of APOL1 alleles (2 versus 0/1 copies) or the HBB variant (1 versus 0 copies) were significantly associated with albuminuria (odds ratio [OR], 3.2; 95% confidence interval [95% CI], 1.7 to 6.1; and OR, 2.6; 95% CI, 1.8 to 3.8, respectively) and albuminuria and/or eGFR<60 ml/min per 1.73 m2 (OR, 2.9; 95% CI, 1.5 to 5.4; and OR, 2.4; 95% CI, 1.7 to 3.5, respectively). The urine albumin-to-creatinine ratio genome-wide association scan identified associations with the HBB variant among all participants, with the strongest association in the Caribbean background group (P=3.1×10-10 versus P=9.3×10-3 for the Mainland background group). In conclusion, African-specific alleles associate with CKD in Hispanics/Latinos, but allele frequency varies by Hispanic/Latino background/ancestry.
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Affiliation(s)
- Holly J Kramer
- Department of Public Health Sciences and Medicine, and.,Division of Nephrology and Hypertension, Loyola University Chicago, Maywood, Illinois
| | | | | | - Alex P Reiner
- Fred Hutchinson Cancer Research Center, Division of Public Health Science, University of Washington School of Public Health, Seattle, Washington
| | - James Lash
- Division of Nephrology, Department of Medicine, and.,Institute for Minority Health Research, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Martha L Daviglus
- Institute for Minority Health Research, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Sylvia E Rosas
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Ana C Ricardo
- Division of Nephrology, Department of Medicine, and.,Institute for Minority Health Research, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | | | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland
| | | | - Carmen Peralta
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | | | | | | | - Jerome Rotter
- Institute for Translational Genomics and Population Sciences Los Angeles, Biomedical Research Institute and Department of Pediatrics, Harbor-University of California at Los Angeles Medical Center, Torrance, California
| | - Kent D Taylor
- Institute for Translational Genomics and Population Sciences Los Angeles, Biomedical Research Institute and Department of Pediatrics, Harbor-University of California at Los Angeles Medical Center, Torrance, California
| | - Jainwen Cai
- Collaborative Studies Coordinating Center, Department of Biostatistics, and
| | - John Eckfeldt
- Advanced Research and Diagnostics Laboratories, Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota; and
| | - Han Chen
- Department of Biostatistics, and
| | - George Papanicolau
- Epidemiology Branch, National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | - Nora Franceschini
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina;
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26
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Mahajan A, Rodan AR, Le TH, Gaulton KJ, Haessler J, Stilp AM, Kamatani Y, Zhu G, Sofer T, Puri S, Schellinger JN, Chu PL, Cechova S, van Zuydam N, Arnlov J, Flessner MF, Giedraitis V, Heath AC, Kubo M, Larsson A, Lindgren CM, Madden PAF, Montgomery GW, Papanicolaou GJ, Reiner AP, Sundström J, Thornton TA, Lind L, Ingelsson E, Cai J, Martin NG, Kooperberg C, Matsuda K, Whitfield JB, Okada Y, Laurie CC, Morris AP, Franceschini N. Trans-ethnic Fine Mapping Highlights Kidney-Function Genes Linked to Salt Sensitivity. Am J Hum Genet 2016; 99:636-646. [PMID: 27588450 PMCID: PMC5011075 DOI: 10.1016/j.ajhg.2016.07.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 07/08/2016] [Indexed: 01/09/2023] Open
Abstract
We analyzed genome-wide association studies (GWASs), including data from 71,638 individuals from four ancestries, for estimated glomerular filtration rate (eGFR), a measure of kidney function used to define chronic kidney disease (CKD). We identified 20 loci attaining genome-wide-significant evidence of association (p < 5 × 10(-8)) with kidney function and highlighted that allelic effects on eGFR at lead SNPs are homogeneous across ancestries. We leveraged differences in the pattern of linkage disequilibrium between diverse populations to fine-map the 20 loci through construction of "credible sets" of variants driving eGFR association signals. Credible variants at the 20 eGFR loci were enriched for DNase I hypersensitivity sites (DHSs) in human kidney cells. DHS credible variants were expression quantitative trait loci for NFATC1 and RGS14 (at the SLC34A1 locus) in multiple tissues. Loss-of-function mutations in ancestral orthologs of both genes in Drosophila melanogaster were associated with altered sensitivity to salt stress. Renal mRNA expression of Nfatc1 and Rgs14 in a salt-sensitive mouse model was also reduced after exposure to a high-salt diet or induced CKD. Our study (1) demonstrates the utility of trans-ethnic fine mapping through integration of GWASs involving diverse populations with genomic annotation from relevant tissues to define molecular mechanisms by which association signals exert their effect and (2) suggests that salt sensitivity might be an important marker for biological processes that affect kidney function and CKD in humans.
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Affiliation(s)
- Anubha Mahajan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Aylin R Rodan
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75229, USA
| | - Thu H Le
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Kyle J Gaulton
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Jeffrey Haessler
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Adrienne M Stilp
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Yoichiro Kamatani
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Gu Zhu
- Genetic Epidemiology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
| | - Tamar Sofer
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Sanjana Puri
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75229, USA
| | - Jeffrey N Schellinger
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75229, USA
| | - Pei-Lun Chu
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Sylvia Cechova
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Natalie van Zuydam
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Johan Arnlov
- Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala 751 85, Sweden; School of Health and Social Studies, Dalarna University, Falun 791 88, Sweden
| | - Michael F Flessner
- National Institute of Diabetes, Digestive, and Kidney Disease, NIH, Bethesda, MD 20892, USA
| | - Vilmantas Giedraitis
- Department of Public Health and Caring Sciences, Molecular Geriatrics, Uppsala University, Uppsala 752 37, Sweden
| | - Andrew C Heath
- Department of Psychiatry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Michiaki Kubo
- Laboratory for Genotyping Development, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Anders Larsson
- Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala 751 85, Sweden
| | - Cecilia M Lindgren
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford OX3 7BN, UK
| | - Pamela A F Madden
- Department of Psychiatry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Grant W Montgomery
- Molecular Epidemiology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
| | - George J Papanicolaou
- Epidemiology Branch, Division of Cardiovascular Sciences, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA
| | - Alex P Reiner
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Johan Sundström
- Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala 751 85, Sweden
| | - Timothy A Thornton
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Lars Lind
- Department of Medical Sciences, Cardiovascular Epidemiology, Uppsala University, Uppsala 751 85, Sweden
| | - Erik Ingelsson
- Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala 752 37, Sweden; Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jianwen Cai
- Collaborative Studies Coordinating Center, Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nicholas G Martin
- Genetic Epidemiology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
| | - Charles Kooperberg
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Koichi Matsuda
- Laboratory of Molecular Medicine, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - John B Whitfield
- Genetic Epidemiology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
| | - Yukinori Okada
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan; Department of Statistical Genetics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Cathy C Laurie
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Andrew P Morris
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; Department of Biostatistics, University of Liverpool, Liverpool L69 3GL, UK.
| | - Nora Franceschini
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC 27514, USA.
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27
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Franceschini N, Deng Y, Flessner MF, Eckfeldt JH, Kramer HJ, Lash JP, Lee DJ, Melamed ML, Moncrieft AE, Ricardo AC, Rosas SE, Kaplan RC, Raij L, Cai J. Smoking patterns and chronic kidney disease in US Hispanics: Hispanic Community Health Study/Study of Latinos. Nephrol Dial Transplant 2016; 31:1670-6. [PMID: 27257272 DOI: 10.1093/ndt/gfw210] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/17/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Intermittent smoking is prevalent among Hispanics, but little is known about whether this smoking pattern associates with increased chronic kidney disease (CKD) risk in this population. The objective of the present study is to identify patterns of exposure associated with CKD in US Hispanics. METHODS We used cross-sectional data on 15 410 participants of the Hispanics Community Health Study/the Study of Latinos, a population-based study of individuals aged 18-74 years, recruited in 2008 to 2011 from four US field centers (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA). Smoking exposure was obtained through a questionnaire. CKD was defined by an estimated glomerular filtration rate of <60 mL/min/1.73 m(2) or a urine albumin-to-creatinine ratio of ≥30 mg/g. RESULTS Approximately 14% of individuals were daily and 7% were intermittent smokers, and 16% were past smokers. There was a significant interaction between smoking status and pack-years of exposure (P = 0.0003). In adjusted models, there was an increased odds of CKD among daily, intermittent and past smokers by pack-years compared with never smokers. The association of intermittent smokers was significant at 10 pack-years [odds ratio (OR) = 1.38, 95% confidence intervals (CI) 1.06, 1.81], whereas for daily smokers this association was observed at 40 pack-years (OR = 1.43, 95% CI 1.09, 1.89). CONCLUSIONS Our findings of increased risk of CKD among Hispanics who are intermittent smokers support screening and smoking cessation interventions targeted to this population for the prevention of CKD. It also suggests novel mechanistic pathways for kidney toxicity that should be further explored in future studies.
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Affiliation(s)
- Nora Franceschini
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - Yu Deng
- Collaborative Studies Coordinating Center, Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michael F Flessner
- National Institute of Diabetes, Digestive, and Kidney Disease, Bethesda, MD, USA
| | - John H Eckfeldt
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | - Holly J Kramer
- Division of Nephrology, Loyola University, Maywood, IL, USA
| | - James P Lash
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | | | | | | | - Ana C Ricardo
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Sylvia E Rosas
- Joslin Diabetes Center, Harvard University, Boston, MA, USA
| | | | | | - Jianwen Cai
- Collaborative Studies Coordinating Center, Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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28
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Stachowska-Pietka J, Waniewski J, Flessner MF, Lindholm B. Concomitant bidirectional transport during peritoneal dialysis can be explained by a structured interstitium. Am J Physiol Heart Circ Physiol 2016; 310:H1501-11. [PMID: 26945084 DOI: 10.1152/ajpheart.00925.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 02/26/2016] [Indexed: 11/22/2022]
Abstract
Clinical and animal studies suggest that peritoneal absorption of fluid and protein from dialysate to peritoneal tissue, and to blood and lymph circulation, occurs concomitantly with opposite flows of fluid and protein, i.e., from blood to dialysate. However, until now a theoretical explanation of this phenomenon has been lacking. A two-phase distributed model is proposed to explain the bidirectional, concomitant transport of fluid, albumin and glucose through the peritoneal transport system (PTS) during peritoneal dialysis. The interstitium of this tissue is described as an expandable two-phase structure with phase F (water-rich, colloid-poor region) and phase C (water-poor, colloid-rich region) with fluid and solute exchange between them. A low fraction of phase F is assumed in the intact tissue, which can be significantly increased under the influence of hydrostatic pressure and tissue hydration. The capillary wall is described using the three-pore model, and the conditions in the peritoneal cavity are assumed commencing 3 min after the infusion of glucose 3.86% dialysis fluid. Computer simulations demonstrate that peritoneal absorption of fluid into the tissue, which occurs via phase F at the rate of 1.8 ml/min, increases substantially the interstitial pressure and tissue hydration in both phases close to the peritoneal cavity, whereas the glucose-induced ultrafiltration from blood occurs via phase C at the rate of 15 ml/min. The proposed model delineating the phenomenon of concomitant bidirectional transport through PTS is based on a two-phase structure of the interstitium and provides results in agreement with clinical and experimental data.
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Affiliation(s)
- Joanna Stachowska-Pietka
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland;
| | - Jacek Waniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland; and
| | - Bengt Lindholm
- Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
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29
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Heyer CM, Sundsbak JL, Abebe KZ, Chapman AB, Torres VE, Grantham JJ, Bae KT, Schrier RW, Perrone RD, Braun WE, Steinman TI, Mrug M, Yu ASL, Brosnahan G, Hopp K, Irazabal MV, Bennett WM, Flessner MF, Moore CG, Landsittel D, Harris PC. Predicted Mutation Strength of Nontruncating PKD1 Mutations Aids Genotype-Phenotype Correlations in Autosomal Dominant Polycystic Kidney Disease. J Am Soc Nephrol 2016; 27:2872-84. [PMID: 26823553 DOI: 10.1681/asn.2015050583] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 12/09/2015] [Indexed: 01/12/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) often results in ESRD but with a highly variable course. Mutations to PKD1 or PKD2 cause ADPKD; both loci have high levels of allelic heterogeneity. We evaluated genotype-phenotype correlations in 1119 patients (945 families) from the HALT Progression of PKD Study and the Consortium of Radiologic Imaging Study of PKD Study. The population was defined as: 77.7% PKD1, 14.7% PKD2, and 7.6% with no mutation detected (NMD). Phenotypic end points were sex, eGFR, height-adjusted total kidney volume (htTKV), and liver cyst volume. Analysis of the eGFR and htTKV measures showed that the PKD1 group had more severe disease than the PKD2 group, whereas the NMD group had a PKD2-like phenotype. In both the PKD1 and PKD2 populations, men had more severe renal disease, but women had larger liver cyst volumes. Compared with nontruncating PKD1 mutations, truncating PKD1 mutations associated with lower eGFR, but the mutation groups were not differentiated by htTKV. PKD1 nontruncating mutations were evaluated for conservation and chemical change and subdivided into strong (mutation strength group 2 [MSG2]) and weak (MSG3) mutation groups. Analysis of eGFR and htTKV measures showed that patients with MSG3 but not MSG2 mutations had significantly milder disease than patients with truncating cases (MSG1), an association especially evident in extreme decile populations. Overall, we have quantified the contribution of genic and PKD1 allelic effects and sex to the ADPKD phenotype. Intrafamilial correlation analysis showed that other factors shared by families influence htTKV, with these additional genetic/environmental factors significantly affecting the ADPKD phenotype.
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Affiliation(s)
- Christina M Heyer
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Jamie L Sundsbak
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | | | | | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Jared J Grantham
- Kidney Institute, Kansas University Medical Center, Kansas City, Kansas
| | - Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Robert W Schrier
- Division of Nephrology, University of Colorado Health Sciences Center, Denver, Colorado
| | - Ronald D Perrone
- Division of Nephrology, Tufts Medical Center, Boston, Massachusetts
| | - William E Braun
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio
| | - Theodore I Steinman
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Michal Mrug
- Division of Nephrology, University of Alabama, Birmingham, Alabama
| | - Alan S L Yu
- Kidney Institute, Kansas University Medical Center, Kansas City, Kansas
| | - Godela Brosnahan
- Division of Nephrology, University of Colorado Health Sciences Center, Denver, Colorado
| | - Katharina Hopp
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Maria V Irazabal
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - William M Bennett
- Legacy Transplant Services, Legacy Good Samaritan Hospital, Portland, Oregon
| | - Michael F Flessner
- National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, Maryland; and
| | - Charity G Moore
- Dickson Advanced Analytics, Carolinas HealthCare System, Charlotte, North Carolina
| | | | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota;
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Kim Y, Ge Y, Tao C, Zhu J, Chapman AB, Torres VE, Yu ASL, Mrug M, Bennett WM, Flessner MF, Landsittel DP, Bae KT. Automated Segmentation of Kidneys from MR Images in Patients with Autosomal Dominant Polycystic Kidney Disease. Clin J Am Soc Nephrol 2016; 11:576-84. [PMID: 26797708 DOI: 10.2215/cjn.08300815] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/21/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Our study developed a fully automated method for segmentation and volumetric measurements of kidneys from magnetic resonance images in patients with autosomal dominant polycystic kidney disease and assessed the performance of the automated method with the reference manual segmentation method. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Study patients were selected from the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease. At the enrollment of the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease Study in 2000, patients with autosomal dominant polycystic kidney disease were between 15 and 46 years of age with relatively preserved GFRs. Our fully automated segmentation method was on the basis of a spatial prior probability map of the location of kidneys in abdominal magnetic resonance images and regional mapping with total variation regularization and propagated shape constraints that were formulated into a level set framework. T2-weighted magnetic resonance image sets of 120 kidneys were selected from 60 patients with autosomal dominant polycystic kidney disease and divided into the training and test datasets. The performance of the automated method in reference to the manual method was assessed by means of two metrics: Dice similarity coefficient and intraclass correlation coefficient of segmented kidney volume. The training and test sets were swapped for crossvalidation and reanalyzed. RESULTS Successful segmentation of kidneys was performed with the automated method in all test patients. The segmented kidney volumes ranged from 177.2 to 2634 ml (mean, 885.4±569.7 ml). The mean Dice similarity coefficient ±SD between the automated and manual methods was 0.88±0.08. The mean correlation coefficient between the two segmentation methods for the segmented volume measurements was 0.97 (P<0.001 for each crossvalidation set). The results from the crossvalidation sets were highly comparable. CONCLUSIONS We have developed a fully automated method for segmentation of kidneys from abdominal magnetic resonance images in patients with autosomal dominant polycystic kidney disease with varying kidney volumes. The performance of the automated method was in good agreement with that of manual method.
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Affiliation(s)
| | | | | | | | - Arlene B Chapman
- Department of Internal Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Vicente E Torres
- Department of Internal Medicine, Mayo College of Medicine, Rochester, Minnesota
| | - Alan S L Yu
- Department of Internal Medicine, Kansas University Medical Center, Kansas City, Kansas
| | - Michal Mrug
- Division of Nephrology, University of Alabama, Birmingham, Alabama
| | | | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Doug P Landsittel
- Internal Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Ricardo AC, Flessner MF, Eckfeldt JH, Eggers PW, Franceschini N, Go AS, Gotman NM, Kramer HJ, Kusek JW, Loehr LR, Melamed ML, Peralta CA, Raij L, Rosas SE, Talavera GA, Lash JP. Prevalence and Correlates of CKD in Hispanics/Latinos in the United States. Clin J Am Soc Nephrol 2015; 10:1757-66. [PMID: 26416946 DOI: 10.2215/cjn.02020215] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 07/13/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND OBJECTIVES The prevalence of ESRD among Hispanics/Latinos is 2-fold higher than in non-Hispanic whites. However, little is known about the prevalence of earlier stages of CKD among Hispanics/Latinos. This study estimated the prevalence of CKD in US Hispanics/Latinos. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This was a cross-sectional study of 15,161 US Hispanic/Latino adults of Cuban, Dominican, Mexican, Puerto Rican, Central American, and South American backgrounds enrolled in the multicenter, prospective, population-based Hispanic Community Health Study/Study of Latinos (HCHS/SOL). In addition, the prevalence of CKD in Hispanics/Latinos was compared with other racial/ethnic groups in the 2007-2010 National Health and Nutrition Examination Survey (NHANES). Prevalent CKD was defined as an eGFR <60 ml/min per 1.73 m(2) (estimated with the 2012 Chronic Kidney Disease Epidemiology Collaboration eGFR creatinine-cystatin C equation) or albuminuria based on sex-specific cut points determined at a single point in time. RESULTS The overall prevalence of CKD among Hispanics/Latinos was 13.7%. Among women, the prevalence of CKD was 13.0%, and it was lowest in persons with South American background (7.4%) and highest (16.6%) in persons with Puerto Rican background. In men, the prevalence of CKD was 15.3%, and it was lowest (11.2%) in persons with South American background and highest in those who identified their Hispanic background as "other" (16.0%). The overall prevalence of CKD was similar in HCHS/SOL compared with non-Hispanic whites in NHANES. However, prevalence was higher in HCHS/SOL men and lower in HCHS/SOL women versus NHANES non-Hispanic whites. Low income, diabetes mellitus, hypertension, and cardiovascular disease were each significantly associated with higher risk of CKD. CONCLUSIONS Among US Hispanic/Latino adults, there was significant variation in CKD prevalence among Hispanic/Latino background groups, and CKD was associated with established cardiovascular risk factors.
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Affiliation(s)
- Ana C Ricardo
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
| | - Michael F Flessner
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - John H Eckfeldt
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Paul W Eggers
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Nora Franceschini
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Alan S Go
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Nathan M Gotman
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Holly J Kramer
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - John W Kusek
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Laura R Loehr
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Michal L Melamed
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Carmen A Peralta
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Leopoldo Raij
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Sylvia E Rosas
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Gregory A Talavera
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - James P Lash
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
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Moore CG, Spillane S, Simon G, Maxwell B, Rahbari-Oskoui FF, Braun WE, Chapman AB, Schrier RW, Torres VE, Perrone RD, Steinman TI, Brosnahan G, Czarnecki PG, Harris PC, Miskulin DC, Flessner MF, Bae KT, Abebe KZ, Hogan MC. Closeout of the HALT-PKD trials. Contemp Clin Trials 2015; 44:48-55. [PMID: 26231556 DOI: 10.1016/j.cct.2015.07.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 07/21/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND The HALT Polycystic Kidney Disease Trials Network consisted of two randomized, double blind, placebo-controlled trials among patients with autosomal dominant polycystic kidney disease. The trials involved 5-8years of participant follow-up with interventions in blood pressure and antihypertensive therapy. We provide a framework for designing and implementing closeout near the end of a trial while ensuring patient safety and maintaining scientific rigor and study morale. METHODS We discuss issues and resolutions for determining the last visit, tapering medications, and unblinding of participants to study allocation and results. We also discuss closure of clinical sites and Data Coordinating Center responsibilities to ensure timely release of study results and meeting the requirements of regulatory and funding authorities. RESULTS Just over 90% of full participants had a 6-month study visit prior to their last visit preparing them for trial closeout. Nearly all patients wanted notification of study results (99%) and treatment allocation (99%). All participants were safely tapered off study and open label blood pressure medications. Within 6months, the trials were closed, primary papers published, and 805 letters distributed to participants with results and allocation. DCC obligations for data repository and clinicaltrials.gov reporting were completed within 12months of the last study visit. CONCLUSIONS Closeout of our trials involved years of planning and significant human and financial resources. We provide questions for investigators to consider when planning closeout of their trials with focus on (1) patient safety, (2) dissemination of study results and (3) compliance with regulatory and funding responsibilities.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - K Ty Bae
- University of Pittsburgh, Pittsburgh, PA, USA
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Isakova T, Ix JH, Sprague SM, Raphael KL, Fried L, Gassman JJ, Raj D, Cheung AK, Kusek JW, Flessner MF, Wolf M, Block GA. Rationale and Approaches to Phosphate and Fibroblast Growth Factor 23 Reduction in CKD. J Am Soc Nephrol 2015; 26:2328-39. [PMID: 25967123 DOI: 10.1681/asn.2015020117] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Patients with CKD often progress to ESRD and develop cardiovascular disease (CVD), yet available therapies only modestly improve clinical outcomes. Observational studies report independent associations between elevated serum phosphate and fibroblast growth factor 23 (FGF23) levels and risks of ESRD, CVD, and death. Phosphate excess induces arterial calcification, and although elevated FGF23 helps maintain serum phosphate levels in the normal range in CKD, it may contribute mechanistically to left ventricular hypertrophy (LVH). Consistent epidemiologic and experimental findings suggest the need to test therapeutic approaches that lower phosphate and FGF23 in CKD. Dietary phosphate absorption is one modifiable determinant of serum phosphate and FGF23 levels. Limited data from pilot studies in patients with CKD stages 3-4 suggest that phosphate binders, low phosphate diets, or vitamin B3 derivatives, such as niacin or nicotinamide, may reduce dietary phosphate absorption and serum phosphate and FGF23 levels. This review summarizes current knowledge regarding the deleterious systemic effects of phosphate and FGF23 excess, identifies questions that must be addressed before advancing to a full-scale clinical outcomes trial, and presents a novel therapeutic approach to lower serum phosphate and FGF23 levels that will be tested in the COMBINE Study: The CKD Optimal Management With BInders and NicotinamidE study.
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Affiliation(s)
- Tamara Isakova
- Division of Nephrology and Hypertension, Department of Medicine and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois;
| | - Joachim H Ix
- Nephrology Section, Veterans Affairs San Diego Healthcare System and Division of Nephrology and Preventive Medicine, University of California, San Diego, San Diego, California
| | - Stuart M Sprague
- NorthShore University Health System-University of Chicago, Pritzker School of Medicine, Evanston, Illinois
| | - Kalani L Raphael
- Salt Lake City Veterans Affairs Healthcare System and Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
| | - Linda Fried
- Renal Section, VA Pittsburgh Healthcare System, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jennifer J Gassman
- Department of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Dominic Raj
- Division of Renal Diseases and Hypertension, the George Washington University, Washington DC
| | - Alfred K Cheung
- Salt Lake City Veterans Affairs Healthcare System and Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
| | - John W Kusek
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland; and
| | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland; and
| | - Myles Wolf
- Division of Nephrology and Hypertension, Department of Medicine and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Torres VE, Abebe KZ, Chapman AB, Schrier RW, Braun WE, Steinman TI, Winklhofer FT, Brosnahan G, Czarnecki PG, Hogan MC, Miskulin DC, Rahbari-Oskoui FF, Grantham JJ, Harris PC, Flessner MF, Moore CG, Perrone RD. Angiotensin blockade in late autosomal dominant polycystic kidney disease. N Engl J Med 2014; 371:2267-76. [PMID: 25399731 PMCID: PMC4284824 DOI: 10.1056/nejmoa1402686] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Hypertension develops early in patients with autosomal dominant polycystic kidney disease (ADPKD) and is associated with disease progression. The renin-angiotensin-aldosterone system (RAAS) is implicated in the pathogenesis of hypertension in patients with ADPKD. Dual blockade of the RAAS may circumvent compensatory mechanisms that limit the efficacy of monotherapy with an angiotensin-converting-enzyme (ACE) inhibitor or angiotensin II-receptor blocker (ARB). METHODS In this double-blind, placebo-controlled trial, we randomly assigned 486 patients, 18 to 64 years of age, with ADPKD (estimated glomerular filtration rate [GFR], 25 to 60 ml per minute per 1.73 m(2) of body-surface area) to receive an ACE inhibitor (lisinopril) and placebo or lisinopril and an ARB (telmisartan), with the doses adjusted to achieve a blood pressure of 110/70 to 130/80 mm Hg. The composite primary outcome was the time to death, end-stage renal disease, or a 50% reduction from the baseline estimated GFR. Secondary outcomes included the rates of change in urinary aldosterone and albumin excretion, frequency of hospitalizations for any cause and for cardiovascular causes, incidence of pain, frequency of ADPKD-related symptoms, quality of life, and adverse study-medication effects. Patients were followed for 5 to 8 years. RESULTS There was no significant difference between the study groups in the incidence of the composite primary outcome (hazard ratio with lisinopril-telmisartan, 1.08; 95% confidence interval, 0.82 to 1.42). The two treatments controlled blood pressure and lowered urinary aldosterone excretion similarly. The rates of decline in the estimated GFR, urinary albumin excretion, and other secondary outcomes and adverse events, including hyperkalemia and acute kidney injury, were also similar in the two groups. CONCLUSIONS Monotherapy with an ACE inhibitor was associated with blood-pressure control in most patients with ADPKD and stage 3 chronic kidney disease. The addition of an ARB did not alter the decline in the estimated GFR. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; HALT-PKD [Study B] ClinicalTrials.gov number, NCT01885559.).
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Affiliation(s)
- Vicente E Torres
- From the Mayo Clinic College of Medicine, Rochester, MN (V.E.T., M.C.H., P.C.H.); University of Pittsburgh School of Medicine, Pittsburgh (K.Z.A., C.G.M.); Emory University School of Medicine, Atlanta (A.B.C., F.F.R.-O.); University of Colorado Health Sciences Center, Denver (R.W.S., G.B.); Cleveland Clinic, Cleveland (W.E.B.); Beth Israel Deaconess Medical Center (T.I.S., P.G.C.) and Tufts Medical Center (D.C.M., R.D.P.) - both in Boston; Kansas University Medical Center, Kansas City (F.T.W., J.J.G.) and the National Institutes of Health, Bethesda, MD (M.F.F.)
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35
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Schrier RW, Abebe KZ, Perrone RD, Torres VE, Braun WE, Steinman TI, Winklhofer FT, Brosnahan G, Czarnecki PG, Hogan MC, Miskulin DC, Rahbari-Oskoui FF, Grantham JJ, Harris PC, Flessner MF, Bae KT, Moore CG, Chapman AB. Blood pressure in early autosomal dominant polycystic kidney disease. N Engl J Med 2014; 371:2255-66. [PMID: 25399733 PMCID: PMC4343258 DOI: 10.1056/nejmoa1402685] [Citation(s) in RCA: 309] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Hypertension is common in autosomal dominant polycystic kidney disease (ADPKD) and is associated with increased total kidney volume, activation of the renin-angiotensin-aldosterone system, and progression of kidney disease. METHODS In this double-blind, placebo-controlled trial, we randomly assigned 558 hypertensive participants with ADPKD (15 to 49 years of age, with an estimated glomerular filtration rate [GFR] >60 ml per minute per 1.73 m(2) of body-surface area) to either a standard blood-pressure target (120/70 to 130/80 mm Hg) or a low blood-pressure target (95/60 to 110/75 mm Hg) and to either an angiotensin-converting-enzyme inhibitor (lisinopril) plus an angiotensin-receptor blocker (telmisartan) or lisinopril plus placebo. The primary outcome was the annual percentage change in the total kidney volume. RESULTS The annual percentage increase in total kidney volume was significantly lower in the low-blood-pressure group than in the standard-blood-pressure group (5.6% vs. 6.6%, P=0.006), without significant differences between the lisinopril-telmisartan group and the lisinopril-placebo group. The rate of change in estimated GFR was similar in the two medication groups, with a negative slope difference in the short term in the low-blood-pressure group as compared with the standard-blood-pressure group (P<0.001) and a marginally positive slope difference in the long term (P=0.05). The left-ventricular-mass index decreased more in the low-blood-pressure group than in the standard-blood-pressure group (-1.17 vs. -0.57 g per square meter per year, P<0.001); urinary albumin excretion was reduced by 3.77% with the low-pressure target and increased by 2.43% with the standard target (P<0.001). Dizziness and light-headedness were more common in the low-blood-pressure group than in the standard-blood-pressure group (80.7% vs. 69.4%, P=0.002). CONCLUSIONS In early ADPKD, the combination of lisinopril and telmisartan did not significantly alter the rate of increase in total kidney volume. As compared with standard blood-pressure control, rigorous blood-pressure control was associated with a slower increase in total kidney volume, no overall change in the estimated GFR, a greater decline in the left-ventricular-mass index, and greater reduction in urinary albumin excretion. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; HALT-PKD [Study A] ClinicalTrials.gov number, NCT00283686.).
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Affiliation(s)
- Robert W Schrier
- From the University of Colorado, Denver (R.W.S., G.B.); University of Pittsburgh School of Medicine, Pittsburgh (K.Z.A., K.T.B., C.G.M.); Tufts Medical Center (R.D.P., D.C.M.) and Beth Israel Deaconess Medical Center (T.I.S., P.G.C.) - both in Boston; Mayo Clinic College of Medicine, Rochester, MN (V.E.T., M.C.H., P.C.H.); Cleveland Clinic, Cleveland (W.E.B.); Kansas University Medical Center, Kansas City (F.T.W., J.J.G.); Emory University School of Medicine, Atlanta (F.F.R.-O., A.B.C.); and the National Institutes of Health, Bethesda, MD (M.F.F.)
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36
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Nolin TD, Aronoff GR, Fissell WH, Jain L, Madabushi R, Reynolds K, Zhang L, Huang SM, Mehrotra R, Flessner MF, Leypoldt JK, Witcher JW, Zineh I, Archdeacon P, Roy-Chaudhury P, Goldstein SL. Pharmacokinetic assessment in patients receiving continuous RRT: perspectives from the Kidney Health Initiative. Clin J Am Soc Nephrol 2014; 10:159-64. [PMID: 25189923 DOI: 10.2215/cjn.05630614] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of AKI and modern continuous RRT (CRRT) methods on drug disposition (pharmacokinetics) and response has been poorly studied. Pharmaceutical manufacturers have little incentive to perform pharmacokinetic studies in patients undergoing CRRT because such studies are neither recommended in existing US Food and Drug Administration (FDA) guidance documents nor required for new drug approval. Action is urgently needed to address the knowledge deficit. The Kidney Health Initiative has assembled a work group composed of clinicians and scientists representing academia, the FDA, and the pharmaceutical and dialysis industries with expertise related to pharmacokinetics, AKI, and/or CRRT. The work group critically evaluated key considerations in the assessment of pharmacokinetics and drug dosing in CRRT, practical constraints related to conducting pharmacokinetic studies in critically ill patients, and the generalizability of observations made in the context of specific CRRT prescriptions and specific patient populations in order to identify efficient study designs capable of addressing the knowledge deficit without impeding drug development. Considerations for the standardized assessment of pharmacokinetics and development of corresponding drug dosing recommendations in critically ill patients with AKI receiving CRRT are proposed.
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Affiliation(s)
- Thomas D Nolin
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
| | - George R Aronoff
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - William H Fissell
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Lokesh Jain
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Rajnikanth Madabushi
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Kellie Reynolds
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Lei Zhang
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Shiew Mei Huang
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Rajnish Mehrotra
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Michael F Flessner
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - John K Leypoldt
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Jennifer W Witcher
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Issam Zineh
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Patrick Archdeacon
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Prabir Roy-Chaudhury
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Stuart L Goldstein
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
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Guay-Woodford LM, Henske E, Igarashi P, Perrone RD, Reed-Gitomer B, Somlo S, Torres VE, Ketchum CJ, Star RA, Flessner MF, Rasooly RS. Filling the holes in cystic kidney disease research. Clin J Am Soc Nephrol 2014; 9:1799-801. [PMID: 24903391 DOI: 10.2215/cjn.03410414] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Kidney disease is a significant medical and public health problem. The National Institute of Diabetes and Digestive and Kidney Diseases recently asked the community to identify research objectives, which, if addressed, could improve understanding of basic kidney function and aid in prevention, treatment, and reversal of kidney disease. The Kidney Research National Dialogue invited interested parties to submit, discuss, and prioritize ideas using an interactive website; 1600 participants posted more than 300 ideas covering all areas of kidney disease, including the cystic kidney diseases. Although much is known about the genetics and pathogenesis of cystic diseases, there remain challenges to our understanding of the fundamental mechanisms of cyst formation, what genes act as modifiers to cause variable responses in different people, and how to detect and monitor disease progression. This article summarizes key research questions for cystic kidney diseases.
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Affiliation(s)
- Lisa M Guay-Woodford
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Elizabeth Henske
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Peter Igarashi
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Ronald D Perrone
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Berenice Reed-Gitomer
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Stefan Somlo
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Vicente E Torres
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Christian J Ketchum
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Robert A Star
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Michael F Flessner
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Rebekah S Rasooly
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
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Wiggins RC, Alpers CE, Holzman LB, He JC, Salant DJ, Chugh SS, Natarajan R, Trachtman H, Brasile L, Star RA, Rys-Sikora KE, Moxey-Mims MM, Flessner MF. Glomerular disease: looking beyond pathology. Clin J Am Soc Nephrol 2014; 9:1138-40. [PMID: 24700796 DOI: 10.2215/cjn.01450214] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The National Institute of Diabetes and Digestive and Kidney Diseases-supported Kidney Research National Dialogue asked the scientific community to formulate and prioritize research objectives aimed at improved understanding of kidney function and disease progression. Over the past 2 years, 1600 participants posted almost 300 ideas covering all areas of kidney disease. An overriding theme that evolved through these discussions is the need to move beyond pathology to take advantage of basic science and clinical research opportunities to improve diagnostic classification and therapeutic options for people with primary glomerular disease. High-priority research areas included focus on therapeutic targets in glomerular endothelium and podocytes, regenerating podocytes through developmental pathways, use of longitudinal phenotypically defined disease cohorts to improve classification schemes, identifying biomarkers, disease-specific therapeutics, autoantibody triggers, and changing the clinical research culture to promote participation in clinical trials. Together, these objectives provide a path forward for improving clinical outcomes of glomerular disease.
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Affiliation(s)
- Roger C Wiggins
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Charles E Alpers
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Lawrence B Holzman
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - John C He
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - David J Salant
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Sumant S Chugh
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Rama Natarajan
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Howard Trachtman
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Lauren Brasile
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Robert A Star
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Krystyna E Rys-Sikora
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Marva M Moxey-Mims
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Michael F Flessner
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
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Bae KT, Sun H, Lee JG, Bae K, Wang J, Tao C, Chapman AB, Torres VE, Grantham JJ, Mrug M, Bennett WM, Flessner MF, Landsittel DP. Novel methodology to evaluate renal cysts in polycystic kidney disease. Am J Nephrol 2014; 39:210-7. [PMID: 24576800 DOI: 10.1159/000358604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 01/08/2014] [Indexed: 01/21/2023]
Abstract
AIM To develop and assess a semiautomated method for segmenting and counting individual renal cysts from mid-slice MR images in patients with autosomal dominant polycystic kidney disease (ADPKD). METHODS A semiautomated method was developed to segment and count individual renal cysts from mid-slice MR images in 241 subjects with ADPKD from the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease. For each subject, a mid-slice MR image was selected from each set of coronal T2-weighted MR images covering the entire kidney. The selected mid-slice image was processed with the semiautomated method to segment and count individual renal cysts. The number of cysts from the mid-slice image of each kidney was also measured by manual counting. The level of agreement between the semiautomated and manual cyst counts was compared using intraclass correlation (ICC) and a Bland-Altman plot. RESULTS Individual renal cysts were successfully segmented using the semiautomated method in all 241 cases. The number of cysts in each kidney measured with the semiautomated and manual counting methods correlated well (ICC = 0.96 for the right or left kidney), with a small average difference (-0.52, with higher semiautomated counts, for the right kidney, and 0.13, with higher manual counts, for the left kidney) in the semiautomated method. However, there was substantial variation in a small number of subjects; 6 of 241 participants (2.5%) had a difference in the total cyst count of more than 15. CONCLUSION We have developed a semiautomated method to segment individual renal cysts from mid-slice MR images in ADPKD kidneys as a quantitative indicator of characterization and disease progression of ADPKD.
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Affiliation(s)
- Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pa., USA
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Kaskel F, Batlle D, Beddhu S, Daugirdas J, Feldman H, Ferris M, Fine L, Freedman BI, Kimmel PL, Flessner MF, Star RA. Improving CKD therapies and care: a National Dialogue. Clin J Am Soc Nephrol 2014; 9:815-7. [PMID: 24509296 DOI: 10.2215/cjn.12631213] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The Kidney Research National Dialogue, supported by the National Institute of Diabetes and Digestive and Kidney Diseases, asked the research and clinical communities to formulate and prioritize research objectives that would improve our understanding of kidney function and diseases. This commentary outlines the high-priority research objectives for CKD. The goal of these research objectives is to enhance knowledge to improve outcomes in people with CKD. Basic and translational research, longitudinal observations, and epidemiologic studies can each point to targets for intervention. Future interventions must be informed by data from well designed, large representative observational studies that include collection of genetic and phenotypic data as well as biospecimens. Interaction of genetic and environmental factors must be part of the analysis, including the influence of diet, comorbid conditions, and medication. The focus should be not only on slowing or preventing progression of CKD, but also on regression of disease to the greatest extent possible.
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Affiliation(s)
- Frederick Kaskel
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
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Miskulin DC, Abebe KZ, Chapman AB, Perrone RD, Steinman TI, Torres VE, Bae KT, Braun W, Winklhofer FT, Hogan MC, Rahbari-Oskoui F, Moore CG, Flessner MF, Schrier RW. Health-related quality of life in patients with autosomal dominant polycystic kidney disease and CKD stages 1-4: a cross-sectional study. Am J Kidney Dis 2013; 63:214-26. [PMID: 24183837 DOI: 10.1053/j.ajkd.2013.08.017] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 08/26/2013] [Indexed: 11/11/2022]
Abstract
BACKGROUND In people with early autosomal dominant polycystic kidney disease (ADPKD), average total kidney volume (TKV) is 3 times normal and increases by an average of 5% per year despite a seemingly normal glomerular filtration rate (GFR). We hypothesized that increased TKV would be a source of morbidity and diminished quality of life that would be worse in patients with more advanced disease. STUDY DESIGN Cross-sectional. SETTING & PARTICIPANTS 1,043 patients with ADPKD, hypertension, and a baseline estimated GFR (eGFR)> 20mL/min/1.73m(2). PREDICTORS (1) eGFR, (2) height-adjusted TKV (htTKV) in patients with eGFR> 60mL/min/1.73m(2). OUTCOMES 36-Item Short Form Health Survey (SF-36) and the Wisconsin Brief Pain Survey. MEASUREMENTS Questionnaires were self-administered. GFR was estimated from serum creatinine using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. htTKV was measured by magnetic resonance imaging. RESULTS Back pain was reported by 50% of patients, and 20% experienced it "often, usually, or always." In patients with early disease (eGFR> 60mL/min/1.73m(2)), there was no association between pain and htTKV, except in patients with large kidneys (htTKV> 1,000mL/m). Comparing across eGFR levels and including patients with eGFRs< 60mL/min/1.73m(2), patients with eGFRs of 20-44mL/min/1.73m(2) were significantly more likely to report that pain impacted on their daily lives and had lower SF-36 scores than patients with eGFRs of 45-60 and ≥60mL/min/1.73m(2). Symptoms relating to abdominal fullness were reported by 20% of patients and were related significantly to lower eGFRs in women, but not men. LIMITATIONS TKV and liver volume were not measured in patients with eGFR < 60mL/min/1.73m(2). The number of patients with eGFRs< 30mL/min/1.73m(2) is small. Causal inferences are limited by cross-sectional design. CONCLUSIONS Pain is a common early symptom in the course of ADPKD, although it is not related to kidney size in early disease (eGFR> 60mL/min/1.73m(2)), except in individuals with large kidneys (htTKV> 1,000 mL/m). Symptoms relating to abdominal fullness and pain are greater in patients with more advanced (eGFR, 20-45mL/min/1.73m(2)) disease and may be due to organ enlargement, especially in women. More research about the role of TKV in quality of life and outcomes of patients with ADPKD is warranted.
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Affiliation(s)
| | - Kaleab Z Abebe
- University of Pittsburgh School of Medicine, Pittsburgh, PA
| | | | | | | | | | - K Ty Bae
- University of Pittsburgh School of Medicine, Pittsburgh, PA
| | | | | | | | | | | | - Michael F Flessner
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
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Bae KT, Tao C, Wang J, Kaya D, Wu Z, Bae JT, Chapman AB, Torres VE, Grantham JJ, Mrug M, Bennett WM, Flessner MF, Landsittel DP. Novel approach to estimate kidney and cyst volumes using mid-slice magnetic resonance images in polycystic kidney disease. Am J Nephrol 2013; 38:333-41. [PMID: 24107679 DOI: 10.1159/000355375] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 08/28/2013] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To evaluate whether kidney and cyst volumes can be accurately estimated based on limited area measurements from magnetic resonance (MR) images of patients with autosomal dominant polycystic kidney disease (ADPKD). MATERIALS AND METHODS MR coronal images of 178 ADPKD participants from the Consortium for Radiologic Imaging Studies of ADPKD (CRISP) were analyzed. For each MR image slice, we measured kidney and renal cyst areas using stereology and region-based thresholding methods, respectively. The kidney and cyst 'observed' volumes were calculated by summing up the area measurements of all the slices covering the kidney. To estimate the volume, we selected a coronal mid-slice in each kidney and multiplied its area by the total number of slices ('PANK2' for kidney and 'PANC2' for cyst). We then compared the kidney and cyst volumes predicted from PANK2 and PANC2, respectively, to the corresponding observed volumes, using a linear regression analysis. RESULTS The kidney volume predicted from PANK2 correlated extremely well with the observed kidney volume (R(2) = 0.994 for the right kidney and 0.991 for the left kidney). The linear regression coefficient multiplier to PANK2 that best fit the kidney volume was 0.637 (95% CI: 0.629-0.644) for the right kidney and 0.624 (95% CI: 0.616-0.633) for the left kidney. The correlation between the cyst volume predicted from PANC2 and the observed cyst volume was also very high (R(2) = 0.984 for the right kidney and 0.967 for the left kidney). The least squares linear regression coefficient for PANC2 was 0.637 (95% CI: 0.624-0.649) for the right kidney and 0.608 (95% CI: 0.591-0.625) for the left kidney. CONCLUSION Kidney and cyst volumes can be closely approximated by multiplying the product of the mid-slice area measurement and the total number of slices in the coronal MR images of ADPKD kidneys by 0.61-0.64. This information will help save processing time needed to estimate total kidney and cyst volumes of ADPKD kidneys.
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Affiliation(s)
- Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pa., USA
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St. Peter WL, Weinhandl ED, Flessner MF. In Reply to ‘Primary Objective of Study of Sitagliptin in Patients With ESRD on Dialysis’. Am J Kidney Dis 2013; 62:642-3. [DOI: 10.1053/j.ajkd.2013.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 06/05/2013] [Indexed: 11/11/2022]
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Breyer MD, Coffman TM, Flessner MF, Fried LF, Harris RC, Ketchum CJ, Kretzler M, Nelson RG, Sedor JR, Susztak K. Diabetic nephropathy: a national dialogue. Clin J Am Soc Nephrol 2013; 8:1603-5. [PMID: 23788618 DOI: 10.2215/cjn.03640413] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The National Institute of Diabetes and Digestive and Kidney Diseases-supported Kidney Research National Dialogue (KRND) asked the scientific community to formulate and prioritize research objectives that would improve our understanding of kidney function and disease. Several high-priority objectives for diabetic nephropathy were identified in data and sample collection, hypothesis generation, hypothesis testing, and translation promotion. The lack of readily available human samples linked to comprehensive phenotypic, clinical, and demographic data remains a significant obstacle. With data and biological samples in place, several possibilities exist for using new technologies to develop hypotheses. Testing novel disease mechanisms with state-of-the-art tools should continue to be the foundation of the investigative community. Research must be translated to improve diagnosis and treatment of people. The objectives identified by the KRND provide the research community with future opportunities for improving the prevention, diagnosis, and treatment of diabetic nephropathy.
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Affiliation(s)
- Matthew D Breyer
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 6707 Democracy Boulevard, Bethesda, MD 20892, USA
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St Peter WL, Weinhandl ED, Flessner MF. Sitagliptin--another option for managing type 2 diabetes in dialysis patients? Am J Kidney Dis 2013; 61:532-5. [PMID: 23497767 DOI: 10.1053/j.ajkd.2013.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 01/10/2013] [Indexed: 11/11/2022]
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Bae K, Park B, Sun H, Wang J, Tao C, Chapman AB, Torres VE, Grantham JJ, Mrug M, Bennett WM, Flessner MF, Landsittel DP, Bae KT. Segmentation of individual renal cysts from MR images in patients with autosomal dominant polycystic kidney disease. Clin J Am Soc Nephrol 2013; 8:1089-97. [PMID: 23520042 DOI: 10.2215/cjn.10561012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To evaluate the performance of a semi-automated method for the segmentation of individual renal cysts from magnetic resonance (MR) images in patients with autosomal dominant polycystic kidney disease (ADPKD). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This semi-automated method was based on a morphologic watershed technique with shape-detection level set for segmentation of renal cysts from MR images. T2-weighted MR image sets of 40 kidneys were selected from 20 patients with mild to moderate renal cyst burden (kidney volume < 1500 ml) in the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP). The performance of the semi-automated method was assessed in terms of two reference metrics in each kidney: the total number of cysts measured by manual counting and the total volume of cysts measured with a region-based thresholding method. The proposed and reference measurements were compared using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS Individual renal cysts were successfully segmented with the semi-automated method in all 20 cases. The total number of cysts in each kidney measured with the two methods correlated well (ICC, 0.99), with a very small relative bias (0.3% increase with the semi-automated method; limits of agreement, 15.2% reduction to 17.2% increase). The total volume of cysts measured using both methods also correlated well (ICC, 1.00), with a small relative bias of <10% (9.0% decrease in the semi-automated method; limits of agreement, 17.1% increase to 43.3% decrease). CONCLUSION This semi-automated method to segment individual renal cysts in ADPKD kidneys provides a quantitative indicator of severity in early and moderate stages of the disease.
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Affiliation(s)
- Kyungsoo Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
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Boertien WE, Meijer E, Li J, Bost JE, Struck J, Flessner MF, Gansevoort RT, Torres VE. Relationship of copeptin, a surrogate marker for arginine vasopressin, with change in total kidney volume and GFR decline in autosomal dominant polycystic kidney disease: results from the CRISP cohort. Am J Kidney Dis 2012; 61:420-9. [PMID: 23089511 DOI: 10.1053/j.ajkd.2012.08.038] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 08/18/2012] [Indexed: 01/20/2023]
Abstract
BACKGROUND Experimental studies indicate that arginine vasopressin (AVP) may have deleterious effects in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD). However, the significance of AVP in human ADPKD is unclear. STUDY DESIGN Longitudinal observational study with 8.5 (IQR, 7.7-9.0) years' follow-up (CRISP [Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease]). SETTING & PARTICIPANTS 241 patients with ADPKD with creatinine clearance >70 mL/min. PREDICTOR Plasma copeptin concentration, a surrogate marker for AVP. OUTCOMES Change in measured glomerular filtration rate (mGFR, assessed by iothalamate clearance) and total kidney volume (measured by magnetic resonance imaging). MEASUREMENTS Baseline copeptin level, plasma and urinary osmolality, and measurements of total kidney volume and mGFR during follow-up. RESULTS In these patients (median age, 34 [IQR, 25-40] years; 38% men; median mGFR, 94 [IQR, 79-145] mL/min/1.73 m(2); median total kidney volume, 859 [IQR, 577-1,299] mL), median copeptin level was 2.9 (IQR, 1.8-5.1) pmol/L. Copeptin was not associated with plasma osmolality (P = 0.3), the physiologic stimulus for AVP release, but was associated significantly with change in total kidney volume during follow-up (P < 0.001). This association remained significant after adjusting for sex, age, cardiovascular risk factors, and diuretic use (P = 0.03). Copeptin level was associated borderline significantly with change in mGFR after adjusting for these variables (P = 0.09). LIMITATIONS No standardization of hydration status at time of copeptin measurement. CONCLUSIONS These data show that in ADPKD, copeptin level, as a marker for AVP, is not correlated with plasma osmolality. Most importantly, high copeptin levels are associated independently with disease progression in early ADPKD. This is in line with experimental studies that indicate a disease-promoting role for AVP.
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Affiliation(s)
- Wendy E Boertien
- Department of Nephrology, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, the Netherlands
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Fülöp T, Hickson DA, Wyatt SB, Bhagat R, Rack M, Gowdy O, Flessner MF, Taylor HA. Sleep-disordered breathing symptoms among African-Americans in the Jackson Heart Study. Sleep Med 2012; 13:1039-49. [PMID: 22841028 DOI: 10.1016/j.sleep.2012.06.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 05/12/2012] [Accepted: 06/09/2012] [Indexed: 11/16/2022]
Abstract
BACKGROUND Sleep-disordered breathing (SDB) is an increasingly recognized risk factor for cardiovascular disease (CVD). Limited data are available from large African American cohorts. METHODS We examined the prevalence, burden, and correlates of sleep symptoms suggestive of SDB and risk for obstructive sleep apnea (OSA) in the Jackson Heart Study (JHS), an all-African-American cohort of 5301 adults. Data on selected daytime and nighttime sleep symptoms were collected using a modified Berlin questionnaire during the baseline examination. Risk of OSA was calculated according to published prediction model. Age and multivariable-adjusted logistic regression models were used to examine the associations between potential risk factors and measures of sleep. RESULTS Sleep symptoms, burden, and risk of OSA were high among men and women in the JHS and increased with age and obesity. Being married was positively associated with sleep symptoms among women. In men, poor to fair perceived health and increased levels of stress were associated with higher odds of sleep burden, whereas prevalent hypertension and CVD were associated with higher odds of OSA risk. Similar associations were observed among women with slight variations. Sleep duration <7h was associated with increased odds of sleep symptoms among women and increased sleep burden among men. Moderate to severe restless sleep was consistently and positively associated with odds of adverse sleep symptoms, sleep burden, and high risk OSA. CONCLUSIONS Sleep symptoms in JHS had a strong positive association with features of visceral obesity, stress, and poor perceived health. With increasing obesity among younger African Americans, these findings are likely to have broad public health implications.
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Affiliation(s)
- Tibor Fülöp
- School of Medicine, University of Mississippi Medical Center, Jackson, MS 39216-4505, United States.
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Fülöp T, Hickson DA, Wyatt SB, Bhagat R, Rack M, Gowdy O, Flessner MF, Taylor HA. Sleep-disordered breathing symptoms among African-Americans in the Jackson Heart Study. Sleep Med 2012. [PMID: 22841028 DOI: 10.1016/j.sleep.2012.06.005.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
BACKGROUND Sleep-disordered breathing (SDB) is an increasingly recognized risk factor for cardiovascular disease (CVD). Limited data are available from large African American cohorts. METHODS We examined the prevalence, burden, and correlates of sleep symptoms suggestive of SDB and risk for obstructive sleep apnea (OSA) in the Jackson Heart Study (JHS), an all-African-American cohort of 5301 adults. Data on selected daytime and nighttime sleep symptoms were collected using a modified Berlin questionnaire during the baseline examination. Risk of OSA was calculated according to published prediction model. Age and multivariable-adjusted logistic regression models were used to examine the associations between potential risk factors and measures of sleep. RESULTS Sleep symptoms, burden, and risk of OSA were high among men and women in the JHS and increased with age and obesity. Being married was positively associated with sleep symptoms among women. In men, poor to fair perceived health and increased levels of stress were associated with higher odds of sleep burden, whereas prevalent hypertension and CVD were associated with higher odds of OSA risk. Similar associations were observed among women with slight variations. Sleep duration <7h was associated with increased odds of sleep symptoms among women and increased sleep burden among men. Moderate to severe restless sleep was consistently and positively associated with odds of adverse sleep symptoms, sleep burden, and high risk OSA. CONCLUSIONS Sleep symptoms in JHS had a strong positive association with features of visceral obesity, stress, and poor perceived health. With increasing obesity among younger African Americans, these findings are likely to have broad public health implications.
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Affiliation(s)
- Tibor Fülöp
- School of Medicine, University of Mississippi Medical Center, Jackson, MS 39216-4505, United States.
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Stachowska-Pietka J, Waniewski J, Flessner MF, Lindholm B. Computer simulations of osmotic ultrafiltration and small-solute transport in peritoneal dialysis: a spatially distributed approach. Am J Physiol Renal Physiol 2012; 302:F1331-41. [PMID: 22301624 DOI: 10.1152/ajprenal.00301.2011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to simulate clinically observed intraperitoneal kinetics of dialysis fluid volume and solute concentrations during peritoneal dialysis. We were also interested in analyzing relationships between processes in the peritoneal cavity and processes occurring in the peritoneal tissue and microcirculation. A spatially distributed model was formulated for the combined description of volume and solute mass balances in the peritoneal cavity and flows across the interstitium and the capillary wall. Tissue local parameters were assumed dependent on the interstitial hydration and vasodilatation induced by glucose. The model was fitted to the average volume and solute concentration profiles from dwell studies in 40 clinically stable patients on chronic ambulatory peritoneal dialysis using a 3.86% glucose dialysis solution. The model was able to describe the clinical data with high accuracy. An increase in the local interstitial pressure and tissue hydration within the distance of 2.5 mm from the peritoneal surface of the tissue was observed. The penetration of glucose into the tissue and removal of urea, creatinine, and sodium from the tissue were restricted to a layer located within 2 mm from the peritoneal surface. The initial decline of sodium concentration (sodium dip) was observed not only in intraperitoneal fluid but also in the tissue. The distributed model can provide a precise description of the relationship between changes in the peritoneal tissue and intraperitoneal dialysate volume and solute concentration kinetics. Computer simulations suggest that only a thin layer of the tissue within 2-3 mm from the peritoneal surface participates in the exchange of fluid and small solutes between the intraperitoneal dialysate and blood.
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Affiliation(s)
- Joanna Stachowska-Pietka
- Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland.
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