1
|
Gosmanova EO, Gemoets DE, Dharia S, Der Mesropian P, Shaikh G, Kovesdy CP, Phelps KR. Determinants of the serum phosphate concentration in chronic kidney disease. Clin Nephrol 2024; 101:82-92. [PMID: 38085074 DOI: 10.5414/cn111260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2024] [Indexed: 01/17/2024] Open
Abstract
If Ccr is creatinine clearance and EP and TRP are rates of phosphate excretion and reabsorption, the serum phosphate concentration (Ps) is the sum of EP/Ccr and TRP/Ccr, i.e., the amounts of phosphate excreted and reabsorbed per volume of filtrate. At equilibrium, influx of phosphate into plasma determines EP, and EP/Ccr quantifies the contribution of phosphate influx to Ps. We used data obtained at 688 clinic visits of 387 patients to analyze the evolution of Ps in chronic kidney disease (CKD) stages G1 - 5 (dialysis excluded). EP/Ccr was calculated as (Pu×crs)/cru and TRP/Ccr as Ps-EP/Ccr (where u is urine, s is serum, and cr is creatinine). Means of these parameters were plotted against CKD stages, and correlations among variables were determined with regression analyses. In comparison to values in CKD stages G1 - 2, EP/Ccr rose and TRP/Ccr fell by the same amount in CKD G3a and G3b, and Ps did not change. In stages G4 and G5, EP/Ccr increased sharply, TRP/Ccr fell minimally, and Ps rose significantly. At estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73m2, TRP/Ccr was the principal determinant of Ps at eGFR < 45 mL/min/1.73m2, contributions of EP/Ccr and TRP/Ccr to Ps were comparable. Taken together, our results show that in CKD stages G4 and G5, the effect of phosphate reabsorption on Ps changes negligibly while that of phosphate influx increases dramatically. Because the tubular response to rising EP/Ccr is limited, maintenance of stable Ps in advanced CKD requires extreme reduction of phosphate influx into plasma. TRP/Ccr may define the lowest attainable Ps.
Collapse
|
2
|
Satarug S, Vesey DA, Gobe GC, Phelps KR. The pathogenesis of albuminuria in cadmium nephropathy. Curr Res Toxicol 2023; 6:100140. [PMID: 38116328 PMCID: PMC10726218 DOI: 10.1016/j.crtox.2023.100140] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 07/10/2023] [Revised: 11/16/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023] Open
Abstract
Background Urinary cadmium excretion (ECd) rises with renal tissue content of the metal. Whereas glomerulopathies are sometimes associated with massive albuminuria, tubular accumulation of Cd typically causes modest albuminuria. Since β2-microglobulinuria (Eβ2M) is an established marker of proximal tubular dysfunction, we hypothesized that a comparison of albuminuria (Ealb) to Eβ2M in Cd-exposed subjects would provide evidence of similar mishandling of both proteins. Methods To depict excretion rates per functional nephron, ECd, Ealb, and Eβ2M were normalized to creatinine clearance (Ccr), a surrogate for the glomerular filtration rate (GFR). Estimation of GFR itself (eGFR) was accomplished with CKD-EPI formulas (2009). Linear and logistic regression analyses were performed to relate Ealb/Ccr, Eβ2M/Ccr, and eGFR to several independent variables. Simple linear regressions of eGFR, Ealb/Ccr, and Eβ2M/Ccr on ECd/Ccr were examined before and after adjustment of dependent variables for age. All regressions were performed after log-transformation of ratios and standardization of all variables. Increments in Ealb/Ccr and Eβ2M/Ccr and decrements in eGFR were quantified through four quartiles of ECd/Ccr. Results As age or ECd/Ccr rose, Ealb/Ccr and Eβ2M/Ccr also rose, and eGFR fell. In linear regressions, slopes relating Ealb/Ccr and Eβ2M/Ccr to ECd/Ccr were similar. After adjustment of dependent variables for age, coefficients of determination (R2) for all regressions rose by a multiple, and slopes approached unity. Ealb/Ccr and Eβ2M/Ccr were similarly associated with each other. Mean Ealb/Ccr and Eβ2M/Ccr rose and mean eGFR fell in stepwise fashion through quartiles of ECd/Ccr. Whereas Eβ2M/Ccr did not vary with blood pressure, Ealb/Ccr rose in association with hypertension in two of the four quartiles. Conclusions Our data indicate that Cd in renal tissue affected tubular reabsorption of albumin and β2M similarly in a large cohort of exposed subjects. The results suggest that Cd reduced receptor-mediated endocytosis and subsequent lysosomal degradation of each protein by a shared mechanism.
Collapse
Affiliation(s)
- Soisungwan Satarug
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
| | - David A. Vesey
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
- Department of Kidney and Transplant Services, Princess Alexandra Hospital, Brisbane, Australia
| | - Glenda C. Gobe
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Kenneth R. Phelps
- Stratton Veterans Affairs Medical Center and Albany Medical College, Albany, NY, USA
| |
Collapse
|
3
|
Abstract
In much of the world, currently employed upper limits of tolerable intake and acceptable excretion of cadmium (Cd) (ECd/Ecr) are 0.83 µg/kg body weight/day and 5.24 µg/g creatinine, respectively. These figures were derived from a risk assessment model that interpreted β2-microglobulin (β2MG) excretion > 300 μg/g creatinine as a "critical" endpoint. However, current evidence suggests that Cd accumulation reduces glomerular filtration rate at values of ECd/Ecr much lower than 5.24 µg/g creatinine. Low ECd/Ecr has also been associated with increased risks of kidney disease, type 2 diabetes, osteoporosis, cancer, and other disorders. These associations have cast considerable doubt on conventional guidelines. The goals of this paper are to evaluate whether these guidelines are low enough to minimize associated health risks reliably, and indeed whether permissible intake of a cumulative toxin like Cd is a valid concept. We highlight sources and levels of Cd in the human diet and review absorption, distribution, kidney accumulation, and excretion of the metal. We present evidence for the following propositions: excreted Cd emanates from injured tubular epithelial cells of the kidney; Cd excretion is a manifestation of current tissue injury; reduction of present and future exposure to environmental Cd cannot mitigate injury in progress; and Cd excretion is optimally expressed as a function of creatinine clearance rather than creatinine excretion. We comprehensively review the adverse health effects of Cd and urine and blood Cd levels at which adverse effects have been observed. The cumulative nature of Cd toxicity and the susceptibility of multiple organs to toxicity at low body burdens raise serious doubt that guidelines concerning permissible intake of Cd can be meaningful.
Collapse
Affiliation(s)
- Soisungwan Satarug
- Kidney Disease Research Collaborative, Level 5, Translational Research Institute, Brisbane, QLD, Australia.
| | - David A Vesey
- Kidney Disease Research Collaborative, Level 5, Translational Research Institute, Brisbane, QLD, Australia
- Department of Nephrology, Princess Alexandra Hospital, Brisbane, QLD, Australia
| | - Glenda C Gobe
- Kidney Disease Research Collaborative, Level 5, Translational Research Institute, Brisbane, QLD, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Kenneth R Phelps
- Stratton Veterans Affairs Medical Center and Albany Medical College, Albany, NY, USA
| |
Collapse
|
4
|
Phelps KR, Gemoets DE, May PM. Chemical evidence for the tradeoff-in-the-nephron hypothesis to explain secondary hyperparathyroidism. PLoS One 2022; 17:e0272380. [PMID: 35913960 PMCID: PMC9342777 DOI: 10.1371/journal.pone.0272380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 07/18/2022] [Indexed: 11/28/2022] Open
Abstract
Background Secondary hyperparathyroidism (SHPT) complicates advanced chronic kidney disease (CKD) and causes skeletal and other morbidity. In animal models of CKD, SHPT was prevented and reversed by reduction of dietary phosphate in proportion to GFR, but the phenomena underlying these observations are not understood. The tradeoff-in-the-nephron hypothesis states that as GFR falls, the phosphate concentration in the distal convoluted tubule ([P]DCT]) rises, reduces the ionized calcium concentration in that segment ([Ca++]DCT), and thereby induces increased secretion of parathyroid hormone (PTH) to maintain normal calcium reabsorption. In patients with CKD, we previously documented correlations between [PTH] and phosphate excreted per volume of filtrate (EP/Ccr), a surrogate for [P]DCT. In the present investigation, we estimated [P]DCT from physiologic considerations and measurements of phosphaturia, and sought evidence for a specific chemical phenomenon by which increased [P]DCT could lower [Ca++]DCT and raise [PTH]. Methods and findings We studied 28 patients (“CKD”) with eGFR of 14–49 mL/min/1.73m2 (mean 29.9 ± 9.5) and 27 controls (“CTRL”) with eGFR > 60 mL/min/1.73m2 (mean 86.2 ± 10.2). In each subject, total [Ca]DCT and [P]DCT were deduced from relevant laboratory data. The Joint Expert Speciation System (JESS) was used to calculate [Ca++]DCT and concentrations of related chemical species under the assumption that a solid phase of amorphous calcium phosphate (Ca3(PO4)2 (am., s.)) could precipitate. Regressions of [PTH] on eGFR, [P]DCT, and [Ca++]DCT were then examined. At filtrate pH of 6.8 and 7.0, [P]DCT was found to be the sole determinant of [Ca++]DCT, and precipitation of Ca3(PO4)2 (am., s.) appeared to mediate this result. At pH 6.6, total [Ca]DCT was the principal determinant of [Ca++]DCT, [P]DCT was a minor determinant, and precipitation of Ca3(PO4)2 (am., s.) was predicted in no CKD and five CTRL. In CKD, at all three pH values, [PTH] varied directly with [P]DCT and inversely with [Ca++]DCT, and a reduced [Ca++]DCT was identified at which [PTH] rose unequivocally. Relationships of [PTH] to [Ca++]DCT and to eGFR resembled each other closely. Conclusions As [P]DCT increases, chemical speciation calculations predict reduction of [Ca++]DCT through precipitation of Ca3(PO4)2 (am., s.). [PTH] appears to rise unequivocally if [Ca++]DCT falls sufficiently. These results support the tradeoff-in-the-nephron hypothesis, and they explain why proportional phosphate restriction prevented and reversed SHPT in experimental CKD. Whether equally stringent treatment can be as efficacious in humans warrants investigation.
Collapse
Affiliation(s)
- Kenneth R. Phelps
- Research Service, Stratton Veterans’ Affairs Medical Center, Albany, NY, Uniyed States of America
- Department of Medicine, Albany Medical College, Albany, NY, Uniyed States of America
- * E-mail:
| | - Darren E. Gemoets
- Research Service, Stratton Veterans’ Affairs Medical Center, Albany, NY, Uniyed States of America
| | - Peter M. May
- Department of Chemistry, Murdoch University, Murdoch, WA, Australia
| |
Collapse
|
5
|
Phelps KR, Mason DL. Parathyroid Hormone, Fibroblast Growth Factor 23, and Parameters of Phosphate Reabsorption. Am J Nephrol 2018; 47:343-351. [PMID: 29779023 DOI: 10.1159/000489270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/15/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND The serum phosphorus concentration ([P]s) is the sum of EP/Ccr and TRP/Ccr, where Ccr is creatinine clearance and EP and TRP are rates of excretion and reabsorption of phosphate. In chronic kidney disease (CKD), parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) mediate reduction of TRP/Ccr, and [PTH] and [FGF23] are linear functions of EP/Ccr. If controls and patients with CKD are considered together, TRP/Ccr is a hyperbolic function of EP/Ccr. Given these observations, we hypothesized that hyperbolas would describe relationships of phosphate reabsorption to [PTH] and [FGF23]. METHODS We studied 30 patients and 28 controls with mean eGFR of 29.5 and 86.0 mL/min/1.73 m2, respectively. All analyses combined both subsets. We measured fasting [PTH] 1-84 and intact [FGF23], and determined contemporaneous EP/Ccr, TRP/Ccr, fractional excretion of phosphorus (FEP), and phosphate tubular maximum per volume of filtrate (TmP/GFR). We examined linear regressions of TRP/Ccr and TmP/GFR on 100/[PTH] and 100/[FGF23]; from linear equations we derived hyperbolic equations relating reabsorptive parameters to hormone concentrations. RESULTS TRP/Ccr and TmP/GFR were linear functions of 100/[PTH] and 100/[FGF23] and hyperbolic functions of [PTH] and [FGF23]. TRP/Ccr and TmP/GFR fell minimally over the ranges of EP/Ccr, [PTH], and [FGF23] seen in CKD. FEP rose with EP/Ccr despite stable phosphate reabsorption. CONCLUSIONS Hyperbolas describe relationships of TRP/Ccr and TmP/GFR to [PTH] and [FGF23] if subjects with normal and reduced GFR are analyzed together. Although FEP rises with [PTH] and [FGF23] as GFR falls, the simultaneous increments do not signify hormonally mediated reductions in phosphate reabsorption.
Collapse
Affiliation(s)
- Kenneth R Phelps
- Stratton Veterans Affairs Medical Center, Albany, New York, USA
- Albany Medical College, Albany, New York, USA
| | | |
Collapse
|
6
|
Phelps KR. Tradeoff-in-the-Nephron: A Theory to Explain the Primacy of Phosphate in the Pathogenesis of Secondary Hyperparathyroidism. Nutrients 2017; 9:E427. [PMID: 28445401 PMCID: PMC5452157 DOI: 10.3390/nu9050427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/10/2017] [Accepted: 04/17/2017] [Indexed: 02/06/2023] Open
Abstract
Chronic kidney disease (CKD) causes secondary hyperparathyroidism (SHPT). The cardinal features of SHPT are persistence of normocalcemia as CKD progresses and dependence of the parathyroid hormone concentration ([PTH]) on phosphate influx (IP). The tradeoff-in-the-nephron hypothesis integrates these features. It states that as the glomerular filtration rate (GFR) falls, the phosphate concentration ([P]CDN) rises in the cortical distal nephron, the calcium concentration ([Ca]CDN) in that segment falls, and [PTH] rises to maintain normal calcium reabsorption per volume of filtrate (TRCa/GFR). In a clinical study, we set GFR equal to creatinine clearance (Ccr) and IP equal to the urinary excretion rate of phosphorus (EP). We employed EP/Ccr as a surrogate for [P]CDN. We showed that TRCa/Ccr was high in patients with primary hyperparathyroidism (PHPT) and normal in those with SHPT despite comparably increased [PTH] in each group. In subjects with SHPT, we examined regressions of [PTH] on EP/Ccr before and after treatment with sevelamer carbonate or a placebo. All regressions were significant, and ∆[PTH] correlated with ∆EP/Ccr in each treatment cohort. We concluded that [P]CDN determines [PTH] in CKD. This inference explains the cardinal features of SHPT, much of the evidence on which other pathogenic theories are based, and many ancillary observations.
Collapse
Affiliation(s)
- Kenneth R Phelps
- Research Service, Stratton Veterans' Affairs Medical Center, Albany, NY 12208, USA.
- Department of Medicine, Division of Nephrology, Albany Medical College, Albany, NY 12208, USA.
| |
Collapse
|
7
|
Phelps KR, Mo J, Czerwinskyj C, Mathew RO. Transient Hypocalcemia in a Dialysis Patient With Paget's disease and Presumed Renal Cell Carcinoma. J Investig Med High Impact Case Rep 2016; 4:2324709616640818. [PMID: 27081654 PMCID: PMC4814942 DOI: 10.1177/2324709616640818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/31/2015] [Revised: 02/09/2016] [Accepted: 02/29/2016] [Indexed: 11/16/2022] Open
Abstract
A 68-year-old man with end-stage renal disease was hospitalized because of radicular pain and weakness in the left arm and hand. Sonography and computed tomography had recently shown a large right renal mass. On admission, magnetic resonance imaging demonstrated vertebral metastases with epidural extension, and radiotherapy was directed to the spine and kidney. Hypocalcemia was first noted on the fourth hospital day. A second computed tomography scan showed bleeding into and around the kidney, and arterial embolization was required to halt the bleeding. Hypocalcemia persisted for at least 27 days at values between 6.0 and 7.7 mg/dL and was consistently associated with ionized calcium concentrations less than or equal to 4.44 mg/dL. After an unrevealing search for a recognized cause, we attributed hypocalcemia to persistent sequestration of calcium in the right retroperitoneum. Exogenous supplementation eventually restored the concentration to normal. In the absence of renal and intestinal loss, hypocalcemia reflects abnormal flux of calcium from the extracellular compartment into tissue. Our patient's repository appears to have been a necrotic and hemorrhagic cancer. Tumor-induced sequestration of calcium should be included in the differential diagnosis of hypocalcemia.
Collapse
Affiliation(s)
- Kenneth R Phelps
- Stratton Veterans Affairs Medical Center, Albany, NY, USA; Albany Medical College, Albany, NY, USA
| | - Jay Mo
- Stratton Veterans Affairs Medical Center, Albany, NY, USA
| | - Chrystina Czerwinskyj
- Stratton Veterans Affairs Medical Center, Albany, NY, USA; Albany Medical College, Albany, NY, USA
| | - Roy O Mathew
- Stratton Veterans Affairs Medical Center, Albany, NY, USA; Albany Medical College, Albany, NY, USA
| |
Collapse
|
8
|
Kulkarni H, Agan BK, Marconi VC, O'Connell RJ, Camargo JF, He W, Delmar J, Phelps KR, Crawford G, Clark RA, Dolan MJ, Ahuja SK. CCL3L1-CCR5 genotype improves the assessment of AIDS Risk in HIV-1-infected individuals. PLoS One 2008; 3:e3165. [PMID: 18776933 PMCID: PMC2522281 DOI: 10.1371/journal.pone.0003165] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 07/30/2008] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Whether vexing clinical decision-making dilemmas can be partly addressed by recent advances in genomics is unclear. For example, when to initiate highly active antiretroviral therapy (HAART) during HIV-1 infection remains a clinical dilemma. This decision relies heavily on assessing AIDS risk based on the CD4+ T cell count and plasma viral load. However, the trajectories of these two laboratory markers are influenced, in part, by polymorphisms in CCR5, the major HIV coreceptor, and the gene copy number of CCL3L1, a potent CCR5 ligand and HIV-suppressive chemokine. Therefore, we determined whether accounting for both genetic and laboratory markers provided an improved means of assessing AIDS risk. METHODS AND FINDINGS In a prospective, single-site, ethnically-mixed cohort of 1,132 HIV-positive subjects, we determined the AIDS risk conveyed by the laboratory and genetic markers separately and in combination. Subjects were assigned to a low, moderate or high genetic risk group (GRG) based on variations in CCL3L1 and CCR5. The predictive value of the CCL3L1-CCR5 GRGs, as estimated by likelihood ratios, was equivalent to that of the laboratory markers. GRG status also predicted AIDS development when the laboratory markers conveyed a contrary risk. Additionally, in two separate and large groups of HIV+ subjects from a natural history cohort, the results from additive risk-scoring systems and classification and regression tree (CART) analysis revealed that the laboratory and CCL3L1-CCR5 genetic markers together provided more prognostic information than either marker alone. Furthermore, GRGs independently predicted the time interval from seroconversion to CD4+ cell count thresholds used to guide HAART initiation. CONCLUSIONS The combination of the laboratory and genetic markers captures a broader spectrum of AIDS risk than either marker alone. By tracking a unique aspect of AIDS risk distinct from that captured by the laboratory parameters, CCL3L1-CCR5 genotypes may have utility in HIV clinical management. These findings illustrate how genomic information might be applied to achieve practical benefits of personalized medicine.
Collapse
Affiliation(s)
- Hemant Kulkarni
- Veterans Administration Research Center for AIDS and HIV-1 Infection, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Brian K. Agan
- Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, Maryland, United States of America
- Infectious Disease Service, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Texas, United States of America
- Henry M. Jackson Foundation, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Texas, United States of America
- San Antonio Military Medical Center, Fort Sam Houston, Texas, United States of America
| | - Vincent C. Marconi
- Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, Maryland, United States of America
- Infectious Disease Service, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Texas, United States of America
- San Antonio Military Medical Center, Fort Sam Houston, Texas, United States of America
| | - Robert J. O'Connell
- Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, Maryland, United States of America
- Infectious Disease Service, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Texas, United States of America
| | - Jose F. Camargo
- Veterans Administration Research Center for AIDS and HIV-1 Infection, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Weijing He
- Veterans Administration Research Center for AIDS and HIV-1 Infection, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Judith Delmar
- Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, Maryland, United States of America
- Infectious Disease Service, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Texas, United States of America
- San Antonio Military Medical Center, Fort Sam Houston, Texas, United States of America
| | - Kenneth R. Phelps
- Stratton Veterans Affairs Medical Center, Albany, New York, United States of America
- Albany Medical College, Albany, New York, United States of America
| | - George Crawford
- Veterans Administration Research Center for AIDS and HIV-1 Infection, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
| | - Robert A. Clark
- Veterans Administration Research Center for AIDS and HIV-1 Infection, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
| | - Matthew J. Dolan
- Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, Maryland, United States of America
- Infectious Disease Service, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Texas, United States of America
- Henry M. Jackson Foundation, Wilford Hall United States Air Force Medical Center, Lackland Air Force Base, Texas, United States of America
- San Antonio Military Medical Center, Fort Sam Houston, Texas, United States of America
- * E-mail: mdolan@ idcrp.org (MJD); (SKA)
| | - Sunil K. Ahuja
- Veterans Administration Research Center for AIDS and HIV-1 Infection, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Microbiology and Immunology and Biochemistry, University of Texas Health Science Center, San Antonio, Texas, United States of America
- * E-mail: mdolan@ idcrp.org (MJD); (SKA)
| |
Collapse
|
9
|
Phelps KR, Stern M, Slingerland A, Heravi M, Strogatz DS, Haqqie SS. Metabolic and skeletal effects of low and high doses of calcium acetate in patients with preterminal chronic renal failure. Am J Nephrol 2002; 22:445-54. [PMID: 12381942 DOI: 10.1159/000065273] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Secondary hyperparathyroidism commonly evolves, as the glomerular filtration rate falls. The metabolic and skeletal effects of a possible remedy, calcium acetate, have not been studied in patients with preterminal chronic renal failure. METHODS Men with a mean creatinine clearance of approximately 30 ml/min took calcium acetate for 24 weeks at doses which provided 507 or 1,521 mg calcium/day with meals. Metabolic determinations were made at intervals of 4-8 weeks, and the bone mineral density (BMD) was measured at the beginning and at the end of the trial. RESULTS The low-dose regimen produced no metabolic or skeletal effect. In subjects prescribed the high-dose regimen, the 24-hour urine phosphorus excretion fell from 0.53 mg/mg creatinine to values ranging from 0.34 to 0.41 mg/mg creatinine. The theoretical phosphorus threshold concentration rose by a maximum of 38.6%, and the serum phosphorus concentration did not change. The mean serum calcium concentration rose by a maximum of 7.2%. The mean fractional changes in parathyroid hormone and 1,25-dihydroxyvitamin D concentrations ranged from -27.0 to -39.6% and from -5.0 to -20.3%, respectively. The BMD increased at L1, L3, and L4. CONCLUSION Calcium acetate prescribed to deliver 1,521 mg calcium/day with meals reduced parathyroid hormone and 1,25-dihydroxyvitamin D concentrations and increased lumbar BMD in men with preterminal chronic renal failure.
Collapse
Affiliation(s)
- Kenneth R Phelps
- Samuel S. Stratton Department of Veterans Affairs Medical Center, Albany Medical College, and State University of New York School of Public Health, Albany, N.Y. 12208, USA.
| | | | | | | | | | | |
Collapse
|
10
|
Phelps KR, Naylor K, Brien TP, Wilbur H, Haqqie SS. Encephalopathy after Bladder Irrigation with Alum: Case Report and Literature Review. Am J Med Sci 1999. [DOI: 10.1016/s0002-9629(15)40610-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
11
|
Abstract
A 70-year-old man with advanced obstructive nephropathy began to hemorrhage from the bladder after decompression with a Foley catheter. Manifestations of encephalopathy appeared after continuous irrigation with 1% alum for 2 days and were associated with elevated serum aluminum concentrations. Repeated treatments with deferoxamine and hemodialysis accomplished some aluminum removal, but the patient succumbed to bronchopneumonia. Brain aluminum content was not excessive at autopsy. A literature review suggests that intact renal function is essential to rapid disposal of a parenteral aluminum load and indicates that most reported instances of encephalopathy after alum irrigation have occurred in patients with compromised renal function. We conclude that alum should not be employed as a bladder irrigant in patients with acute or chronic renal failure.
Collapse
Affiliation(s)
- K R Phelps
- Medical, Laboratory Medicine, and Surgical Services, Stratton Department of Veterans' Affairs Medical Center, and Albany Medical College, New York 12208, USA
| | | | | | | | | |
Collapse
|
12
|
Haqqie SS, Phelps KR, Singh J, Urizar RE. Wegener's granulomatosis in a patient with apparent drug-induced acute interstitial nephritis. Am J Med Sci 1998; 315:216-9. [PMID: 9519938 DOI: 10.1097/00000441-199803000-00014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We describe a patient whose clinical presentation was suggestive of drug-induced acute interstitial nephritis (AIN). A renal biopsy and serologic testing led instead to the diagnosis of Wegener's granulomatosis (WG) with necrotizing crescentic glomerulonephritis. Treatment with corticosteroids and cyclophosphamide resulted initially in complete recovery of renal function, and an exacerbation of acute renal failure after doses of these agents had been tapered responded to resumption of the original regimen. We report this case to emphasize the potentially identical presentations of AIN and WG. Since the two conditions are treated differently, we suggest that the diagnosis of AIN should be accepted only after biopsy confirmation.
Collapse
Affiliation(s)
- S S Haqqie
- Samuel S. Stratton Department of Veterans Affairs Medical Center and Albany Medical College, New York 12208, USA
| | | | | | | |
Collapse
|
13
|
Haqqie SS, Phelps KR, Singh J, Urizar RE. Wegener's Granulomatosis in a Patient With Apparent Drug-Induced Acute Interstitial Nephritis. Am J Med Sci 1998. [DOI: 10.1016/s0002-9629(15)40310-6] [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] [Indexed: 10/22/2022]
|
14
|
|
15
|
Low CL, Phelps KR, Bailie GR. Relative efficacy of haemoperfusion, haemodialysis and CAPD in the removal of procainamide and NAPA in a patient with severe procainamide toxicity. Nephrol Dial Transplant 1996; 11:881-4. [PMID: 8671917 DOI: 10.1093/oxfordjournals.ndt.a027421] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- C L Low
- Albany College of Pharmacy, Stratton VA Medical Center, Albany, NY 12208, USA
| | | | | |
Collapse
|
16
|
Phelps KR, Bansal M, Twersky J. Jaw enlargement complicating secondary hyperparathyroidism in three hemodialysis patients. Clin Nephrol 1994; 41:173-9. [PMID: 8187362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Over a period of two years we saw three patients with longstanding chronic renal failure in whom the size and shape of the jaws had gradually changed. Clinical, metabolic, and radiologic observations suggested that secondary hyperparathyroidism had caused the disfigurement, and bone histology supported this conclusion in each case. The appearance of our subjects resembled that of patients morbidly afflicted with osteitis fibrosa before its association with hyperparathyroidism was widely known. Jaw enlargement is a potential consequence of secondary hyperparathyroidism in dialysis patients.
Collapse
Affiliation(s)
- K R Phelps
- Department of Medicine, Albany Medical College, New York 12208
| | | | | |
Collapse
|
17
|
|
18
|
Ahuja SK, Ahuja SS, Thelmo W, Seymour A, Phelps KR. Necrotizing pancreatitis and multisystem organ failure associated with toxoplasmosis in a patient with AIDS. Clin Infect Dis 1993; 16:432-4. [PMID: 8452954 DOI: 10.1093/clind/16.3.432] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Extraneural manifestations of toxoplasmosis often are not recognized antemortem in patients with AIDS. We describe a patient who was seropositive for human immunodeficiency virus and presented with lethargy, abdominal tenderness, rapidly progressive ventilatory failure, rhabdomyolysis, myoglobinuria, and disseminated intravascular coagulation. Although the diagnosis of pancreatitis was not considered while the patient was alive, an autopsy demonstrated pancreatic necrosis associated with toxoplasmal cysts. No other infection was evident. This case suggests that Toxoplasma gondii can cause severe pancreatitis in patients with AIDS.
Collapse
Affiliation(s)
- S K Ahuja
- Department of Medicine, Kings County Medical Center, Brooklyn
| | | | | | | | | |
Collapse
|
19
|
Affiliation(s)
- S S Ahuja
- Department of Medicine, Kings County Hospital Center, Brooklyn, NY
| | | | | | | | | |
Collapse
|
20
|
|
21
|
Abstract
We describe two HIV-seropositive patients with acute pneumococcal empyema and pericarditis. Cardiac tamponade evolved rapidly in each patient and was reversed with prompt surgical intervention. In each case, immunologic abnormalities were detected which could have facilitated local spread of infection and progression to tamponade. Pericarditis, an otherwise rare manifestation of pneumococcal infection in the antibiotic era, should be anticipated in HIV-seropositive patients with pneumococcal empyema.
Collapse
Affiliation(s)
- M M Karve
- Department of Medicine, Kings County Hospital Center, Brooklyn
| | | | | | | |
Collapse
|
22
|
Phelps KR, Ginsberg SS, Cunningham AW, Tschachler E, Dosik H. Case report: adult T-cell leukemia/lymphoma associated with recurrent strongyloides hyperinfection. Am J Med Sci 1991; 302:224-8. [PMID: 1928233 DOI: 10.1097/00000441-199110000-00006] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Adult T-cell leukemia/lymphoma (ATLL) was demonstrated postmortem in a 47-year-old woman initially manifesting severe hypercalcemia and a vertebral compression fracture. Hyperinfection with Strongyloides stercoralis preceded the appearance of ATLL by several months and ultimately dominated the terminal course. Although HTLV-I and S. stercoralis commonly infect the same host, only three other cases of concomitant ATLL and hyperinfection have been reported in English. The apparent rarity of this association suggests that immunologic sequelae of ATLL do not predispose to dissemination and multiplication of Strongyloides. Observations pertinent to this conclusion are reviewed.
Collapse
Affiliation(s)
- K R Phelps
- Department of Medicine, State University of New York Health Science Center, Brooklyn
| | | | | | | | | |
Collapse
|
23
|
Abstract
In a patient with persistent diarrhea, renal acid excretion was examined because fecal alkali loss was insufficient to account for chronic metabolic acidosis. Bicarbonate wasting did not occur at physiologic serum concentrations, and the patient's ability to lower urine pH after an acid load was within normal limits. Glomerular filtration rate and the maximal rate of distal hydrogen ion secretion were unequivocally reduced, however, and ammonium excretion ws consequently inadequate. Unanticipated hypophosphaturia limited urinary titratable acidity. This case demonstrates that renal dysfunction may contribute significantly to acidosis associated with diarrhea and shows that defects in renal acid excretion may be superficially inapparent.
Collapse
Affiliation(s)
- K R Phelps
- Department of Medicine, King's County Hospital Center, New York, N.Y
| | | |
Collapse
|
24
|
Abstract
The destructive potential of Pneumocystis carinii infection in patients with AIDS has been amply documented. This report describes a homosexual man with P. carinii pneumonia (PCP) complicated by pneumatocoeles and pneumomediastinum. The pneumomediastinum almost completely resolved with successful antimicrobial therapy. Pneumomediastinum, like pneumothorax, should be anticipated in patients with AIDS and PCP.
Collapse
|
25
|
Phelps KR, Einhorn TA, Vigorita VJ, Jones G, Lundin AP. Persistence of dialysis osteomalacia despite treatment with 24R,25-dihydroxycholecalciferol. Nephron Clin Pract 1989; 51:197-206. [PMID: 2783766 DOI: 10.1159/000185285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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] [Indexed: 01/02/2023] Open
Abstract
Five patients with symptomatic osteomalacia undergoing chronic hemodialysis took 24R,25-dihydroxycholecalciferol, 10 micrograms/day, for periods of 6-20 months. Four patients took calcitriol simultaneously in doses consistent with normocalcemia, but the 5th was unable to do so because of recurrent hypercalcemia. In the group as a whole, despite achievement of physiologic plasma concentrations of 24,25-dihydroxyvitamin D, we could demonstrate no metabolic or histologic benefit of therapy. Substantial osteomalacia persisted in all posttreatment biopsy specimens, appearing more severe in some cases and less severe in others. At the doses prescribed, the results of treatment of dialysis osteomalacia with 24R,25-dihydroxycholecalciferol were clinically unsatisfactory.
Collapse
Affiliation(s)
- K R Phelps
- Department of Medicine, State University of New York Health Science Center, Brooklyn
| | | | | | | | | |
Collapse
|
26
|
Abstract
A patient undergoing hemodialysis is described in whom osteomalacia developed despite protracted treatment with calcitriol. Appropriately stained biopsy sections exhibited iron at all marrow-osteoid interfaces and a small fraction of trabecular mineralization fronts. Aluminum, the metal usually associated with osteomalacia in patients undergoing hemodialysis, was not histochemically demonstrable, even though spectrophotometrically measured bone aluminum content was substantial. These observations suggest two interpretations: iron may have caused osteomalacia through effects on bone cells and at mineralization fronts; alternatively, aluminum may have caused osteomalacia while remaining histochemically undetectable. It is possible that both metals exerted toxic effects simultaneously.
Collapse
Affiliation(s)
- K R Phelps
- Department of Medicine, State University of New York Health Science Center, Brooklyn 11203
| | | | | | | |
Collapse
|
27
|
Vigorita VJ, Einhorn TA, Phelps KR. Microscopic bone pathology in two cases of surgically treated secondary hyperparathyroidism. Report of a distinct skeletal lesion. Am J Surg Pathol 1987; 11:205-9. [PMID: 3826480 DOI: 10.1097/00000478-198703000-00005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We report bone biopsy findings in two hemodialysis patients with a history of secondary hyperparathyroidism treated by parathyroidectomy. Discrete, punched-out lesions in trabecular bone, which show little evidence of resorption or osteoblast activity, probably correspond to previous zones of osteoclastic tunneling resorption. Because we have seen these lesions in no other clinical setting, we suggest that they are residua of healed secondary hyperparathyroidism in dialysis patients. Their persistence may be due in part to aluminum intoxication.
Collapse
|
28
|
Abstract
The pathogenesis of osteomalacia was investigated in three patients with chronic metabolic acidosis. Serum levels of parathyroid hormone and vitamin D metabolites were measured, and bone biopsy specimens were analyzed after double tetracycline labeling. Parathyroid hormone concentrations were normal in patients 1 and 3 and slightly elevated in patient 2. Vitamin D metabolism was undisturbed. Static indicators of bone remodeling substantiated the diagnosis of osteomalacia in each case. In patient 1 fluorescent microscopy revealed no evidence of tetracycline uptake. In patients 2 and 3 active mineralization was evident at all osteoid seams, but because double labels were rare, the mineral apposition rate appears to have been substantially reduced in most bone-forming units. Our results indicate that acidosis-induced osteomalacia, unlike that due to vitamin D deficiency, may be associated with mineral deposition at every possible site. Nevertheless, like other causes of osteomalacia, metabolic acidosis prevents mineral apposition at a normal rate even if mineral deposition is ubiquitous. We suggest that titration of newly deposited phosphate causes the observed impairment of mineral apposition and ultimately leads to osteomalacia.
Collapse
|
29
|
|
30
|
Abstract
A 77-year-old diabetic man with a creatinine clearance of 23--27 ml/min developed hyperkalemia while receiving heparin for peripheral arterial insufficiency. Discontinuation of this agent led to resolution of hyperkalemia as the plasma aldosterone concentration multiplied by sixfold. Renal insufficiency may have predisposed this patient to the development of hyperkalemia when heparin therapy suppressed aldosterone synthesis.
Collapse
|
31
|
|
32
|
|