Excerpts from the US Renal Data System 2009 Annual Data Report

Direct imaging of APP proteolysis in living cells

Alzheimer’s disease is a multifactorial disorder caused by the interaction of genetic, epigenetic and environmental factors. The formation of cytotoxic oligomers consisting of Aβ peptide is widely accepted as being one of the main key events triggering the development of Alzheimer’s disease. Aβ peptide production results from the specific proteolytic processing of the amyloid precursor protein (APP). Deciphering the factors governing the activity of the secretases responsible for the cleavage of APP is still a critical issue. Kits available commercially measure the enzymatic activity of the secretases from cells lysates, in vitro. By contrast, we have developed a prototypal rapid bioassay that provides visible information on the proteolytic processing of APP directly in living cells. APP was fused to a monomeric variant of the green fluorescent protein and a monomeric variant of the red fluorescent protein at the C-terminal and N-terminal (mChAPPmGFP), respectively. Changes in the proteolytic processing rate in transfected human neuroblastoma and rat neuronal cells were imaged with confocal microscopy as changes in the red/green fluorescence intensity ratio. The significant decrease in the mean red/green ratio observed in cells over-expressing the β-secretase BACE1, or the α-secretase ADAM10, fused to a monomeric blue fluorescent protein confirms that the proteolytic site is still accessible. Specific siRNA was used to evaluate the contribution of endogenous BACE1. Interestingly, we found that the degree of proteolytic processing of APP is not completely homogeneous within the same single cell, and that there is a high degree of variability between cells of the same type. We were also able to follow with a fluorescence spectrometer the changes in the red emission intensity of the extracellular medium when BACE1 was overexpressed. This represents a complementary approach to fluorescence microscopy for rapidly detecting changes in the proteolytic processing of APP in real time. In order to allow the discrimination between the α- and the β-secretase activity, we have created a variant of mChAPPmGFP with a mutation that inhibits the α-secretase cleavage without perturbing the β-secretase processing. Moreover, we obtained a quantitatively robust estimate of the changes in the red/green ratio for the above conditions by using a flow cytometer able to simultaneously excite and measure the red and green fluorescence. Our novel approach lay the foundation for a bioassay suitable to study the effect of drugs or particular conditions, to investigate in an unbiased way the the proteolytic processing of APP in single living cells in order, and to elucidate the causes of the variability and the factors driving the processing of APP.

Hidden targets of ubiquitin proteasome system: To prevent diabetic nephropathy

Diabetic nephropathy (DN) is the major cause of end stage renal failure. Although, several therapeutic targets have emerged to prevent the progression of DN, the number of people with DN still continues to rise worldwide, suggesting an urgent need of novel targets to prevent DN completely. Currently, the role of ubiquitin proteasome system (UPS) has been highlighted in the pathogenesis and progression of various diseases like obesity, insulin resistance, atherosclerosis, cancers, neurodegerative disorders and including secondary complications of diabetes. UPS mainly involves in protein homeostatis through ubiquitination (post translational modification) and proteasomal degradation of various proteins. Ubiquitination, not only involves in proteasomal degradation, but also directs the substrate proteins to participate in multitude of cell signalling pathways. However, very little is known about ubiquitination and UPS in the progression of DN. This review mainly focuses on UPS and its components including E2 conjugating enzymes, E3 ligases and deubiquitinases (DUBs) in the development of DN and thus may help us to find novel therapeutic targets with in UPS to prevent DN completely in future.

Minimally Invasive Therapy for Upper Tract Urothelial Cell Cancer

Minimally invasive therapy for upper tract urothelial cell cancer has assumed an important role in the management of this relatively uncommon genitourinary malignancy. In this review, current standards for patient selection, surgical approach, as well as overall outcomes will be discussed. Moreover, the use of intraluminal agents in upper tract disease is examined along with its efficacy and associated complications.

Association of estimated glomerular filtration rate and urine albumin-to-creatinine ratio with incidence of cardiovascular diseases and mortality in chinese patients with type 2 diabetes mellitus - a population-based retrospective cohort study

BACKGROUND

Estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) are renal markers associated with risks of cardiovascular diseases (CVD) and all-cause mortality in diabetic patients. This study aims to quantify such risks in Chinese diabetic patients based on eGFR and UACR.

METHODS

This was a territory-wide retrospective cohort study on primary care diabetic patients with documented eGFR and UACR but without baseline CVD in 2008/2009. They were followed up till 2013 on CVD events and mortality. Associations between eGFR/UACR and incidence of CVD/mortality were evaluated by multivariable Cox proportional models adjusted with socio-demographic and clinical characteristics.

RESULTS

The data of 66,311 patients who had valid baseline eGFR and UACR values were analysed. The risks of CVD events and mortality increased exponentially with the decrease in eGFR, with a hazard ratio (HR) increasing from 1.63 to 4.55 for CVD, and from 1.70 to 9.49 for mortality, associated with Stage 3 to 5 CKD, compared to Stage 1 CKD. UACR showed a positive linear association with CVD events and mortality. Microalbuminuria was associated with a HR of 1.58 and 2.08 for CVD and mortality in male (1.48 and 1.79 for female), respectively, compared to no microalbuminuria. Male patients with UACR 1-1.4 mg/mmol and eGFR ≥90 ml/min/1.73 m2 (60-89 ml/min/1.73 m2) had a HR of 1.25 (1.43) for CVD. Female patients with UACR 2.5-3.4 mg/ml and eGFR ≥90 ml/min/1.73 m2 (60-89 ml/min/1.73 m2) had a HR of 1.45 (1.65) for CVD.

CONCLUSIONS

Risks of CVD events and mortality increased exponentially with eGFR drop, while UACR showed positive predictive linear relationships, and the risks started even in high-normal albuminuria. UACR-based HR was further modified according to eGFR level, with risk progressed with CKD stage. Combining eGFR and UACR level was more accurate in predicting risk of CVD/mortality. The findings call for more aggressive screening and intervention of microalbuminuria in diabetic patients.

A Randomized, Single-Blind, Crossover Trial of Recovery Time in High-Flux Hemodialysis and Hemodiafiltration

Background

The choice between hemodiafiltration (HDF) or high-flux hemodialysis (HD) to treat end-stage kidney disease remains a matter of debate. The duration of recovery time after treatment has been associated with mortality, affects quality of life, and may therefore be important in informing patient choice. We aimed to establish whether recovery time is influenced by treatment with HDF or HD.

Study Design

Randomized patient-blinded crossover trial.

Settings & Participants

100 patients with end-stage kidney disease were enrolled from 2 satellite dialysis units in Glasgow, United Kingdom.

Intervention

8 weeks of HD followed by 8 weeks of online postdilution HDF or vice versa.

Outcomes

Posttreatment recovery time, symptomatic hypotension events, dialysis circuit clotting events, and biochemical parameters.

Measurements

Patient-reported recovery time in minutes, incidence of adverse events during treatments, hematology and biochemistry results, quality-of-life questionnaire.

Results

There was no overall difference in recovery time between treatments (medians for HDF vs HD of 47.5 [IQR, 0-240] vs 30 [IQR, 0-210] minutes, respectively; P = 0.9). During HDF treatment, there were significant increases in rates of symptomatic hypotension (8.0% in HDF vs 5.3% in HD; relative risk [RR], 1.52; 95% CI, 1.2-1.9; P < 0.001) and intradialytic tendency to clotting (1.8% in HDF vs 0.7% in HD; RR, 2.7; 95% CI, 1.5-5.0; P = 0.002). Serum albumin level was significantly lower during HDF (3.2 vs 3.3 g/dL; P < 0.001). Health-related quality-of-life scores were equivalent.

Limitations

Single center; mean achieved HDF convection volume, 20.6 L.

Conclusions

Patients blinded to whether they were receiving HD or HDF in a randomized controlled crossover study reported similar posttreatment recovery times and health-related quality-of-life scores.

Chronic Heart Failure and Comorbid Renal Dysfunction - A Focus on Type 2 Cardiorenal Syndrome

The most important advancements in the Cardiorenal syndrome (CRS) are its definition and subsequent classifications. When the predominant pathology and pathophysiology is the heart, i.e. chronic heart failure (CHF), and where any renal impairment (RI) subsequent to this is secondary, the classification is type 2 CRS. There are unique differences in the pathophysiology and progression of individual subclasses. It is important to understand the evolution of CHF and consequences of subsequent RI as they are becoming increasingly prevalent, aggravate morbidity and mortality and limit many therapeutic options. In this paper we discuss the significance of the type 2 CRS patients in the context of the thematic series.

Clinical outcomes and quality of life in hemodialysis diabetic patients versus non-diabetics

Background

Diabetes is the leading cause of end stage renal disease (ESRD) worldwide.

Objectives

We compared the clinical outcomes in diabetic patients on hemodialysis (HD) with non-diabetics.

Patients and Methods

Adult maintenance HD patients (N= 532) from 9 HD facilities were enrolled to this prospective cohort study in September 2012. Causes of death, hospitalization, and HD exit were recorded in a median 28 months follow up period.

Results

Forty-one percent of patients were diabetic. Diabetic patients compared to non-diabetics had significantly higher age (62.2 ± 11.2 versus 53.1 ± 16.7 years), lower dialysis duration (median: 23 versus 30 months), more cardiovascular comorbidities (64% versus 28%) , higher C-reactive protein (CRP) levels (median: 3.80 versus 2.25 mg/L), lower serum albumin (3.86 ± 0.35 versus 3.93 ± 0.35 g/dL), lower intact parathyroid hormone (iPTH) (median: 272 versus 374 ρg/mL), higher serum triglyceride (167 ± 91 versus 139 ± 67 mg/dL) and low density lipoprotein (LDL) (82.5 ± 24.5 versus 77.5 ± 23.8 mg/dL), and worse short form health survey (SF36) score (45.7 ± 20.9 versus 52.7 ± 20.5). Annual admission rate was higher in diabetics (median: 0.86 versus 0.43) and diabetic foot involved 16% of their admissions. Transplantation rate was 4 and 9 per 100 patient years in diabetics and non-diabetics, respectively. Death rate was two folds higher in diabetics (24 versus 12 per 100 patient years). Cardiovascular diseases ( ± infections/other causes) comprised 80.5% of death in diabetics and 54.5% in non-diabetics. In Cox regression proportional hazard multivariate analysis, hazard risk of death in diabetics was 1.9 times higher than non-diabetics.

Conclusions

Clinical outcomes and health related quality of life (HRQOL) are much worse in diabetic compared to non-diabetic HD patients mainly due to more frequent of cardiovascular diseases (CVDs).

The effect of vibration on the severity of restless legs syndrome in hemodialysis patients

Introduction: The restless legs syndrome (RLS) is a neurological disorder in patients undergoing hemodialysis. This syndrome causes individual's disturbed rest, discomfort, and stress, and secondarily to weakened functioning and disturbance in occupational activities and familial life. Objectives: The present study aimed at investigate the effect of vibration on the severity of the manifestation of symptoms of RLS in hemodialysis patients. Patients and Methods: This is an interventional before-after study conducted on 80 patients with RLS in hemodialysis wards of Yazd hospitals. The samples were selected randomly and intervention was performed on the patients as vibration for 10 minutes three times per week during 4 succeeding weeks. The questionnaire of severity of RLS was completed before the study and at the last day of intervention before and after vibration. The data were analyzed with SPSS 23 using descriptive statistics and paired t test (P<0.05). Results: Our findings showed that most patients were at the moderate level of severity of symptoms before (68.8%) and after (78.8%) intervention and there was a significant difference in the mean score of RLS between before (18.99) and after (12.82) intervention (P=0.001). Conclusion: Based on the results of this study, it can be concluded that vibration decreases the severity of symptoms of RLS in hemodialysis patients. Hence, it is recommended that vibration be used as a cost-effective and safe procedure to improve the symptoms of RLS in this group of patients.

Rationale and study design of the prospective, longitudinal, observational cohort study "rISk strAtification in end-stage renal disease" (ISAR) study

Background

The ISAR study is a prospective, longitudinal, observational cohort study to improve the cardiovascular risk stratification in endstage renal disease (ESRD). The major goal is to characterize the cardiovascular phenotype of the study subjects, namely alterations in micro- and macrocirculation and to determine autonomic function.

Methods/design

We intend to recruit 500 prevalent dialysis patients in 17 centers in Munich and the surrounding area. Baseline examinations include: (1) biochemistry, (2) 24-h Holter Electrocardiography (ECG) recordings, (3) 24-h ambulatory blood pressure measurement (ABPM), (4) 24 h pulse wave analysis (PWA) and pulse wave velocity (PWV), (5) retinal vessel analysis (RVA) and (6) neurocognitive testing. After 24 months biochemistry and determination of single PWA, single PWV and neurocognitive testing are repeated. Patients will be followed up to 6 years for (1) hospitalizations, (2) cardiovascular and (3) non-cardiovascular events and (4) cardiovascular and (5) all-cause mortality.

Discussion/conclusion

We aim to create a complex dataset to answer questions about the insufficiently understood pathophysiology leading to excessively high cardiovascular and non-cardiovascular mortality in dialysis patients. Finally we hope to improve cardiovascular risk stratification in comparison to the use of classical and non-classical (dialysis-associated) risk factors and other models of risk stratification in ESRD patients by building a multivariable Cox-Regression model using a combination of the parameters measured in the study.

Clinical trials identifier

ClinicalTrials.gov NCT01152892 (June 28, 2010)

Statins and Renin Angiotensin System Inhibitors Dose-Dependently Protect Hypertensive Patients against Dialysis Risk

Background

Taiwan has the highest renal disease incidence and prevalence in the world. We evaluated the association of statin and renin–angiotensin system inhibitor (RASI) use with dialysis risk in hypertensive patients.

Methods

Of 248,797 patients who received a hypertension diagnosis in Taiwan during 2001–2012, our cohort contained 110,829 hypertensive patients: 44,764 who used RASIs alone; 7,606 who used statins alone; 27,836 who used both RASIs and statins; and 33,716 who used neither RASIs or statins. We adjusted for the following factors to reduce selection bias by using propensity scores (PSs): age; sex; comorbidities; urbanization level; monthly income; and use of nonstatin lipid-lowering drugs, metformin, aspirin, antihypertensives, diuretics, and beta and calcium channel blockers. The statin and RASI use index dates were considered the hypertension confirmation dates. To examine the dose–response relationship, we categorized only statin or RASI use into four groups in each cohort: <28 (nonusers), 28–90, 91–365, and >365 cumulative defined daily doses (cDDDs).

Results

In the main model, PS-adjusted hazard ratios (aHRs; 95% confidence intervals [CIs]) for dialysis risk were 0.57 (0.50–0.65), 0.72 (0.53–0.98), and 0.47 (0.41–0.54) in the only RASI, only statin, and RASI + statin users, respectively. RASIs dose-dependently reduced dialysis risk in most subgroups and in the main model. RASI use significantly reduced dialysis risk in most subgroups, regardless of comorbidities or other drug use (P < 0.001). Statins at >365 cDDDs protected hypertensive patients against dialysis risk in the main model (aHR = 0.62, 95% CI: 0.54–0.71), regardless of whether a high cDDD of RASIs, metformin, or aspirin was used.

Conclusion

Statins and RASIs independently have a significant dose-dependent protective effect against dialysis risk in hypertensive patients. The combination of statins and RASIs can additively protect hypertensive patients against dialysis risk.

Recent analytical approaches to detect exhaled breath ammonia with special reference to renal patients

The ammonia odor from the exhaled breath of renal patients is associated with high levels of blood urea nitrogen. Typically, in the liver, ammonia and ammonium ions are converted into urea through the urea cycle. In the case of renal dysfunction, urea is unable to be removed and that causes a buildup of excessive ammonia. As small molecules, ammonia and ammonium ions can be forced into the blood-lung barrier and occur in exhaled breath. Therefore, people with renal failure have an ammonia (fishy) odor in their exhaled breath. Thus, exhaled breath ammonia can be a potential biomarker for monitoring renal diseases during hemodialyis. In this review, we have summarized the source of ammonia in the breath of end-stage renal disease patient, cause of renal disorders, exhaled breath condensate, and breath sampling. Further, various biosensor approaches to detect exhaled ammonia from renal patients and other ammonia systems are also discussed. We conclude with future perspectives, namely colorimetric-based real-time breathing diagnosis of renal failure, which might be useful for prospective studies.

Comparison of the risk of de novo cardiovascular disease between hemodialysis and peritoneal dialysis in patients with end-stage renal disease

BACKGROUND

The purpose of the study was to compare the risk of de novo cardiovascular disease (CVD) between hemodialysis (HD) and peritoneal dialysis (PD) in patients with incident end-stage renal disease (ESRD).

METHODS

From a Taiwanese universal insurance claims database, we identified 45309 incident ESRD patients without preexisting CVD from 2000 to 2010. Using the propensity score matching method, we included 6516 patients in HD and PD groups, respectively. All patients were followed up until the end of 2011. The Cox proportional hazards regression model was employed to calculate the impact of dialysis modality on the risk of new onset cardiovascular events including ischemic heart disease, and congestive heart failure (CHF).

RESULTS

No difference was observed in the overall risk of de novo ischemic heart disease between the propensity score-matched HD and PD groups (HD versus PD, adjusted hazard ratio [HR]: 1.03, 95% confidence interval [CI]: 0.86-1.22). However, HD was associated with a higher risk of de novo CHF (adjusted HR: 1.29, 95% CI: 1.13-1.47) than PD was. The risk of de novo CHF was particularly high in the first year under dialysis treatment for propensity score-matched HD patients, compared to PD patients.

CONCLUSIONS

No difference was observed in the overall risk of de novo major ischemic heart events between HD and PD patients. However, HD was associated with a higher risk of de novo CHF than PD in the first year under dialysis treatment.

Latency for cytomegalovirus impacts T cell ageing significantly in elderly end-stage renal disease patients

The number of elderly patients with end-stage renal disease (ESRD) has increased significantly during the last decade. Elderly ESRD patients are vulnerable to infectious complications because of an aged immune system. Additional immunological ageing effects may be derived from the uraemic environment and cytomegalovirus (CMV) latency. Elderly patients may be affected by these factors in particular, but data in this age group are limited. To assess the degree of immunological ageing and proliferative capacity of T lymphocytes, 49 elderly ESRD patients (defined as aged ≥ 65 years) on the renal transplantation waiting list were recruited and compared to 44 elderly healthy individuals (HI), matched for age and CMV serostatus. CMV latency was associated with more highly differentiated CD4⁺ and CD8⁺ T cells in both elderly HI and patients. Elderly CMV seropositive ESRD patients showed a substantial reduction in the number of naive CD4⁺ and CD8⁺ T cells compared with age- and CMV serostatus-matched HI. Elderly ESRD patients also showed significantly decreased numbers of central memory CD4⁺ and CD8⁺ T cells compared with HI, independently of CMV serostatus. In addition, thymic output and relative telomere length of both CD4⁺ and CD8⁺ T cells were decreased in CMV seropositive ESRD patients compared with HI. The proliferative capacity of T cells was similar for patients and HI. Elderly ESRD patients have an advanced aged T cell compartment when compared to age-matched healthy controls, which is driven mainly by CMV latency.

Test of the recommended dialysis dose on one-year mortality of nondiabetic maintenance hemodialysis patients; observations from a single dialysis unit

BACKGROUND

The optimal delivered dialysis dose has been of a great interest for the last three decades, though a clear cut point has not been reached yet. We aimed to evaluate the relationship between one-year mortality and the delivered dialysis dose, which was recommended by Kidney Disease Outcomes Quality Initiative (KDOQI), in our maintenance hemodialysis (MHD) patients.

METHODS

This was a single center, prospective observational study with one year of follow-up. Patients with extremes of age, BMI, residual renal function, diabetes mellitus, severe infection malignancy, and recent hospitalization within the last three months were excluded. Demographic, anthropometric, laboratory, and outcome data (mortality as the primary) were prospectively collected. Patients were classified into two groups according to baseline spKt/V levels; group 1 (n = 20): spKt/V ≤ 1.4, group 2 (n = 60): spKt/V > 1.4.

RESULTS

Median (IQR) age and hemodialysis vintage of all patients (M/F: 41/39) were 49.5 (29) years and 60 (94) months, respectively. Both groups had similar characteristics, with the exception of significantly higher BMI (24 vs. 21.7, p = 0.012), serum creatinine and uric acids, and lower spKt/V (1.30 vs. 1.71, p < 0.001) in group 1. Overall death occurred in seven (8.75%) patients (5 from group 1 and 2 from group 2). Patients in group 1 had significantly higher one-year mortality rate and shorter survival time (25% vs. 3.3%, p = 0.003 and 43.9 vs. 47.3 weeks, p = 0.003, respectively).

CONCLUSIONS

Higher spKt/V (>1.4) was associated with a lower one-year mortality in this small cohort of patients.

Increased oxidative stress in diabetic nephropathy and its relationship with soluble Klotho levels

BACKGROUND

In the present study, we aimed to assess the relationship between the levels of soluble Klotho (s-Klotho) and oxidative stress markers in diabetic nephropathy patients with different stages of chronic kidney disease (CKD) and albuminuria levels.

METHODS

We enrolled 109 patients with type 2 diabetes (mean age, 61.63 ± 9.77 years) and 32 healthy controls (mean age, 49.53 ± 7.32 years) between January and June 2014.  Patients were classified into three groups based on their urinary albumin/creatinine ratio (UACR). Blood samples were collected to measure the levels of s-Klotho, serum creatinine, calcium, phosphorus, 25-hydroxyvitamin D3, and parathyroid hormone (PTH). We used the total oxidant status (TOS), total antioxidant status (TAS), ischemia-modified albumin (IMA), and ischemia-modified albumin ratio (IMAR) values to measure the oxidative status. Moreover, the oxidative stress index (OSI) was estimated as the percentage ratio of TOS/TAS values.

RESULTS

The TOS, TAS, and OSI values were significantly greater in the diabetic nephropathy patients compared to controls (p <0.001). When patients were classified based on their UACR, we noted that the TOS, OSI, and IMA values did not significantly differ, although the TAS (p <0.001), and IMAR (p =0.002) values significantly differed between the groups. The s-Klotho levels also significantly differed (p =0.031) between the groups. These s-Klotho levels exhibited a significant positive correlation with TOS (r =0.186, p =0.034) and OSI (r =0.207 p =0.018), but showed no correlation with the estimated glomerular filtration rate; UACR; HbA1c, calcium, phosphorus, and PTH levels; and TAS, IMA, and IMAR values.

CONCLUSION

Oxidative stress is greater in patients with diabetic nephropathy, and the TOS was positively correlated with s-Klotho levels in diabetic patients. The therapeutic reduction of oxidative stress in patients with diabetic nephropathy could improve the renal and cardiovascular outcomes. Hippokratia 2016, 20(3): 198-203.

Comparison of Turkish and US haemodialysis patient mortality rates: an observational cohort study

BACKGROUND

There are significant differences between countries in the mortality rates of haemodialysis (HD) patients. The extent of these differences and possible contributing factors are worthy of investigation.

METHODS

As of March 2009, all patients undergoing HD or haemodiafiltration for >3 months (n = 4041) in the Turkish clinics of the NephroCare network were enrolled. Data were prospectively collected for 2 years through the European Clinical Dialysis Database. Mean age ± standard deviation was 58.7 ± 14.7 years, 45.9% were female and 22.9% were diabetic. Comparison with US data was performed by applying an indirect standardization technique, using specific mortality rates for patients on HD by age, gender, race and primary diagnosis as provided by the 2012 US Renal Data System Annual Data Report as reference.

RESULTS

The crude mortality rate in Turkey was 95.1 per 1000 patient-years. Compared with the US reference population, the annual mortality rate for Turkey was significantly lower, irrespective of gender, age and diabetes. After adjustments for age, gender and diabetes, the mortality risk in the Turkish cohort was 50% lower than US whites [95% confidence interval (CI) 0.46-0.54, P < 0.001], 44% lower than US African-Americans (95% CI 0.52-0.61, P < 0.001) and 20% lower than Asian-Americans (95% CI 0.74-0.86, P < 0.05).

CONCLUSIONS

The annual mortality rate of prevalent HD patients was found to be significantly lower in the studied Turkish cohort compared with that published by the US Renal Data System Annual Data Report. Differences in practice patterns may contribute to the divergence.

Cell cycle re-entry sensitizes podocytes to injury induced death

Podocytes are terminally differentiated renal cells, lacking the ability to regenerate by proliferation. However, during renal injury, podocytes re-enter into the cell cycle but fail to divide. Earlier studies suggested that re-entry into cell cycle results in loss of podocytes, but a direct evidence for this is lacking. Therefore, we established an in vitro model to test the consequences of re-entry into the cell cycle on podocyte survival. A mouse immortalized podocyte cell line was differentiated to non-permissive podocytes and stimulated with e.g. growth factors. Stimulated cells were analyzed for mRNA-expression or stained for cell cycle analysis using flow cytometry and immunocytofluorescence microscopy. After stimulation to re-entry into cell cycle, podocytes were stressed with puromycin aminonucleoside (PAN) and analyzed for survival. During permissive stage more than 40% of immortalized podocytes were in the S-phase. In contrast, S-phase in non-permissive differentiated podocytes was reduced to 5%. Treatment with b-FGF dose dependently induced re-entry into cell cycle increasing the number of podocytes in the S-phase to 10.7% at an optimal bFGF dosage of 10 ng/ml. Forty eight hours after stimulation with bFGF the number of bi-nucleated podocytes significantly increased. A secondary injury stimulus significantly reduced podocyte survival preferentially in bi-nucleated podocytes In conclusion, stimulation of podocytes using bFGF was able to induce re-entry of podocytes into the cell cycle and to sensitize the cells for cell death by secondary injuries. Therefore, this model is appropriate for testing new podocyte protective substances that can be used for therapy.

Reduced Cardiovascular Mortality Associated with Early Vascular Access Placement in Elderly Patients with Chronic Kidney Disease

BACKGROUND

Elderly patients with cardiovascular comorbidities are more likely to die before progressing to the need for undergoing hemodialysis; so deferring their predialysis vascular access (VA) surgery has been suggested. However, recent declines in cardiovascular mortality in the US population may have changed this consideration. We assessed whether there has been a parallel decrease in cardiovascular comorbidity in elderly chronic kidney disease (CKD) patients undergoing predialysis access surgery, and whether this impacted clinical outcomes after access creation and cardiovascular events after hemodialysis initiation.

METHODS

We identified 3,418 elderly patients undergoing predialysis VA creation from 2004 to 2009, divided them into 3 time cohorts (2004-2005, 2006-2007 and 2008-2009), and assessed their clinical outcomes during 2 years of follow-up.

RESULTS

There was a progressive decrease in patients with history of peripheral vascular disease (from 66.5 to 59.7%, p < 0.005), heart failure (from 47.0 to 35.8%, p < 0.005), and myocardial infarction (from 6.5 to 3.3%, p < 0.001) from 2004 to 2009. Death before hemodialysis decreased from 17.5 to 12.6%, survival without hemodialysis increased from 14.5 to 19.0%, and hemodialysis initiation remained constant at ∼68% (p < 0.001). The incidence of death or cardiovascular event in the first year of hemodialysis decreased from 2004-2005 to 2008-2009 (HR 0.83, 95% CI 0.69-0.99; p = 0.04).

CONCLUSION

In the context of a changing population from 2004 to 2009, a progressive decrease in cardiovascular comorbidities in elderly CKD patients undergoing predialysis VA surgery was associated with a decrease in death before hemodialysis and cardiovascular events after starting hemodialysis. These insights should be translated into more thoughtful consideration as to which elderly patients should undergo predialysis access surgery.

Prediction of Mortality in Incident Hemodialysis Patients: A Validation and Comparison of CHADS2, CHA2DS2, and CCI Scores

Background

The CHADS2 and CHA2DS2 scores are usually applied for stroke prediction in atrial fibrillation patients, and the Charlson comorbidity index (CCI) is a commonly used scale for assessing morbidity. The role in assessing mortality with score system in hemodialysis is not clear and comparisons are lacking. We aimed at evaluating CHADS2, CHA2DS2, and CCI scores to predict mortality in incident hemodialysis patients.

Methods

Using data from the Nation Health Insurance system of Taiwan (NHIRD) from 1 January 2005 to 31 December 2009, individuals ≧20 y/o who began hemodialysis identified by procedure code and receiving dialysis for > 3 months were included for our study. Renal transplantation patients after dialysis or PD patients were excluded. We calculated the CHADS2, CHA2DS2, and CCI score according to the ICD-9 code and categorized the patients into three groups in each system: 0–1, 2–3, over 4. A total of 3046 incident hemodialysis patients enrolled from NHIRD were examined for an association between the separate scoring systems (CHADS2, CHA2DS2, and CCI score) and mortality.

Results

CHADS2 and CHA2DS2 scores revealed good predictive value for total mortality (CHADS2 AUC = 0.805; CHA2DS2 AUC = 0.790). However, the CCI score did not reveal a similarly satisfying result (AUC = 0.576).

Conclusions

Our results show that CHADS2 and CHA2DS2 scores can be applied for mortality prediction in incident hemodialysis patients.

Untargeted plasma and tissue metabolomics in rats with chronic kidney disease given AST-120

Chronic kidney disease (CKD) results in the accumulation of metabolic waste products that are normally cleared by the kidney, known as uremia. Many of these waste products are from bacteria metabolites in the gut. Accumulation of uremic toxins in plasma and tissue, as well as the gut-plasma-tissue metabolic axis are important for understanding pathophysiological mechanisms of comorbidities in CKD. In this study, an untargeted metabolomics approach was used to determine uremic toxin accumulation in plasma, liver, heart and kidney tissue in rats with adenine-induced CKD. Rats with CKD were also given AST-120, a spherical carbon adsorbent, to assess metabolic changes in plasma and tissues with the removal of gut-derived uremic toxins. AST-120 decreased >55% of metabolites that were increased in plasma, liver and heart tissue of rats with CKD. CKD was primarily defined by 8 gut-derived uremic toxins, which were significantly increased in plasma and all tissues. These metabolites were derived from aromatic amino acids and soy protein including: indoxyl sulfate, p-cresyl sulfate, hippuric acid, phenyl sulfate, pyrocatechol sulfate, 4-ethylphenyl sulfate, p-cresol glucuronide and equol 7-glucuronide. Our results highlight the importance of diet and gut-derived metabolites in the accumulation of uremic toxins and define the gut-plasma-tissue metabolic axis in CKD.

Store-operated calcium entry and diabetic complications

Store-operated Ca(2+) entry (SOCE) is mediated by the store-operated Ca(2+) channel (SOC) that opens upon depletion of internal Ca(2+) stores following activation of G protein-coupled receptors or receptor tyrosine kinases. Over the past two decades, the physiological and pathological relevance of SOCE has been extensively studied. Recently, accumulating evidence suggests associations of altered SOCE with diabetic complications. This review focuses on the implication of SOCE as it pertains to various complications resulting from diabetes. We summarize recent findings by us and others on the involvement of abnormal SOCE in the development of diabetic complications, such as diabetic nephropathy and diabetic vasculopathy. The underlying mechanisms that mediate the diabetes-associated alterations of SOCE are also discussed. The SOCE pathway may be considered as a potential therapeutic target for diabetes-associated diseases.

Is kidney function affecting the management of myocardial infarction? A retrospective cohort study in patients with normal kidney function, chronic kidney disease stage III-V, and ESRD

Patients with chronic kidney disease (CKD) are three times more likely to have myocardial infarction (MI) and suffer from increased morbidity and higher mortality. Traditional and unique risk factors are prevalent and constitute challenges for the standard of care. However, CKD patients have been largely excluded from clinical trials and little evidence is available to guide evidence-based treatment of coronary artery disease in patients with CKD. Our objective was to assess whether a difference exists in the management of MI (ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction) among patients with normal kidney function, CKD stage III–V, and end-stage renal disease (ESRD) patients. We conducted a retrospective cohort study on patients admitted to Staten Island University Hospital for the diagnosis of MI between January 2005 and December 2012. Patients were assigned to one of three groups according to their kidney function: Data collected on the medical management and the use of statins, platelet inhibitors, beta-blockers, and angiotensin converting enzyme inhibitors/angiotensin receptor blockers were compared among the three cohorts, as well as medical interventions including: catheterization and coronary artery bypass graft (CABG) when indicated. Chi-square test was used to compare the proportions between nominal variables. Binary logistic analysis was used in order to determine associations between treatment modalities and comorbidities, and to account for possible confounding factors. Three hundred and thirty-four patients (mean age 67.2±13.9 years) were included. In terms of management, medical treatment was not different among the three groups. However, cardiac catheterization was performed less in ESRD when compared with no CKD and CKD stage III–V (45.6% vs 74% and 93.9%) (P<0.001). CABG was performed in comparable proportions in the three groups and CABG was not associated with the degree of CKD (P=0.078) in binary logistics regression. Cardiac catheterization on the other hand carried the strongest association among all studied variables (P<0.001). This association was maintained after adjusting for other comorbidities. The length of stay for the three cohorts (non-CKD, CKD stage III–V, and ESRD on hemodialysis) was 16, 17, and 15 days, respectively and was not statistically different. Many observations have reported discrimination of care for patients with CKD considered suboptimal candidates for aggressive management of their cardiac disease. In our study, medical therapy was achieved at high percentage and was comparable among groups of different kidney function. However, kidney disease seems to affect the management of patients with acute MI; percutaneous coronary angiography is not uniformly performed in patients with CKD and ESRD when compared with patients with normal kidney function.

Impact of dialysis modality on the survival of patients with end-stage renal disease and prior stroke

PURPOSE

Of patients with end-stage renal disease (ESRD), 8-16 % had a history of stroke at dialysis initiation. We used the National Health Insurance Research Database of Taiwan to evaluate whether peritoneal dialysis (PD) or hemodialysis (HD) confers a survival advantage for patients with incident ESRD and prior stroke.

METHODS

We identified 975 patients undergoing PD and 975 propensity score-matched patients with newly diagnosed ESRD and prior stroke undergoing HD between 2000 and 2010. Both cohorts were followed up until the end of 2011. Comparisons of the risks of mortality between PD and HD were analyzed using the Cox proportional hazards regression model.

RESULTS

In the propensity score-matched cohorts, there was a 2.4 per 100 person-years greater mortality in patients with PD (20.4 vs. 18.0 per 100 person-years) with an adjusted hazard ratio (HR) of 1.20 (95 % CI 1.06-1.36). For patients with diabetes, ESRD and prior stroke, patients undergoing PD had inferior survival compared with those undergoing HD (adjusted HR 1.22, 95 % CI 1.05-1.43), particularly among female patients (adjusted HR 1.55, 95 % CI 1.25-1.91). For patients with ESRD and prior stroke but without diabetes, there was no significant difference in mortality between PD and HD (adjusted HR 1.20, 95 % CI 0.96-1.50).

CONCLUSIONS

PD was associated with overall poorer survival among patients with diabetes, ESRD and prior stroke and with similar overall survival among patients with ESRD and prior stroke, but without diabetes, compared with HD.

Cost Effectiveness of Sucroferric Oxyhydroxide Compared with Sevelamer Carbonate in the Treatment of Hyperphosphataemia in Patients Receiving Dialysis, from the Perspective of the National Health Service in Scotland

BACKGROUND

Hyperphosphataemia is common and harmful in patients receiving dialysis. Treatment options include noncalcium-based phosphate binders such as sevelamer carbonate (SC) and sucroferric oxyhydroxide (PA21).

OBJECTIVE

The aim of this study was to determine the health economic impact of PA21-based strategies compared with SC-based strategies, from the perspective of the Scottish National Health Service (NHS).

METHODS

A Markov model was constructed based on data from a randomised clinical trial comparing PA21 and SC. Model input parameters were derived from published literature, national statistics and unpublished sources. Costs (price year 2012) and effects were discounted at 3.5 %. Analysis with a lifelong time horizon yielded the incremental cost-effectiveness ratio (ICER), expressed as cost or savings per quality-adjusted life-year (QALY) gained or forgone. Deterministic and probabilistic sensitivity analysis was performed to explore uncertainties around assumptions and model input parameters.

RESULTS

In the base-case analysis, phosphorus reductions for PA21 and SC were 1.93 and 1.95 mg/dL. Average undiscounted survival was estimated to be 7.61 years per patient in both strategies. PA21 patients accrued less QALYs (2.826) than SC patients (2.835), partially due to differential occurrence of side effects. Total costs were ₤ 13,119 and ₤ 14,728 for PA21 and SC, respectively (difference per patient of ₤ 1609). By using PA21 versus SC, one would save ₤ 174,999 (or ₤ 123,463 when including dialysis and transplantation costs) for one QALY forgone. A scenario modelling the nonsignificant reduction in mortality (relative risk 0.714) observed in the trial yielded an ICER for PA21 of ₤ 22,621 per QALY gained. In probabilistic sensitivity analysis of the base-case, PA21 was dominant in 11 %, and at least cost-effective in 53 %, of iterations, using a threshold of ₤ 20,000 per QALY gained.

CONCLUSIONS

The use of PA21 versus SC in hyperphosphataemic patients being intolerant of calcium-based phosphate binders may be cost saving and yields only very limited disadvantages in terms of quality-adjusted survival. PA21 appears to be cost-effective from the perspective of the Scottish NHS.

Effect of Kidney Function on Drug Kinetics and Dosing in Neonates, Infants, and Children

Neonates, infants, and children differ from adults in many aspects, not just in age, weight, and body composition. Growth, maturation and environmental factors affect drug kinetics, response and dosing in pediatric patients. Almost 80% of drugs have not been studied in children, and dosing of these drugs is derived from adult doses by adjusting for body weight/size. As developmental and maturational changes are complex processes, such simplified methods may result in subtherapeutic effects or adverse events. Kidney function is impaired during the first 2 years of life as a result of normal growth and development. Reduced kidney function during childhood has an impact not only on renal clearance but also on absorption, distribution, metabolism and nonrenal clearance of drugs. 'Omics'-based technologies, such as proteomics and metabolomics, can be leveraged to uncover novel markers for kidney function during normal development, acute kidney injury, and chronic diseases. Pharmacometric modeling and simulation can be applied to simplify the design of pediatric investigations, characterize the effects of kidney function on drug exposure and response, and fine-tune dosing in pediatric patients, especially in those with impaired kidney function. One case study of amikacin dosing in neonates with reduced kidney function is presented. Collaborative efforts between clinicians and scientists in academia, industry, and regulatory agencies are required to evaluate new renal biomarkers, collect and share prospective pharmacokinetic, genetic and clinical data, build integrated pharmacometric models for key drugs, optimize and standardize dosing strategies, develop bedside decision tools, and enhance labels of drugs utilized in neonates, infants, and children.

A Novel Mouse Model of Peritoneal Dialysis: Combination of Uraemia and Long-Term Exposure to PD Fluid

Different animal models for peritoneal dialysis (PD) have been used in the past decades to develop PD fluids compatible with patient life and to identify markers of peritoneal fibrosis and inflammation. Only few of those studies have taken into account the importance of uraemia-induced alterations at both systemic and peritoneal levels. Moreover, some animal studies which have reported about PD in a uremic setting did not always entirely succeed in terms of uraemia establishment and animal survival. In the present study we induced uraemia in the recently established mouse PD exposure model in order to obtain a more clinically relevant mouse model for kidney patients. This new designed model reflected both the slight thickening of peritoneal membrane induced by uraemia and the significant extracellular matrix deposition due to daily PD fluid instillation. In addition the model offers the opportunity to perform long-term exposure to PD fluids, as it is observed in the clinical setting, and gives the advantage to knock out candidate markers for driving peritoneal inflammatory mechanisms.

Genetics of Type 2 Diabetes in African Americans

Type 2 diabetes (T2D) is a global health problem showing substantial ethnic disparity in disease prevalence. African Americans have one of the highest prevalence of T2D in the USA but little is known about their genetic risks. This review summarizes the findings of genetic regions and loci associated with T2D and related glycemic traits using linkage, admixture, and association approaches in populations of African ancestry. In particular, findings from genome-wide association and exome chip studies suggest the presence of both ancestry-specific and shared loci for T2D and glycemic traits. Among the European-identified loci that are transferable to individuals of African ancestry, allelic heterogeneity as well as differential linkage disequilibrium and risk allele frequencies pose challenges and opportunities for fine mapping and identification of causal variant(s) by trans-ancestry meta-analysis. More genetic research is needed in African ancestry populations including the next-generation sequencing to improve the understanding of genetic architecture of T2D.

Prevalence and predictors of aortic dilation as a novel cardiovascular complication in children with end-stage renal disease

Background: Cardiovascular disease is the leading cause of death in children with end-stage renal disease (ESRD). Isolated aortic dilation (AD) is rare in children. We aimed to determine the prevalence and the risk factors for AD in children with ESRD. Methods and study design: We reviewed records of all ESRD patients followed at our institution from January 2007 to October 2012. AD was defined as Z-score > 2 in the dimension of at least one of the following echocardiographic aortic parameters: annulus, root at the sinus, sino-tubular junction, ,or ascending aorta. Results: The records of 78 patients on dialysis and 19 kidney transplant recipients were available. 30 patients (30.9%) had AD. Multivariate analysis revealed independent associations of AD with body mass index (BMI) Z-score (OR = 0.52, 95% confidence interval (CI): 0.35 – 0.78) and ESRD secondary to glomerular disease (OR = 4.58, 95% CI: 1.45 – 14.46). We developed a classification and regression tree (CART) model to identify patients at low vs. high AD risk. Our model classified 62 patients of the cohort (64%) to be high- or low-risk, with a positive predictive value of 89% and a negative predictive value of 100%. Conclusion: Our data suggest that AD, as a possible marker of aortopathy and early aneurysm formation, is a novel and prevalent cardiovascular complication in ESRD children. Glomerular disease and low BMI Z-score appear to be potent predictors. CART modeling helps identify high-risk children, potentially guiding decisions regarding targeted echocardiographic evaluations.

Molecular mechanisms of renal blood flow autoregulation

Diabetes and hypertension are the leading causes of chronic kidney disease and their incidence is increasing at an alarming rate. Both are associated with impairments in the autoregulation of renal blood flow (RBF) and greater transmission of fluctuations in arterial pressure to the glomerular capillaries. The ability of the kidney to maintain relatively constant blood flow, glomerular filtration rate (GFR) and glomerular capillary pressure is mediated by the myogenic response of afferent arterioles working in concert with tubuloglomerular feedback that adjusts the tone of the afferent arteriole in response to changes in the delivery of sodium chloride to the macula densa. Despite intensive investigation, the factors initiating the myogenic response and the signaling pathways involved in the myogenic response and tubuloglomerular feedback remain uncertain. This review focuses on current thought regarding the molecular mechanisms underlying myogenic control of renal vascular tone, the interrelationships between the myogenic response and tubuloglomerular feedback, the evidence that alterations in autoregulation of RBF contributes to hypertension and diabetes-induced nephropathy and the identification of vascular therapeutic targets for improved renoprotection in hypertensive and diabetic patients.

The Risk of Septicemia in End-Stage Renal Disease With and Without Renal Transplantation: A Propensity-Matched Cohort Study

End-stage renal disease (ESRD) is a well-known risk factor for septicemia. Renal transplantation (RTx) is the treatment of choice for ESRD. However, RTx recipients should undergo long-term immunosuppressive therapy. The aim of this study was to evaluate the risk of septicemia in ESRD patients with and without RTx.This cohort study used the National Health Insurance (NHI) data of Taiwan from 2000 to 2010. The RTx group consisted of 3286 RTx recipients. The non-RTx comparison group also consisted of 3286 subjects with ESRD matched by propensity scores for age, sex, index date, comorbidities, and medications. The subjects were followed until the end of 2011 to evaluate the septicemia risk.The risk of septicemia was lower in the RTx group than the non-RTx group, with an adjusted hazard ratio of 0.73 [95% confidence interval (CI) = 0.64-0.84, P < 0.001]. In addition, we observed insignificantly lower intensive care unit (ICU) admission rate (35.8% vs. 39.8%) and lower 30-day all-cause mortality rate (17.2% vs. 18.5%) in the RTx group than the non-RTx group. However, the mean cost for septicemia in the RTx group was insignificantly higher than the non-RTx group (7175 vs. 6421 USD, P = 0.39).RTx recipients had a significantly reduced risk of developing septicemia compared to the propensity-matched non-RTx ESRD patients. The ICU admission and 30-day all-cause mortality rates also slightly decreased in RTx recipients but without statistical significance.

Shear wave elastography in chronic kidney disease: a pilot experience in native kidneys

Background

There currently is a need for a non-invasive measure of renal fibrosis. We aim to explore whether shear wave elastography (SWE)-derived estimates of tissue stiffness may serve as a non-invasive biomarker that can distinguish normal and abnormal renal parenchymal tissue.

Methods

Participants with CKD (by estimated GFR) and healthy volunteers underwent SWE. Renal elasticity was estimated as Young’s modulus (YM) in kilopascals (kPa). Univariate Wilcoxon rank-sum tests were used.

Results

Twenty-five participants with CKD (median GFR 38 mL/min; quartile 1, quartile 3 28, 42) and 20 healthy controls without CKD underwent SWE performed by a single radiologist. CKD was associated with increased median YM (9.40 [5.55, 22.35] vs. 4.40 [3.68, 5.70] kPa; p = 0.002) and higher median intra-subject inter-measurement estimated YM’s variability (4.27 [2.89, 9.90] vs. 1.51 [1.21, 2.05] kPa; p < 0.001).

Conclusions

SWE-derived estimates of renal stiffness and intra-subject estimated stiffness variability are higher in patients with CKD than in healthy controls. Renal fibrosis is a plausible explanation for the observed difference in YM. Further studies are required to determine the relationship between YM, estimated renal stiffness, and renal fibrosis severity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0120-7) contains supplementary material, which is available to authorized users.

Invariance of measures to understand decision-making for pursuing living donor kidney transplant

Living donor kidney transplant is the ideal treatment option for end-stage renal disease; however, the decision to pursue living donor kidney transplant is complex and challenging. Measurement invariance of living donor kidney transplant Decisional Balance and Self-Efficacy across gender (male/female), race (Black/White), and education level (no college/college or higher) were examined using a sequential approach. Full strict invariance was found for Decisional Balance and Self-Efficacy for gender and partial strict invariance was found for Decisional Balance and Self-Efficacy across race and education level. This information will inform tailored feedback based on these constructs in future intervention studies targeting behavior change among specific demographic subgroups.

Shared decision-making in end-stage renal disease: a protocol for a multi-center study of a communication intervention to improve end-of-life care for dialysis patients

Background

End-stage renal disease carries a prognosis similar to cancer yet only 20 % of end-stage renal disease patients are referred to hospice. Furthermore, conversations between dialysis team members and patients about end-of-life planning are uncommon. Lack of provider training about how to communicate prognostic data may contribute to the limited number of end-of-life care discussions that take place with this chronically ill population. In this study, we will test the Shared Decision-Making Renal Supportive Care communication intervention to systematically elicit patient and caretaker preferences for end-of-life care so that care concordant with patients’ goals can be provided.

Methods/design

This multi-center study will deploy an intervention to improve end-of-life communication for hemodialysis patients who are at high risk of death in the ensuing six months. The intervention will be carried out as a prospective cohort with a retrospective cohort serving as the comparison group. Patients will be recruited from 16 dialysis units associated with two large academic centers in Springfield, Massachusetts and Albuquerque, New Mexico. Critical input from patient advisory boards, a stakeholder panel, and initial qualitative analysis of patient and caretaker experiences with advance care planning have informed the communication intervention. Rigorous communication training for hemodialysis social workers and providers will ensure that standardized study procedures are performed at each dialysis unit. Nephrologists and social workers will communicate prognosis and provide advance care planning in face-to-face encounters with patients and families using a social work-centered algorithm. Study outcomes including frequency and timing of hospice referrals, patient and caretaker satisfaction, quality of end-of-life discussions, and quality of death will be assessed over an 18 month period.

Discussion

The Shared Decision-Making Renal Supportive Care Communication intervention intends to improve discussions about prognosis and end-of-life care with end-stage renal disease patients. We anticipate that the intervention will help guide hemodialysis staff and providers to effectively participate in advance care planning for patients and caretakers to establish preferences and goals at the end of life.

Trial registration

NCT02405312 

Changes in pulse pressure during hemodialysis treatment and survival in maintenance dialysis patients

BACKGROUND AND OBJECTIVES

Pulse pressure has been shown as a risk factor for mortality in patients on maintenance hemodialysis (MHD). However, the effect of change in pulse pressure during hemodialysis on survival in a large cohort of patients on MHD has not been sufficiently investigated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study examined the association between time-varying Δ pulse pressure (postdialysis minus predialysis pulse pressure) and mortality in a cohort of 98,577 patients on MHD (July 2001-June 2006) using Cox proportional hazard models with restricted cubic splines.

RESULTS

The average patient age was 62 years old; among the patients, 33% were black and 59% had diabetes. During 134,814 patient-years of at-risk time, 16,054 (16%) patients died, with 6827 (43%) of the deaths caused by cardiovascular causes. In the models including adjustment for either predialysis systolic BP or mean arterial BP, there was a U-shaped association between change in pulse pressure during hemodialysis and all-cause mortality. In the systolic BP plus case mix plus malnutrition-inflammation complex syndrome-adjusted model, large declines in pulse pressure (>-25 mmHg) and increases in pulse pressure >5 mmHg were associated with higher all-cause mortality (reference: ≥-5 to <5 mmHg): hazard ratios (95% confidence intervals [95% CIs]) for change pulse pressures of <-25, ≥-25 to <-15, ≥-15 to <-5, 5 to <15, 15 to <25, and ≥25 mmHg were 1.21 (95% CI, 1.14 to 1.29), 1.03 (95% CI, 0.97 to 1.10), 1.01 (95% CI, 0.96 to 1.06), 1.06 (95% CI, 1.01 to 1.11), 1.17 (95% CI, 1.11 to 1.24), and 1.15 (95% CI, 1.08 to 1.23), respectively. The U-shaped association was observed with cardiovascular death.

CONCLUSIONS

Modest reductions in pulse pressure after hemodialysis are associated with the greatest survival, whereas large declines or rises in pulse pressure are related to higher mortality. Trials determining how to modify pulse pressure response to improve survival in the hemodialysis population are indicated.

Effect of High-Flux Dialysis on Circulating FGF-23 Levels in End-Stage Renal Disease Patients: Results from a Randomized Trial

BACKGROUND

In patients undergoing maintenance hemodialysis (HD), increased levels of circulating fibroblast growth factor-23 (FGF-23) are independently associated with cardiovascular events and mortality. Interventional strategies aiming to reduce levels of FGF-23 in HD patients are of particular interest. The purpose of the current study was to compare the impact of high-flux versus low-flux HD on circulating FGF-23 levels.

METHODS

We conducted a post-hoc analysis of the MINOXIS study, including 127 dialysis patients randomized to low-flux (n = 62) and high-flux (n = 65) HD for 52 weeks. Patients with valid measures for FGF-23 investigated baseline and after 52 weeks were included.

RESULTS

Compared to baseline, a significant increase in FGF-23 levels after one year of low-flux HD was observed (Delta plasma FGF-23: +4026 RU/ml; p < 0.001). In contrast, FGF-23 levels remained stable in the high flux group (Delta plasma FGF-23: +373 RU/ml, p = 0.70). The adjusted difference of the absolute change in FGF-23 levels between the two treatment groups was statistically significant (p < 0.01).

CONCLUSIONS

Over a period of 12 months, high-flux HD was associated with stable FGF-23 levels, whereas the low-flux HD group showed an increase of FGF-23. However, the implications of the different FGF 23 time-trends in patients on high flux dialysis, as compared to the control group, remain to be explored in specifically designed clinical trials.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS) DRKS00007612.

Galectin-3 as a new biomarker of diastolic dysfunction in hemodialysis patients

BACKGROUND

Galectin-3 (gal-3) is an emerging prognostic biomarker in heart failure (HF). Clinical and experimental studies suggest that gal-3 is an important mediator of HF. Here we aimed to examine the relationship between gal-3 and diastolic dysfunction in patients undergoing maintenance hemodialysis (HD).

METHODS

We examined the relationship between plasma gal-3 levels and left ventricular diastolic function. Plasma gal-3 was measured in 87 subjects with chronic HD and in 45 healthy controls using biochemical evaluations. Conventional echocardiography and pulsed tissue Doppler assessment were performed in all patients. Left ventricular diastolic dysfunction (LVDD) was defined as E' < 8 cm/s. The E/E' ratio was used as the main determinant of LVDD grade.

RESULTS

The mean gal-3 concentrations were: 16.05 ng/ml (13.89-19.75) in healthy controls; 14.54 ng/ml (10.85-17.65) in HD patients with normal diastolic function; and 23.30 ng/ml (20.12-26.87) in HD patients with LVDD (p  < 0.01). Plasma gal-3 levels correlated with E/E' (r = 0.933, p  < 0.01), left atrial volume index (r = 0.713, p  < 0.01), and E' (r = -0.685, p  < 0.01). ROC analysis showed that the best gal-3 cut-off point for the diagnosis of LVDD was 20.12 ng/ml with a sensitivity of 67.6 % and specificity of 84.6 % (AUC = 0.803).

CONCLUSION

We suggest that gal-3 may be a promising biomarker for the detection of LVDD in HD patients.

Renal Biopsy in Type 2 Diabetic Patients

The majority of diabetic patients with renal involvement are not biopsied. Studies evaluating histological findings in renal biopsies performed in diabetic patients have shown that approximately one third of the cases will show pure diabetic nephropathy, one third a non-diabetic condition and another third will show diabetic nephropathy with a superimposed disease. Early diagnosis of treatable non-diabetic diseases in diabetic patients is important to ameliorate renal prognosis. The publication of the International Consensus Document for the classification of type 1 and type 2 diabetes has provided common criteria for the classification of diabetic nephropathy and its utility to stratify risk for renal failure has already been demonstrated in different retrospective studies. The availability of new drugs with the potential to modify the natural history of diabetic nephropathy has raised the question whether renal biopsies may allow a better design of clinical trials aimed to delay the progression of chronic kidney disease in diabetic patients.

Short-term outcomes of hip fractures in patients aged 90 years old and over receiving surgical intervention

Background

The knowledge about short-term outcomes of nonagenarians undergoing surgery for hip fracture in Asian is limited.

Methods

The patients with hip fractures who underwent hip hemiarthroplasty and open reduction with internal fixation (ORIF) for management during the period from 2008 to 2012 were identified and their medical record was retrospectively reviewed.

Results

During the study period, a total of 101 patients underwent surgery for management of hip fractures, and the age of patients ranged from 90 to 96 years. The sites of hip fracture were intertrochanteric (n = 57, 56.4%) and the neck of the femur (n = 44, 43.6%). Most of the patients had American Society of Anesthesiologists scores of 3(n = 55) or 4 (in 44 patients). 80.2% (n = 81) underwent the operation within one day after admission; however, there were 13 patients (12.9%) that underwent surgery 48 or more hours later. ORIF and hemiarthroplasty were performed for 63 (62.4%) and 38 (37.6%) patients, respectively. Overall, the 30-day and 1-year mortality rates were 9.9% (10/101) and 17.3% (13/75), respectively. Multivariate analysis showed that the 30-day mortality was significantly associated only with end-stage renal disease (ESRD) (Odds ratio, 11.13, 95% confidence interval, 1.275–97.881, P = .029).

Conclusions

The short-term outcome of surgical management for Asian nonagenarians with hip fractures is favorable in selected patients.

Haemodialysis-induced hypoglycaemia and glycaemic disarrays

In patients with diabetes receiving chronic haemodialysis, both very high and low glucose levels are associated with poor outcomes, including mortality. Conditions that are associated with an increased risk of hypoglycaemia in these patients include decreased gluconeogenesis in the remnant kidneys, deranged metabolic pathways, inadequate nutrition, decreased insulin clearance, glucose loss to the dialysate and diffusion of glucose into erythrocytes during haemodialysis. Haemodialysis-induced hypoglycaemia is common during treatments with glucose-free dialysate, which engenders a catabolic status similar to fasting; this state can also occur with 5.55 mmol/l glucose-containing dialysate. Haemodialysis-induced hypoglycaemia occurs more frequently in patients with diabetes than in those without. Insulin therapy and oral hypoglycaemic agents should, therefore, be used with caution in patients on dialysis. Several hours after completion of haemodialysis treatment a paradoxical rebound hyperglycaemia may occur via a similar mechanism as the Somogyi effect, together with insulin resistance. Appropriate glycaemic control tailored for patients on haemodialysis is needed to avoid haemodialysis-induced hypoglycaemia and other glycaemic disarrays. In this Review we summarize the pathophysiology and current management of glycaemic disarrays in patients on haemodialysis.

Intestinal organoids: a model of intestinal fibrosis for evaluating anti-fibrotic drugs

BACKGROUND & AIMS

Intestinal fibrosis is a critical complication of Crohn's disease (CD). Current in vitro models of intestinal fibrosis cannot model the complex intestinal architecture, while in vivo rodent models do not fully recapitulate human disease and have limited utility for large-scale screening. Here, we exploit recent advances in stem cell derived human intestinal organoids (HIOs) as a new human model of fibrosis in CD.

METHODS

Human pluripotent stem cells were differentiated into HIOs. We identified myofibroblasts, the key effector cells of fibrosis, by immunofluorescence staining for alpha-smooth muscle actin (αSMA), vimentin, and desmin. We examined the fibrogenic response of HIOs by treatment with transforming growth factor beta (TGFβ) in the presence or absence of the anti-fibrotic drug spironolactone. Fibrotic response was assayed by expression of fibrogenic genes (COL1A1 (collagen, type I, alpha 1), ACTA2 (alpha smooth muscle actin), FN1 (fibronectin 1), MYLK (myosin light chain kinase), and MKL1 (megakaryoblastic leukemia (translocation) 1)) and proteins (αSMA).

RESULTS

Immunofluorescent staining of organoids identified a population of myofibroblasts within the HIO mesenchyme. TGFβ stimulation of HIOs produced a dose-dependent pro-fibrotic response. Spironolactone treatment blocked the fibrogenic response of HIOs to TGFβ.

CONCLUSIONS

HIOs contain myofibroblasts and respond to a pro-fibrotic stimulus in a manner that is consistent with isolated human myofibroblasts. HIOs are a promising model system that might bridge the gap between current in vitro and in vivo models of intestinal fibrosis in IBD.

Protective role of insulin-like growth factor-1 receptor in endothelial cells against unilateral ureteral obstruction-induced renal fibrosis

Insulin-like growth factor-1 receptor (IGF-1R) can regulate vascular homeostasis and endothelial function. We studied the role of IGF-1R in oxidative stress-induced endothelial dysfunction. Unilateral ureteral obstruction (UUO) was performed in wild-type (WT) mice and mice with endothelial cell (EC)-specific IGF-1R knockout (KO). After UUO in endothelial IGF-1R KO mice, endothelial barrier dysfunction was more severe than in WT mice, as seen by increased inflammatory cell infiltration and vascular endothelial (VE)-cadherin phosphorylation. UUO in endothelial IGF-1R KO mice increased interstitial fibroblast accumulation and enhanced extracellular protein deposition as compared with the WT mice. Endothelial barrier function measured by transendothelial migration in response to hydrogen peroxide (H2O2) was impaired in ECs. Silencing IGF-1R enhanced the influence of H2O2 in disrupting the VE-protein tyrosine phosphatase/VE-cadherin interaction. Overexpression of IGF-1R suppressed H2O2-induced endothelial barrier dysfunction. Furthermore, by using the piggyBac transposon system, we expressed IGF-1R in VE cells in mice. The expression of IGF-1R in ECs also suppressed the inflammatory cell infiltration and renal fibrosis induced by UUO. IGF-1R KO in the VE-cadherin lineage of bone marrow cells had no significant effect on the UUO-induced fibrosis, as compared with control mice. Our results indicate that IGF-1R in the endothelium maintains the endothelial barrier function by stabilization of the VE-protein tyrosine phosphatase/VE-cadherin complex. Decreased expression of IGF-1R impairs endothelial function and increases the fibrosis of kidney disease.

Plasma High-Sensitivity C-Reactive Protein Level is Associated with Impaired Estimated Glomerular Filtration Rate in Hypertensives

BACKGROUND

Both inflammation and chronic kidney disease (CKD) are related to cardiovascular disease. Whether inflammatory biomarkers are associated with impaired glomerular filtration rate (GFR) is unclear in hypertensives.

METHODS

We recruited hypertension patients from the cardiovascular clinic of a tertiary medical center in Taiwan. GFR was calculated using the 7-item Modification of Diet in Renal Disease (MDRD) study equation and impaired GFR (IGFR) was defined as GFR less than 60 ml/min/1.73 m(2). High-sensitivity C-reactive protein (hsCRP) kits were used for the measurement of the CRP levels.

RESULTS

In our study, 572 consecutive hypertensive patients were enrolled. The range of patient age was 26-91 years (mean 60.5 ± 11.7), and hsCRP and GFR ranged from 0.01 to 9.99 mg/L and 16.6 to 239.6 ml/min//1.73 m(2), respectively. HsCRP levels were correlated with GFR (p = 0.01) and the presence of IGFR (p = 0.009). Multivariate regression analysis showed hsCRP (p = 0.03), age (p < 0.001) and urinary albumin-to-creatinine ratio (UACR) (p = 0.002) are independent factors associated with GFR. Furthermore, hsCRP levels [odds ratio (OR) = 1.16, 95% CI = 1.03-1.31, p = 0.02], age (OR = 1.09, 95% CI = 1.07-1.12, p < 0.001), and UACR (OR = 1.02, 95% CI = 1.01-1.04, p < 0.001) independently predicted the presence of IGFR using binary logistic regression analysis.

CONCLUSIONS

Information obtained from our study showed that hsCRP is associated with IGFR in hypertensives.

KEY WORDS

Chronic kidney disease; C-reactive protein; Glomerular filtration rate; Hypertension; Inflammation.

Prevention of Central Line–Associated Bloodstream Infections in Hemodialysis Patients

An increasing proportion of central line-associated bloodstream infections (CLABSIs) are seen in outpatient settings. Many of such infections are due to hemodialysis catheters (HD-CLABSIs). Such infections are associated with substantial morbidity, mortality, and excess healthcare costs. Patients who receive dialysis through a catheter are 2–3 times more likely to be hospitalized for infection and to die of septic complications than dialysis patients with grafts or fistulas. Prevention measures include minimizing the use of hemodialysis catheters, use of CLABSI prevention bundles for line insertion and maintenance, and application of antimicrobial ointment to the catheter exit site. Instillation into dialysis catheters of antimicrobial solutions that remain in the catheter lumen between dialyses (antimicrobial lock solutions) has been studied, but it is not yet standard practice in some dialysis units. At least 34 studies have evaluated the impact of antimicrobial lock solutions on HD-CLABSI rates. Thirty-two (94%) of the 34 studies demonstrated reductions in HD-CLABSI rates among patients treated with antimicrobial lock solutions. Recent multicenter randomized controlled trials demonstrated that the use of such solutions resulted in significantly lower HD-CLABSI rates, even though such rates were low in control groups. The available evidence supports more routine use of antimicrobial lock solutions as an HD-CLABSI prevention measure in hemodialysis units.

Hypolipidemic, Hepatoprotective and Renoprotective Effects of Cydonia Oblonga Mill. Fruit in Streptozotocin-Induced Diabetic Rats

Diabetes mellitus is associated with complications in several different systems of the body, and the incidence of diabetes is rapidly increasing worldwide. The objective of the present study was to evaluate the effect of aqueous extract of Cydonia oblonga Mill. Fruit on lipid profile and some biochemical parameters in streptozotocin-induced diabetic rats. The extract showed anti hyper lipidemic activity as evidenced by significant decreases in serum triglyceride, total cholesterol, and low density lipoprotein cholesterol (LDL-C) levels along with the elevation of high density lipoprotein cholesterol (HDL-C) in the diabetic rats. The biochemical liver functional tests were also analyzed and it was shown that serum biomarkers of liver dysfunction, including alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) were significantly reduced in aqueous extract of Cydonia oblonga Mill. treated diabetic rats. In addition, our results showed that the oral administration of the extract prevented diabetes-induced increase in serum urea and creatinine levels as the markers of renal dysfunction. In conclusion, the present study indicates that aqueous extract of Cydonia oblonga Mill. Is able to improve some of the symptoms associated with diabetes and possesses hypolipidemic, hepatoprotective, and renoprotective effects in streptozotocin-induced diabetic rats.

Mechanisms and biological functions of autophagy in diseased and ageing kidneys

Autophagy degrades pathogens, altered organelles and protein aggregates, and is characterized by the sequestration of cytoplasmic cargos within double-membrane-limited vesicles called autophagosomes. The process is regulated by inputs from the cellular microenvironment, and is activated in response to nutrient scarcity and immune triggers, which signal through a complex molecular network. Activation of autophagy leads to the formation of an isolation membrane, recognition of cytoplasmic cargos, expansion of the autophagosomal membrane, fusion with lysosomes and degradation of the autophagosome and its contents. Autophagy maintains cellular homeostasis during stressful conditions, dampens inflammation and shapes adaptive immunity. A growing body of evidence has implicated autophagy in kidney health, ageing and disease; it modulates tissue responses during acute kidney injuries, regulates podocyte homeostasis and protects against age-related renal disorders. The renoprotective functions of autophagy in epithelial renal cells and podocytes are mostly mediated by the clearance of altered mitochondria, which can activate inflammasomes and apoptosis, and the removal of protein aggregates, which might trigger inflammation and cell death. In translational terms, autophagy is undoubtedly an attractive target for developing new renoprotective treatments and identifying markers of kidney injury.

Do physicians with diabetes have differences in dialysis use and survival than other patients with diabetes

AIMS

To assess whether the increased knowledge and resources available to physicians led to differences in dialysis and survival rates between physicians and non-physician patients with diabetes.

METHODS

All newly diagnosed (1997-2009) type 2 diabetes patients aged ≥35 years from the National Health Insurance Program of Taiwan database were included. After propensity score matching (1:10), we estimated the relative risk of dialysis and death using Cox proportional hazards model adjusted for demographic characteristics and comorbidities.

RESULTS

Physicians with diabetes were more likely to start dialysis than general patients, with a 48% increased hazard risk (HR) (P=0.006). Physicians with diabetes had significantly lower risk of death (HR: 0.88; P=0.025). However, those requiring dialysis had a non-significant increased risk of death (HR: 1.19). There was an increased HR for death in older physicians (HR: 1.81; P<0.001) and those with cancer or catastrophic illness. The HR of dialysis (7.89; P<0.0001) increased dramatically with increasing Charlson Comorbidity Index scores.

CONCLUSIONS

Physicians with DM survived longer than other patients with diabetes, likely benefiting from their professional resources in disease control and prevention. Nonetheless, they displayed no advantage from their medical backgrounds compared with the general patients if they developed end stage renal disease.

ADAM17 at the interface between inflammation and autoimmunity

The discovery of the disintegrin and metalloproteinase 17 (ADAM17), originally identified as tumor necrosis factor-a converting enzyme (TACE) for its ability as sheddase of TNF-α inspired scientists to attempt to elucidate the molecular mechanisms underlying ADAM17 implication in diseased conditions. In recent years, it has become evident that this protease can modify many non matrix substrates, such as cytokines (e.g. TNF-α), cytokine receptors (e.g. IL-6R and TNF-R), ligands of ErbB (e.g. TGF-α and amphiregulin) and adhesion proteins (e.g. Lselectin and ICAM-1). Several recent studies have described experimental model system to better understand the role of specific signaling molecules, the interplay of different signals and tissue interactions in regulating ADAM17-dependent cleavage of most relevant substrates in inflammatory diseases. The central question is whether ADAM17 can influence the outcome of inflammation and if so, how it performs this regulation in autoimmunity, since inflammatory autoimmune diseases are often characterized by deregulated metalloproteinase activities. This review will explore the latest research on the influence of ADAM17 on the progression of inflammatory processes linked to autoimmunity and its role as modulator of inflammation.