Adipose and serum zinc alpha-2-glycoprotein (ZAG) expressions predict longitudinal change of adiposity, wasting and predict survival in dialysis patients.

There were limited data on adipose and serum zinc alpha-2-glycoprotein (ZAG) expression and its association with body composition in patients with advanced chronic kidney disease (CKD). This study aimed to quantify adipose and serum ZAG expression and evaluate their association with body composition and its longitudinal change, together with mortality in incident dialysis patients. We performed a single-center prospective cohort study. Patients who were planned for peritoneal dialysis were recruited. ZAG levels were measured from serum sample, subcutaneous and pre-peritoneal fat tissue obtained during peritoneal dialysis catheter insertion. Body composition and functional state were evaluated by bioimpedance spectroscopy and Clinical Frailty Scale respectively at baseline and were repeated 1 year later. Primary outcome was 2-year survival. Secondary outcomes were longitudinal changes of body composition. At baseline, the average adipose and serum ZAG expression was 13.4 ± 130.0-fold and 74.7 ± 20.9 µg/ml respectively. Both adipose and serum ZAG expressions independently predicted adipose tissue mass (ATM) (p = 0.001, p = 0.008, respectively). At 1 year, ATM increased by 3.3 ± 7.4 kg (p < 0.001) while lean tissue mass (LTM) remained similar (p = 0.5). Adipose but not serum ZAG level predicted change in ATM (p = 0.007) and LTM (p = 0.01). Serum ZAG level predicted overall survival (p = 0.005) and risk of infection-related death (p = 0.045) after adjusting for confounders. In conclusion, adipose and serum ZAG levels negatively correlated with adiposity and predicted its longitudinal change of fat and lean tissue mass, whilst serum ZAG predicted survival independent of body mass in advanced CKD patient.

Effect of Erythropoiesis-Stimulating Agent Therapy in Patients Receiving Palliative Care of Chronic Kidney Disease.

BACKGROUND: Despite the increasing use of erythropoiesis-stimulating agent (ESA) in patients receiving dialysis, few studies have examined the benefits of ESA for patients with chronic kidney disease receiving palliative care. OBJECTIVE: We designed a retrospective observational study to evaluate the effect of ESA in treating anemia of renal disease among adult patients receiving palliative care instead of dialysis. The primary objective was to assess whether ESA can reduce the transfusion burden and hospitalization. RESULTS: Thirty-nine patients receiving ESA were matched with a control group of 39 patients without ESA. Their mean age and glomerular filtration rates were 76.7 (10.2) years and 11.6 (5.7) mL/min/1.73 m2, respectively. Baseline hemoglobin levels were comparable in the ESA and control groups; their corresponding values were 10.2 (1.5) and 10.1 (1.4) g/dL. During 1-year observation period, 34 units of red cell transfusion occurred in patients receiving ESA, whereas 128 units of red cell were transfused to patients in control group. Patients in the control group had higher transfusion rate (incidence rate ratio [IRR]: 3.63; 95% confidence interval [CI]: 2.49-5.31; P < .00001) and higher admission rates (IRR: 2.34; 95% CI: 1.80-3.03; P < .000001) than the ESA group even after adjustment for comorbidities. CONCLUSIONS: High disease burden of palliative care among patients with stage 4 to 5 chronic kidney disease was reflected by transfusion requirement and hospitalization rates, both of which were shown to be significantly ameliorated by ESA treatment.

Peritoneal protein clearance predicts mortality in peritoneal dialysis patients.

BACKGROUND: Peritoneal protein clearance has been suggested to be a marker of peritoneal inflammation and systemic endothelial dysfunction. METHODS: We enrolled 711 consecutive incident PD patients. Baseline peritoneal protein clearance and other clinical information were reviewed. All patients were followed for at least 1 year for all-cause and cardiovascular mortality. RESULTS: The average PD effluent protein loss was 6.41 ± 2.16 g/day; peritoneal protein clearance was 97.15 ± 41.55 mL/day. The average duration of follow-up was 50.8 ± 36.2 months. Multivariate linear regression analysis showed that serum albumin, C-reactive protein, and mass transfer area coefficients of creatinine were independently associated with peritoneal protein clearance. By multivariate Cox regression analysis, age, Charlson comorbidity score, volume of overhydration and peritoneal protein clearance were independent predictors of all-cause mortality. Every 10 mL/day increase in peritoneal protein clearance confers 10.4% increase in risk of all-cause mortality (95% confidence interval 2.6-18.7%, p = 0.008). Peritoneal protein clearance was also associated with cardiovascular mortality by univariate analysis, but the association became insignificant after adjusting for confounding factors Cox regression analysis. CONCLUSIONS: Baseline peritoneal protein clearance is an independent predictor of all-cause mortality in incident PD patients. Routine measurement of peritoneal protein clearance may facilitate patient risk stratification.

Causes of nephrotic syndrome and nephrotic-range proteinuria are different in adult Chinese patients: A single centre study over 33 years.

AIM: The reported causes of nephrotic syndrome (NS) varies between different countries. Less is known about the causes of nephrotic-range proteinuria (NPU). We aimed to evaluate the underlying causes of NS and NPU. METHODS: This was a single-centre, retrospective study of adult patients who underwent renal biopsy between 1983 and 2015 in a tertiary referral hospital in Hong Kong. We determined the distribution of histopathological diagnoses with regard to the age subgroups and time periods. RESULTS: Among 7456 patients who underwent renal biopsy, 982 and 838 patients had NS and NPU, respectively. The most common diagnosis in NS was minimal change disease (MCD) (33.3%), followed by membranous nephropathy (MN) (23.6%) and lupus nephritis (LN) (12.8%); whereas the most common diagnosis in NPU was LN (27.4%), followed by immunoglobulin A nephropathy (IgAN) (21.4%) and diabetic nephropathy (DN) (9.3%). In the NS group, MCD was the most common diagnosis in young adults while MN was the leading cause in the elderly. On the other hand, LN was the most common pathology in the NPU group until the age of 60. Over the past three decades, there was a trend of decrease in the proportion of IgAN in both NS and NPU group, while a combined pathology of hypertensive nephrosclerosis and diabetic nephropathy (HTNS and DN) increased significantly. CONCLUSIONS: The causes of NS and NPU in Chinese adults were different and may represent two distinct pathological identities. The spectrum of renal histopathology among these two groups changed significantly over time.

Peritoneal Dialysis Catheter Revision and Replacement by Nephrologist for Peritoneal Dialysis Catheter Malfunction.

BACKGROUND: Catheter malfunction is an important cause of technique failure for peritoneal dialysis (PD) patients, and is commonly managed by surgeons or intervention radiologists. We reviewed our experience in catheter revision or replacement by nephrologists. METHOD: We reviewed the clinical outcome and complication rate of 95 consecutive patients who had PD catheter malfunction, with catheter revision or replacement by nephrologist. RESULT: Amongst the 95 patients, 32 had catheter revision, 24 catheter replacement via the original wound, and 39 catheter replacement via a new mini-laparotomy wound. Catheter survival was 71.6% at 1 month and 48.4% at 6 months; technique survival was 88.4% at 1 month and 77.4% at 6 months. When the 3 types of procedure were analyzed separately, technique survival at 1 month was 96.8, 75.0, and 89.7%, respectively, for patients who received catheter revision, catheter replacement via the original wound, and catheter replacement via a new mini-laparotomy wound (p = 0.0002), although their catheter survival rates were not significantly different. Also, 2 patients had bleeding that required urgent surgical exploration, 2 had wound infection, and 8 had peritonitis within 4 weeks after the surgery. CONCLUSION: PD catheter revision and replacement by nephrologist has an acceptable catheter survival and a reasonable complication rate. Given that prompt intervention is an important consideration, catheter revision and replacement by nephrologist is a suitable method for the management of catheter malfunction.

Relatives in silent kidney disease screening (RISKS) study: A Chinese cohort study.

AIM: Family members of patients with end-stage renal disease (ESRD) have higher risk for chronic kidney disease (CKD). Limited study has examined the risk of developing CKD in relatives of patients in earlier stages of CKD. METHODS: From January 2008 to June 2009, the Hong Kong Society of Nephrology studied first-degree relatives of stage 1-5 CKD patients from 11 local hospitals. A total of 844 relatives of 466 index CKD patients (stages 1-2: 29.6%; stage 3: 16.7%; stage 4: 10.9%; stage 5: 42.7%) were reviewed for various risk factors of CKD. We also defined a composite marker of kidney damage by the presence of one or more following features: (i) positive urine protein, (ii) spot urine protein-to-creatinine ratio ≥0.15 mg/mg, (iii) hypertension and (iv) estimated glomerular filtration rate (eGFR) ≤60 mL/min per 1.73 m2 and determine its association with participant and index patient factors. RESULTS: Among these 844 relatives, 23.1%, 25.9% and 4.4% of them had proteinuria (urine protein ≥1+), haematuria (urine red blood cell ≥1+) and glycosuria (urine glucose ≥1+), respectively. Proteinuria (P = 0.10) or glycosuria (P = 0.43), however, was not associated with stages of CKD of index patients. Smoking participants had a significantly lower eGFR (102.7 vs. 107.1 mL/min per 1.73 m2 ) and a higher prevalence of proteinuria (33.6% vs. 21.4%). Multivariate analysis showed that older age, male gender, obesity, being parents of index patients and being the relatives of a female index patient were independently associated with a positive composite marker. CONCLUSION: First-degree relatives of all stages of CKD are at risk of developing CKD and deserve screening. Parents, the elderly, obese and male relatives were more likely to develop markers of kidney damage.

Manifestation of tranexamic acid toxicity in chronic kidney disease and kidney transplant patients: A report of four cases and review of literature.

AIM: Tranexamic acid (TXA) is a synthetic anti-fibrinolytic agent commonly used for the prevention and treatment of bleeding disorders. The aim of this study is to describe the clinical manifestation of TXA toxicity in chronic kidney disease (CKD) patients. METHODS: From 2005 to 2014, we encountered four CKD patients who experienced severe complications related to TXA. Clinical manifestations and outcome of these patients were recorded. We then performed a qualitative literature review of published cases of TXA toxicity in CKD patients in the PubMed database from 1 January 1972 to 31 December 2015. RESULTS: In our centre, two peritoneal dialysis (PD) patients developed neurotoxicity after intravenous TXA use for surgical bleeding and one PD patient developed neurotoxicity after oral TXA use for post-polypectomy colonic bleeding. One kidney transplant recipient developed acute obstructive uropathy due to retention of blood clot at the pelvi-ureteric junction of graft kidney after taking oral TXA for menorrhagia. Dosage of TXA was not adjusted according to renal function in all cases. All of them recovered without permanent disability after TXA was stopped. From our literature search, we identified two cases of neurotoxicity (one PD, one stage 4 CKD patient), one case of retinal toxicity in a haemolysis (HD) patient, one case of ligneous conjunctivitis in a CKD patient, and one case of toxic epidermal necrolysis in a CKD patient. CONCLUSION: Neurotoxicity is a very common clinical manifestation of TXA toxicity in CKD patients. Thrombotic complication is rare. Dosage adjustment of TXA is essential in CKD patients.

Newer antibiotics for the treatment of peritoneal dialysis-related peritonitis.

Peritonitis is a debilitating infectious complication of peritoneal dialysis (PD). Drug-resistant bacterial peritonitis typically has a lower response rate to antibiotics. In the past 15 years, newer antibiotics with activities against drug-resistant Gram-positive bacteria have been developed. In most circumstances, peritonitis due to methicillin-resistant staphylococci responds to vancomycin. If vancomycin cannot be used due to allergy and/or non-susceptibility, there is increasing evidence that linezolid and daptomycin are the drugs of choice. It is reasonable to start linezolid orally or intravenously, but subsequent dose reduction may be necessary in case of myelosuppression. Daptomycin can be given intravenously or intraperitoneally and has excellent anti-biofilm activity. Other treatment options for drug-resistant Gram-positive bacterial peritonitis include teicoplanin, tigecycline and quinupristin/dalfopristin. Teicoplanin is not available in some countries (e.g. the USA). Tigecycline can only be given intravenously. Quinupristin/dalfopristin is ineffective against Enterococcus faecalis and there is only low-quality evidence to support its efficacy in the treatment of peritonitis. Effective newer antibiotics against drug-resistant Gram-negative bacteria are lacking. Polymyxins can be considered, but evidence on its efficacy is limited. In this review, we will discuss the potential use of newer antibiotics in the treatment of drug-resistant bacterial peritonitis in PD patients.

Functional and histological improvement after everolimus rescue of chronic allograft dysfunction in renal transplant recipients.

BACKGROUND: We tested the strategy of mTOR inhibitors with calcineurin inhibitor minimization in renal transplant recipients with known chronic allograft dysfunction. METHODS: In this open-label, single-arm study, renal transplant patients were recruited after biopsy-confirmed chronic allograft dysfunction in the absence of acute rejection episode within 2 months, with proteinuria <0.8 g/day, and serum creatinine <220 µmol/L or estimated glomerular filtration rate >40 mL/min/1.73 m(2). They were converted to everolimus (aiming for trough everolimus level 3-8 ng/mL) with cyclosporine minimization, to assess the effect on renal function, rate of glomerular filtration rate decline, and longitudinal transplant biopsy at 12 months. RESULTS: Seventeen Chinese patients (median transplant duration, 4.2 years) were recruited; no patients discontinued study medication. The mean slope of the glomerular filtration rate over time was -4.31±6.65 mL/min/1.73 m(2) per year in the year before everolimus, as compared with 1.29±5.84 mL/min/1.73 m(2) per year in the 12 months of everolimus therapy, a difference of 5.61 mL/min/1.73 m(2) per year (95% confidence interval [CI], 0.40-10.8) favoring everolimus therapy (P=0.036). Serial renal biopsy histology showed significant decrease of tubular atrophy (15.7%±11.3% versus 7.1%±7.3%, P=0.005) and interstitial fibrosis (14.8%±11.5% versus 7.2%±8.2%, P=0.013). Intrarenal expression of TGF-ß1 mRNA showed a nonsignificant decrease after everolimus treatment. CONCLUSION: In renal transplant recipients with biopsy-confirmed chronic allograft dysfunction, we found a significant beneficial effect of everolimus rescue therapy and calcineurin inhibitor minimization strategy on the improvement of glomerular filtration rate decline rate. In secondary analysis, everolimus was shown to slow down the disease progression by reducing the tubular atrophy and interstitial fibrosis scoring.

Urinary mRNA levels of ELR-negative CXC chemokine ligand and extracellular matrix in diabetic nephropathy.

BACKGROUND: Inflammation and fibrosis play important roles in the progression of diabetic nephropathy. We determine the urinary mRNA levels of ELR-CXC chemokine ligand and extracellular matrix in diabetic nephropathy. METHODS: We studied 26 patients with biopsy-proven diabetic nephropathy, 15 with hypertensive nephrosclerosis and 10 healthy controls. Urinary mRNA levels of CXCL9, CXCL10, CXCL11, collagen I A1 chain, collagen IV A3 chain and fibronectin were measured. Patients were followed for 36.9 ± 7.4 months to determine the rate of glomerular filtration rate (GFR) decline. RESULTS: Urinary mRNA levels of CXCL10 and CXCL11 are decreased, and those of collagen I A1 chain and fibronectin are increased in diabetic nephropathy. Baseline estimated GFR correlates with urinary mRNA level of CXCL9 (r = 0.583, p = 0.002) and CXCL11 (r = 0.703, p < 0.0001), respectively. The rate of GFR decline significantly correlates with urinary CXCL9 (r = -0.618, p = 0.0008) and CXCL11 mRNA levels (r = -0.726, p < 0.0001). Multivariate linear regression analysis confirms that urinary CXCL9 mRNA level is independently associated with the rate of GFR decline, while the correlation with urinary CXCL11 mRNA level has borderline significance. CONCLUSION: Urinary CXCL9 and CXCL11 mRNA levels correlate with baseline renal function. The rate of renal function decline correlates with urinary CXCL9 mRNA level. Our results suggest that urinary CXCL9 mRNA levels may be used for risk stratification of diabetic nephropathy.

Long-term outcome of biopsy-proven minimal change nephropathy in Chinese adults.

BACKGROUND: Minimal change nephropathy is a common cause of primary nephrotic syndrome in adults. However, there are few studies of its clinical course, response to treatment, and long-term outcome. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 340 consecutive adult patients with nephrotic syndrome and biopsy-proven minimal change nephropathy treated in a university hospital from 1984 until 2004. FACTORS: Treatment response groups: primary steroid resistance, frequent relapse (≥4 relapses within 1 year), infrequent relapse (≥1 relapse but not frequent relapse), and no relapse (reference group); disease pattern. OUTCOME: Medical problems after diagnosis; patient survival; renal survival. RESULTS: Median time to remission was 10 (IQR, 8-12) weeks; 179 (52.6%) had no relapse, 42 (12.4%) had infrequent relapses, 86 (25.3%) were frequent relapsers or steroid dependent, and 33 (9.7%) had primary steroid resistance. After a median follow-up of 174.7 (IQR, 119.7-235.0) months, 32 patients developed end-stage renal disease and 62 died (25 after progression to end-stage renal disease). Cox regression analysis showed that age and treatment response groups were the independent predictors of patient survival. Compared to the no-relapse group, the infrequent-relapse group had significantly better patient survival (adjusted HR, 0.19; 95% CI, 0.08-0.44; P<0.001), whereas the primary-steroid-resistance group had significantly worse patient survival (adjusted HR, 5.87; 95% CI, 1.83-18.85; P<0.001). Renal survival was excellent except in the primary-steroid-resistance group. LIMITATIONS: Retrospective study. CONCLUSIONS: A substantial proportion of adult patients with minimal change nephropathy continue to have disease flares more than 10 years after the initial presentation, and medical problems after diagnosis are common.

The safety and short-term efficacy of aliskiren in the treatment of immunoglobulin a nephropathy--a randomized cross-over study.

BACKGROUND: Laboratory research and previous study suggest that aliskiren, a direct renin inhibitor, has anti-proteinuric effects. We conducted a randomized crossover study to evaluate the anti-proteinuric effect of aliskiren in patients with immunoglobulin A (IgA) nephropathy. METHODS: We studied 22 patients with biopsy-proven IgA nephropathy and persistent proteinuria despite angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). Patients were randomized to either oral aliskiren 300 mg/day or placebo for 16 weeks and then crossed over to the other treatment arm after a washout period. Proteinuria, estimated glomerular filtration rate (eGFR), blood pressure, and serum potassium were monitored. RESULTS: After aliskiren treatment, there was a significant reduction in proteinuria in 4 weeks (1.76±0.95 to 1.03±0.69 g:g-Cr, p<0.0001), which remained at a low level throughout the treatment period. There was a significant difference in proteinuria between the aliskiren and placebo groups from 4 to 16 weeks after treatment (p<0.01 for all comparisons). After aliskiren treatment, there were modest but statistically significant reductions in eGFR (57.2±29.1 to 54.8±29.3 ml/min/1.73 m(2), p = 0.013) and diastolic blood pressure (72.6±12.3 to 66.2±11.2 mmHg, p<0.0001). None of the patient developed severe hyperkalemia (serum potassium ≥6.0 mmol/l) during the study period. CONCLUSIONS: Aliskiren has anti-proteinuric effect in patients with IgA nephropathy and persistent proteinuria despite ACE inhibitor or ARB. Further studies are needed to confirm the renal protecting effect of direct renin inhibition in chronic proteinuric kidney diseases. TRIAL REGISTRATION: ClinicalTrials.gov NCT00870493.

Relationship between myeloid-related protein 8/14 and survival of Chinese peritoneal dialysis patients.

BACKGROUND: Myeloid-related protein 8/14 (MRP8/14) is released by cells of myeloid lineage upon inflammatory challenges. Experimental data suggested that MRP8/14 is important in the initiation and progression of inflammation and cardiovascular diseases. We examined the relation between serum MRP8/14 level and cardiovascular disease in Chinese peritoneal dialysis (PD) patients. METHODS: We studied 102 new PD patients (58 males, mean age 57.3 ± 11.9 years). Baseline serum MRP8/14 was determined and grouped to quartiles for analysis. All patients were then followed for an average of 23.9 ± 6.9 months. RESULTS: There was a trend of lower 3-year cardiovascular event-free survival for patient quartiles with high serum MRP8/14 levels (log-rank test, p = 0.064). The 3-year actuarial survival was significantly lower for quartile groups with higher MRP8/14 levels (96.0, 94.7, 72.9, and 62.5% for quartiles 1-4, respectively, p = 0.003). Cox regression analysis showed that serum MRP8/14 level and Kt/V were independent predictors of actuarial survival; in this model, every 1 µg/ml increase in serum MRP8/14 level confers a 25.1% increase in risk of death (95% confidence interval, 1.3-54.4%, p = 0.037). There was no significant difference in technique survival between the MRP8/14 quartile groups. CONCLUSION: A high baseline serum MRP8/14 level was associated with a lower actuarial survival in Chinese PD patients. The pathogenic role of MRP8/14 in the cardiovascular disease of PD patients needs further investigation.

Relationship between serum levels of tumour necrosis factor-related apoptosis-inducing ligand and the survival of Chinese peritoneal dialysis patients.

AIM: Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) can counteract inflammation and atherosclerosis, both common causes of morbidity in peritoneal dialysis (PD) patients. We examined the relation between serum soluble TRAIL (sTRAIL) levels and the outcome of Chinese PD patients. METHODS: We studied 116 new PD patients (67 males, age 56.7 ± 13.4 years). Baseline serum sTRAIL level was determined and grouped to tertiles 1 (lowest) to 3 (highest). All patients were followed for 20.9 ± 7.0 months. RESULTS: Patient survival was 83.4%, 74.2% and 100% for tertiles 1 to 3, respectively, at 24 months (P = 0.021). Multivariate Cox regression analysis showed that serum sTRAIL level was an independent predictor of patient survival after adjusting for confounding factors (adjusted hazard ratio 0.962, 95% confidence interval [CI] 0.935-0.991, P = 0.010). CONCLUSION: A higher baseline serum sTRAIL level was associated with a better survival of PD patients. The detailed mechanism deserves further investigation.

The width of the basement membrane does not influence clinical presentation or outcome of thin glomerular basement membrane disease with persistent hematuria.

Thin basement membrane disease (TBMD) typically presents with persistent microscopic hematuria, and is usually defined as a glomerular basement membrane (GBM) thickness < 250 nm. Previous studies showed that neither the degree of thinning nor the extent of the abnormality correlate with the patient's clinical presentation or prognosis. To further define this, we enrolled a study group of 41 patients with isolated microscopic hematuria and a normal renal biopsy, except those with a GBM thickness of 250-320 nm, and compared them with 33 patients with traditional TBMD. We found no difference in baseline demographic or clinical parameter between the groups. After follow-up averaging 110 months, there was no significant difference in the risk of detectable or overt proteinuria, hypertension, or impaired renal function between the groups. By the end of the study, only five patients from the study group and four from the TBMD group had no outcome event. By Cox regression analysis, independent predictors of overt proteinuria were male gender, age at biopsy, baseline renal function, proteinuria, and hypertension. Age at biopsy was the only independent predictor for hypertension, and baseline proteinuria was the only independent predictor for impaired renal function. GBM thickness did not predict any outcome event. Hence, lifelong follow-up is advised, as the clinical features and prognosis of these patients with persistent microscopic hematuria and marginally thin GBM are similar to traditional TBMD.

The Oxford classification of IgA nephropathy: rationale, clinicopathological correlations, and classification.

IgA nephropathy is the most common glomerular disease worldwide, yet there is no international consensus for its pathological or clinical classification. Here a new classification for IgA nephropathy is presented by an international consensus working group. The goal of this new system was to identify specific pathological features that more accurately predict risk of progression of renal disease in IgA nephropathy, thus enabling both clinicians and pathologists to improve individual patient prognostication. In a retrospective analysis, sequential clinical data were obtained on 265 adults and children with IgA nephropathy who were followed for a median of 5 years. Renal biopsies from all patients were scored by pathologists blinded to the clinical data for pathological variables identified as reproducible by an iterative process. Four of these variables: (1) the mesangial hypercellularity score, (2) segmental glomerulosclerosis, (3) endocapillary hypercellularity, and (4) tubular atrophy/interstitial fibrosis were subsequently shown to have independent value in predicting renal outcome. These specific pathological features withstood rigorous statistical analysis even after taking into account all clinical indicators available at the time of biopsy as well as during follow-up. The features have prognostic significance and we recommended they be taken into account for predicting outcome independent of the clinical features both at the time of presentation and during follow-up. The value of crescents was not addressed due to their low prevalence in the enrolled cohort.

Factors associated with sudden death in peritoneal dialysis patients.

BACKGROUND: Relatively little is known of the epidemiology and predictors of sudden death in peritoneal dialysis (PD) populations. We aimed to identify the risk factors of sudden death among PD subjects. METHODS: To explore clinical correlates of sudden death in PD patients, we conducted a population-based case-control study using data from a single dialysis unit. Cases (n=24) were defined as all PD patients that met the criteria for sudden death during January 2003 through December 2006. We also selected 48 control subjects that were selected from the prevalent PD patient name list compiled in alphabetical order. Data on the hemoglobin, potassium, and calcium levels, residual renal function, dialysis adequacy, cardiovascular risks, comorbid conditions, concurrent use of aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, and erythropoietin, electrocardiographic and echocardiographic findings were extracted from case notes and computer records. Confounders were controlled by logistic regression. RESULTS: Over a period of 4 years, 24 PD patients (mean age 61.4+/-9.5 years, median duration of dialysis 3.1 years) experienced sudden death. Univariate analyses showed that patients that died suddenly were more likely to be male and to have diabetes mellitus, a history of smoking, and a lower small solute clearance as measured by Kt/V. Cases of sudden death were also more likely to have received blood transfusion within the previous 1 year. There were no significant differences between patients and controls for residual renal function, serum potassium levels, control of blood pressure and mineral metabolism, or hemoglobin levels. Multivariate regression analysis confirmed independent association between recent blood transfusion and increased odds of sudden death [adjusted odds ratio (OR) 5.18, 95% confidence interval (CI) 1.44-18.6]. Two other factors significantly associated with risk of sudden death were male gender (adjusted OR 4.16, 95% CI 1.14-15.2) and diabetes mellitus (adjusted OR 5.33, 95% CI 1.53-18.6). CONCLUSION: This study shows that recent blood transfusion is associated with an increased likelihood of sudden death in PD patients. The mechanisms that underlie this observation are unclear.

Oral calcitriol for the treatment of persistent proteinuria in immunoglobulin A nephropathy: an uncontrolled trial.

BACKGROUND: Laboratory research and previous retrospective study suggest that vitamin D and its analogues have profound effects on immune system function and glomerular mesangial cell proliferation. We conducted an open-label study to evaluate the antiproteinuric effect of calcitriol on proteinuria in patients with immunoglobulin A (IgA) nephropathy. STUDY DESIGN: Open-label prospective uncontrolled trial. SETTING & PARTICIPANTS: 10 patients (3 men) with biopsy-proven IgA nephropathy and persistent proteinuria despite angiotensin-converting enzyme-inhibitor or angiotensin receptor blocker therapy in a tertiary referral center. INTERVENTION: Calcitriol, 0.5 microg, twice weekly for 12 weeks. OUTCOME MEASURES: Changes in proteinuria, renal function, serum transforming growth factor beta (TGF-beta) and angiotensin II levels. RESULTS: After calcitriol treatment, there was a significant overall decrease in proteinuria with time by using a general linear model with repeated measures (P = 0.03). There was a progressive decrease in urine protein-creatinine ratio from 1.98 +/- 0.74 to 1.48 +/- 0.81 g/g (P = 0.007) during the first 6 weeks that persisted throughout the study period. No significant change in blood pressure or renal function was noted. There was a simultaneous decrease in serum TGF-beta level, and percentage of decrease in serum TGF-beta level significantly correlated with percentage of change in proteinuria (Spearman r = 0.643; P = 0.02). Serum angiotensin II level did not change throughout the study. One patient experienced transient hypercalcemia that normalized after a dosage decrease. No other major adverse effect was reported. LIMITATIONS: This small study is uncontrolled and does not examine the long-term effect of calcitriol therapy. CONCLUSION: Twice-weekly oral calcitriol has a modest antiproteinuric effect in patients with IgA nephropathy and persistent proteinuria despite angiotensin-converting enzyme-inhibitor or angiotensin receptor blocker therapy. Additional studies are needed to confirm the renal protecting effect of calcitriol in patients with chronic proteinuric kidney diseases.

Revascularization for post-transplant renal artery stenosis.

BACKGROUND: Percutaneous transluminal angioplasty has now been increasingly accepted as a primary treatment option for transplant renal artery stenosis. METHODS: This single-centre study evaluated the treatment effect of percutaneous transluminal angioplasty as primary intervention among 18 consecutive patients with angiographically demonstrated transplant renal artery stenosis. RESULTS: Patients (14 men and 4 women, mean age 49 +/- 9 years) were followed up for a mean duration of 21.6 months after procedure. Highly significant improvement was noted in the mean arterial pressure (from baseline 105.9 +/- 10.4 mmHg to 98.6 +/- 10.0 mmHg, P < 0.001), systolic blood pressure (148.5 mmHg to 137.1 mmHg, P = 0.002) and diastolic blood pressure (85.3 mmHg to 79.4 mmHg, P = 0.002). Estimated glomerular filtration rate before and 6 months after intervention was 41.4 +/- 16.8 mL/min per 1.73 m(2) and 42.0 +/- 16.2 mL/min per 1.73 m(2), respectively (P = 0.82). CONCLUSION: These findings show that percutaneous transluminal angioplasty in transplant renal artery stenosis appears to have a significant beneficial effect on hypertension but less impact on the improvement in renal function.