Screening Algorithm for BK Virus-Associated Nephropathy Using Sequential Testing of Urinary Cytology: A Probabilistic Model Analysis.

BACKGROUND: Incorporating urinary cytology in BK virus (BKV) screening algorithm potentially reduces the screening cost for BK viral nephropathy. We aimed to evaluate the test performances and screening cost of sequential 2-stage screening consisting of urine cytology followed by BKV serum quantitative polymerase chain reaction (PCR). METHODS: Ninety-five kidney transplant recipients who had BKV serum quantitative PCR/urine cytology tested and verified with histopathology (the reference gold standard) were included. A probabilistic model was constructed to evaluate the test performance and screening cost of 2-stage screening, and was compared with screening with urine cytology or serum viral load alone. RESULTS: At a viral load threshold of ≥104 copies/ml, the sensitivity and specificity of quantitative PCR alone were 83% (95% CI 69-96) and 91% (95% CI 83-97), respectively. The sensitivity and specificity of urine cytology alone were 91% (95% CI 79-100) and 74% (95% CI 60-91), respectively. Sequential 2-stage screening resulted in loss in sensitivity but a net gain in specificity (viral load threshold ≥104 copies/ml - sensitivity, 75% (95% CI 60-91); specificity, 98% (95% CI 95-99)). Two-stage screening also had superior positive predictive value and is cost effective when BKV-associated nephropathy prevalence is below 94%. CONCLUSIONS: Our study had demonstrated a favorable test performance and cost efficiency of 2-stage BKV screening.

Risk factors associated with brachial-ankle pulse wave velocity among peritoneal dialysis patients in Macao.

BACKGROUND: Cardiovascular disease is the leading cause of mortality among peritoneal dialysis (PD) patients in Macao. Increased arterial stiffness determined by pulse wave velocity (PWV) has been established as an independent predictor of cardiovascular mortality in end-stage renal disease patients. The present study aims to investigate the relationship between arterial stiffness and its associated risk factors in chronic PD patients. METHODS: A total of 96 chronic PD patients (48 males/48 females) were included in the cross-sectional study. Arterial stiffness was assessed by brachial-ankle PWV (baPWV). Patients were divided into two subgroups according to mean baPWV value. On enrollment, clinical characteristics and biochemical parameters were collected. RESULTS: Compared with low baPWV group patients, high baPWV group patients were significant older (p<0.001) and more likely to have a high proportion of female gender (p=0.004) as well as previous CVD history (p=0.008). Serum albumin, pre-albumin levels and residual renal creatinine clearance (CCr) were significantly lower but the serum ferritin level was significantly higher in high baPWV group patients than in low baPWV group patients (all p<0.01). BaPWV was positively associated with age (r=0.534, p<0.001), Charlson comorbidity index (r=0.350, p<0.001) and serum ferritin level (r=0.340, p=0.001). Meanwhile, baPWV negatively correlated with serum albumin (r=-0.479, p<0.001), pre-albumin levels (r=-0.320, p=0.003) and residual renal CCr (r=-0.177, p=0.048). Age-adjusted partial correlation test found a significant correlation between baPWV and CRP (r=0.462, p<0.001). Multivariate regression analysis showed that baPWV was independently associated with age (p<0.001), serum albumin level (p=0.015), CRP (p=0.019) and residual renal CCr (p=0.045). CONCLUSION: Arterial stiffness, assessed by baPWV, had an independent correlation with age, serum albumin level, CRP level and residual renal CCr among PD patients in Macao.

A randomized trial comparing conventional swan-neck straight-tip catheters to straight-tip catheters with an artificial subcutaneous swan neck.

OBJECTIVE: To evaluate the safety and efficacy of inserting a straight-tip Tenckhoff catheter configured with a subcutaneous artificial swan neck. DESIGN: Clinical outcomes of conventional swan-neck straight-tip catheters and Tenckhoff straight-tip catheters implanted with an artificial subcutaneous swan neck were compared in a prospective randomized controlled trial in a single-center setting. PATIENTS AND METHODS: Patients undergoing peritoneal dialysis catheter insertion were randomized to receive either a double-cuff straight-tip Tenckhoff catheter with an artificial subcutaneous swan-neck (TC) or a conventional double-cuff straight-tip swan-neck catheter (SN). The primary outcome was catheter exit-site infection rate; the secondary outcomes were catheter-related mechanical events and surgery-related bleeding. RESULTS: A total of 39 consecutive patients were enrolled: 20 into the TC group and 19 into the SN group. More exit-site infections were observed in the SN group than in the TC group, although the difference was not statistically significant (0.97 vs 0.51 episodes per patient-year, p = 0.0657). However, there were more peritonitis episodes in the TC group than in the SN group (0.35 vs 0.15 episodes per patient-year, p = 0.0256). Exit-site and main wound bleeding post surgery were generally mild and similar in the 2 groups. No events of dialysate leakage, catheter tip migration, or subcutaneous cuff protrusion were observed in patients of either group. Outflow failure due to mechanical causes occurred in 2 patients in the TC group and in 1 patient in the SN group during the intermittent peritoneal dialysis period; all were corrected successfully by laparoscopic omentectomy. CONCLUSIONS: Placement of the double-cuff straight-tip Tenckhoff catheter configured with an artificial subcutaneous swan neck appears to be an effective and safe procedure. It may be a good alternative to the conventional swan-neck catheter.

Increased utilization of peritoneal dialysis to cope with mounting demand for renal replacement therapy--perspectives from Asian countries.

With the number of end-stage renal disease (ESRD) patients growing, one of the crucial questions facing health care professionals and funding agencies in Asia is whether funding for dialysis will be sufficient to keep up with demand. During the ISPD's 2006 Congress, academic nephrologists and government officials from China, Hong Kong, India, Indonesia, Japan, Macau, Malaysia, Philippines, Singapore, Taiwan, Thailand, and Vietnam participated in a roundtable discussion on dialysis economics in Asia. The focus was policy and health care financing. The roundtable addressed ESRD growth in Asia and how to obtain enough funding to keep up with the growth in patient numbers. Various models were presented: the "peritoneal dialysis (PD) first" policy model, incentive programs, nongovernmental organizations providing PD, and PD reimbursement in a developing economy. This article summarizes the views of the participant nephrologists on how to increase the utilization of PD to improve on clinical and financial management of patients with ESRD.

Prevalence and risk factors associated with peripheral artery disease in elderly patients undergoing peritoneal dialysis.

BACKGROUND: Rapid growth of the elderly peritoneal dialysis (PD) population is posing a special challenge for renal teams. Peripheral artery disease (PAD) has been reported to be an independent predictor of cardiovascular and all-cause mortality in hemodialysis patients. However, the prevalence and associated risk factors for PAD in elderly PD patients have not yet been fully investigated. METHODS: A total of 69 elderly PD patients were included in the present study. PAD was defined as either an ankle-brachial index < 0.9 or a history of intermittent claudication, lower-limb amputation, foot ulcers, or gangrene. On enrollment, clinical and biochemical characteristics were collected. RESULTS: The overall prevalence of PAD was 31.9%. Compared with non-PAD patients, PAD patients were significantly older and more likely to be female and have longer PD duration and lower diastolic blood pressure (P < 0.001, = 0.002, 0.018, and 0.007, respectively). Serum albumin level (P < 0.001) and residual renal Kt/V value (P < 0.001) were significantly lower, but the serum C-reactive protein level (P = 0.005) was significantly higher, in PAD patients compared with non-PAD patients. Logistic regression analysis showed that serum albumin level (odds ratio = 1.485, P = 0.040) and residual renal Kt/V value (odds ratio = 1.725, P = 0.016) were independently associated with PAD. CONCLUSION: A high prevalence of PAD appeared among elderly PD patients in Macao. Serum albumin level and residual renal Kt/V value were independently related to PAD.

Successful treatment of hepatitis C after kidney transplantation with combined interferon alpha-2b and ribavirin.

The management of acute hepatitis C virus (HCV) infection after renal transplantation (RT) remains controversial, due to the potential risk of interferon-induced graft dysfunction. There is little experience with combined interferon and ribavirin therapy in this group of patients. We treated four consenting RT recipients who developed acute de novo HCV infection with a combination of interferon-alpha 2b and ribavirin. After 48 weeks' treatment, sustained virologic and biochemical remission were achieved in three patients infected with HCV genotypes 1a, 2, and 6a, respectively. The median time from treatment onset to ALT normalization was 8 weeks. The fourth patient was a non-responder infected with genotype 1b. Dose-dependent hemolysis was the most frequent side-effect. No patient developed allograft dysfunction. Our experience indicates that the judicious use of combined interferon and ribavirin can be considered in selected RT recipients with severe acute hepatitis C infection.