Treating peritoneal dialysis catheter exit-site granulomas with chlorhexidine swabstick: A pilot study.

BACKGROUND: Silver nitrate cauterisation is the conventional treatment for peritoneal dialysis catheter exit-site granulomas. However, it requires to be performed by nurses, patients often experience pain and chemical burns. Therefore, the appropriateness and applicability of using 2% aqueous chlorhexidine swabstick as an alternative was explored in two nephrology centres in Hong Kong. OBJECTIVE: To examine possibility of conducting full trial using chlorhexidine swabstick compared with silver nitrate. DESIGN: A pilot study. PARTICIPANTS: Fort-four patients with exit-site granulomas were equally, randomly allocated to receive chlorhexidine swabstick or silver nitrate. MEASUREMENTS: Both groups were followed for 6 weeks to evaluate the time of granuloma subsidence and adverse effects. Pain and treatment satisfaction were assessed using numerical rating scale and self-developed questionnaire, respectively. RESULTS: Healing rates were 94.4% (17 of 18) using chlorhexidine swabstick,100% (21 of 21) using silver nitrate (p = 0.46). The mean time of granuloma subsidence was significantly longer when using chlorhexidine swabstick (32.8 days) than silver nitrate (12.3 days, p=0.02). The chlorhexidine swabstick group reported significantly fewer adverse effects (11.1%, 2 of 18, p = 0.01) compared with the silver nitrate group (52.4%, 11 of 21). The chlorhexidine swabstick group had lower mean pain score (0.5 of 11) than the silver nitrate group (2.4 of 11, p < 0.01). The satisfaction scores between the two groups had no substantial difference. CONCLUSION: Chlorhexidine swabstick took long time to remove granulomas but had similar success rate, less pain, fewer adverse effects than silver nitrate. Additional research is warranted to examine the applicability of chlorhexidine swabstick.

Cancer Incidence and Mortality in Chronic Dialysis Population: A Multicenter Cohort Study.

BACKGROUND: Different studies in the past have shown that the risk of cancer development is increased in chronic dialysis patients. However, data concerning the cancer risk in Asian dialysis patients was scarce. More importantly, there was lack of information about the cancer-specific mortality in dialysis patients. METHODS: A multicenter retrospective cohort study of 6,254 patients who started either chronic peritoneal dialysis or hemodialysis between 1994 and 2014 in 4 renal units in Hong Kong. Patterns of cancer incidence and mortality in our dialysis patients were compared with those of the general population using standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) respectively. RESULTS: With 14,887 person-years of follow-up, 220 cancers were recorded. The SIR of all cancers was 1.44 (95% CI 1.26-1.65). A trend of an increased SIR was observed in young patients and within the first year of dialysis. Colorectum was the most common site of cancer (20%) while kidney cancer carried the highest risk (SIR 12.28, 95% CI 8.44-17.08). The SMR of all cancers was 0.91 (95% CI 0.72-1.13) and only kidney cancer had higher cancer mortality risk (SMR 4.92, 95% CI 1.80-10.70). SMR was highest in young patients and then decreased with age. CONCLUSIONS: The incidence of cancers in our chronic dialysis patients was elevated. Our findings of substantially increased risks in young patients, particularly in relation to kidney cancer, suggest that we can adopt a more individualized approach to cancer screening in chronic dialysis patients.

Validation of a risk prediction score for proximal neoplasia in colorectal cancer screening: a prospective colonoscopy study.

This study developed a clinical scoring system to predict the risks of PN among screening participants for colorectal cancer. We recruited 5,789 Chinese asymptomatic screening participants who received colonoscopy in Hong Kong (2008-2014). From random sampling of 2,000 participants, the independent risk factors were evaluated for PN using binary regression analysis. The odds ratios for significant risk factors were used to develop a scoring system, with scores stratified into 'average risk' (AR):0-2 and 'high risk' (HR):3-5. The other 3,789 subjects formed an independent validation cohort. Each participant received a score calculated based on their risk factors. The performance of the scoring system was evaluated. The proportion of PN in the derivation and validation cohorts was 12.6% and 12.9%, respectively. Based on age, gender, family history, body mass index and self-reported ischaemic heart disease, 85.0% and 15.0% in the validation cohort were classified as AR and HR, respectively. Their prevalence of PN was 12.0% and 18.1%, respectively. Participants in the HR group had 1.51-fold (95% CI = 1.24-1.84, p < 0.001) higher risk of PN than the AR group. The overall c-statistics of the prediction model was 0.71(0.02). The scoring system is useful in predicting the risk of PN to prioritize patients for colonoscopy.

Diagnostic Accuracy of a Qualitative Fecal Immunochemical Test Varies With Location of Neoplasia But Not Number of Specimens.

BACKGROUND & AIMS: We compared the accuracy of a qualitative fecal immunochemical test (FIT) in identifying patients with proximal vs distal advanced neoplasia and evaluated whether analysis of 2 specimens performed better than analysis of 1 specimen. Distal advanced neoplasia was defined as colorectal cancer (CRC), any colorectal adenoma ≥10 mm in diameter, high-grade dysplasia, or a lesion with villous or tubulovillous histologic characteristics in a location distal to the splenic flexure, including the descending colon, the rectosigmoid, and the rectum. METHODS: We collected data from 5343 subjects (50-70 years old) who received 2 FITs (Hemosure; cutoff value, 10 µg hemoglobin/g feces) before colonoscopy in an invitational CRC screening program in Hong Kong from 2008 through 2012. We calculated the FIT's sensitivity, specificity, positive predictive value (PPV), and negative predictive value in detecting colorectal neoplasia. RESULTS: Of the participants, 13.6%, 12.2%, and 6.0% had distal, proximal, and synchronous distal or proximal neoplasia, respectively. Advanced neoplasia was detected in 291 subjects (5.4%); 22 (0.4%) had CRC. FIT detected distal advanced adenoma with 39.7% sensitivity (95% confidence interval [CI], 32.0%-48.0%) vs proximal advanced adenoma with 25.0% sensitivity (95% CI, 17.3%-34.6%; P = .014), distal advanced neoplasia with 40.0% sensitivity (95% CI, 32.5%-47.9%) vs proximal advanced neoplasia with 27.9% sensitivity (95% CI, 20.0%-37.4%; P = .039), and any distal adenoma ≥10 mm, irrespective of other lesion characteristics, with 39.5% sensitivity (95% CI, 31.0%-48.7%) vs. proximal adenoma with 25.3% sensitivity (95% CI, 16.5%-36.6%; P = .038). The specificity of FIT in detecting CRC was similar between the proximal and distal colon. FIT detected distal lesions with higher PPV than proximal lesions. One FIT detected advanced neoplasia with 31.8% sensitivity (95% CI, 25.9%-38.4%) and 92.4% specificity (95% CI, 91.6%-93.2%), whereas 2 FITs detected advanced neoplasia with 34.1% sensitivity (95% CI, 28.0%-40.8%; P = .617) and 91.9% specificity (95% CI, 91.0%-92.7%; P = .327). FIT detected distal advanced neoplasia with greater sensitivity and higher PPV than proximal advanced neoplasia. CONCLUSIONS: In an analysis of data from subjects who underwent CRC screening in Hong Kong, FIT detected distal advanced neoplasia with higher sensitivity than proximal advanced neoplasia. Analysis of 1 vs 2 specimens by FIT identified advanced neoplasia with similar test characteristics.

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.

A study of the clinical and biochemical profile of peritoneal dialysis fluid low in glucose degradation products.

OBJECTIVE: Although peritoneal dialysis (PD) is a widely accepted form of renal replacement therapy, concerns remain regarding the bioincompatible nature of standard PD fluid (PDF). Short-term studies of new biocompatible PDFs low in glucose degradation products (GDPs) reveal divergent results with respect to peritoneal integrity. METHODS: We studied 125 patients on maintenance PD who were assigned, by simple randomization, to receive either conventional or low-GDP PDF at PD initiation. Parameters of dialysis adequacy and peritoneal transport of small solutes were determined at initiation and after a period of maintenance PD at the time when serum and overnight effluent dialysate were simultaneously collected and assayed for various cytokines, chemokines, adipokines, and cardiac biomarkers. All patients were further followed prospectively for an average of 15 months from the day of serum and effluent collection to determine patient survival and cardiovascular events. RESULTS: Patients treated with conventional or low-GDP PDF were matched for sex, age, duration of dialysis, dialysis adequacy, and incidence of cardiovascular disease or diabetes. After an average of 2.3 years of PD treatment, the weekly total and peritoneal creatinine clearance, and the total and peritoneal Kt/V were comparable in the groups. However, urine output was higher in patients using low-GDP PDF despite there having been no difference between the groups at PD initiation. Patients using low-GDP PDF also experienced a slower rate of decline of residual glomerular filtration and urine output than did patients on conventional PDF. Compared with serum concentrations, effluent concentrations of tumor necrosis factor α, hepatocyte growth factor, macrophage migration inhibitory factor, interleukins 8 and 6, C-reactive protein, and leptin were found to be higher in both groups of patients after long-term PD, suggesting that the peritoneal cavity was the major source of those mediators. Compared with patients on low-GDP PDF, patients on conventional fluid showed elevated leptin and reduced adiponectin levels in serum and effluent. The effluent concentration of interleukin 8 was significantly lower in patients using low-GDP PDF. The survival rate and incidence of cardiovascular complications did not differ between these groups after maintenance PD for an average of 3.6 years. CONCLUSIONS: It appears that low-GDP PDF results in an improvement of local peritoneal homeostasis through a reduction of chronic inflammatory status in the peritoneum.

The acetyl-coenzyme A carboxylase beta (ACACB) gene is associated with nephropathy in Chinese patients with type 2 diabetes.

BACKGROUND: A single-nucleotide polymorphism (SNP), rs2268388, in the acetyl-coenzyme A carboxylase beta (ACACB) gene is associated with susceptibility to type 2 diabetic nephropathy (T2DN) in Japanese and European-American populations. Whether this association also exists in Chinese patients is unclear. Attempts at replication in small Singaporean and Korean samples were not significant. METHODS: Eight ACACB SNPs were genotyped in 595 subjects with type 2 diabetes mellitus born in Hong Kong or southern China, 295 with advanced T2DN and 300 with long-standing diabetes lacking nephropathy. Association analyses were focused primarily on SNP rs2268388 and secondarily on flanking SNPs and haplotypes. RESULTS: Adjusting for age, gender and diabetes duration, ACACB SNP rs2268388 was significantly associated with advanced T2DN (odds ratio = 2.39; recessive model; P = 0.0129). CONCLUSION: These results in the Chinese replicate the association between T2DN and rs2268388, as seen in Japanese and European Americans. The ACACB gene and attendant alterations in fatty acid oxidation may play important roles in susceptibility to T2DN. Targeting this pathway may provide novel treatment options for the prevention of diabetic nephropathy.

Long-term study of mycophenolate mofetil treatment in IgA nephropathy.

Since the efficacy of mycophenolate mofetil (MMF) to treat immunoglobulin A (IgA) nephropathy is controversial, we extended our original study by following 40 Chinese patients with established IgA nephropathy for 6 years. All patients were maintained on their angiotensin blockade medication and half were randomized to receive MMF for 6 months. After 6 years, 11 patients required dialysis (2 from the MMF and 9 from the control group). Significantly, only 3 treated (as compared to 10 control) patients reached the composite end point of serum creatinine doubling or end-stage renal disease. Linear regression showed the annualized decline in the estimated glomerular filtration rate was significantly less in the MMF-treated group. Urinary protein excretion and the albumin-to-creatinine ratio were lower with MMF treatment during the first 24 months, beyond which there was no difference between groups. Multivariable Cox regression analysis showed that the baseline estimated glomerular filtration rate and proteinuria, and change in the urine albumin-to-creatinine ratio at 1 year to be important predictors of progression to end-stage renal disease. We found that among Chinese patients with IgA nephropathy who had mild histologic lesions and persistent proteinuria despite maximal angiotensin blockade, MMF treatment may result in transient and partial remission of proteinuria in the short-term and renoprotection in the long-term.

Prophylaxis against gram-positive organisms causing exit-site infection and peritonitis in continuous ambulatory peritoneal dialysis patients by applying mupirocin ointment at the catheter exit site.

OBJECTIVE: We evaluated the effectiveness of local application of mupirocin ointment at the catheter exit site in preventing exit-site infection and peritonitis attributable to gram-positive organisms in continuous ambulatory peritoneal dialysis patients. METHODS: This prospective randomized controlled trial included 154 patients. They were randomly allocated to a mupirocin-treated group (group M) and a control group (group C). Group M included 73 patients (47.4%) who were instructed to apply mupirocin ointment to the catheter exit site once daily after the routine daily exit-site dressing. Group C included 81 patients (52.6%) who continued their usual daily exit-site care without applying mupirocin. The two groups were followed to see whether there would be any difference in the frequency of exit-site infection and peritonitis or in the infecting organisms. RESULTS: Interim data were collected at 5 months after the start of the study. Those data showed a significantly lower incidence of exit-site infection and peritonitis attributable to gram-positive organisms in group M as compared with group C. The incidence of gram-positive exit-site infection in group C was 1 episode per 36.8 patient-months; in group M, the incidence was 1 episode per infinity patient-months (0 incidence in 5 months, p < 0.05). The incidence of gram-positive peritonitis in group C was 1 episode per 40.5 patient-months; in group M, the incidence was 1 episode per 365 patient-months (p < 0.05). Mupirocin treatment had no significant effect on the incidence of exit-site infection and peritonitis attributable to other organisms. Before mupirocin treatment, we saw a trend toward higher infection rates in diabetic patients and nasal carriers of Staphylococcus aureus as compared with non diabetic patients and nasal non carriers, although the differences were not statistically significant. Mupirocin brought the infection rate attributable to gram-positive organisms to an equally low level in diabetic and non-diabetic patients, and in nasal carriers and nasal non carriers of S. aureus. No adverse effect of local application of mupirocin was reported. CONCLUSION: Local application of mupirocin ointment at the catheter exit site is a safe and effective method of preventing exit-site infection and peritonitis involving gram-positive organisms.