Relationship between Serial Serum Neutrophil-Lymphocyte Ratio, Cardiovascular Mortality, and All-Cause Mortality in Chinese Peritoneal Dialysis Patients.

INTRODUCTION: It is believed that the excessive cardiovascular (CV) burden of patients on peritoneal dialysis (PD) is closely associated with chronic inflammation. Neutrophil-lymphocyte ratio (NLR) is an inflammatory marker that was shown to correlate with CV outcomes. However, little is known about the significance of serial monitoring of serum NLR. We aimed to determine the prognostic value of serial NLR on all-cause mortality and CV mortality in PD patients. METHODS: Serial measurement of NLR was obtained from 225 incident PD patients in a single center, with each measurement 1 year apart. Patients were divided into two groups ("high" vs. "low") by the median value of NLR. The primary and secondary outcome measure was all-cause and CV mortality, respectively. RESULTS: After a median of follow-up for 43.9 months, patients with lower baseline NLR demonstrated a higher survival rate (p = 0.01). Patients with persistently high NLR values on serial measurement had the lowest survival rate (p = 0.03). Multivariate Cox regression showed that this group of patients had significantly higher all-cause mortality (HR: 1.74, 95% CI: 1.09-2.79, p = 0.02). However, the NLR failed to demonstrate a statistically significant relationship with CV mortality. CONCLUSIONS: While baseline NLR was an independent predictor of all-cause mortality in PD patients, persistent elevation in NLR appeared to further amplify the risk. Regular monitoring of serial serum NLR may enable early identification of patients who are at risk of adverse outcome.

The choice of comorbidity scoring system in Chinese peritoneal dialysis patients.

BACKGROUND: Several comorbidity scoring systems have been developed and validated, mostly in western hemodialysis patients with a high risk of cardiovascular disease. The performance of comorbidity scoring, however, depends on the patient population. In this study, we determine the optimal comorbidity scoring system for predicting survival of incident Chinese PD patients. METHODS: We studied 461 incident PD patients. The performance of Charlson Comorbidity Index (CCI), Hemmelgarn score, and Liu score as the survival predictor was compared. RESULTS: The mean age was 57.7 ± 13.7 years. The median CCI, Hemmelgarn, and Liu scores were 4 [inter-quartile range (IQR) 2-5], 1 (IQR 0-2), and 4 (IQR 2-5), respectively. Patients were followed for 45.5 ± 33.0 months. All 3 comorbidity scores were predictors of patient survival by univariate analysis. After adjusting for confounding factors, CCI was the best predictor of patient survival among the 3 indices, with each point increase in CCI conferring 31% excess in mortality risk [95% confidence interval (CI) 21-41%, p < 0.001]. In contrast, each point increase in Liu score confers 20% excess in mortality risk (95% CI 13-27%, p < 0.001). Although the Hemmelgarn score is an independent predictor of patient survival, over 70% of patients score 0 or 1 by this system, limiting its role as a prognostic marker. CONCLUSION: CCI should be the preferred method for quantifying comorbidity load in incident Chinese PD patients, and it is a good predictor of survival in this group of patients.

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.

Treatment of Enterococcal Peritonitis in Peritoneal Dialysis Patients by Oral Amoxicillin or Intra-Peritoneal Vancomcyin: a Retrospective Study.

BACKGROUND/AIMS: Enterococcal peritonitis in peritoneal dialysis (PD) patients is associated with a high complication rate. The optimal treatment regimen of PD-related enterococcal peritonitis is controversial. The latest international guideline recommends intra-peritoneal (IP) vancomycin. Although ampicillin is often effective for systemic enterococcal infections, they have little in vitro activity when added to common PD solutions. Since oral amoxicillin achieves therapeutic drug level in the peritoneal cavity, we explore the efficacy of oral amoxicillin for enterococcal peritonitis. METHODS: We studied 105 episodes of enterococcal peritonitis over 20 years in our unit; 43 (41.0%) were treated with oral amoxicillin, and 62 (59.0%) with IP vancomycin. Their clinical outcome was reviewed. RESULT: The overall primary response rate to oral amoxicillin and IP vancomycin was 76.4% and 85.5%, respectively (p = 0.3). The complete cure rate of oral amoxicillin and IP vancomycin was 55.8% and 54.8%, respectively (p = 0.8). When the 5 episodes of ampicillin-resistant Enterococcus episodes were excluded, the primary response rate and complete cure rate of oral amoxicillin were 86.8% and 63.2%, respectively. CONCLUSION: Oral amoxicillin has an excellent primary response rate and complete cure rate for PD-related peritonitis episodes caused by Enterococcus species, indicating that oral amoxicillin is a valid and convenient therapeutic option for enterococcal peritonitis episodes.

Asymptomatic fluid overload predicts survival and cardiovascular event in incident Chinese peritoneal dialysis patients.

BACKGROUND: Fluid overload is common among asymptomatic peritoneal dialysis (PD) patients. We aim to determine the prevalence and prognostic significance of fluid overload, as measured by bioimpedance spectroscopy, in asymptomatic incident PD patients. METHODS: We performed a single-center study on 311 incident PD patients. Volume status was represented by the volume of overhydration (OH), OH/extracellular water (ECW) ratio, ECW/total body water (TBW) ratio, and ECW to intracellular water (ICW) ratio (E:I ratio). Patient survival, technique survival and cardiovascular event-free survival were determined. RESULTS: The median period of follow up was 27.3 months. Fluid overload was present in 272 patients (87.5%) when defined as OH volume over 1.1L. All hydration parameters significantly correlated with Charlson Comorbidity Index, and inversely with total Kt/V, and serum albumin. Multivariate cause-specific Cox analysis showed that volume status independently predicted patient survival; every 0.1 unit increase in E:I ratio was associated with 24.5% increase in all-cause mortality (adjusted cause-specific hazard ratio [ACSHR] 1.245, p = 0.002). Hydration status was also an independent predictor of cardiovascular event-free survival after excluding hospital admission for congestive heart failure; each 0.1 unit increase in E:I ratio was associated with 18.7% decrease in cardiovascular event-free survival (ACSHR 1.187, p = 0.011). In contrast, hydration parameters were not associated with technique survival. CONCLUSIONS: Fluid overload is common in asymptomatic incident PD patients and is a strong predictor of patient survival and cardiovascular event. The impact of bioimpedance spectroscopy-guided fluid management on the outcome of PD patients deserves further study.

Urinary mitochondrial DNA level in non-diabetic chronic kidney diseases.

BACKGROUND: Mitochondrial dysfunction plays an important role in the pathogenesis and progression of chronic kidney disease (CKD). We study the relation between urinary mitochondrial DNA (mtDNA) levels and renal dysfunction in non-diabetic CKD. METHODS: We recruited 32 CKD patients (20 had hypertensive nephrosclerosis, 12 had IgA nephropathy). Urinary supernatant mtDNA level was measured and compared to baseline clinical and pathological parameters. The patients were followed 57.8 ±â€¯30.5 months for renal function decline. RESULTS: The average urinary supernatant mtDNA level was 222.0 ±â€¯210.3 copy/µL. There was a modest but significant correlation between urinary mtDNA level and proteinuria (Spearman's r = 0.387, p = 0.035), but not any other baseline clinical or pathological parameter. Urinary mtDNA level had a significant inverse correlation with the slope of GFR decline (r = -0.402, p = 0.023). Urinary mtDNA level is a predictor of renal survival even after adjusting for baseline proteinuria with multivariate Cox analysis. In this model, every increase in urinary mtDNA by 100 copy/µL confers a 25.0% increase in risk of doubling of serum creatinine or need of dialysis (95%CI, 0.7% to 55.1%). CONCLUSION: Mitochondrial DNA is readily detectable in the urinary supernatant of non-diabetic CKD, and its level correlates with the rate of renal function decline and predicts the risk of doubling of serum creatinine or need of dialysis. Further studies are needed to determine the value of urinary supernatant mtDNA level as a prognostic indicator of non-diabetic CKD.

Peritoneal dialysis-related peritonitis caused by Pseudomonas species: Insight from a post-millennial case series.

BACKGROUND: Pseudomonas peritonitis is a serious complication of peritoneal dialysis (PD). However, the clinical course of Pseudomonas peritonitis following the adoption of international guidelines remains unclear. METHODS: We reviewed the clinical course and treatment response of 153 consecutive episodes of PD peritonitis caused by Pseudomonas species from 2001 to 2015. RESULTS: Pseudomonas peritonitis accounted for 8.3% of all peritonitis episodes. The bacteria isolated were resistant to ceftazidime in 32 cases (20.9%), and to gentamycin in 18 cases (11.8%). In 20 episodes (13.1%), there was a concomitant exit site infection (ESI); in another 24 episodes (15.7%), there was a history of Pseudomonas ESI in the past. The overall primary response rate was 53.6%, and complete cure rate 42.4%. There was no significant difference in the complete cure rate between patients who treated with regimens of 3 and 2 antibiotics. Amongst 76 episodes (46.4%) that failed to respond to antibiotics by day 4, 37 had immediate catheter removal; the other 24 received salvage antibiotics, but only 6 achieved complete cure. CONCLUSIONS: Antibiotic resistance is common amongst Pseudomonas species causing peritonitis. Adoption of the treatment guideline leads to a reasonable complete cure rate of Pseudomonas peritonitis. Treatment with three antibiotics is not superior than the conventional two antibiotics regimen. When there is no clinical response after 4 days of antibiotic treatment, early catheter removal should be preferred over an attempt of salvage antibiotic therapy.

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.