Epidemiology of culture-negative peritonitis in Iranian patients on continuous ambulatory peritoneal dialysis.

INTRODUCTION Culture-negative peritonitis is a major challenge in the treatment of peritonitis in continuous ambulatory peritoneal dialysis (CAPD). This study aimed to evaluate the culture-negative peritonitis in patients from the Iranian CAPD Registry. MATERIALS AND METHODS Data of 1472 patients from 26 CAPD centers were analysed. Peritonitis was defined as any clinical suspicion together with peritoneal leukocyte count of 100/mL and more. RESULTS The patients had been on PD for a mean of 500 ± 402 days. There were a total of 660 episodes of peritonitis observed among 299 patients (peritonitis rate of 1 episode in 34.1 patient-months). Excluding patients with both negative and positive culture results, there were 391 episodes of peritonitis in 220 patients (174 culture-positive episodes in 97 patients and 217 culture-negative episodes in 123). The 1- to 4-year patient survival rates were 85%, 75%, 69%, and 59% for the patients with culture-positive peritonitis, and 92%, 78%, 73% and 63% for the patients with culture-negative peritonitis, respectively (P = .34). The technique survival rates were 90%, 57%, 42%, and 27% and 95%, 85%, 74%, and 40%, respectively (P = .001). On follow-up, there were higher rates of active PD patients, lower rates of PD dropouts, and higher rates of kidney transplantation in patients with culture-negative peritonitis compared to those with culture-positive peritonitis. CONCLUSIONS In our patients, the prevalence of culture-negative peritonitis was high (55.9%). Patient survival with culture-negative peritonitis was comparable to those with culture-positive peritonitis and technique survival was higher among those with culture-negative peritonitis.