Predictors of culture-negative peritoneal dialysis-associated peritonitis: a single center, retrospective study

Abstract Background Empirical antibiotic treatment against peritoneal dialysis (PD)-related peritonitis should be immediately initiated before PD effluent culture results are obtained. As culture results guide the choice of antibiotics, culture-negative peritonitis (CNP) is a serious issue. In addition, the identification of the causative organism often indicates a possible source of infection. This study aimed to clarify the predictors of CNP. Methods This single-center, retrospective study was conducted from November 2007–December 2018 in patients undergoing PD with peritonitis at our institution, where 204 peritonitis episodes (57 culture-negative, 147 culture-positive) were investigated based on demographics, and clinical parameters. CNP predictors were investigated using logistic regression. Results CNP rate was significantly higher in female and in patients with higher platelet counts, lower dialysate cell counts at peritonitis diagnosis, and higher serum β 2 -microglobulin levels. In multivariate logistic regression, female sex (odds ratio [OR] 2.69, 95% confidence interval [CI] 1.31–5.54), dialysate cell count at diagnosis (OR0.99, 95% CI 0.99–0.99), and serum β 2 -microglobulin level (OR 1.04, 95% CI 1.00–1.07) were significantly associated with CNP. The areas under the receiver operating characteristic curve for female patients, dialysate cell counts at diagnosis of peritonitis, serum β 2 -microglobulin level, and female patients + dialysate cell counts at diagnosis of peritonitis + serum β 2 -microglobulin level were 0.604, 0.694, 0.603, and 0.751, respectively. Conclusions Female sex, dialysate cell counts at peritonitis diagnosis, and serum β 2 -microglobulin levels may be predictors of CNP.