Diagnostic value of NLR and PLR for peritoneal dialysis-related infection

Objective To investigate the diagnostic and predictive value of peripheral blood neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) for peritoneal dialysis(PD)-related infection. Methods Clinical data of 71 PD patients complicated with PD related infections and 102 maintenance PD patient hospitalized in the same period were retrospectively analyzed for evaluation of peritoneal function and dialysis adequacy. The patients were divided into two groups according to occurrence of peritoneal dialysis-related infection or the best cut-off values of NLR and PLR, so as to analyze the relationship of NLR, and PLR with PD related infection. Receiver operating characteristic curve (ROC) was used to evaluate diagnostic and predictive value of NLR or PLR alone and combination between NLR and PLR for PD related infection. Results A total of 173 cases were included in the study. Spearman correlation analysis suggested, PD related infection exhibited positive correlation with NLR, PLR, white blood cell count in peritoneal dialysate and hypersensitivity C-reaction protein (hs-CRP) (all P<0.05); and had negative correlation with serum albumin, blood magnesium and blood phosphorus (all P<0.05). NLR had positive correlation with PD related infection, PLR, white blood cell count in peritoneal dialysate and hs-CRP (all P<0.05); negative correlation with blood magnesium and serum albumin (all P<0.05); and no correlation with blood phosphorus. PLE was positively correlated with PD related infection, NLR, white blood cell count in peritoneal dialysate and hs-CRP (all P<0.05); and negatively correlated with blood magnesium, blood phosphorus and serum albumin(all P<0.05). Univariate Logistic regression analysis showed, low serum albumin (OR=0.808,95% CI 0.748~0.874, P<0.001), low blood magnesium (OR=0.001,95% CI 0.000~0.015, P<0.001), low blood phosphorus (OR=0.324,95% CI 0.165~0.635, P=0.001), high hs-CRP (OR=1.246,95% CI 1.149~1.351, P<0.001), and high NLR (OR=1.570, 95% CI 1.315~1.815, P<0.001) and high PLR (OR=1.010,95% CI 1.006~1.014, P<0.001) were risk factors for PD related infection. Multivariate analysis showed that low serum albumin (OR=0.837,95% CI 0.704~0.995, P=0.043), high hs-CRP (OR=1.296,95% CI 1.149~1.461, P<0.001) and high NLR (OR=1.522,95% CI 1.055~2.195, P=0.025) were risk factors for PD-related infection. From the ROC curve, it can be seen that the sensitivity and specificity of NLR, PLR, NLR and PLR combination and hs-CRP in the diagnosis of PD-related infection were 64.8%,87.3%;53.5%, 87.3%;94.4%, 98.0%; 93.0%, 90.2%, respectively. Conclusions The levels of NLR, PLR, white blood cell count in peritoneal dialysate and hs-CRP in peritoneal dialysis patients with PD-related infection were significantly higher than those without PD-related infection, while albumin, serum magnesium and serum phosphorus were significantly decreased. High NLR, high hs-CRP and low serum albumin are risk factors for peritoneal dialysis-associated infection. In addition, the sensitivity and specificity of NLR combined with PLR in the clinical diagnosis of peritoneal dialysis-related infection were higher than those of hs-CRP.