Lipopolysaccharide Evaluation in Peritoneal Dialysis Patients with Peritonitis.

Background:Lipopolysaccharide (LPS), also known as endotoxin, is cell wall component of Gram-negative (GN) bacteria, which may contribute to the progression of a local infection to sepsis. Previous studies demonstrate that LBP is detectable in peritoneal effluents of peritoneal dialysis (PD) patients and it is significantly elevated in PD patients with peritonitis caused by both GN and Gram-positive (GP) bacteria.Aim:The aim of this study was to evaluate LPS levels in PD patients; in particular, we investigated different LPS levels in the context of GP and GN peritonitis.Material and Methods:We enrolled 49PD (61% Continuous Ambulatory PD and 39% Automated PD) patients: 37 with peritonitis and 12 without. Quantitative determination of LPS was performed by Enzyme-linked Immunosorbent Assay Kitin peritoneal and plasma samples.Results:Quantitative analysis of peritoneal and plasma LPS showed significantly higher levels in PD patients with peritonitis compared to patients without (p= 0.001). Furthermore, we divided patients with peritonitis in 2 groups on the basis of Gram staining (GP 27; GN 12). Peritoneal and plasma LPS levels showed significantly lower levels in PD patients with GP peritonitis than in patients with GN (p= 0.001). The median level of LPS showed no significant differences between patients without peritonitis and with GP peritonitis (p= 0.195). On the contrary, LPS levels showed significantly higher levels in PD patients with GN peritonitis compared to patients without peritonitis (p= 0.001). A significant positive correlation was observed between peritoneal white blood cells count (pWBC) and peritoneal LPS (Spearman's rho = 0,412,p= 0.013). However, no statistically significant correlation was observed between plasma LPS and WBC count.Conclusion:We observed LPS presence in all PD patients. In particular, our results demonstrated that LPS is significantly elevated in PD patients with GN peritonitis. Furthermore, pWBC and LPS levels increased proportionally in PD patients with peritonitis. Peritoneal and plasma LPS levels could be a useful marker for diagnosis and management of GN peritonitis in PD patients.