Neutrophil gelatinase-associated lipocalin in peritoneal dialysis reflects status of peritoneum.

Background: Ultrafiltration failure and peritonitis are the most important limitations of peritoneal dialysis (PD). The aim of our study was to evaluate peritoneum damage through neutrophil gelatinase-associated lipocalin (NGAL), white blood cell (WBC) count and cancer antigen 125 (CA125). 
Patients and methods: Thirty patients with peritonitis and 30 patients undergoing continuous ambulatory peritoneal dialysis (CAPD) were studied for 12 months. In the peritonitis group, blood samples and peritoneal fluid (lp) were collected before the onset of peritonitis, at the onset of peritonitis (T1) and every day until its resolution. CAPD patients were divided into 3 groups according to the treatment received. Long-dwell effluents were collected for NGAL, WBC count and Ca125 assessment.
Results: In the peritonitis group, at time T1, NGAL levels were higher compared with baseline values. lpNGAL levels decreased at least 24 hours earlier than peritoneal WBC (lpWBC). At ROC analysis, lpNGAL was characterized by a very good diagnostic profile identifying treatment failure. In CAPD patients, the highest NGAL values were observed in the icodextrin group. An inverse correlation between lpNGAL, pKt/V and peritoneal ultrafiltration volume was also found. 
Conclusion: Mesothelial cells have an active role in the structural and functional alteration of the peritoneum during PD, and NGAL represents a valid biomarker for peritoneum evaluation.