Concentration of Adipokines in Peritoneal Effluent: A New Marker of Acute Peritonitis in Peritoneal Dialysis Patients?

Abstract

An early and reliable diagnostic procedure for acute peritonitis in patients on peritoneal dialysis (PD) without typical clinical symptoms remains an important challenge in modern nephrology. During the first days of peritonitis, establishing the diagnosis based on peritoneal effluent pleocytosis and inflammatory markers [C-reactive protein (CRP) or interleukin-6] is not efficient in all cases. Increased peritoneal membrane permeability is a well-known consequence of peritonitis. Therefore, we evaluated the concentrations of selected circulating adipose tissue-derived proteins in the peritoneal effluent of PD patients with episodes of acute peritonitis. Concentrations of adiponectin and leptin, in both plasma and peritoneal effluent, were assessed in 24 adult PD patients with peritonitis episodes confirmed by clinical symptoms and/or microbiological tests, and in 23 PD patients without signs and symptoms of inflammation (control group). In peritoneal effluent collected from patients with acute peritonitis (also without pleocytosis or increased CRP), both adiponectin and leptin concentrations were markedly elevated: adiponectin 744.1 (344.2 - 1144.1) ng/mL vs 4.8 (3.1 - 6.5) ng/mL; leptin 16.3 (9.4 - 23.1) ng/mL vs 5.1 (0.5 - 9.6) ng/mL. Receiver operating characteristic analyses revealed that peritoneal effluent adiponectin concentration >180 ng/mL has 100% sensitivity and 100% specificity, while peritoneal effluent leptin concentration >11.0 ng/mL has 58.3% sensitivity and 95.5% specificity for the diagnosis of acute peritonitis. The increases in adiponectin and leptin concentrations in peritoneal effluent were not consequences of changes in their plasma levels. A positive correlation between peritoneal effluent and plasma concentrations of adiponectin and leptin in patients with peritonitis was found. Increased concentration of leptin and especially adiponectin in peritoneal effluent seems to be a valuable and new early marker of high peritoneal membrane permeability due to acute peritonitis.