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