Future expectations of diagnostic approaches for treating endogenous peritonitis in patients on peritoneal dialysis.

The Authors Reply We appreciate Dr. Windpessl M. and colleagues for their supportive comments and additional references regarding our case report (1). The phrase “the absence of evidence is not the evidence of absence,” proposed by the authors is a good suggestion for physicians investigating the cause of peritonitis in patients on peritoneal dialysis (PD). According to a recent report from the UK, “peritonitis is still the Achilles’ heel of peritoneal dialysis” (2). The routes of infection for peritonitis in PD patients primarily involve contamination during PD bag exchange, tunnel infection caused by exit-site infection and endogenous causes of peritonitis. Unfortunately, it is sometimes not possible to obtain specific findings of endogenous peritonitis, aside from the results of bacterial cultures. If bacterial cultures are negative, the appropriate opportunity for surgical intervention may be lost. In such cases, it is important for physicians to suspect peritonitis as an endogenous infection. With respect to why it is difficult to diagnose endogenous peritonitis in patients with PD, peritonitis caused by infections associated with contamination during PD bag exchange is common in PD patients (3), and clinicians must distinguish endogenous peritonitis from PD-related peritonitis. In order to decrease the incidence of contamination during PD bag exchange, education is required for both PD patients and medical staff. In the future, it may be possible to develop a surrogate biomarker for distinguishing endogenous peritonitis from contaminated peritonitis and design contamination-free PD bag exchange systems, such as completely closed bag exchange systems.