Incidence and significance of peritoneal eosinophilia during peritoneal dialysis-related peritonitis.

To determine the incidence and significance of peritoneal eosinophilia (PEo) during peritoneal dialysis (PD)-related peritonitis. Retrospective observational study. Tertiary-care public hospital. We performed a cytological study of dialysate at the start of 465 cases of peritonitis diagnosed between January 1987 and May 2002. Cases associated with PEo (> 10% eosinophils) were classified according to their infectious or seemingly noninfectious origin. We compared the two groups, trying to disclose differentiating patterns of presentation. We found PEo in 42 cases. Infectious peritonitis was the final diagnosis in 22 of the 42 cases; a diagnosis of idiopathic eosinophilic peritonitis was finally established in 20 cases. The etiologic spectrum of infectious peritonitis with PEo did not differ markedly from the global spectrum of peritonitis in our unit. Infectious peritonitis with PEo tended to appear later in the course of PD therapy, presented with more severe clinical symptoms, displayed higher total peritoneal leukocyte and neutrophil counts, and showed lower degrees of PEo than idiopathic eosinophilic peritonitis, but overlap between the groups was significant. Peritoneal eosinophilia is infrequent but not rare during infectious PD-related peritonitis. Our findings agree with established concepts on idiopathic eosinophilic peritonitis, but overlap in presentation with infectious eosinophilic peritonitis is significant, which should be taken into consideration at the time of planning therapy for this condition.