Cytology of peritoneal fluid from patients on continuous ambulatory peritoneal dialysis

Peritoneal fluids from 41 patients on continuous ambulatory peritoneal dialysis (CAPD) were examined. The patients were divided into a short-term group (18 patients with CAPD up to one year) and a long-term group (23 patients with CAPD for one to seven years). Peritoneal fluids from a control group, consisting of ten nondialysis patients with ascites, were also examined. The cellular background of the peritoneal fluids and, in particular, the morphology of the mesothelial cells were studied. The following were found to be significantly increased in the CAPD groups: background lymphocytes, mesothelial exfoliation in three-dimensional clusters, mesothelial nuclear size and the number of mesothelial nucleoli. All of these features increased slightly with an increased duration of the dialysis. These findings emphasize that peritoneal dialysis of any duration can induce significantly atypical changes in mesothelial cells.