Analysis of cellular populations in peritoneal effluents of children on CAPD.

The characterization of cellular populations in peritoneal effluents (PE) of CAPD patients has been the subject of few studies. In order to establish a possible correlation between PE cells and clinical parameters, we studied the immunocompetent cells that are found in uncomplicated patients. In this study we used cytofluorimetric analysis to characterize phenotypically immunocompetent PE cells. We studied 17 children with a mean age of 8.7 +/- 5.3 years, who had been on CAPD for a mean duration of 16 months. The patients never suffered from peritonitis. The effluents were collected after overnight dialysis and centrifuged to concentrate cells. Surface phenotype of PE cells was tested with a panel of monoclonal antibodies. The analysis of 40 PE samples showed that the various cell types were present with different frequencies, suggesting that a dominant phenotype cannot be defined. The ratio between M3 positive cells (monocytic-macrophagic lineage) and T3 positive cells (T lymphocytes) showed a tendency to decrease after initiation of CAPD. T4/T8 ratio in all samples did not differ from that of peripheral lymphocytes. A high frequency of activated T cells (41% +/- 13), defined by the presence of DR antigens on T3+ M3- cells, was seen in PE and confirmed by the high frequency of T cells expressing the IL-2 receptor.