[Flow cytometric analysis of mesothelial cells in peritoneal dialysis effluent]

According to recent reports, deformity and size of mesothelial cells reflect mesothelial condition. We applied flow cytometry (FCM) to the analyzation of mesothelial cells in peritoneal dialysis effluent (PDE) and the relationship between the period of peritoneal dialysis (PD) and peritoneal function. Eighteen patients treated for two to 89 months by PD were selected. Their dialysate: plasma creatinine ratio (D/P creatinine)was 0.67 +/- 0.086 (0.53 to 0.87). Overnight PDE was drained and centrifuged. The cell population of peritoneal cells identified by anti-cytokeratin, CD14 and 45 antibodies was studied by FCM. Cytokeratin positive cells were identified as mesothelial cells, distinct from macrophages, granulocytes or lymphocytes. The forward scatter (FSC) of cytokeratin positive cells, fluorescence intensity of cytokeratin and percentage of cytokeratin-positive cells in PDE were 395.6 +/- 55.5 (298.31 to 527.72), 333.9 +/- 272.9 (67.55 to 1,071.95), and 6.75 +/- 6.1% (0.44 to 21.14), respectively. There was a positive correlation between D/P creatinine and FSC, and a negative correlation between D/P creatinine and cytokeratin fluorescence intensity or the percentage of cytokeratin positive cells. However, there was no correlation between the period of PD and FSC, cytokeratin fluorescence intensity or the percentage of cytokeratin-positive cells. It was suggested that the alteration of mesothelial cells is not necessarily influenced by the period of PD, but influences peritoneal function. It was found that the analysis of cell population by FCM reflects the morphological and functional changes in the peritoneum of patients on PD.