Phenotypic characterization of monocytes and macrophages from CAPD patients

The purpose of this study was to phenotypically characterize and compare peripheral blood monocytes from CAPD patients with peritoneal macrophages isolated from their peritoneal dialysis effluents. Monocytes/macrophages were labeled with fluorescent ligands or monoclonal antibodies specific for 1) receptors for C5a, formyl-met-leu-phe (fMLP); Fc region of IgG; C3b (CR1); and C3bi (CR3), 2) Class II histocompatibility antigens HLA-DR and HLA-DQ; and 3) monocyte/macrophage surface antigen CD14. The cells were analyzed using flow cytometry. Results indicated that there were no differences between monocytes and peritoneal macrophages in their receptor expression for fMLP, CR1, or CR3. However, paired t-testing indicated that peritoneal macrophages had significantly increased expression of Fc and C5a receptors, as well as enhanced antigen expression of HLA-DR, HLA-DQ, and CD14. These results suggest that peritoneal macrophages from CAPD patients are activated with increased expression of receptors and antigens important in host defense.