Analysis of peritoneal macrophages in continuous ambulatory peritoneal dialysis patients

Peritoneal macrophages (PMC) from patients undergoing continuous ambulatory peritoneal dialysis (CAPD) were compared to peritoneal macrophages from healthy volunteers and to peritoneal blood monocytes (PBM) from CAPD patients, hemodialysis patients, and healthy volunteers. PMC from CAPD patients had morphology similar to PMC and PBM from healthy volunteers. HLA-DR antigen and Fc receptors were present on the cell surface. These monocytes had similar sequential morphologic changes in long-term culture compared to PBM from healthy volunteers. Phagocytosis, hydrogen peroxide generation and bactericidal activity were the same in PMC from CAPD patients as in PBM from healthy volunteers. Chemotaxis and eicosanoid precursor uptake studies suggest that PMC from CAPD patients may be relatively immature bone-marrow-derived cells. Although these cells function well as phagocytes, further study is warranted to define their immune competence, many components of which develop during differentiation into mature macrophages and may therefore be deficient in patients undergoing CAPD.