Expansion of CD14+CD16+blood monocytes in patients with chronic renal failure undergoing dialysis: Possible involvement of macrophage colony-stimulating factor

A novel subpopulation of blood monocytes coexpressing CD16 antigen and low levels of CD14 antigen (CD14+CD16+ monocytes) has recently been identified, and expansion of these CD14+CD16+ monocytes has been reported under some p athological conditions. In this study, we examined the immunophenotype of b lood monocytes in patients with chronic renal failure (CRF) who were underg oing hemodialysis (HD, n = 52) or continuous ambulatory peritoneal dialysis (CAPD, n = 36) using two-color immunofluorescence flow cytometry, The perc entage and absolute number of CD14+CD16+ monocytes were significantly highe r (p < 0.001) in both HD and CAPD patients compared with those in healthy c ontrol subjects, We also determined the plasma concentrations of hematopoie tic growth factors and cytokines using an enzyme-linked immunosorbent immun oassay. The plasma levels of macrophage colony-stimulating factor (M-CSF) w ere markedly increased in both HD and CAPD patients relative to the normal controls. The plasma M-CSF levels correlated significantly with the number of CD14+CD16+ monocytes in the whole group of subjects. These findings sugg est that elevated endogenous M-CSF levels may participate in the expansion of CD14+CD16+ monocytes in CRF patients undergoing dialysis. Copyright (C) 2001 S. Karger AG. Basel.