Text Box: EXPRESSION OF MEMBRANE COMPLEMENT REGULATORY PROTEIN ON THE SURFACE OF CD16+ MONOCYTE / MACROPHAGE IN THE BLOOD OF PATIENTS WITH GLOMERULONEPHRITIS Li Hongxiang, Zhang JY, Sun NZ Jinan General Military Hospital, Jinan, China Objective: To investigate the expression of membrane cofactor protein (MCP),decay accelerating factor (DAF) and homologous restriction factor-20 (HRF-20) on CD16+ monocyte/macrophage (Mo/MΦ) in patients with glomerulonephritis (GN) . Methods: We tested the expression levels of MCP, DA F and HRF-20 on the surface of CD16+ Mo/MΦby Flow Cytometry and the levels of serum C3d by ELISA in 136 patients with GN , divided into mini-change (MC), glomerulosclerosis (GS), membranous nephropathy (MN) and proliferative glomerulonephritis (PGN) . Results: The expressions of MCP, DAF and HRF-20 on the surface of CD16+ Mo/MΦand the serum levels of C3d and C3d-IC in the patients with GS, MN or PGN were significantly higher than those in controls. There was a significant positive correlation between the expression of MCP, DAF and HRF-20 on the surface of CD16+ Mo/MΦand the serum level of C3d in the patients with GS ,MN or PGN. Conclusions: The expression of MCP, DAF and HRF-20 on the surface of CD16+Mo/MΦis significantly up-regulated by serum C3d in the patients with GS, MN or PGN, protecting CD16+Mo/MΦfrom activated complement . CD16+ Mo/MΦcan infiltrate and result in pro-inflammation effect on the kidneys , taking part in the initiation and progression of GN. 2368