RESUMEN
1] Measure the percentage of membrane cofactor protein [MCP, CD46] expression on mononuclear cells. 2] Evaluate its role in the pathogenesis of systemic lupus erythematosus [SLE]. 3] Correlate it with disease activity or activated complement system. Thirty Egyptian SLE patients [27 females and 3 males] were enrolled in this study. All of them were subjected to thorough clinical examination and laboratory tests including complete blood picture, ESR, serum C3 and C4, serum creatinine, in addition to complete urine analysis and estimation of the percentage of MCP expression on monocuclear cells using flowcytometry. Ten normal healthy subjects were included as a control group. They were matched for age and sex with SLE patients. The percentage of MCP expression differentiated lupus patients from the control subjects and the difference was statistically highly significant [p<0.0001]. Moreover, MCP expression correlated with SLE disease activity scores [r=0.82], and with the parameters of renal damage such as serum creatinine [r=0.33] and serum C3 [r=-0.55]. This might implicate its role as an important indicator for active evolution of SLE as well as in the pathogenesis of lupus nephritis. This study suggests a role of MCP as a useful marker in evaluating SLE activity and a possible therapeutic implicator as a complement inhibitor in SLE patients