Abstract: Objective To investigate the expression of costimulatory molecules CD80 and CD86 on peripheral blood lymphocytes(PBLC)in patients with systemic lupus erythematosus(SLE)and its significance.Methods The expression of CD80 and CD86 on PBLC was measured by flow cytometric assay in 30 patients with SLE and 25 normal controls.Results Expression of CD86 on PBLC in patients with SLE was significantly lower than that of normal controls(P<0.01).No significant difference was observed between SLE patients and normal controls in CD80 expression.There was no difference of expression of CD80 and CD86 on PBLC between SLE patients with and without renal disease.The CD80 and CD86 levels of active SLE patients were similar to that of inactive SLE patients and were not correlated with the SLEDAI scores,ANA titers,IgG and C3 serum levels.Conclusion The expression of CD86 on PBLC in SLE patients was decreased,which may be related to the pathogenesis of SLE.

Key words: Lupus erythematosus,systemic, Antigens,CD80, Antigens,CD86