Expression Of CD80 And CD86 On Peripheral Blood Lymphocytes In Patients With Systematic Lupus Erythematosus

Objective In systemic lupus erythematosus (SLE) autoantibody production is antigen driven and T cell dependent. Activation of T cells requires signalling through costimulatory molecules. Of these, the CD28-CD80/CD86 pathways is well known. This study was undertaken to investigate the expression of costimulatory molecule CD80 and CD86 on peripheral blood lymphocytes(PBLC) from patients with SLE.Methods Flow cytometry and monoclonal antibodies were used to measure the expression of CD80 and CD86 on lymphocytes, CD19+ and CD19- subsets of lymphocytes in peripheral blood from 41 patients with SLE and 21 normal controls. Meanwhile anti-dsDNA antibody was detected and the SLEDAI score was calculated for each patient.Results 1. The percentages of CD80+ and CD86+ cells in PBLC from patients with SLE were significantly higher compared with normal controls(P<0.001) and no difference was observed between active group and inactive group. There were no changes in the percentages of B cells expressing CD80 and CD86 between patients and controls, while the amount of B cells,CD80+ B cells and CD86+ B cells were increased in active group(P<0.05). The percentages of non-B cells expressing CD80 and CD86 were significantly higher in both active group and inactive group than that in controls(P<0.001). 2. The amount of B cells,CD80+ B cells and CD86+ B cells in peripheral blood from patients with SLE were correlated with the SLEDAI score(r=0.364,0.360,0.353,P<0.05). The amount of CD86+ lymphocytes,CD86+ B cells and non-B cells showed positive correlation with levels of anti-dsDNA antibody in SLE patients(r=0.549,P<0.01;r=0.419,P<0.05;r=0.508,P<0.01) and were higher in patients with leukopenia than that in patients without leukopenia(P<0.01). Conclusion In patients with SLE the expression of CD80 and CD86 on PBLC are increased. CD80 and CD86 expression on non-B cells are increased but no changes on B cells. The amount of CD80+ and CD86+ B cells are associated with disease activity. CD86 expression on lymphocytes is related to autoantibody production and may be invovled in the development of leukopenia in SLE. Our findings suggest that the aberrant expression of CD80 and CD86 on PBLC may be a factor in the pathogenesis of SLE.