A possible role of apoptosis for regulating autoreactive responses in systemic lupus erythematosus

Abstract

It has been reported that apoptotic cells are increased inthe peripheral blood from patients with systemic lupuserythematosus (SLE), where dysfunctions of T helper 1 (Th1) cells are known. In order to study whether apoptosis of Th1cells is associated with the pathogenesis of SLE, earlyapoptotic cells in various T-cell subsets were detected using fluorescence-labeled annexin V (AnV). AnV binding was most frequently observed in CD4/CCR5/ T cells, andAnV binding rate (%) in this subset was higher in SLE thanin normal controls (14.7 2.6), although that in activeSLE(43.6 7.3) tended to be lower than that in inactive SLE (48.0 6.8). CD95=Fas expression was also increased i both active and inactive SLE. In some SLE patients, AnV binding rate changed in inverse proportion to titer of the serum anti-DNA antibody and in proportion to serum complement activity. These data suggest that apoptosis in Th1 cells is important in the pathogenesis of SLE and might play arole in regulating over-activation or autoreactive responses by T cells.