CD95 EXPRESSION AND CD95-MEDIATED APOPTOSIS OF T-CELLS IN MULTIPLE-SCLEROSIS - NO DIFFERENCES FROM NORMAL INDIVIDUALS AND NO RELATION TO HLA-DR2

CD95-mediated apoptosis is a potent endogenous pathway of T cell elimi nation that has been suggested to be altered in multiple sclerosis (MS ). MS is associated with the HLA-DR2, Dw2, DQ6 HLA class II haplotype. We have previously reported that T cell lines hom HLA-DR2-positive in dividuals show enhanced production of tumor necrosis factor (TNF), a c ytokine homologous to CD95 ligand, in response to specific antigen. He re we have studied CD95 expression and susceptibility to CD95-mediated apoptosis in peripheral blood mononuclear cells (PBMC) and activated T cells of 20 healthy individuals and 20 MS patients, half of whom wer e HLA-DR2-positive. MS patients did not differ from healthy individual s in either parameter. There was also no difference in CD95 expression or CD95-mediated apoptosis when MS patients and healthy individuals w ere grouped and compared according to HLA-DR status. These data reveal no differential regulation of PBMC/T cell apoptosis induced by CD95 r eceptor ligation in MS and show no impact of HLA-DR2 status on PBMC/T cell susceptibility to the same apoptotic stimulus. However, to assess the contribution of T cell apoptosis to the pathogenesis of MS furthe r studies on other details of the complex system leading to T cell apo ptosis are required. (C) 1998 Elsevier Science B.V.