In vivo activated peripheral T cells in autoimmune disease.

Starting from the observation, if that in patients suffering from inflammatory bowel diseases elevated numbers of activated peripheral immunocytes can be detected in correlation to the activity of the disease, subpopulations of lymphocytes in immune-mediated disorders were analyzed for the expression of activation associated antigens. It was found that in patients with immunovasculitis, sarcoidosis, M. Behçet, multiple sclerosis, antibody-mediated hemophilia, SLE,--but not in those with scleroderma--, increased numbers of activated immunocytes could be detected during acute exacerbation, whereas, in remission, the population of activated immunocytes was in the upper normal range. Analyses of phenotypes revealed that the majority of activated immunocytes are T cells. However, a variable minority of cells bear B cell associated determinants. As is the case in total peripheral T cells, the T4 to T8 ratio was in a normal range. Only in Behçet disease and immunovasculitis was the ratio of activated T4 positive to activated T8 positive lymphocytes found to be decreased. In contrast to T cells in patients with inflammatory bowel disease, the majority of activated T cells in the autoimmune disorders under study does not express Fc alpha-receptors. In Behçet disease and immunovasculitis moreover, the incidence of activated Leu 7 positive (= natural killer) cells is low compared to T cells from patients with Crohn's disease or ulcerative colitis. These experiments lead to the conclusion that the assessment of activated immunocytes may serve as a parameter in the evaluation of the clinical activity of autoimmune diseases.(ABSTRACT TRUNCATED AT 250 WORDS)