Expression of Fas antigen on T cell subpopulations in peripheral blood of patients with relapsing-remitting multiple sclerosis.

ABSTRACT

BACKGROUND: During the relapse of multiple sclerosis, the activation of T cells, autoreactive to myelin antigens in blood, enhanced and maintained as a result of anomalous mechanisms of their earlier elimination, leads on para- and autocrine basis to the activation of antigen- non-specific cells of immune system. In consequence, activated cells secrete a range of proinflammatory cytokines and display activation antigen expression on their surface, which results in blood-brain barrier damage. The differentiation of lymphocytes into effector cells in blood during MS relapse is to increase the number of cells supporting inflammatory reactions and simultaneously to reduce the number of cells which play a role of suppressors. Fas antigen is present among activation antigens found on T cells. Once this antigen has been combined with the ligand, it transmits apoptic signal to the cell. The presence of Fas antigen on activated peripheral blood T cells may enable us to estimate their activation and it may also indicate a potential to eliminate those cells from blood. The aim of the study was to provide a quantitative assessment of the subpopulations of CD3, CD4 and CD8 lymphocytes in peripheral blood and to investigate Fas antigen expression on these subsets in patients with relapsing-remitting multiple sclerosis, in relation to clinical activation of the disease. MATERIAL AND METHODS: Thirty-five patients participated in the study, including 14 patients finding themselves in clinical relapse of the disease and 21 patients in the state of remission. Additionally, 21 healthy subjects were included. Quantitative assessment of individual subpopulations and Fas co-expression was carried out with the use of monoclonal antibodies anti CD3, CD4 and CD8 as well as anti CD95 antibodies, and flow cytometer Pas/Dako Galaxy. RESULTS: The differences in the percentage of particular lymphocytes between 3 groups proved insignificant. Patients in the relapse of the disease showed significantly greater Fas expression on subpopulations CD3 and CD4 when compared to the results obtained from remission patients and control subjects. This difference was not observed for Fas expression on subset CD8. CONCLUSIONS: The investigation of Fas receptor expression may be useful in order to monitor clinical course of the disease, which is characterised by the periods of exacerbation and remission.