A contribution of B cells and autoantibodies has been demonstrated in MS leading to interest in the use of such autoantibodies as diagnostic or prognostic markers and as a basis for immunomodulatory therapy. ELISA and Western fail to detect reactivity against epitopes displayed by native antigens expressed on myelin sheats. We describe a cell-based assay that specifically identifies serum antibodies directed against three major myelin autoantigens: MBP, PLP and MOG. The method detects antibody binding to recombinant antigens in their native conformation on MBP, PLP and MOG transfected mammalian (hamster ovary) cells. 36 patients with relapsing-remitting MS diagnosed according to criteria of McDonald were recruited. Age 38.2 and duration of the disease 7.1. Serum anti-MBP, anti-PLP and anti-MOG IgG autoantibodies were detected in MS patients and 35 healthy donors by FACS analysis. Compared with healthy controls the titres of IgG autoantibodies directed against membrane-bound recombinant myelin antigens were most significantly increased for PLP, no quite significant for MBP and not significant for MOG. The titres of anti-MBP antibodies were low in contrast to high titre of anti-MOG antibodies in both groups suggesting a nonspecific binding. The cell-based assay detection of autoantibodies directed against recombinant myelin antigens could be a useful tool providing the serological markers in diagnosis and progression of MS. Indeed, it could allow obtaining molecular characteristics of disease in each patient in term of an antibody response against certain myelin and non-myelin antigens. We have shown that in RRMS patients elevated level of serum antibodies against PLP is significant, what should be considered in search for specific immunomodulatory therapy in MS.