Multiple sclerosis (MS) is a multicomponent disease characterized by inflammation, neurodegeneration, and cancellation of the central nervous system recovery mechanisms. The cause of MS is still unknown, but it is undeniable that genetic, environmental and immune factors are involved in the etiopathogenesis of this complex and heterogeneous disease. From the aspect of immunopathogenesis, until recently the opinion prevailed that autoreactive T lymphocytes played a major role, the activation of which is a key step in MS. The knowledge of the effector and regulatory roles of B cells supports a new concept of MS immunopathogenesis that is based on the highly com-plex interaction of T and B cells, with B cells actively participating in cellular immunity by directing the intensity and quality of cellular immune response. The mechanisms of B cell activity in MS immunopathogenesis are multiple and include antigen presentation and T cell costimulation, cytokine secretion, antibody synthesis, and formation of ectopic lymphoid B cell aggregates in the intrameningeal spaces. The importance of B cells has been confirmed by modern therapeutic options for the treatment of MS.
Keywords: B-Lymphocytes; Immunity, Cellular; Inflammation; Multiple Sclerosis; T-Lymphocytes.