[THE MECHANISMS OF ACTION OF RITUXIMAB].

Rituximab is a chimeric monoclonal antibody containing constant kappa-regions of the Fc fragment of IgGI human immunoglobulin and variable fragments of IgG murine immunoglobulin. This modified immunoglobulin structure makes rituximab capable of specifically recognizing CD20 antigen that is mainly expressed on B-lymphocytes. The review considers four main mechanisms of rituximab action leading to reduction of the population of B-lymphocytes in patients with lymphoproliferative processes. All these mechanisms are probably operative under clinical conditions, however, their relative contributions to the clinical effect of rituximab can vary and are yet not defined in full.