Rituximab.

Rituximab is a chimeric mouse-human monoclonal antibody against the CD 20 antigen on the surface of B lymphocytes. It binds to CD20 and causes B cell death by antibody dependant cell-mediated cytotoxicity, complement mediated cytotoxicity and apoptosis. It leads to rapid and sustained depletion of B cells. It is licensed for use in adults with CD20 positive B-cell lymphoma and rheumatoid arthritis. In children, it has been used in a variety of off-label indications with promising results. It has proved useful as salvage therapy in relapsed refractory non-Hodgkins lymphoma and leukemia, and in hematological conditions including chronic immune thrombocytopenic purpura, hemophilia with inhibitors, and autoimmune hemolytic anemia. It has also proved effective in autoimmune conditions like primary systemic vasculitis and systemic lupus erythematosis. Nephrotic syndrome and opsoclonus-myoclonus syndrome are among the emerging indications for rituximab. In solid organ transplantation, rituximab is useful in the prevention and treatment of acute and chronic rejection as well as in post transplantation lymphoproliferative disease. Toxicity includes acute infusion reactions, susceptibility to bacterial infections, and reactivation of viral infections.