Rituximab in the treatment of polyneuropathy associated with anti‐MAG antibodies

No causative or curative therapy exists for the polyneuropathy associated with antibodies to myelin‐associated glycoprotein (anti‐MAG). Rituximab is a mouse‐human chimeric antibody that specifically eliminates B‐cells and B‐cell precursors. Preliminary results suggest a beneficial effect on antibody‐dependent autoimmune diseases. Nine patients with an anti‐MAG–associated IgM polyneuropathy received rituximab once weekly for 4 weeks. In all patients, the number of B‐cells in the peripheral blood declined below levels of detection, and the IgM levels decreased between 35% and 82% (median, 58%). In eight patients, lowering of the anti‐MAG antibody titers of more than 52% was observed. Clinical status improved in six patients, remained stable in two, and worsened in one. The motor nerve conduction velocity improved by at least 10% in one ulnar nerve in seven patients and worsened in two. Rituximab was well tolerated and is a promising new drug in the treatment of patients with anti‐MAG–associated polyneuropathy. Muscle Nerve 27:611–615, 2003