Treatment experience in patients with anti–myelin‐associated glycoprotein neuropathy

We report our experience with 24 consecutively treated patients (15 men and 9 women, median age 64 years) with anti–myelin‐associated glycoprotein (anti‐MAG) neuropathy. The rates of response to plasma exchange (40%), immune globulin (16%), and cyclophosphamide‐based therapy (36%) were similar. Five (24%) responded to the first treatment modality, 32% to a second, alternative modality, and 31% to a third. Only 4 of 12 responders had sustained improvement; the others relapsed after a median of 7 months. In those 4 patients, the median immunoglobulin M (IgM) level dropped by 25% compared to an increase of 24% in the nonresponders ( P = 0.04). Thus, most patients with anti‐MAG neuropathy failed to have sustained improvement after treatment, and none of the therapies emerged as superior. Disability improved transiently after therapy in approximately 50% of cases. A 25% reduction of the IgM level predicted sustained improvement, but was difficult to achieve. There were no clinical or electrodiagnostic features associated with a treatment response, nor did a reduction of the anti‐MAG antibody titer correlate with clinical improvement. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 778–786, 2001