Methods.

Ten patients with anti-MAG polyneuropathy responding to rituximab, 375 mg/sq for four consecutive weekly infusions, were prospectively studied for 36 months. The effects of the initial treatment in 13 patients and the type of assessment were previously described. 3 The baseline clinical and laboratory data of the 10 responding patients are reported in the table. All but one patient (no. 1) had an IgM monoclonal gammopathy of undetermined significance and a symptom duration of up to 2 years. Three patients had not been previously treated for the neuropathy, whereas seven were unresponsive to immune or cytostatic therapies. We considered as responders patients who improved at month 12 by at least one point in two clinical scales including MRC sumscore (appendix e-1 on the Neurology® Web site at www. neurology. org), INCAT Disability Scale (appendix e-2), and INCAT sensory sumscore (ISS)(appendix e-3). During follow-up, patients underwent clinical, immunologic, and electrophysiologic evaluations every 6 months without additional rituximab infusions, or other therapies. Clinical deterioration was defined as worsening by one point in at least two scales.