UNDETERMINED SIGNIFICANCE

Although polyneuropathies associated with IgM and IgG monoclonal gam-mopathies have been well described, polyneuropathy with IgA monoclonal gammopathy of undetermined significance (MGUS) is less commonly seen and has not been well studied. We reviewed the clinical and electrodiag-nostic features of 5 such patients, and the sural nerve biopsy findings in 4 of them. One patient was diabetic, while 4 were free of other diagnoses commonly associated with neuropathy. Clinical presentations were varied. Electrodiagnostic and histological studies ranged from primary demyelina-tion to primary axon loss to a mixed axonaVdemyelinating picture. Three patients who were treated appeared to respond to prednisone or intrave-nous gamma globulin, despite clear clinical, electrodiagnostic, and histolog-ical differences. We conclude that the polyneuropathy associated with IgA MGUS is heterogeneous, similar to that in IgM and IgG MGUS. A trial of immunomodulating therapy appears to be warranted in such patients if the neuropathy is sufficiently severe. 0 1993 John Wiley & Sons, Inc. Key words: paraproteinemias monoclonal gammopathy neuropathy electromyography sural nerv