Multiple antibodies to nerve glycoconjugates in a patient with neuropathy and monoclonal IgA gammopathy.

Several immunological abnormalities were found in a patient with mixed axonal and demyelinating neuropathy in association with a prominent monoclonal IgA lamda band in his serum. He had antibodies to the major LM1 ganglioside of human nerve that were restricted to the IgA class, but they were polyclonal and distinct from the major monoclonal IgA component. He also had a low level of a monoclonal IgM lamda antibody to the myelin-associated glycoprotein and sulfate-3-glucuronyl paragloboside that was not detected by routine immunofixation. The observations made on this complex patient, are presented in the context of emphasizing that immunological reactivities to neural antigens that are not due to the principal monoclonal antibody may be present in patients with neuropathy in association with gammopathy.