Autopsy-proven amyotrophic lateral sclerosis, Waldenström's macroglobulinemia, and antibodies to sulfated glucuronic acid paragloboside.

Antibodies to myelin-associated glycoprotein (MAG) are found in patients with both monoclonal gammopathy and sensorimotor peripheral neuropathy but almost never in patients with amyotrophic lateral sclerosis (ALS). Ninety percent of patients with anti-MAG activity also have antibodies to sulfated glucuronic acid paragloboside (SGPG). We studied a patient with autopsy-proven ALS who had high titers of anti-SGPG but normal anti-MAG--one more unexplained immunologic abnormality in ALS.