ANTI-MAG AND ANTI-SGPG ANTIBODIES IN NEUROPATHY

We compared the binding of human antibodies from patients with neuropa thy to the myelin-associated glycoprotein (MAG), to its cross-reactive glycolipid sulfoglucuronyl paragloboside (SGPG), and to sections of p eripheral nerve. Titers were correlated with the clinical presentation and results of electrophysiological and pathological studies. Most pa tients had a predominantly sensory or sensorimotor demyelinating neuro pathy and highly elevated antibodies to both MAG and SGPG, but 2 had h ighly elevated antibodies to MAG alone, and 1 to SGPG alone. Two patie nts had predominantly motor neuropathy and highly elevated antibodies to SGPG which reacted with MAG by Western blot but not by enzyme-linke d immunosorbent assay. One patient had amyotrophic lateral sclerosis a nd antibodies to SGPG but not to MAG. These studies indicate that the neuropathic syndrome associated with anti-MAG or -SGPG antibodies are more heterogeneous than previously suspected, and that although most o f the antibodies react with both MAG and SGPG, some may react with MAG or SGPG alone. (C) 1996 John Wiley & Sons, Inc.