Reactivity with neural cell adhesion molecules in sera from patients with demyelinating diseases.

Sera from 5 patients with IgM gammopathy and peripheral neuropathy reacted strongly by a sensitive immunospot enzyme-linked immunosorbent assay test with the myelin-associated glycoprotein (MAG) purified from human and bovine brains and the novel neural cell adhesion molecule J1 and associated glycoproteins from human brain. Two other members of the L2/HNK-1 family of cell adhesion molecules, the L1 glycoprotein and the neural cell adhesion molecule N-CAM, are not recognized significantly more strongly by these sera than by sera from patients with multiple sclerosis. Sera from patients with Guillain-Barré syndrome and amyotrophic lateral sclerosis and from healthy humans did not react with any of the glycoproteins tested at the serum concentrations used.