IgM in a human neuropathy related to paraproteinemia binds to a carbohydrate determinant in the myelin-associated glycoprotein and to a ganglioside.

Abstract

The IgM in 3 patients with paraproteinemia and peripheral neuropathy bound to human myelin-associated glycoprotein (MAG) that had been purified to homogeneity by gel filtration on Sepharose CL-6B. The antigenic determinant reacting with the IgM from all 3 patients was in the carbohydrate part of the MAG molecule. The IgM from the same 3 patients bound to a single ganglioside of human sciatic nerve. The IgM paraproteins in these patients react with a carbohydrate determinant that is shared between MAG and a peripheral nerve ganglioside.