Variability in immunohistochemistries of IgM M-proteins binding to sulfated glucuronyl paragloboside

Serum IgMs from 4 of 12 patients with polyneuropathy and IgM M-proteins tha t bind to sulfated glucuronyl paragloboside (SGPG) strongly immunostained t he human peripheral nerve myelin (group A), whereas those from the other ei ght patients strongly immunostained the cytoplasm of the Schwann cells surr ounding the myelin sheath with only weak staining of the myelin (group B). Strong immunostaining of peripheral myelin by IgMs from group A patients ma y be due to the strong cross-reactivities against PO and peripheral myelin protein-22 (PMP-22). which are localized in compact myelin. Only three pati ents (all in group B) showed some response to the immunotherapies. Weak rea ctivities to P0 and and PMP-22 might indicate the possibility of improvemen t after the immunotherapies. (C) 2001 Elsevier Science B.V. All rights rese rved.