A direct electron microscopic immunocytochemical study of IgM paraproteinemic neuropathy.

Direct electron microscopic immunohistochemistry of the sural nerve of a patient with neuropathy and an IgMk paraprotein demonstrated that immunoglobulin was deposited throughout the compact myelin. These findings support the notion that immunoglobulin deposition plays a role in the pathogenesis of the neuropathy in vivo.