Immunoglobulin depositions in peripheral nerves in polymyositis.

An immunocytochemical study was performed in 6 peripheral nerve specimens from 6 cases of polymyositis. The results revealed that depositions of IgG, IgM, IgA and C3 were found in the epineurium, perineurium and the walls of capillaries. These findings demonstrated that depositions of immunoglobulins and the complement-mediated immunoreaction may play an important role in pathogenesis of polymyositis with peripheral nerve involvements.