Immunohistochemical study of glial cytoplasmic inclusion in multiple system atrophy

: Recently, glial cytoplasmic inclusion (GCI) has been demonstrated to be argyrophilic cytoplasmic body by silver staining in the oligodendroglia of patients with multiple system atrophy. We observed such GCIs in all 20 cases of multiple system atrophy. No GCI was noticed in all 6 cases of hereditary spinocerebellar degenerations. Immunohistochemically, GCI was stained positively with antibodies to ubiquitin, alpha-tubulin, and beta-tubulin, of which characteristics is consistent with previous reports. In addition, GCI was first demonstrated to react with an antibody to microtubule-associated protein-1B(5), which is one of the proteins of cytoskeleton organization and a component of cross-bridges between microtubular assembly. The result suggests strong relationship between the formation of the OCI and immunohistochemical expression of MAP-1B(5).