An enzyme-linked immunosorbent assay for antibodies against acid soluble skeletal muscle antigen in myasthenia gravis.

An enzyme-linked immunosorbent assay (ELISA) system has been developed for measuring serum antibodies against citric-acid extract of human skeletal muscles. With this assay, 80% of myasthenia patients with thymoma gave positive results. No sera from patients with neurological diseases other than myasthenia gravis (MG) gave positive results. The result of this study indicates that the ELISA system is useful as an adjunct for the diagnosis of MG particularly in the patients associated with thymoma and that the ELISA method can also be used as a prognostic marker following thymectomy in patients with MG.