[Assay of acetylcholine receptor antibodies in myasthenia gravis. A study of 329 sera (author's transl)].

Antibodies directed against acetylcholine receptors were investigated in 329 sera by a radioimmunological technique using human muscle. Eighty-six per cent of patients with generalized myasthenia gave positive results. The percentage of positivity reached 90% when a receptor lipid extract was used. Fifty-six per cent of 25 sera from patients with ocular myasthenia were positive. Conversely, no antibody was detected in controls (other neurological diseases, normal subjects), except for two lupus patients. In addition to its diagnostic value, the assay of antibodies to acetylcholine receptors proved useful in the follow-up of myasthenic patients (notably neonates) treated by thymectomy, immunodepressants and plasmapheresis.