A lipid-associated acetylcholine receptor as an antigen in diagnosis of myasthenia gravis.

Antibodies to the acetylcholine receptor are detected in over 85% of myasthenic patients' sera when acetylcholine receptors extracted from human muscle are used as the antigen. As recent data have shown the importance of the lipid environment for receptor function, we have used a lipid-associated acetylcholine receptor as the antigen for antibody determination. This fraction was shown to discriminate better between normal human sera and sera from myasthenic patients with low antibody titres. Among 12 sera from myasthenic patients in which antibodies were undetectable with the delipidated receptor as the antigen, seven were positive with the lipid-associated receptor. This lipid-associated fraction could be used beneficially for research and clinical investigation.