A solid-phase enzyme immunoassay for anti-acetylcholine receptor antibody in myasthenia gravis patients

A solid-phase enzyme immunoassay for the measurement of anti-acetylcholine receptor antibodies in the sera of patients with myasthenia gravis is reported. Sufficient amounts of acetylcholine receptor for the sensitive detection of anti-acetylcholine receptor antibody were directly fixed to Costar serocluster 96-well EIA plates coated with poly-L-lysine hydrobromide. The solid-phase enzyme immunoassay detected anti-acetylcholine receptor antibodies in 91% of the myasthenia gravis patients including 4 out of 4 ocular type myasthenia patients, anti-acetylcholine receptor antibodies of which were not detectable by the immunoprecipitation assay. Correlation between antibody titers measured by enzyme immunoassay and the immunoprecipitation assay was significant.