An enzyme-linked immunoassay for thyroid microsomal antibodies.

An enzyme-linked immunoassay (ELISA) for microsomal antibody is described. The method was found to be rapid, sensitive and precise and analysis of 115 serum samples showed good correlation between the ELISA and the conventional tanned red cell haemagglutination test. The presence of thyroglobulin antibody, rheumatoid factor, antinuclear factor or gastric parietal cell antibodies did not interfere in the microsomal antibody ELISA but some sera with mitochondrial antibody activity appeared to cause a non-specific effect. The ELISA was particularly useful for analysing microsomal antibody production by Hashimoto lymphocyte cultures and in some cases antibody synthesis could be studied in the absence of mitogen. The high capacity of the ELISA combined with its sensitivity suggest that it will be a valuable technique for studying microsomal autoantibody activity both in serum and in lymphocyte cultures.