Enzyme-linked immunoassay of monoclonal and serum microsomal autoantibodies.

An automated enzyme-linked immunoassay for the detection of antibodies to human thyroid microsomes has been assessed. This assay correlated closely with the established commercial passive haemagglutination method. Variations in the purity of crude microsome preparations and the degree of thyroglobulin contamination make careful comparison of different preparations essential for meaningful interpretation of results, and attempts to circumvent these problems by further purification of microsome preparations using gel filtration are discussed. The application of this method for routine screening of serum samples is demonstrated using populations of normal subjects and patients with rheumatoid arthritis and anti-glomerular basement membrane disease. This assay has also permitted the establishment of murine hybrid myelomas secreting monoclonal antibodies to human thyroid microsomes.