Abstract
A number of thyroid autoantibody/antigen systems have previously been described. Methods currently available for the detection of thyroid autoantibodies have inherent disadvantages. This study was designed to test the application of two types of labelled antibody techniques to the investigation of three thyroid autoantibody/antigen systems. A radioassay is described, in which autoantibodies were trapped by immobilised antigen, and detected by 125Iodine labelled anti-human IgG antiserura. The assay was applied to the detection of anti-microsomal autoantibodies, but was subsequently abandoned because of poor precision and deterioration of the labelled antiserum. An enzyme immunoassay was developed and applied to the detection of anti-thyroglobulin autoantibodies. This method was shown to be precise, specific and sensitive, and to correlate with a haemagglutin— ation method. The thyroid microsomal antigen, previously prepared for the radioassay, was examined using a chromatographic procedure monitored indirectly by the enzyme immuno-assay. This study showed the contamination of the microsomal preparation by thyroglobulin, and allowed the preparation of microsomes free of thyroglobulin. The development of an enzyme immunoassay for the detection of thyroid hormone binding autoantibodies is described, together with the application of the assay to a study of the incidence of such antibodies in the serum of patients with a variety of thyroid disorders. A thyroid hormone uptake method was used for comparison purposes. No unequivocally positive samples were encountered in this study, apart from that used to establish the methodology. In some of the experimental work, a new automated enzyme immunoassay processor was used. A brief evaluation of this equipment is presented. The results of the experimental work are discussed in relation to other reported findings.