Thyroid autoantibodies

The characteristics of thyroid autoantibodies are reviewed and new assays for the autoantibodies described, in particular point of care (POC) tests for thyroid peroxidase (TPO) autoantibodies and for thyroglobulin (Tg) autoantibodies. These POC tests depend on the ability of the autoantibodies to inhibit gold labelled human monoclonal antibodies binding to TPO or to Tg. The POC tests show similar sensitivity and specificity to conventional ELISA for the autoantibodies. A new ELISA to measure autoantibodies to the TSH receptor (TRAb) is described, is based on TSH receptor coated onto plate wells by way of a monoclonal antibody. Comparison of porcine and human TSH receptors indicates that there is no advantage in using human TSHR in assay systems based on competition between TRAb and bovine or porcine TSH for immobilised TSHR. In terms of the origins of Graves' disease, it is speculated that this most common overt autoimmune disease in man might have occurred first when Homo sapiens sapiens migrated rapidly out of Africa about 100,000 years ago.