1. The analysis of the antibody response in autoimmune thyroid disease has followed several historical trends. It was the investigation of thyroid-reactive antibody that allowed the initial characterization of the three principle thyroid autoantigens, thyroglobulin, thyroid peroxidase and the thyroid stimulating hormone receptor.
2. Analysis can be grouped under two broad areas: analysis of the physiological and pathological effects of the antibody, and analysis of the structure of the antibodies themselves. This review will focus on the latter.
3. Within recent years there has been a great increase in knowledge of thyroid-reactive antibody structure, principally through the adoption of phage display combinatorial library methodologies. While this latter technique has established some general principles for antibodies to thyroglobin and especially thyroid peroxidase, there is still a substantial gap in our knowledge of the antibody response to the thyroid stimulating hormone receptor.
4. Thyroid peroxidase antibodies have a relatively restricted V-region usage, and there is a correlation between the V-regions used and the epitope on thyroid peroxidase bound. In particular the Vκ light chain, Vκl(O12), is associated with reactivity to one epitope.
5. The purpose of this review is to bring together the latest results concerning the molecular analysis of the antibody response in autoimmune thyroid disease, to highlight areas of ignorance and conflict, and to discuss the methods adopted to circumvent the problems associated with analysis of the antibody response.