Autoantibodies against thyroid constituents and CIC in Graves' disease associated with exophthalmos

ABSTRACT

32 patients [19 female, 13 male]- suffering from Graves' disease with exophthalmus and five without exophthalmus were studied for various autoantibodies including anti-thyroglobulin [ATAB], anti-microsomal antibody [AMAB], anti-parietal antibodies [APAB] and also circulating immune complex [CIC]. 43 normal subjects were tested concurrently. Immunofluorescent technique was employed for autoantibody detection. Frozen sections of human thyroid tissue and rat stomach were utilized as antigen sources for thyroid and parietal CIC estimated by PEG [polyethylene glycol] precipitation method and the specific classes of immunoglobulins were detected by SRID [single radial immunodiffusion]. The results were analyzed statistically. From the point of view of presence of antibodies, there were significant differences between patients and control groups [P= 0.005]. Comparing Graves' with or without exophthalmus, no significant difference was seen between autoantibody levels, but higher titers of CIC were elucidated in the latter group. We will discuss that autoantibodies have an important role in thyroid autoimmune diseases and also that CIC may have a critical role in the pathogenesis of exophthalmus associated with Graves' disease