Anti-thyroid antibodies in primary thyroid disorders

Abstract

Autoantibodies to various components of the thyroid gland have been implicated in the causation of primary hyperthyroidism and hypothyroidism. A study aimed at establishing the association, if any, of the presence of anti-thyroid autoantibodies with primary dysfunctional thyroid disorders was carried out at the Clinical Chemistry and Immunology laboratories of the Kenyatta National Hospital (K.N.H.). The study involved 57 hyperthyroid and 15 hypothyroid patients seen over a period of 6 months, of which 58 were females and 14 were males. The patients were tested for the presence of antimicrosomal and antithyroglobulin antibodies. Results showed that 36.1 % of the patients tested positive for the antithyroglobulin antibodies (a-TgAbs) whil~ 51.4% were positive for the antimicrosomal antibodies (a-TPOAbs). Antimicrosomal antibodies were detected in 57.1 % and 50% of the male and female patients respectively (p=0.76). Fifty percent of the hypothyroid patients were found to have the a-TgAbs while only thirty three percent of the hyperthyroid group had the antibody. Twenty three out of twenty six patients (88.5%) who tested positive for a-TgAbs were also positive for a-TPOAbs (p=O.O16). Most of those who tested positive for these antibodies were aged 31-50 years (p=0.30 and 0.214 for c-TgAbs and a-TPOAbs respectively). The findings of this study show that the antimicrosomal and thyroglobulin antibodies are common in patients with primary thyroid disease and should be considered in the pathogenesis of these disorders. Their measurement should be considered in the evaluation of patients suspected of having autoimmune thyroid disease.