Autoantibody profile in thyroid diseases in black Kenyans.

ABSTRACT

A controlled prospective study of autoantibody profile on black Kenyan patients with non-toxic goitre (116), thyrotoxicosis (131) and age, sex matched hospital controls is reported. The prevalence of thyroid microsomal and thyroglobulin antibodies is 3.5% in smooth non-toxic goitre and is 5.2% in the nodular non-toxic goitre compared to 1% of the control. The results reflect that autoimmune thyroiditis is less common in Kenyan hospital controls and smooth simple goitre which is even more pronounced in case of multinodular simple goitre as compared to the Caucasians. The prevalence of microsomal antibody of 54% and the occurrence of high titres in 19% of the toxic group is relatively similar in Caucasians and black Kenyans. However, thyroglobulin antibody and parietal cell antibody are far less frequent in the Kenyan toxic group as compared to Caucasians. In conclusion, the black Kenyan toxic cases are reluctant to produce thyroglobulin and parietal cell antibodies while microsomal antibody production is unaffected. The latter is thought to be more significant in the development and progression of autoimmune thyroiditis. The dissociated behaviour of the two thyroid specific antibodies and thyrogastric axis in black Kenyans strongly suggest that the immunogenetic control of these and the related diseases is different in them as compared to the Caucasians.