Correlation of HLA and thyroid antibodies with clinical course of thyrotoxicosis treated with antithyroid drugs.

The prevalence of HLA-B8 in thyrotoxic (Graves' disease) patients who relapsed after withdrawal of antithyroid drugs was high (69%) compared with that in patients who remained in remission (40%) and in healthy controls (28%). B8-positive patients were 1-8 times more likely to relapse after withdrawal of drug therapy than B8-negative patients. The persistence of thyroid microsomal antibodies after withdrawal of therapy correlated significantly with the presence of HLA-B8. This association was more pronounced in patients who remained in remission. From this it might be assumed that B8 is also associated with the persistence of thyroid T.S.H. (thyroid-stimulating hormone) receptor stimulating antibodies. In view of these findings, it is suggested that patients who are thyrotoxic might be typed for HLA, and those who are B8-negative could be given a trial of long-term antithyroid drug therapy.