TREATMENT OF GRAVES-DISEASE WITH THE BLOCK-REPLACE REGIMEN OF ANTITHYROID DRUGS - THE EFFECT OF TREATMENT DURATION AND IMMUNOGENETIC SUSCEPTIBILITY ON RELAPSE

Antithyroid drugs are commonly used as first-line treatment for Graves ' disease, but the optimum regimen for inducing remission remains uncl ear. We gave the block-replace regimen of carbimazole plus thyroxine t o 100 patients for 6 or 12 months, to determine whether prolonged trea tment is associated with fewer relapses. The remission rate one year a fter cessation of treatment was 59% with the 6 month course and 65% wi th 12 months; this was not significantly different. We also analysed H LA markers identified by restriction fragment length polymorphisms and could not confirm the recently reported associations of outcome with HLA-DR4 or with an HLA-DQA2 allele. These results show that six months treatment with a block-replace regimen of antithyroid drugs is probab ly sufficient, in the UK, to achieve maximum remission of Graves' dise ase and that there are no HLA markers which clearly predict outcome.