The prediction of relapse after drug treatment of Graves' disease by assay of long acting thyroid stimulator-protector (LATS-P).

In a study of fifty-two patients with Graves' disease followed for 1 year after stopping antithyroid drugs, a strong relationship has been found between serum LATS-P and relapse. In those with serum LATS-P activity on stopping therapy, twenty-one (88%) out of twenty-four relapsed. In those with no LATS-P activity on stopping antithyroid drugs only eight (29%) out of twenty-eight relapsed and in five LATS-P was detectable at relapse. The overall prevalence of positive assays for LATS-P at relapse (90%) was similar to that seen in untreated Graves' disease.