CLINICAL-FEATURES OF PATIENTS WITH GRAVES-DISEASE UNDERGOING REMISSION LIFTER ANTITHYROID DRUG-TREATMENT

The clinical course of 306 Graves' patients treated with methimazole ( MMI) was reviewed with the aim of establishing criteria able to predic t remission of hyperthyroidism after medical treatment. One hundred an d ninety-four (149 females, 45 males) of 306 (63.4%) patients had rela pse of hyperthyroidism after antithyroid drug (ATD) withdrawal. Relaps e was more frequent during the first months of the follow-up, but stil l it was observed 3 years after MMI withdrawal. The relapse rate was d ependent on the age of the patient, the size of goiter, and the level of TSH-receptor antibody (TRAb) at diagnosis, being observed in 40 of 47 (85%) patients with high (>30 U/L) TRAb level and in 54 of 101 (53% ) patients with low TRAb level (less than or equal to 30 U/L; p<.0002) . Remission was more frequent (43.3%) in patients having the combinati on goiter size less than or equal to 40 mt, TRAb level less than or eq ual to 30 U/L, than in patients with goiter size >40 mt and high TRAb levels (9%). In the subgroup of patients with the combination: goiter less than or equal to 40 mL- TRAb less than or equal to 30 U/L - age a t onset >40 years, the remission rate was 80%, and all relapses occurr ed within the first 9 months after MMI withdrawal. In conclusion, our study confirms that hyperthyroidism relapses in the majority of patien ts with Graves' disease treated with ATD. Among different clinical and laboratory features, age at onset of hyperthyroidism, goiter size and TRAb level are particularly helpful in identifying those patients who are more prone to undergo a remission of hyperthyroidism after medica l treatment and may be useful to select the minority of Graves' patien ts who will benefit from antithyroid drug treatment as a first choice.