[Clinical epidemiology of Basedow's disease in Belgium].
Graves' disease (GD) patients treated with antithyroid drugs (ATD) have overall relapse rates of 30-50% after ATD discontinuation. Conflicting data have been reported with regard to the usefulness of adding thyroxine (I-T4) during and after ATD treatment. Also, clinicians are still in search of useful factors to predict remission/recurrence after ATD withdrawal. Eighty two consecutive patients were treated with ATD for 15 months, combined with 12 months of I-T4. Then, patients were randomized (placebo-controlled double blind protocol) to continuing I-T4 versus a placebo for one year.


RESULTS
I-T4 administration during and after ATD treatment did not affect favorably the outcome, the final recurrence rate being 31%, in both placebo and I-T4 groups. Two factors were identified as independent and synergistic markers of a significantly increased risk of recurrence after ATD withdrawal: smoking and TSH receptor antibodies (TSHR-Ab) remaining positive at the end of ATD. Non smoking patients with a negative TSHR-Ab (end ATD) had a low (18%) recurrence risk, while smoking patients also with a negative TSHR-Ab had a higher (57%) recurrence risk. Non smoking patients with a positive TSHR-Ab (end ATD) had a 86% recurrence risk. Finally, smoking patients with a positive TSHR-Ab (end ATD) all recurred within 6 months.


CONCLUSIONS
1) T4 administration after ATD withdrawal does not improve recurrence rates; 2) two parameters, smoking and positive TSHR-Ab (at end ATD), were valid--albeit not absolute-predictors of the risk of recurrence in ATD-treated patients with Graves' disease.
Glinoer
D
D
Département de Médecine Interne, C.H.U. Saint-Pierre, U.L.B.
D000328:Adult; D000906:Antibodies / Q000097:blood; D013956:Antithyroid Agents / Q000627:therapeutic use*; D001530:Belgium / Q000453:epidemiology; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D006111:Graves Disease / Q000188:drug therapy* / Q000453:epidemiology / Q000209:etiology / Q000276:immunology; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D011989:Receptors, Thyrotropin / Q000097:blood; D012008:Recurrence; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013974:Thyroxine / Q000627:therapeutic use*
D000906:Antibodies; D013956:Antithyroid Agents; D011989:Receptors, Thyrotropin; D013974:Thyroxine