IMMUNOLOGICAL AND LONG-TERM THYROID-FUNCT ION EVOLUTION IN GRAVES-DISEASE ACCORDING TO DIFFERENT THERAPEUTIC OPTIONS

BACKGROUND: A prospective study was carried out to compare the evoluti on of thyroid hormones, thyroglobulin (Tg) and immunoglobulins inhibit ing the binding of thyrotropin to its receptor (TBII) in patients with Graves disease treated with antithyroid drugs, radioactive iodine and subtotal thyroidectomy. METHODS: Ninety-five patients with Graves dis ease were studied, being distributed according to clinical criteria: G roup I (n = 35) patients treated with antithyroid drugs; Group II (n = 30) patients who received I-131; and Group III (n = 30) patients trea ted with subtotal thyroidectomy. The thyroid hormones, Tg, antithyrogl obulin antibodies and TBII were determined by radioimmunoassay (RIA), prior to treatment, and at 1, 3, 6, 12, 24, and 36 months of Follow up , except in those patients from Group III who were followed up to 24 m onths. RESULTS: The rate of reactivation at 12 months did not signific antly differ among the three groups. At 24 months a higher percentage of reactivations was observed in Group I (42 %), versus Group II (16 % , p < 0.001) and Group III (13 %, p < 0.005). At 36 months reactivatio n was 30 % in Group I, versus 5 % in Group II (p < 0.01). Upon compari son of the TBII Values among the three groups, the highest basal value s corresponded to Group III with significant differences being found v ersus Group I (p < 0.05) and Group II (p < 0.001). TBII concentrations in the three groups studied remained high at 6 and 12 months with no significant differences being observed. Negativization was shown in th e TBII at 24 months in Group II with a significant difference being se en versus Group I and III. At 36 months negativization was seen in the TBII in Group I with significant differences with respect to Group II . CONCLUSIONS: The rate of reactivation following antithyroid treatmen t is greater to that obtained in groups treated with iodine or surgery . The earliest negativization of TBII was obtained with radioiodine.