[Antibodies against TSH receptors (TRAb) as indicators in prognosing the effectiveness of Tiamazol therapy for Grave's Disease].

The aim of the study was to evaluate the usefulness of TRAb determinations in prognosing and monitoring the efficacy of conservative treatment in Graves' disease. The examinations were performed in 54 patients. During the 18-month observation all the patients were treated with Tiamazol. The control group consisted of 20 healthy volunteers. The TRAb levels were determined before as well as 12 and 18 months after thyrostatic treatment. Simultaneously, the levels of TSH and FT4 were analysed. Moreover, all the patients underwent ultrasound examinations to assess the size of the thyroid gland. The findings of the 18-month follow up showed that in 31 patients (57%) the thyroid function became normal (group I--euthyreosis), in 23 patients (43%) hyperactivity persisted (group II--hyperthyreosis). The TRAb levels were analysed in both groups of patients. An increased initial level of TRAb was found in the hyperactivity group mean -54.39 + 31.21 U/l which was statistically significantly different from the TRAb levels in the euthyreosis group mean -29.13 +/- 19.14 U/l and in controls mean -2.75 +/- 2.06 U/l (p < 0.001 for both parameters). After 12-month treatment increased values of antibodies were still observed in this group of patients (mean -39.96 +/- 33.40 U/l) in comparison with the euthyreosis group (mean -9.87 +/- 8.33 U/l) and controls (mean -2.75 +/- 2.06 U/l) (p < 0.001 for both parameters). After 18-month treatment the TRAb levels in group II remained increased (mean -40.17 +/- 33.06) while in group I normal levels were achieved. The sizes of the thyroid gland were compared between the individual groups. In the hyperactivity group after 18-month treatment, the thyroid size was the biggest (mean -41.09 +/- 13.94 ml) and was statistically significantly different when compared to the average size in the euthyreosis group mean -31.65 +/- 11.74 ml (p < 0.01) and in controls mean -14.45 +/- 2.37 ml (p < 0.001). The levels of antibodies against TSH receptors are useful parameters in prognosis and monitoring the treatment effectiveness in Graves' disease. High initial levels of antibodies are the poor prognostic factors. The TRAb determinations are of some prognostic value not only before but also 12 months since the onset of therapy. The lack of antibody level normalization during treatment is connected with persisting hyperactivity. The TRAb concentration correlates with the thyroid size.