КЛИНИЧЕСКОЕ ЗНАЧЕНИЕ И ПРОГНОСТИЧЕСКАЯ РОЛЬ АНТИТЕЛ К РЕЦЕПТОРУ ТТГ У ДЕТЕЙ С БОЛЕЗНЬЮ ГРЕЙВСА

Abstract

The aim of the study was to determine the clinical meaning of TSH receptor antibody (TRAb) measurement in patients with Graves’ disease (GD). We measured the level of total TRAb using the 1 st generation of enzyme multiplied immunoas# say and studied thyroid status in 30 children with GD at the onset of disease, every 6 months on antithyroid drug therapy and during 12 months after its discontinuation. We investigated the correlation between the changes of thyroid hormones, thyroid volume and TRAb, so as TRAb level and risk of relapse. Results. At disease onset 87% of children presented with “positive” TRAb values, 13% were considered “ambiguous”. TRAb level normalization was evident in 56% patients in mean 13 ± 5 months of therapy, but 23% demonstrated its elevation in future, mean 1.8 ± 0.2 IU/L. TRAb level and thy# roid volume (rs = 0.5, p = 0.01), TRAb and FT4 levels (rs = 0.5, p=0.01) on therapy positively correlated. After discontin# uation of medication in 38.9% of patients thyrotoxicosis relapsed (all patients with TRAb > 10 IU/L, 37.5% of patients with TRAb 1–10 IU/L, and 14.3% with “negative” values). At the onset of disease Ме TRAb was 12.0 (1.42–38.9) IU/L in relapse group and 6.6 (1.43–25.7) IU/L (р > 0.05) in remission group; at the end of the treatment it became 3.85 (0.64–68.9) IU/L and 0.63 (0.12–6.4) IU/L (р = 0.025) respectively. After therapy discontinuation the relapse group trended to TRAb elevation compared to remission group. “Support” methimazole dose was 0.06 ± 0.04 mg/kg/day in remission group and 0.16 ± 0.04 mg/kg/day (р = 0.003) in relapse group. Conclusion. Measurement of TRAb in children with GD is very useful for prediction of disease progression and therapy results. High TRAb level at the onset of disease and at the end of therapy, absence of normalization on therapy are the risk factors for relapse after therapy discontinuation.