ESPE Abstracts

Background: Thyrotropin receptor (TSH-R) stimulating autoantibodies (TSAb) are present in 90-100% of patients with Graves’ disease (GD). TSAb are functional, impact thyroid function, and are clinically relevant. This study we performed in a pediatric patients with dynamic of Graves’ disease before and during methimazole therapy and in patient with Hashimoto’s thyroiditis using a novel and ultra-rapid TSAb andTBAb bioassay.

Methods: All samples from AITD patients and healthy controls were tested with a new “TurboTM” TSAb & TBAb bioassay (Thyretain®, Quidel) with a readout that is based on a cyclic AMP-activated luciferase. The negative values for anti-thyroid receptor antibodies were: (< 0,024 IU/L) for Turbo TSAb and (< 40% Inhibition) for Turbo TBAb.

Results: Of 117, selected pediatric AITD patients (Graves’ disease and Hashimoto thyroiditis), positive for TSAb and TBAb were 41 and 34 patients, respectively. Median age was 12 years (patients n=82 /controls n=35; 12/10.5 years) and female: male ratio was 1,65. Of 82 samples, 43 (52.5%), 30 (36,5%) and 7 (11%) were hyperthyroid, hypothyroid and euthyroid respectively. The TSH-R-Ab assays were negative in 35 healthy controls devoid of autoimmune thyroid and endocrine disorders. In the TurboTM cAMP TSAb assays was detected TSAb in 36 untreated GD patients (100%) and 3 treated by methimazole (27%) samples. The TurboTM TSAb bioassay highly correlated with thyroid function (P=0.028). Three of 82 (4%) samples showed dual TSH-R-Ab positivity in the Turbo TBAb and TSAb bioassays.

Conclusions: This is the largest reported collective of TSAb-positive samples in Graves’ pediatric patients, measured by a rapid and reliable “TurboTM” TSAb bioassay. TSAb markedly affects thyroid function. Furthermore, the novel TurboTM stimulating bioassay is very useful for clinical utility in the monitoring of therapy of pediatric Graves’ patients.