Endocrine Abstracts

Background: Thyrotropin receptor (TSH-R) stimulating autoantibodies (TSAb) are present in 95-99% of patients with Graves’ disease (GD). TSAb are functional, impact thyroid function, and are clinically relevant. This study we performed in pediatric patients with dynamic of Graves’ disease before and during methimazole therapy and in a patient with Hashimoto’s thyroiditis (HT) using a novel and ultra-rapid TSAb bioassay.

Methods: All samples from patients with autoimmune thyroid disease (AITD) and healthy controls were tested at the accredited and certified academic thyroid lab of the JGU Medical Center (Mainz, Germany) with a new “TurboTM” TSAb 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 Results: Median age was 12 years (patients n = 80 / healthy controls n = 35; 12/10.5 years) and female: male ratio was 1,65. Of 80 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. Of 80, selected pediatric AITD patients (GD and HT), 41 were positive for TSAb. In the TurboTM cAMP TSAb assay was detected TSAb in 36 untreated GD patients (100%) and 5 treated by methimazole samples. The TurboTM TSAb bioassay highly correlated with thyroid function (P = 0.028). Three of 80 (3.75%) samples showed dual TSH-R-Ab positivity.

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

Key words: Graves‘ disease, autoimmunity, TSAb, children