Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: FP28-Thyroid Autoimmunity
Sunday, June 16, 2013: 10:45 AM-11:15 AM
Presentation Start Time: 11:05 AM
Room 103 (Moscone Center)

Poster Board SUN-434
Tanja Diana*1, Artur T. Bossowski2, Marek Niedziela3, Maria Segni4, Michael Kanitz1, Katharina A. Ponto1 and George Jean Kahaly1
1Gutenberg University Medical Center, Mainz, Germany, 2Medical Univ in Bialystok, Bialystok, Poland, 3Poznan University of Medical Sci, Poznan, Poland, 4Policlinico Umberto Primo Univer, Rome, Italy
Objective: Pediatric Graves´ disease (GD) is rarely accompanied with extrathyroidal manifestations. In this large prospective multicenter trial, the role of thyroid-stimulating autoantibodies (TSAb) is investigated in GD children with and without orbital disease (GO).

Methods: TSAb levels were measured with a commercial bioassay that uses a chimeric TSH-R and a CRE-dependent luciferase. TSAb results were expressed as percentage of specimen-to-reference ratio (SRR%). Values ≥140% were considered positive. Samples of children with GD, type 1 diabetes (T1D) and healthy controls (C) were measured for thyroid binding inhibiting immunoglobulins (TBII, automated electrochemiluminescence immunoassay).

Results: A total of 164 sera samples were obtained from 85 GD children (73 female, mean age ± SD 14.24 ± 3.9 years, 40 children with GD/GO). Sera from 50 euthyroid controls (27 female, 12.4 ± 4.3 yrs.) and 50 with T1D (23 female, 13.69 ± 3.7 yrs.) were included. TSAb and TBII were detected in 148/164 (90%) and 138 (84%) samples, respectively (p<0.001). In untreated children, TSAb and TBII were present in 54/57 (95%) and 48/57 (84%) samples, respectively (p<0.001). Also, median TSAb levels were markedly higher in untreated children with GD/GO vs. those with GD, only (SRR% 470 vs. 372, p=0.002). During antithyroid drug treatment, children with GD/GO who became euthyroid still had very high median TSAb levels compared with children with GD, only (SRR% 451 vs. 226, p<0.001). In line with this, TSAb were highly prevalent in treated children with GD/GO (57/58, 98%) vs. in GD only (37/48, 77%, p<0.001). TSAb serum levels were higher in female than in male children with GD/GO (SRR% 474 vs. 381, p=0.02). Median TSAb serum levels in children less than 12 years were higher than those >12 yrs. (SRR% 466 vs. 418, p<0.001). All children with T1D and C were TSAb (SRR% 45 and 42) and TBII negative (both 0.5 IU/L).

Conclusions: Serum TSAb levels are a biomarker of disease severity and extrathyroidal manifestations in pediatric GD.

Disclosure: GJK: Researcher, QUIDEL, CA, USA, Consultant, QUIDEL, CA, USA. Nothing to Disclose: TD, ATB, MN, MS, MK, KAP

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm