AB0963 ROLE OF THYROID HORMONES IN JUVENILE IDIOPATHIC ARTHRITIS
Authors: Ninel Revenco, Rodica Eremciuc
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> The frequency of autoimmune thyroid disease have been reported in adults with systemic autoimmune diseases. However, little is known about the association between those diseases and rheumatic disorders during childhood, such as juvenile idiopathic arthritis (JIA). <h3>Objectives</h3> Our objective was to evaluate the correlation between the thyroid function and the clinical presentation in children with juvenile idiopathic arthritis. <h3>Methods</h3> Ninety-seven children (56 female, 41 male, median age 9.57 years, range 1.1–17.5 years) with juvenile idiopathic arthritis were evaluated. All patients underwent thyroid function tests (TSH, free T<sub>4</sub> and free T<sub>3</sub>), antithyroglobulin (TgA) and antiperoxidase (TPOA) antibodies. All patients had a thyroid high-resolution sonography examination. Patients with nodules on US examination, low-TSH level and/or high thyroid hormone levels or positive TPOA and/or TgA values were referred to thyroid scintigraphy. The gained data was correlated with disease activity indices. Thyroid autoimmunity was evaluated by fluorescence enzymatic immunoassays of TgA and TPOA antibodies, considering TgA &gt;50 IU/ml and TPOA&gt;100 IU/ml as positive values. <h3>Results</h3> Fifty-one of the cases were classified as oligoarticular, thirty-one as seronegative polyarticular, two as seropositive polyarticular, eleven as systemic, and two as enthesitis related- juvenile idiopathic arthritis. No cases of overt clinical and biochemical hypothyroidism were found among children with juvenile idiopathic arthritis. On opposite, mean thyroid free T3 levels were higher in 36.4% of cases and free T4 in 29,7% cases. Anti-TPO antibodies were found in 5 of 97 patients (5.15%) and anti-TG antibodies were found in 2 patients (2.06%). All patients with thyroid antibodies positives were females. The ultrasound examination of thyroidal gland revealed abnormalities in 41% cases, most of them cystic changes (33.7%) and hypo-echogenicity (28,57%). In those patients with thyroid nodules on US examination, the thyroid scintigraphy did not revealed pathological activity or other processes. Although, 2 patients presented mean thyroid volume above 2SDS according their age reference values. An increased vascular flow patter on Doppler examination of thyroidal gland was found in 26% cases. Correlation and regression analysis showed low age at diagnosis and longer duration of the disease to be predictors for those thyroid disorders. <h3>Conclusion</h3> These data seem to suggest careful monitoring of thyroid function and thyroid autoantibodies just in children with juvenile idiopathic arthritis presenting clinical symptoms of thyroid involvement. <h3>References</h3> [1] Fröhlich E., Wahl R., Thyroid Autoimmunity: Role of anti-thyroid antibodies in thyroid and extra-thyroidal diseases, Front. Immunol. 8:521. doi: 10.3389/fimmu.2017.00521 [2] Stagi S. et all., Thyroid function, autoimmune thyroiditis and coeliac disease in juvenile idiopathic arthritis, Rheumatology2005;44:517–520, doi:10.1093/rheumatology/keh531 <h3>Disclosure of Interests</h3> None declared