Autoimmune thyroid disease in children and adolescents with idiopathic pulmonary arterial hypertension.

Background: Previous studies have reported a high prevalence of autoimmune thyroid disease (AITD) in adult patients with pulmonary arterial hypertension (PAH). The aim of this retrospective study was to determine the prevalence of AITD in children and adolescents with idiopathic PAH (IPAH). Methods and Results: The study group included 16 patients who had been diagnosed as having idiopathic PAH when they were younger than 15 years old; all were younger than 20 years of age. Thyroid function and antithyroid antibody levels were examined regularly at 6-12-month intervals and when there were clinical signs of thyroid dysfunction. In total, 7 patients (44%) had AITD; 2 patients developed Graves' disease, 2 developed silent thyroiditis, and 3 had antithyroid antibodies with euthyroidism. The duration after PAH onset and the prostacyclin (PGO(2)) treatment period were significantly longer in patients with AITD (7.6+/-2.1 and 7.4+/-2.3 years, respectively) than in patients without AITD (5.0+/-1.1 and 4.8+/-1.2 years, respectively; P<0.01 and P<0.05). Conclusions: The prevalence of AITD is high in children and adolescents with IPAH, so evaluation of thyroid function is important to prevent deterioration of right heart failure. (Circ J 2010; 74: 371-374)