Çocuk ve Adölesan Yas Grubundaki Hipertiroidili Olguların Değerlendirmesi ve Uzun Süreli Izlemi

Abstract

The aim of this study was to determine the causes of hyperthyroidism in children and adolescents and evaluate clinical course and treatment results of Graves disease which is the major cause of hyperthyroidism in this age group. The study population consisted of 80 patients who were diagnosed as hyperthyroidism between 2000-2012 at Hacettepe University Division of Pediatric Endocrinology. The diagnosis of hyperthyroidism was based on demonstration of elevated serum free T3 and/or free T4 levels in combination with suppressed TSH levels and clinical signs of hyperthyroidism. Graves disease was defined in the presence of clinical and laboratory signs of hyperthyroidism with positive TSH receptor antibodies or ophthalmopaty. Hashimoto thyroiditis was diagnosed in the presence of clinical signs and symptoms of hyperthyroidism with negative TSH receptor antibodies and elevated thyroid autoantibodies and/or goiter, increased thyroid echogenity on ultrasonography. Relapse was defined as reoccurance of signs and symptoms of hyperthyroidism after at least 18 months of antithyroid drug treatment. Clinical and laboratory data concerning presentation symptoms, signs, thyroid hormones and thyroid antibody levels, treatment regimes, side effects and treatment outcome were retrieved from patient files. The causes of hyperthyroidism were Graves disease in 62 patients, Hashimoto’s thyroiditis in 13 patients, drug or cytokine induced in 4 patients, and TSH receptor activating mutation in 1 patient. The medical records of 62 patients with GD (45 girls and 17 boys ) were examined. Patients with Graves disease presented at the mean age of 11.59±3.65 years, 62.9% of them were pubertal at presentation. Graves disease was seen more often in girls than in boys at puberty. The ratio of girls to boys was 1,3/1 before puberty whereas it was 4,6/1 at puberty (p=0,031). Fifteen patients (24.2%) with Graves disease had family history of hyperthyroidism. At presentation, all patients with Graves disease were started on antithyroid drug treatment. Twenty patients were treated with antithyroid drugs alone, 15 of whom were euthyroid and 5 were hypothyroid after a mean treatment period of 31.86±19.21 months. Twentyfour (60%) patients had vii relapse after mean 36,39±12,62 months of antithyroid drug treatment when the drug was stopped or the dose was decreased. In the follow-up, 19 patients were given radioiodine (RAI) treatment. Two doses of RAI were required in 5 patients whose first radioiodine doses were less than 150 μCi/gram of thyroid tissue. Therefore, we recommend that RAI dose should be at least 150 μCi/gram of thyroid tissue to achieve hypothyroidism and avoid thyroid malignancy. Surgery was performed in 11 patients. The most common causes of surgery or radioiodine treatment were relapse or not achieving remission with medical treatment, antithyroid drug side effects or multinodular goiter. Antithyroid drug side effects were observed in 19 patients (30.6%) with Graves disease which were as follows: elevated transaminases in 12,9%, leukopenia in 9,7%, thrombocytopenia in 3,2%, arthritis/ arthralgia in 3,2% and allergic rash in 1,6% of patients. Antithyroid drug side effects were seen more frequently in prepubertal patients than pubertal patients (43,5% versus 23,1%). Transaminase elevation was observed in six (26,1%) of the prepubertal patients whereas it was seen in two (5,1%) of the pubertal patients (p=0,018). Antithyroid drugs are considered as the first treatment choice in patients younger than 10 years old but transaminase levels should be monitored closely at this age group. Prepubertal patients with Graves disease had significantly lower body mass index SDS than pubertal patients (p=0,037). Two patients with Graves disease were found to have thyroid papillary carcinoma, both had multiple thyroid nodules. Fine needle aspiration cytology was suspicious in one and benign in the other patient while thyroidectomy revealed thyroid carcinoma in both of them. Surgery should be preferred in patients with high TSH receptor antibodies, thyroid nodules or large thyroid in the case of medical treatment failure. Medical treatment duration was significantly shorter in Hashimoto thyroiditis reflecting the transient period of hyperthyroidism (p=0,003). Free T3, free T4 were significantly higher and TSH was significantly lower in Graves disease than in Hashimoto thyroiditis (p<0,001, p=0,002, p=0,038). Graves disease should be considered in patients with severe hyperthyroidism and in the presence of long term antithyroid drug requirement.