Clinical Course of Hashimoto's Thyroiditis and Effects of Levothyroxine Therapy on the Clinical Course of the Disease in Children and Adolescents

OBJECTIVE The aim of this study was to evaluate the clinical course of Hashimoto's thyroiditis (HT) in children and adolescents and the effects of levothyroxine therapy on the clinical course and laboratory findings. METHODS The clinical and laboratory data of 101 patients with HT at presentation and during a three-year follow-up period were retrospectively evaluated using patient records. RESULTS The mean age of the patients at the time of diagnosis was 12.3 ± 2.90 years and female/male ratio was 5.7/1. The complaint at the time of hospital presentation was goiter in 57.8% of the patients. At baseline, 36.7% of the patients were euthyroid, whereas 32.7% had subclinical hypothyroidism, 16.6 % of subjects were evaluated as hypothyroid. Twelve of the 28 patients who were initially euthyroid and not receiving therapy developed subclinical or overt hypothyroidism during the first 18 months of the follow-up period and were started on thyroid medication. At presentation, the mean anti-thyroglobulin (anti-Tg) and anti-thyroperoxidase antibody levels were 450 ± 725 IU/mL and 392 ± 428 IU/mL, respectively and at the end of the follow-up period, a significant decrease was observed in the anti-Tg levels of patients receiving levothyroxine from the beginning. CONCLUSIONS Thyroid functions of the patients with HT should be monitored periodically for hypothyroidism. Levothyroxine therapy may positively affect the clinical course of the disease and the antibody titers.