Evaluation of clinical, laboratory, and treatment follow-up of children diagnosed with chronic autoimmune thyroiditis (hashimoto's disease)

Chronic autoimmune thyroiditis is an autoimmune disease. In areas where iodine supplementation is provided, goitre is the most common cause of acquired hypothyroidism in children and adolescents. It is thought to develop due to the interaction of endogenous and environmental factors. In the study, the records of patients diagnosed with autoimmune thyroiditis (AT) and followed up in the Pamukkale University Faculty of Medicine Paediatric Endocrinology Clinic between 2012 and 2022 were examined retrospectively, and the aim was to evaluate their clinical and laboratory data. Cases were grouped according to thyroid functions. 326 (52.7%) were euthyroid, 139 (22.5%) were subclinical hypothyroid, 49 (7.9%) were compensated hypothyroid, 67 (10.8%) were overt hypothyroid, and 38 (6.1%) were hyperthyroid. The average age was 12.37  3.65 years. The averages of euthyroid and hyperthyroid cases were higher than those of compensated hypothyroid cases. The girl/boy ratio was 4.5/1. The mean height SDSs were within the normal range of -0.16  1.31. The average bone age was found to be 0.16  1.36 years behind. The mean BMI-SD values were within the normal range of 0.16  1.44. There was no difference between thyroid function groups in all these data. Of the 593 cases with pubertal evaluation, 152 (26%) were prepubertal and 441 (74%) were pubertal. The number of pubertal cases was high in all groups. Goitre was detected in 168 (27%) cases during a physical examination. Goitre was more common in girls than boys and in overt hypothyroidism in thyroid function groups. At admission, there was neck swelling in 42 (6.8%) of the cases, growth retardation in 34 (5.5%), fatigue-weakness in 30 (4.8%), and hair loss in 30 (4.8%). There was rapid weight gain in 30 (4.8%), constipation in 12 (1.4%), and menstrual irregularity in 19 (8.8%) of 215 menstruating cases. There were no symptoms or findings in 316 (51%) cases. The 118 (19%) cases were accompanied by autoimmune disease. The most common was type 1 diabetes mellitus, with 79 (12%) cases. The 7 (1.1%) cases were diagnosed with Down syndrome and the 5 (0.8%) cases with Turner syndrome. Autoimmune disease developed in 13 (2.6%) of the 501 cases that did not have autoimmune disease during follow-up. First-degree relatives of 109 (17.6%) cases and other relatives of 51 (8.2%) cases had thyroid disease. TPOAb was 80% positive, and TGAb was 74.2% positive. Both were positive in 52.8% of cases. Both antibody levels were lower in the euthyroid group than in the other groups. The thyroid volume-SD mean was high at 2.7  5.6. There were 345 (87.7%) cases with thyroiditis findings on ultrasound. While there was no significant difference between thyroid volume-SD and thyroid function groups, AT findings were most frequently seen in overt hypothyroidism. There were nodules in 67 (17%) of the cases, and papillary thyroid cancer developed in 2 cases during follow-up. Levothyroxine (LT4) was started on admission in almost all hypothyroid cases. The average starting dose of LT4 was 1.48  0.81 mcg/kg/day. The initial dose was higher in overt hypothyroidism. LT4 was started in 7% of euthyroid cases during follow-up. It was observed that 88% of euthyroid cases who were followed for at least one year remained euthyroid. During the follow-up, no statistically significant difference was detected in autoantibody levels between years in the general group and thyroid function groups. As a result, early diagnosis and treatment of hypothyroidism due to AT is important, especially in preventing growth losses. Cases with AT need to be followed up for autoimmune diseases and thyroid cancers that may develop during follow-up. First-degree relatives should also be evaluated for AT. While the thyroid functions of children with AT may improve over time, progression to hypothyroidism may also occur, so cases should be followed up regardless of whether they receive treatment. Keywords: chronic autoimmune thyroiditis, Hashimoto's thyroiditis, autoimmune thyroid diseases, thyroid dysfunctions