Investigation of the Triggering Role of Infectious Agents in the Pathogenesis of Autoimmune Thyroiditis in Children and Adolescents

Objective: Autoimmune thyroiditis (AIT) is a common endocrine disorder in paediatrics. Although genetic and environmental factors contribute to its development, infectious agents have also been considered as triggers. This study examined the potential role of Epstein–Barr virus (EBV), cytomegalovirus (CMV), parvovirus B19, HIV, HCV, and toxoplasma gondii in paediatric AIT. Öz Amaç: Otoimmün tiroidit (AIT), pediatrik endokrinolojide yaygın görülen bir hastalıktır. Genetik ve çevresel faktörlerin yanı sıra enfeksiyöz ajanların da hastalığın gelişiminde rol oynayabile ceği öne sürülmüştür. Bu çalışma, EpsteinBarr virüsü (EBV), sitomegalovirüs (CMV), Parvovirüs B19, HIV, HCV ve Toxoplasma gondii'nin pediatrik AIT'deki potansiyel rolünü incelemektedir. Material and Methods: Forty nine patients (aged 1–18 years) who presented to the Paediatric Infectious Diseases and Paedi atric Endocrinology outpatient clinics and were diagnosed with autoimmune thyroiditis (AIT) within the previous six months were included in the study. Viral serology was routinely performed during the evaluation for lymphadenopathy in the Paediatric Infectious Diseases clinic. The diagnosis of AIT was based on positive thyroid autoantibodies (antiTG, antiTPO, and TSI), with or without thyroid dysfunction, and ultrasound findings suggestive of thyroiditis. Clinical and laboratory data were retrospectively analysed using SPSS version 22. Results: The median age was 13.1 years (IQR: 4.6). Of the patients, 14.3% (n=7) were male and 85.7% (n=42) were female. Four patients had Graves' disease, and the rest had Hashimoto's thyroiditis. Treatment was required in 53.1% (n=26). Parvovirus IgM was positive in three patients, EBV VCA IgM in four, and both in one. No significant differences in antiTPO or antiTG levels were found between the seropositive and seronegative patients. No cases had HIV or HCV, and 97% tested negative for Toxoplasma gondii antibodies. Conclusion: Parvovirus B19 and EBV may contribute to AIT pathogenesis, but larger studies are needed to confirm these findings.