ESPE Abstracts

Background: The pathogenesis of autoimmune thyroid diseases depends on many factors including genetic predisposition and environmental factors. Graves' disease and Hashimoto's thyroiditis are associated with an impaired immunological tolerance to antigen molecules in the thyroid gland. Abnormal immunotolerance results from impaired suppression involving regulatory T cells in peripheral immunocompetent tissues (Tregs). It is known that patients with autoimmune thyroid diseases are more likely to develop focal lesions in the thyroid tissue, and Hashimoto's thyroiditis and Graves' disease predispose to thyroid cancer. We would like to evaluate the levels of microRNA molecules (miR-15a-5p, miR-126-3p, miR-142-5p and miR-150-5p) in children with thyroid disorders, and their predisposition to cancer. MicroRNAs (miRNAs) are small non-coding RNA molecules, approximately 22 nucleotides long, that regulate gene translation by silencing or degrading target mRNAs. They are involved in many biological processes relevant to pathogenetic processes. Due to their important involvement in many processes, including proliferation, metabolism, haemostasis, apoptosis and inflammation, they are recognised as novel diagnostic and prognostic biomarkers for many diseases. There are no studies evaluating the concentration of these molecules in children.

Aim: The aim of this study is to analyse blood concentrations of miR-15a-5p, miR-126-3p, miR-142-5p and miR- 150-5p in pediatric patients with Graves' disease, Hashimoto's thyroiditis and nodular thyroid compared to a control group of healthy subjects.

Methods: The study includes a population of children and adolescents aged 10-18 years with autoimmune thyroid diseases and nodular thyroid. The study group was divided into 40 subjects with Graves' disease, 26 subjects with Hashimoto's thyroiditis, 21 subjects with nodular thyroid and a control group of 23 healthy subjects. The miR-15a-5p, miR-126-3p, miR-142-5p and miR-150-5p molecules will be determined by immunoassay using BioVendor reagents.

Results: In the group of patients with autoimmune thyroid diseases there are higher concentrations of miR-15a-5p molecule compared to the control group of healthy patients, while miR-126-3p and miR-142-5p, miR-150-5p molecules are lower in patients with nodular thyroid disease. The analysis of blood concentrations of these molecules in clinical practice will allow us to determine the predisposition to the development of autoimmune thyroid disease and nodular disease and possibly detect symptoms of thyroid gland dysfunction earlier and start treatment accordingly.