Objectives: To analyze the inf luence of the CTLA-4(+49G/A)rs231775 gene polymorphism on the degree of thyroid gland enlargement in patients operated for nodular goiter secondary to autoimmune thyroiditis (NGAIT) and thyroid adenomas (TA). Also, to analyze the clinical course of the disease, depending on the genotype of this gene.
Methods: The CTLA-4 (rs231775) genes’ polymorphism was studied by Real-Time Polymerase Chain Reaction in 95 patients with NGAIT, 30 patients with TA and 25 healthy individuals.
Results: It has been found that, in patients with nodular goiter secondary to autoimmune thyroiditis, hyperplasia of the thyroid gland is associated with the wild A allele of the CTLA-4 gene (AA- and AG-genotypes): IB and III levels of hyperplasia are more likely to occur in carriers of the AA genotype by 30.13% and 26.35%, and the second degree of the thyroid gland enlargement- in patients with the AG-genotype by 33.52% and 34.04%, respectively.
Conclusions: The incidence of hypertrophic form of autoimmune thyroiditis is associated with AA- and AG-genotypes of the CTLA-4 gene, characterized by a particular severity, with the rapid development of an “aggressive“ proliferative process in the thyroid tissue, according to sonographic findings. The carrier of the GG genotype is associated with atrophic origin of autoimmune thyroiditis; the tissue is characterized by a high content of cells in which there are atypical or follicular changes of an unclear genesis.
Key words: nodular goiter secondary to autoimmune thyroiditis, adenoma of the thyroid gland, hyperplasia, APO-1 / FAS, CTLA-4 and BCL-2 gene polymorphisms.
Abbreviations: NGAIT – nodular goiter with autoimmune thyroiditis, AIT- autoimmune thyroiditis, TG – thyroid gland, TA – thyroid adenoma.