The role of oxidative stress in the development of autoimmune thyroiditis: current state of the problem (literature review)

The review article examines the issues of autoimmune thyroiditis (AIT) pathogenesis. Analysis of current scientific data revealed an increase in the number of cases of this disease (6–11 % worldwide among the adult population), and the need for further research to understand its etiology, diagnosis and treatment is emerging. This review considers oxidative stress that is the accumulation of active harmful agents (free radicals, prooxidants, reactive oxygen species), which initiate cell damage and lead to the development of various pathological conditions. The study on the mechanism of free-radical damage caused by reactive oxygen species will open opportunities for the introduction and optimization of antioxidant therapy of patients with AIT in order to slow down the progression of the disease. In the occurrence of damage to thyroid cells, the formation of antibodies and lymphocytic infiltration of the gland play an important role. It has been noted that genetic factors precede the occurrence of pathological changes. Loss of immune tolerance to thyroid autoantigens such as thyroid peroxidase (TPO), thyroglobulin (TG) is the basis for the deve­lopment of AIT. The important role of oxidative stress and reactive oxygen species in the pathogenesis of the disease has been noted. It has been shown that at its onset, AIT is asymptomatic, the formation of antibodies to TPO and TG precedes disease occurrence and may indicate latent AIT. The prevalence of latent AIT varies in different countries of the world and ranges from 2 to 20 %, and among women, it was 4–6 times higher than in men. Over time, latent AIT turns into subclinical and overt thyroiditis with hypothyroidism. The incidence of overt AIT in different countries ranges from 27 to 273 per 100,000 population. Diagnosis of AIT is made by clinical signs, positivity to serum antibodies against TPO, TG and lymphocytic infiltration on cytological examination. The main treatment direction is the management of hypothyroidism with hormone replacement therapy. A relationship between AIT and a possible malignant transformation has been suggested in several studies and involves immunological/hormonal pathogenic links although specific correlation is still debated and needs to be further investigated in prospective studies.