Clinical and pathogenetic features of thyropathies diagnosed during the post-COVID-19 period

Introduction. The past COVID-19 pandemic has influenced the course of many diseases including endocrine pathology. However, little is known about the clinical and pathogenetic features of thyroid pathology of the post-COVID-19 period.Aim. Evaluate the clinical and pathogenetic features of thyropathies diagnosed during the post-COVID-19 period.Materials and methods. A cross-sectional study included 250 patients with newly diagnosed thyroid diseases. 73 participants denied a history of COVID-19 and 177 suffered from it within the previous 9 months. Thyroid status and thyroid ultrasound examination were assessed. IgG SARS-Cov-2 levels were tested in 40 patients with a history of COVID-19. Fine needle aspiration biopsy was performed in 61 patients including 41 with a history of COVID-19. In the main group, all the samples were additionally investigated by immunocytochemical analysis with SARS-CoV-2 protein antibodies.Results. Among the patients with COVID-19 history higher levels of fT4 (13.6 [12.4; 15.5] vs 12.8 [11.0; 15.3] µmol/l, p = 0.046) and a lower proportion of patients with euthyroidism (122 (68.9%) vs 59 (80.8%), p = 0.037) were detected. In the main group there were more cytological samples with macrophages accumulations (16 (39.0%) vs 2 (10.0%), p = 0.017), however, immunocytochemical study did not reveal any SARS-Cov-2-positive samples. During the post-COVID-19 period, approximately 60% of patients with subclinical thyroid dysfunctions experienced spontaneous normalization. There were correlations between IgG SARS-Cov-2 levels and parameters characterizing the structural and functional state of the thyroid gland.Conclusion. The most typical clinical feature of post-COVID-19 thyropathies was a smaller proportion of individuals with euthyroidism. Mild thyroid dysfunctions identified during the post-COVID-19 period tended to develop spontaneous normalization in 60% of cases. The immunocytochemical tests indicate the absence of SARS-Cov-2 persistence in the thyroid tissue. COVID-19-associated immunopathological reactions are involved in the pathogenesis of post-COVID-19 thyropathies.