ABSTRACT
PURPOSE: To study the levels of pathogenic and non-pathogenic Th17 and Th22 cells in autoimmune thyroid disorders patients. Although Th17 cells seem to play an important role in the pathogenesis of thyroid autoimmune disorders, the specific subsets of these lymphocytes have not been analyzed in this condition. METHODS: We assessed the levels of Th17 (pathogenic and non-pathogenic) and Th22 cells in peripheral blood and thyroid glands of autoimmune thyroid disorders patients (n = 26, 16 with Graves' disease and 10 with Hashimoto's thyroiditis) and 15 healthy controls by multi-parametric flow cytometry and immunofluorescence microscopy. RESULTS: We found increased levels of pathogenic Th17 lymphocytes and Th22 cells in peripheral blood from autoimmune thyroid disorders patients. In addition, these cells were detected in thyroid glands from HT patients. Furthermore, we found significant correlations between the levels of these cells and disease activity, disease duration, and the presence of ophthalmopathy. CONCLUSIONS: The increased levels of pathogenic Th17 lymphocytes and Th22 cells in autoimmune thyroid disorders suggest their involvement in the pathogenesis of this condition.