Elevated interleukin-1 in peripheral blood mononuclear cells contributes to the pathogenesis of autoimmune thyroid diseases, especially of Hashimoto thyroiditis

Purpose of the study: To explore the relationship between IL-1 expression and two common autoimmune thyroid diseases: Hashimoto thyroiditis (HT) and Graves' disease (GD). Materials and methods: qRT-PCR, Quantiglo ELISA, and flow cytometry were used to evaluate the expression levels of IL-1 in serum, peripheral blood mononuclear cells (PBMCs), and thyroid tissue samples from patients with HT or GD. Local infiltration of monocytes was assessed by immunohistochemical study of patients' thyroid tissue samples. Results: Although no significant differences in IL-1 levels were found between samples of serum from patients with HT or GD and normal controls, we found that IL-1 mRNA and protein levels in PBMCs of HT patients were significantly higher than those of patients with GD, which were in turn higher than the level in normal controls. In addition, IL-1 mRNA was also increased in thyroid gland tissue from patients with HT compared to those with GD, and this was accompanied by increased local infiltration of monocytes into thyroid tissues. Correlation analysis of the clinical samples validated the association of high IL-1 levels with the pathogenesis of HT. Conclusion: Our study suggests that IL-1 may be an active etiologic factor in the pathogenesis of HT and thus present a new target for novel diagnostics and treatment.