Interleukins as markers of inflammation in malignant and benign thyroid disease

Thyroid disorders, including thyroid cancer and autoimmune thyroid diseases, have been closely associated with inflammation. This study aims to investigate the role of inflammation in thyroid disease by assessing serum cytokine levels in patients with malignant and benign thyroid conditions. Serum levels of ten interleukins (IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 and IL-13) were quantitatively determined in 20 patients with thyroid cancer, 38 patients with benign thyroid disease and 50 healthy controls by multiplex technology. Serum IL-1 beta, IL-2, IL-4, IL-5 and IL-6 levels were strongly associated with each other. IL-10 and IL-12 correlated with IL-1 beta, IL-5, IL-6, and with each other. Age was inversely correlated with serum levels of IL-2, IL-4 and IL-13. A positive correlation between T3 and IL-13 levels was also observed. Significantly higher levels of IL-6, IL-7, IL-10 and IL-13, as well as significantly lower levels of IL-8 were observed in patients with benign and malignant thyroid disease compared to controls. The combination of IL-13 and IL-8 in a two-marker panel was highly efficient in discriminating thyroid disorders (AUC 0.90). Malignant and benign thyroid conditions are associated with altered expression levels of interleukins, supporting the association between thyroid disease and underlying inflammatory processes.