Association of serum IL-2, IL-6, and IL-17 levels with the activity of thyroid-associated ophthalmopathy

Abstract

Objective To investigate the involvement of interleukin(IL)-2, IL-6, and IL-17 in the disease activity of thyroid-associated ophthalmopathy(TAO). Methods The baseline serum levels of interleukin(IL)-2, IL-6, and IL-17, measured by enzyme-1inked immunosorbent assay, were compared among 80 TAO patients, 30 Graves' disease(GD)patients without ophthalmopathy, and 30 healthy subjects(NC)to determine the TAO-associated changes of cytokines. Based on clinical activity score(CAS), TAO patients were divided into non-active or active groups. Then, a cohort of 45 patients with active moderate-to-severe TAO received iv methylprednisolone therapy for 12 weeks, and changes in serum cytokines were evaluated. Results Serum IL-2 levels were gradually increased in NC, GD, and TAO groups(P 0.05), but higher compared with NC group(P 0.05). The serum levels of IL-17 were positively related with CAS and thyrotropin receptor antibody(P<0.01). After methylprednisolone therapy for 12 weeks, significant decreases of IL-6 and IL-17 levels compared to their baseline levels(P<0.05)were observed while IL-2 showed no significant change. Conclusion The serum level of IL-2 was decreased in TAO patients, while the serum levels of IL-6 and IL-17 were increased. In addition, IL-17 might serve as a useful biomarker for evaluating TAO activity. (Chin J Endocrinol Metab, 2015, 31: 946-950) Key words: Thyroid-associated ophthalmopathy; Clinical activity score; Cytokines; Glucocorticoids