Adipocytokines in Graves' orbitopathy and the effect of high-dose corticosteroids

Abstract

Graves' orbitopathy (GO) is a serious, progressive eye condition seen in patients with autoimmune thyroid disease. GO is characterized by inflammation and swelling of soft orbital tissues. Adipose tissue produces cytokine mediators called adipokines. The present study focuses on the relationship between serum levels of selected adipokines in patients with GO, comparing them with the control group, and uniquely describes the effect of high-dose systemic corticosteroids (HDSC) on their levels. For the purposes of this study, we collected blood samples before and after the treatment with HDSC from 60 GO patients and 34 control subjects and measured serum levels of adiponectin, AIF-1, A-FABP and FGF-21. Levels of adiponectin significantly differed among the three study groups (ANOVA p = 0.03). AIF-1 levels were also significantly different among the study groups (ANOVA p < 0.0001). AIF-1 was significantly associated with the presence of GO after adjusting for clinical factors (age, sex, smoking and BMI) and level of TSH (odds ratio 1.003, p < 0.01). This finding could enforce targeting macrophages in treatment strategies for GO since AIF-1 is considered as a marker of their activation.

Keywords: Graves’ orbitopathy; adipokines; methylprednisolone.

Figure 1

Levels of studied adipokines in controls, patients before HDSC and after HDSC. Panel A: adiponectin (μg/ml); Panel B: AIF-1 (pg/ml); Panel C: A-FABP (ng/ml); Panel D: FGF-21 (pg/ml). Y axis concentrations are in log 10. *p < 0.05 and †p < 0.001 in patients before treatment vs. control group, @p < 0.001 in patients after treatment vs. control group