Hepcidin and Iron Homeostasis in Patients with Subacute Thyroiditis and Healthy Subjects

Hepcidin is an acute-phase protein involved also in regulation of iron homeostasis. The aim of the study was to prospectively assess for the first time the hepcidin_EL concentration in patients with subacute thyroiditis (SAT), to identify biochemical determinants of hepcidin_EL concentration and evaluate the potential role of hepcidin in SAT diagnosis and monitoring.

Out of 40 patients with SAT initially recruited, restrictive inclusion criteria fulfilled 21 subjects aged 45 ± 10 years and 21 healthy control subjects (CS). Hepcidin_EL concentration, thyroid status, and iron homeostasis were evaluated at SAT diagnosis and following therapy and compared with CS.

The median hepcidin_EL concentration at SAT diagnosis is higher than that in CS (48.8 (15.9-74.5) ng/mL vs. 18.2 (10.2-23.3) ng/mL, p = 0.009) and is significantly lower after treatment (4.0 (1.2-10.0) ng/mL, p = 0.007) compared with CS. The ROC analysis for hepcidin_EL at SAT diagnosis revealed that area under the curve (AUC) is 0.735 (p = 0.009), and the cut-off for hepcidin_EL concentration is 48.8 ng/mL (sensitivity 0.52 and specificity 0.95). Hepcidin_EL in SAT patients correlated with CRP (r = 0.614, p = 0.003), ferritin (r = 0.815, p < 0.001), and aTPO (r = -0.491, p = 0.024). On multiple regression, the correlation between hepcidin_EL and ferritin was confirmed (p < 0.001).

SAT is accompanied by a significant increase in hepcidin, which reflects an acute-phase inflammatory process. Parameters of iron homeostasis improved significantly while inflammatory indices got lower following recovery. The potential role of hepcidin as a predictive factor of the risk of SAT relapse needs to be assessed in studies on larger groups of SAT patients.