Serum hepcidin evaluation as a promising biomarker in juvenile idiopathic arthritis.

Objectives: An important area of research in juvenile idiopathic arthritis (JIA) aims to identify sensitive and reliable biomarkers of disease activity. The key iron-regulatory hormone hepcidin-25 (HEP) has been advocated as a potential biomarker to assess anaemia of chronic disease and iron deficiency in adults with rheumatoid arthritis.

Methods: We performed a cross-sectional study evaluating the utility of serum HEP in 79 non-systemic onset JIA patients (14 males, 65 females), with/without anaemia, determining its correlations with disease activity, assessed by the JIA Disease Activity Score (JADAS)-27, anaemia parameters, and iron status indices.

Results: Significant positive correlations for serum HEP levels were found with the JADAS-27 score (r=0.8988, p<0.0001), and significant differences were found in HEP serum levels between active and inactive patients (8.6 IQR 10.0 ng/mL vs. 2.9 IQR 1.9 ng/mL; p<0.0001). Mean serum HEP concentrations were significantly greater in high disease activity group than in others (p<0.0001). At the ROC curve, an HEP level >4.35 ng/mL discriminated subjects with active disease with a sensitivity of 91.8% and a specificity of 80.0% (AUC: 0.93; 95% CI: 0.88-0.98). Moreover, HEP levels were significantly higher in anaemic, iron repleted and active disease patients.

Conclusions: HEP is associated with JIA disease activity, and it could be useful in early detection and monitoring of disease exacerbations. These findings highlight that inflammation plays a major role in HEP induction and point out that HEP could be directly implicated in the JIA inflammatory cascade.