Serum hepcidin evaluation as a promising biomarker in juvenile idiopathic arthritis

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.

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.

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.

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.