Evaluation of serum ferritin and its correlation with disease activity in non-systemic juvenile idiopathic arthritis

Abstract

Background: Serum ferritin is considered as an acute phase reactant that often increases in presence of an active inflammation. Its status as a disease activity marker is well-established in systemic juvenile idiopathic arthritis (JIA), but underexplored in other categories. The objective of this study was to evaluate the relation of serum ferritin with disease activity in non-systemic categories of JIAMethods: A prospective analytical study was carried out involving 46 JIA patients (diagnosed and categorized on the basis of ILAR criteria) with high disease activity based on juvenile arthritis disease activity score27 (JADAS27). childhood health assessment questionnaire (CHAQ), erythrocyte sedimentation rate (ESR), serum ferritin, pain VAS (visual analog scale), parent global VAS, JADAS27 were measured at initial visit, six months and one year.Results: 40 (21 female, 19 male) out of 46 patients completed follow-up of 1 year. Amongst them, 11 patients had systemic arthritis, 10 had oligoarthritis, 11 had RF positive polyarthritis and 8 had RF negative polyarthritis. Their median ages at the initial visit were 7, 6.5, 8 and 7.5 years respectively. Serum ferritin, CRP, ESR, CHAQ score and JADAS decreased over time in all four categories of JIA. Median ESR, ferritin, CHAQ and JADAS27 were higher in systemic JIA compared to other groups in all three visits. Serum ferritin significantly correlated with JADAS27 at all three visits in systemic arthritis; at initial visit in oligoarthritis; at initial visit and 6 months in both RF positive and RF negative polyarthritis.Conclusions: In patients with systemic JIA, serum ferritin showed significant correlation throughout disease course even when the disease activity was low. But in non-systemic categories of JIA serum ferritin had a significant positive correlation with disease activity only when the disease activity was high.