Aggrecan, Biglycan, and Decorin as Potential Biomarkers of Osteoarticular Changes in Juvenile Idiopathic Arthritis

<p>Proteoglycans and their fragments can potentially serve as diagnostic or theragnostic bi-omarkers for diseases characterized by dysregulated extracellular matrix remodeling, such as juvenile idiopathic arthritis. Therefore, our study aimed to evaluate the diagnostic utility of plasma proteoglycan profiles—i.e., aggrecan, decorin, and biglycan—released from osteoarticular structures into the blood of children with juvenile idiopathic arthritis, as potential biomarkers of tissue destruction and/or indicators of the efficacy of therapy with the biologic agent etanercept. The study was conducted on 263 blood samples col-lected from 25 healthy children and 34 children with juvenile idiopathic arthritis at vari-ous stages of the disease: immediately after diagnosis, following treatment with disease-modifying antirheumatic drugs (methotrexate, sulfasalazine, and prednisone), and during 3, 6, 12, 18, and 24 months of therapy with etanercept. Quantitative levels of aggrecan, biglycan, and decorin were measured using ELISA kits. In children with JIA, plasma aggrecan levels were elevated at diagnosis, decreased after ineffective DMARD therapy, and increased again at 24 months of etanercept treatment despite clinical improvement. In contrast, biglycan levels remained unchanged compared to healthy controls but declined significantly during etanercept therapy, while decorin levels were elevated in untreated and DMARD-treated patients yet normalized after 24 months of biologic treat-ment. In summary, decorin appears to be the most promising biomarker for both the di-agnosis and monitoring of etanercept therapy in juvenile idiopathic arthritis, while bi-glycan seems to be the best biochemical marker for monitoring the effectiveness of ETA therapy in JIA.</p><p><br /></p>