Achille Marino, Marco Pandolfi, Maria Giovanna Lommano, Stefania Costi, Francesco Baldo, Saverio La Bella, Cecilia Beatrice Chighizola, Nicolino Ruperto, Roberto Caporali, Paediatric Rheumatology International Trials Organisation (PRINTO) and the Pediatric Rheumatology of the Milan and Lombardy Area (PRAGMA)
The progressive elucidation of juvenile idiopathic arthritis (JIA) pathogenesis has led to growing interest in biomarkers to support diagnosis, subset classification, detection of subclinical inflammation, and/or prediction of disease course and therapeutic response (theragnostic biomarkers). JIA management in clinical practice currently follows a 'trial and error strategy', in which the treatment with the highest response chances is selected mainly based on the clinical phenotype. However, this strategy poses significant challenges, as a substantial proportion of patients fail to achieve sustained remission or experience disease flares. Here, we discuss key determinants of personalized medicine in non-systemic JIA, including ultrasound imaging, synovial fluid and tissue analysis, and circulating biomarkers. In the future, integrating multidimensional data may offer a unique opportunity to identify distinct disease endotypes, anticipate disease trajectory, and, once prospectively validated, inform targeted therapeutic strategies.