Influence of the timing of biological treatment initiation on Juvenile Idiopathic Arthritis long-term outcomes

Background Juvenile idiopathic arthritis (JIA) treatment is aimed at inducing remission to prevent joint destruction and disability. However, it is unclear what is the long-term impact on health-related outcomes of the timing of biological disease-modifying antirheumatic drug (bDMARD) initiation in JIA. Our aim was to evaluate the long-term impact of the time between JIA onset and the initiation of a bDMARD in achieving clinical remission, on physical disability and health-related quality of life (HRQoL). Methods Adult JIA patients registered in the Rheumatic Diseases Portuguese Register (Reuma.pt) and ever treated with bDMARD were included. Data regarding socio-demographic, JIA-related characteristics, disease activity, physical disability (HAQ-DI), HRQoL (SF-36), and treatments were collected at the last visit. Patients were divided into 3 groups ([less than or equal to] 2 years, 2-5 years, or > 5 years), according to the time from disease onset to bDMARD initiation. Regression models were obtained considering remission on/off medication, HAQ-DI, SF-36, and joint surgeries as outcomes and time from disease onset to bDMARD start as an independent variable. Results Three hundred sixty-one adult JIA patients were evaluated, with a median disease duration of 20.3 years (IQR 12.1; 30.2). 40.4% had active disease, 35.1% were in remission on medication, and 24.4% were in drug-free remission; 71% reported some degree of physical disability. Starting a bDMARD > 5 years after disease onset decreased the chance of achieving remission off medication (OR 0.24; 95% CI 0.06, 0.92; p = 0.038). Patients who started a bDMARD after 5 years of disease onset had a higher HAQ and worse scores in the physical component, vitality, and social function domains of SF-36, and more joint surgeries when compared to an earlier start. Conclusion Later initiation of bDMARDs in JIA is associated with a greater physical disability, worse HRQoL, and lower chance of drug-free remission in adulthood. Keywords: Juvenile idiopathic arthritis, Long-term outcomes, bDMARDs, Physical disability, Quality of life