Background Currently, biological agents are not approved for the treatment of persistent oligoarticular juvenile idiopathic arthritis (oJIA). However, there are persistent oJIA patients unresponsive to the conventional treatment consisting of NSAIDs, intra-articular corticosteroids (IAS) and methotrexate (MTX), in whom biological treatment is considered.
Objectives We aimed to evaluate the effectiveness and safety of TNF-blocking agents in all Dutch patients with persistent oJIA included in the Arthritis and Biologicals in Children (ABC) register until February 2011. An additional aim was to explore if persistent oJIA patients treated with TNF inhibitors resemble other non-systemic JIA patients (patients with all JIA categories except systemic JIA) included in the register.
Methods The Dutch Arthritis and Biologicals in Children Register is an ongoing multicenter prospective study which, since 1999, has aimed to include Dutch children with JIA using biological agents. Response to biological treatment was evaluated using the JIA core-set disease-activity variables and the Wallace criteria for inactive disease.
Results Until February 2011, sixteen persistent oJIA patients (68.8% female) had been included in the register. Median age at onset was 8.4 years (IQR 2.1-13.5), 18.8% had a history of uveitis, and 56.3% were ANA-positive. All had previously been treated with MTX, and 81.3% with IAS. Most patients started etanercept; adalimumab was started in two patients who had active arthritis and uveitis. Median follow-up after introduction of biological treatment was 13.7 months (IQR 8.3-16.7). Though patients with persistent oJIA had less affected joints, they had similarly high patient/parent assessments of pain and wellbeing as other non-systemic JIA patients treated with TNF-inhibitors. Additionally, their physician evaluated the disease activity as moderately high.
After 3 months of treatment, disease activity had decreased and the disease was inactive in 63% of patients. Joint counts decreased from a median of two (IQR1-4) to no active joints (IQR 0-2); the physician global assessment of disease activity decreased from median 36 (IQR 4-65) to zero (IQR 0-30). After 15 months the disease was inactive in 90% of patients. TNF-alpha blockers were tolerated well.
Conclusions TNF-blocking agents seem an effective and justifiable option in persistent oJIA when treatment with IAS and MTX has failed. On some measures of disease activity, the persistent oJIA patients currently treated with TNF-inhibitors resemble other non-systemic JIA patients from our register. Larger studies are needed to identify factors that characterize these more severely affected persistent oJIA patients, so treatment strategy for these patients can be adapted in an early stage of the disease.
Disclosure of Interest J. Anink: None Declared, M. Otten: None Declared, F. Prince: None Declared, E. Hoppenreijs: None Declared, N. Wulffraat: None Declared, J. Swart: None Declared, R. ten Cate: None Declared, M. van Rossum: None Declared, J. van den Berg: None Declared, K. Dolman: None Declared, Y. Koopman-Keemink: None Declared, W. Armbrust: None Declared, S. Kamphuis: None Declared, P. van Pelt: None Declared, S. Gorter: None Declared, L. van Suijlekom-Smit Grant/Research support from: Dutch Board of Health Insurances, Pfizer International, Abbott, Consultant for: Pfizer International