Background Juvenile idiopathic arthritis (JIA) is the most frequent rheumatic disease in children with a progressive disabling course when not adequately treated, and often with persisting activity into adulthood. The primary treatment target in JIA is to achieve the clinical remission or at least minimal disease activity (Consolaro et al. 2012). An early aggressive treatment is given taking into account the “window of opportunity” (Hinze et al. 2015). Close monitoring (every 1–3 months (mo) during active disease) with appropriate therapeutic adaptation to reach the desired state within 3 to a maximum of 6 mo is recommended (Smolen et al. 2010).

Objectives To evaluate the implementation of treat to target (T2T) recommendations into practice during the first 6 mo on biological treatment (BT) in estonian JIA patients.

Methods Retrospective review of monitoring the disease activity in JIA patients in whom BT was started during the period Jan 1st 2013-June 30th 2014. Disease activity was estimated according to ACR 2011 criteria (Magni-Manzoni et al. 2008, Wallace et al. 2011) at the start of BT, at 3-4 mo, and at 6 mo on BT.

Results During the study period, BT was started in 32 patients (14 boys, 18 girls). Mean age at the onset of JIA was 8y 10mo ±5.5; mean disease duration at the start of BT was 2y 4mo ±2.6. All subtypes of JIA were represented in the study group, 16 of patients were with polyarticular disease course. 91% of patients received anti-TNFα medications.

The mean number of active joints at the start of BT and at 3-4 mo after differed significantly (3.5±4.4 vs 1.3±2.4; p<0.0001); the same was found when comparing the values at the start and at 6 mo on BT (3.5±4.4 vs 1.2±2.4; p<0.001). The tendency was the same for the mean number of joints with limitation of motion (LOM) and physician's visual analogue scale (VAS); the differences were statistically relevant. The mean value of erythrocyte sedimentation rate (ESR) was lower at 3-4 mo on BT than at the start (4.4±3.4 vs 8.7±7.6; p=0.0116). No difference was found when comparing the mean values of ESR at 6 mo and at the start; at 6 mo the mean value was significantly higher than at 3-4 mo (6.5±5.7 vs 4.4±3.4; p=0.0046), which might reflect the diminishing of the effect of BT. The latter finding is supported by the fact that the mean numbers of active joints, joints with LOM and physician's VAS at 6 mo on BT did not show relevant differences when comparing with the values at 3-4 mo. In 7 cases the BT was changed due to ineffectiveness or unwanted reactions.

The primary treatment target - inactive disease or minimal disease activity (in oligo-, poly- and systemic arthritis patients) was achieved in 18/27 (66.7%) at 3-4 mo and in 17/27 (63%) patients at 6 mo.

Conclusions Tight monitoring of disease activity during the first 6 months on BT using the ACR criteria gives a good overview of the effectiveness of the treatment. The implementation of recommendations of T2T into everyday practice serves the aim of achieving at least minimal disease activity or even remission.

Disclosure of Interest None declared