AB0932 PREDICTORS OF FLARE FOLLOWING ETANERCEPT WITHDRAWAL IN PATIENTS WITH RHEUMATOID FACTOR NEGATIVE JUVENILE IDIOPATHIC ARTHRITIS DURING 48 MONTHS OF FOLLOW-UP

Abstract

Background Little is known about the risk of flare after etanercept (ETN) withdrawal in children with Juvenile Idiopathic Arthritis (JIA). Recently we conducted a retrospective chart review of 110 patients with JIA who discontinued ETN due to persistent clinically inactive disease (CID) on medication and were followed up to 12 months after ETN withdrawal. We showed that 60% of patients flared with arthritis. Male gender, presence of ANA and elevated CRP at baseline were associated with higher risk of flare. Objectives To evaluate frequency and timing of flares during 48 months of follow-up after withdrawal of ETN first course in patients with JIA who attained clinical remission on medication and to identify predictors of early flares ( 2). Methods The 110 patients enrolled in the previous study with oligo (o-JIA) and RF-negative polyarticular JIA (p-JIA) who received a first course of ETN for at least 18 months and maintained clinically inactive disease (CID) for at least 6 months on treatment, were followed for 48 months after withdrawal of first course of ETN. We excluded patients that switched or swapped to other biologics or with limited follow-up. Demographic and clinical features at onset, at baseline (initiation of ETN) and at time of disease flares were collected. Results Among the cohort of the study, 10 patients (9%) were lost to follow-up and 18 (16%) switched/swapped to other biologics during 48 months of follow-up after withdrawal of ETN first course. Of the 82 patients included in the analysis, 55 (67%) were treated with only one course of ETN, while 27 (33%) received more than one course of ETN. The median age at disease onset was 3.6 years (IQR 1.9-8.5) and 72% of patients were female, ANA positive patients had a younger age at onset and were more frequently o-JIA. After withdrawal of ETN first course, 70 of the 82 (85%) patients enrolled flared with arthritis, without evident differences between o-JIA and p-JIA. Disease duration at diagnosis and at ETN start, total number of joints involved and total MTX treatment duration were not associated with flare. Patients who flared were more frequently males (p=0.017) and ANA positive (p=0.026), presented with higher levels of CRP (p=0.029) at baseline and had longer total ETN treatment duration (p=0.0046). Higher values of CRP were associated with a higher risk of repeated flares (p=0.0094). No predictors of early flares were identified in this group. When we analysed the 55 patients treated with one course of ETN, 48 (87%) flared during follow-up. Patients who flared were more frequently ANA positive (p=0.015), presented higher CRP levels (p=0.042) at baseline and concomitant MTX at ETN withdrawal (p=0.009). Higher levels of CRP was also associated with higher numbers of repeated flares (p=0.049). No predictors of early flares were identified in this subgroup. Conclusion Our results show that almost 90% of patients with JIA experience at least one flare after ETN withdrawal during 48 months of follow-up. Our findings confirmed that male gender, positive ANA and elevated CRP at baseline are associated with a higher risk of flare. Higher CRP levels at baseline resulted also associated with a higher risk of repeated flares.