AB0940 OBESITY AND NUMBER OF ACTIVE JOINTS AT TUMOR NECROSIS FACTOR-INHIBITOR START ARE ASSOCIATED WITH SHORTER REMISSION DURATION AFTER WITHDRAWAL IN PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS: PRELIMINARY RESULTS FROM A MONOCENTRIC COHORT

Background No recommendations on appropriate withdrawal of tumor necrosis factor-inhibitors (TNFi), once remission status has been achieved in patients with juvenile idiopathic arthritis (JIA), are currently available1. With regards to possible predictors of flare, the role of obesity has not been investigated yet. Objectives To investigate to role of obesity at start of TNFi therapy on remission duration and flare rate after TNFi withdrawal in JIA patients. Methods The charts of JIA patients followed at the study center and treated with TNFi as first biologic from 2009 to 2015, who reached remission and with at least one year of follow up after withdrawal, were retrospectively reviewed. Exclusion criteria were: systemic JIA and pJIA RF-positive. Demographic and clinical features were registered, including: ILAR JIA subtype, occurrence of uveitis, ANA status, number of active joints at TNFi start and at flare onset, BMI (z-score and percentile at time of biologic withdrawal for determining obesity, overweight and underweight), concomitant DMARDs. For each patient we registered the remission duration and the occurrence of flare after 12 months from TNFi withdrawal. For comparison of continuous and categorical variables we respectively used the Mann-Whitney and Fisher’s exact probability test. Spearman’s test was used for correlation analysis. Data were expressed as median and interquartile range (IQR 25-75) and analyzed with SPSS 25.0. P values Results 57 JIA patients were included: 34 of them (59.6%) flared within 12 months after TNFi withdrawal with a median of 5 months (IQR 3-8). Obesity was found in 6 patients (10.5%), overweight in 7 (12.2%) and underweight in 6 (10.5%). No statistically significant difference in the aforementioned factors was found in patients who flared, if compared with patients who did not flare. In obese patients we observed a shorter remission duration (p = 0.04). In addition, remission duration was inversely correlated with the number of active joints at TNFi start (r = -0.40 p = 0.03). A multiple linear regression analysis was performed with remission duration as dependant variable and active joints at TNFi start (p = 0.007; B = -0.47) and obesity (p = 0.05 B = 0.31) as explanatory variables. Conclusion In our cohort the number of active joints at TNFi start and obesity were both associated to shorter remission duration after anti-TNF withdrawal. In particular obesity, a modifiable factor involved in several pathological conditions, should be handled more carefully in order to optimize JIA management. Larger studies need to confirm our preliminary data. References [1] Shoop-Worrall SJW, Kearsley-Fleet L, Thomson W, Verstappen SMM, Hyrich KL. How common is remission in juvenile idiopathic arthritis: A systematic review. Semin Arthritis Rheum. 2017Dec;47(3):331-337. Disclosure of Interests Fabio Basta: None declared, Hanan Jadoun: None declared, Maria Isabella Petrone: None declared, Angela Aquilani: None declared, Andrea Uva: None declared, Rebecca Nicolai: None declared, Fabrizio De Benedetti Grant/research support from: Abbvie, SOBI, Novimmune, Roche, Novartis, Sanofi, Pfizer, Silvia Magni-Manzoni Consultant for: Abbvie, Speakers bureau: Abbvie