OA36 Systemic juvenile idiopathic arthritis: the Great Ormond Street Hospital experience (2005-2021)

Abstract Background/Aims sJIA is a complex, systemic-inflammatory disorder. The proposed biphasic model of disease suggests that unchecked early auto-inflammation driven by increased innate immune activation, including dysregulation of IL-1 and IL-6, may lead to a state of chronic T-lymphocyte activation. This leads to an unfavourable balance of T-effector and regulatory cells that can drive chronic arthritis over time. It is therefore unsurprising that there is growing evidence to support instigation of IL-1 or IL-6 blockade as first-line treatment in sJIA. Early cytokine antagonist therapy could abrogate development of a population of these arthritis-causing T-cells to avert chronic systemic inflammation and arthritis. Aims: 1) describe clinical presentations, therapeutic interventions, complications, and remission rates at different time-points over disease course in sJIA; 2) identify potential therapeutic signals in patients with sJIA who received biologic treatment early in disease course compared to those who did not. Methods Retrospective review of all patients with sJIA at GOSH (02/10/05-21/10/21, inclusive). Data collected: patient demographics; clinical and laboratory data; treatment history; adverse events. Time-points for data collection: at diagnosis; 3-months; 1-year; last follow-up. Descriptive statistics reported as median and range or IQR for continuous variables, and as absolute frequencies and percentages for categorical variables. Comparisons of quantitative variables were made by Mann-Whitney U-test. Categorical data were compared using Fisher’s exact test (p-values0.05 were considered significant). Results A total of 76 children (female n = 40, 53%) were diagnosed with sJIA; median age was 4.5 years (range 0.6-14.1). A biologic disease modifying anti-rheumatic drug (bDMARD) alone was commenced as first-line treatment in 28% (n = 21/76) of the cohort; however, at last review, 84% (n = 64/76) had received treatment with a bDMARD. Clinically inactive disease (CID) was achieved by 88% (n = 67/76) of the cohort at last review; however, only 32% (24/76) achieved treatment-free CID. At 1-year follow-up, CID was achieved in a significantly greater proportion of children who received treatment with a bDMARD within 3-months of diagnosis compared to those who did not (90% versus 53%, p = 0.002). Conclusion We propose a UK treatment-algorithm for children diagnosed with sJIA (see figure). We recommend reappraisal of the current NHS England commissioning policy. Disclosure C. Foley: None. D. McKenna: None. K. Gallagher: None. K. McLellan: None. H. Alkhdher: None. S. Lacassagne: None. E. Moraitis: None. C. Papadopoulou: None. C. Pilkington: None. M. Al Obaidi: None. D. Eleftheriou: None. P. Brogan: None.