AB0576 DEFINING INTERFERON MEDIATED CONDITIONS (DEFINITION): IFN ASSAYS AND CLINICAL FEATURES OF ESTABLISHED ANA-ASSOCIATED AUTOIMMUNE DISEASES

Background A large body of evidence has shown that type I IFN (IFN-I) biomarkers are associated with worse clinical features within each ANA-associated rheumatic disease (ARMD). IFN-I also predict response to IFN-targeted and other therapies. DEFINITION is an observational study explore the associations across course spectrum ARMDs. This a preliminary analysis for subsection on established ARMD. Objectives To determine whether patients high have greater impact including activity, functional impairment quality life. Methods Adults current or previous positive ANA either criteria any ARMD (SLE, pSS, IIM, SSc, MCTD) consultant diagnosis (may be undifferentiated if symptoms>12 months and/or treated immunosuppressants. We collected demographics, deprivation, participation, cardiovascular risk comorbidity variables, diagnostic ARMD, life patient-reported outcome measures, Disease activity was summarised using composite validated instruments classify organ system as severe, moderate, mild inactive (equivalent BILAG A-D/E SLE). pathway activation measured gene expression Score B memory cell tetherin. used Spearman correlations unsupervised hierarchical clustering find between outcomes biomarkers. Results Of 294 patients, 23/294 (18%) were male, mean (SD) age 50 (14), index multiple deprivation decile 4.9 (3.1), Charlson 2.1 (1.5). Current therapy prednisolone (24.5%), hydroxychloroquine (45.2%), methotrexate (17.7%), mycophenolate (11.9%), azathioprine (10.2%), rituximab (8.5%), cyclophosphamide (0.3%). 104 had SLE, 111 UCTD, 33 19 myositis, 14 SSc 13 MCTD. There significant association (F= 2.52, p=0.030) tetherin 4.34, p<0.001) but not (F=0.66, p=0.653). In pairwise only one weak relationship SF36 PCS found (R=0.33, p<0.001). No substantive scores features. However, all yielded 5 clusters role sociodemographic variables revealed further relationships activity. Cluster 1: symptoms, low comorbidity, affluence; 2: older, 3: younger, affluence, poor QoL; 4: BILAG; 5: BILAG. Conclusion complex confounded by socioeconomic which must considered in stratification studies. REFERENCES: NIL. Acknowledgements: Disclosure Interests Jack Arnold: None declared, Lucy Marie Carter Consultant of: UCB, Katherine Dutton: Sabih-Ul Hassan: Zoe Wigston: Md Yuzaiful Yusof Aurinia Shouvik Dass Roche, Abbvie, UCB Chugai. Edward Vital Speakers bureau: AstraZeneca Novartis, Paid instructor for: Pfizer, Aurinia, Lilly, Genentech, Otsuka, GSK Capella.