P209 Subgroups of refractory rheumatoid arthritis and difficult to treat features highlight differences in comorbidity and smoking history - a single-centre observational study

Abstract Background/Aims Limited therapeutic efficacy and ‘difficult to treat’ (D2T) characteristics mean some rheumatoid arthritis (RA) patients cycle through multiple therapies to achieve their treatment targets. The aim of this study was to evaluate for subgroups of refractory RA (RefRA) in a real-world population and describe D2T characteristics. Methods Patients on their third or more targeted therapy were identified from the electronic health record (EHR) at Manchester Royal Infirmary. Demographic and clinic information were obtained. Raised disease activity was identified as DAS28ESR>3.2. Findings of power Doppler joint synovitis on ultrasound (PDUS) if undertaken within a month of clinical assessment. These data were used to categorise patients as raised disease activity and PD positive (persistent inflammatory RefRA, PIRRA) or raised disease activity in the absence of PD (non-inflammatory RefRA, NIRRA). Descriptive analyses were used to describe the characteristics in the two groups. Missing data were counted as negative observations. Results 82 patients who were on a third advanced therapy or higher were identified. 41/82 (50%) had raised disease activity and 32/41 (78%) had MSUS performed. 18/32 (56%) of these were PIRRA and 14/32 (44%) were NIRRA. Table 1 details demographic and clinical characteristics in the two groups as well as the controlled RefRA population. The PIRRA group had more erosive disease [13/18 (72%) PIRRA vs 8/14 (57%) NIRRA] and smoking history [9/18 (50%) of PIRRA vs 5/14 (35%) of NIRRA]. The PIRRA group also had greater levels of co-morbidity but previous bDMARD toxicity was comparable between the two groups. Whilst the DAS28ESR was higher in the PIRRA group, there were only marginal differences in the tender and swollen joint counts and CRP compared to NIRRA. The controlled RefRA population as expected showed notably lower DAS28-ESR and individual components although more similar to the PIRRA group with regards to comorbidity. Conclusion Just over half of the ref-RA cohort with raised disease activity had MSUS-detected synovitis and may be regarded as PIRRA. The PIRRA group had higher disease activity although joint counts and even acute phase were comparable. Higher smoking history and comorbidity appear to distinguish PIRRA and NIRRA in this cohort. Disclosure G. Rogers: None. Y. Tan: None. R. Shukla: None. R. Gorodkin: None. B. Parker: None. I. Bruce: None. J. Humphreys: None. A. Barton: None. K. Hyrich: None. E. Bruce: None. P. Ho: None. M.H. Buch: None.