POS0489 PREDICTIVE FACTORS FOR THE FLARE OF PATIENTS WITH RHEUMATOID ARTHRITIS (RA) IN ULTRASOUND REMISSION (US-R)

Abstract

BackgroundFlares are frequent in patients with rheumatoid arthritis(RA), with 30–50% experiencing a disease flare within the first 2 years of clinical remission(CR).Ultrasound (US) synovitis despite CR have more subsequent flares than those who show both CR and ultrasound remission(USR). Plenty of studies examined clinical course and predictive factors for flare among patients with RA in CR or LDA. But few studies have examined those with USR and using US as daily rheumatologic practice through a follow-up period. Therefore, the clinical course and flare predictor of RA patients in US-R under daily US practice is unclear.ObjectivesThe objective of this study among RA patients in CR/LDA with USR under on-demand and yearly US practice was as follows (1) to investigate the clinical course and change of disease activity from baseline, (2) to investigate the predictive factors for the flare over 2 years.MethodsAll patients met the following criteria: (1) RA classified according to the American College of Rheumatology (ACR) 2010 revised criteria; (2) age >18 years; (3) at least 12 months disease duration; (4) maintaining the same RA treatment at least 6 months; (5) being in CR or LDA according to either DAS28 CRP or SADI/CDAI; (6) being in USR.USR was defined as absence of joint synovitis, tenditis, tenosynovitis in the bilateral wrist, 2nd-5th MCP and PIP joints, and any tender or swollen joints. Demographic and treatment characteristics, clinical dates, US assessment were evaluated at the time of baseline, 1-year, and 2-years (yearly-US). US was additionally assessed if the patients showed clinical manifestations of the flare in any period (on-demand US). Questionnaires were also collected at baseline to assess physical function, psychiatric disorders and catastrophizing: HAQ-DI, BS-POP and Pain Catastrophizing Scale (PCS). Rheumatologists could employ DMARD treatment as an individual approach based on the joint decision between the patient and the rheumatologist without any restrictions. The flare was defined when patients received additional DMARD or glucocorticoids or encountered Power Doppler (PD) US flare. Baseline factors for the shorter time to the flare were analyzed by multivariate COX regression analysis, adjusting for age, gender, BMI, and DAS28 CRP. A P value ≤ 0.05 was regarded as being significant. All analyses were performed with EZR statistical software.ResultsIn total, 85 patients were enrolled in the study. Baseline characteristics are depicted in Table 1. 62 patients (73%) fulfilled CR criteria.The change of DAS28-CRP from baseline to 1-year and 2-years was -0.1±0.7, -0.08±0.75. The rate of LDA/CR and USR was as follows: 92% and 91% at 1-year, 90% and 89% at 2-years. Over 2 years, 35 patients (42%) had the flare and the mean time to the flare was 11.8±7.0 months. PDUS flares were reported in 4 patients (5%) at 1-year and 2-year US assessment, even though they had no clinical signs of flares. An association of ACPA (HR=2.6, 95%CI:1.0-6.9, p=0.05), Stage Ⅲ (HR=4.2, 95%CI:1.5-11.6, p=0.005), CRP (HR=21.9, 95% CI:3.5-137, p<0.001), opioids use (HR=5.8, 95% CI:2.0-17, p=0.001) on the shorter time to the flare was revealed. CR, DMARD treatment, HAQ-DI, BS-POP, and Pain Catastrophizing Scale (PCS) were not associated with the flare.ConclusionUnder on-demand and yearly US assessment over 2 years for RA patients in LDA/CR with USR, the flare occurred frequently but most of the patients showed sustained LDA/CR and USR at 1- year and 2- years. Baseline factors should be considered for predicting the flare.Table 1.variablemean（SD）/n（％）N=85Age,（year）, mean（SD）68.7（11.7）Female, n（ ％）61 (71.8)BMI22(4.3)Disease duration（year）9.2（8.0）musculoskeletal co-morbidity, n（ ％）33（38）psychiatric disorder n,（ ％）9（10.6）Pain Catastrophizing Scale, 0-5215(13)Stage（Ⅰ/Ⅱ/Ⅲ/Ⅳ）31/32/16/6Tender joints（of 28）, n1.0（1.3）Swollen joints（of 28）, n0.3（0.9）ACPA-positve, n（ ％）64（75）DAS28 CRP1.9±0.6CDAI4.0（2.8）HAQ-DI0.26（0.5）CRP (mg/dl)0.15(0.1)bDMARDs use, n（％）19 (22)tsDMARDs use, n（％）12(14)MTX use, n(%)28(67)PSL use, n(%)15(17)REFERENCES:NIL.Acknowledgements:NIL.Disclosure of InterestsNone Declared.