AB0820 Remission criteria in non-radiographic axial spondyloarthritis: don’t miss subclinical inflammation

Background With the advent of the treat-to-target strategy (T2T), clinical remission has become the main objective to achieve in patients with rheumatic diseases. Contrary to rheumatoid arthritis, the T2T strategy is less codified in axial spondyloarthritis, even more in non-radiographic SpA (nr-axSpA) [1]. More importantly, T2T based on imaging remission and guidance for tapering medication has not been extensively studied. Objectives The objective of this study was to investigate the prevalence of bone marrow edema in the sacroiliac joint of nr-axSpA patients in remission. Methods We undertook a cross-sectional study including nr-axSpA patients according to the ASAS criteria, treated with NSAIDs. Socio demographic data as well disease characteristics were recorded. Disease activity parameters were also collected including the duration of morning stiffness, the number night awakening, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). MRI-SIJ was performed for all the patients. All the images were screened for bone marrow edema with the corresponding sequence (short tau inversion). To define remission, we used in addition to BASDAI<4, more stringent criteria: BASDAI<4 and CRP<6 mg/l and ESR<20 mm/h and EGM<4 [2]. The level of significance was fixed for p<0.05. Results The study included 43 nr-axSpA patients. There was a female predominance with a sex ratio of 0.43. The mean age of the patients was 42±12 years [20-71] and the mean disease duration was 17±9.7 years [4-38]. The mean ESR and CRP were 2.2 mg/L [2-65] and 6.4mm/h [1-47], respectively. A higher level of acute phase reactants was found in 40.5% of cases (ESR: 35.7%, CRP: 11.9%). Forty percent of the patients had high CRP or ESR despite BASDAI<4. According to BADSAI<4, of the 15 patients in remission, BME was displayed in 43.5% of the cases. According to the used criteria, 25.6% of the patients were in remission, of which 45.4% exhibited BME in the sacroiliac joint. There was no statistically significant association between disease activity according to the used definition and the presence of BME (p=0.473). Nr-axSpa patients in remission without BME had more durable morning stiffness and articular involvement without reaching a statistically significant difference (p=0.361, p=0.08 respectively). Similarly, we did not find an association between this subgroup and sex, age, night awakenings, the presence of HLAB27 (p>0.05). Conclusion Our study showed that even when using stringent criteria, subclinical remission evidenced by BME was not achieved in nr-ax SpA. Nevertheless, imaging remains one important parameter to consider in therapeutic decision making. More studies are needed to identify the best criteria for an optimal remission in this population. References [1]Aouad K, De Craemer AS, Carron P. Can Imaging Be a Proxy for Remission in Axial Spondyloarthritis?. Rheum Dis Clin North Am. 2020;46(2):311-25. [2]Navarro-Compán V, Plasencia-Rodríguez C, de Miguel E, et al. Anti-TNF discontinuation and tapering strategies in patients with axial spondyloarthritis: a systematic literature review. Rheumatology (Oxford). 2016;55(7):1188-94. Disclosure of Interests None declared