THU0169 COMPARISON OF THE SYNOVIAL RESPONSE TO MECHANICAL STRESS AMONG PATIENTS WITH RHEUMATOID ARTHRITIS IN CLINICAL REMISSION ON METHOTREXATE OR ANTI-TNF

Abstract

Background: Physiologically, the joint synovium responds to physical activity according to the frequency and intensity of the efforts, producing slight effusion without detectable hyperemia. In patients with RA in remission, a similar response can be expected, since it is understood that the immune-mediated inflammatory component has been controlled physiopathologically. Our interest is to determine whether once clinical remission has been reached, treatment with MTX or antiTNF produces the same normalization of the synovial behaviour. Our interest is to determine whether once clinical remission has been reached, treatment with MTX or antiTNF produces the same normalization of the synovial behavior. Objectives: The aim of the present study is to compare the synovial response to mechanical stress of patients with Rheumatoid Arthritis (RA) in remission treated with Methotrexate (MTX) or Etanercept (ETN). Methods: Descriptive observational study. We included patients with RA in remission (DAS28<2.6) for at least 6 months on MTX or MTX and anti-TNF-alpha therapy (ETN). An ultrasound examination protocol was developed for the 2nd, 3rd and 4th MCP and non-dominant hand carpus for gray scale (GS) and power Doppler signal detection (sPD) according to EULAR/OMERACT definitions. Two ultrasound examinations were performed on each patient, before and 24 hours after starting a manual digital flexure exercise program against resistance measured by a handheld dynamometer CAMRY™ model EH101-17. Total synovitis scores in EG (0-12) and sPD (0-12) were compared. Results: We included 37 patients on MTX treatment (median dose 15mg/week, range 7.5-25mg/week) and 16 patients on ETN treatment (median dose 50mg/week, range 25-50 mg/week). The baseline ultrasound score in the MTX treatment group was 1.6 SD 1.4 in EG and 2.2 SD 0.5 in PDs. After carrying out the controlled dynamometric effort, the score was 2.4 SD 1.9 in GS and 4.4 SD 1.5 in PDs (P<0.05 and P<0.001, respectively). In patients treated with TNEs, the basal score in GS was 1.3 SD 0.6 in GS and 0.6 SD 0.3 in PDs. After the controlled dynamometric effort, the score was 1.8 DE 0.9 in EG and 0.7 DE 0.4 in PDs (P=0.07 and P<0.001, respectively). In the group of patients treated with MTX, four subjects reported joint tenderness after physical effort. Conclusion: Our observations are congruent with previous experiences in which it has been observed that physical stress translates into synovial changes detectable by ultrasonographic studies. Our results, although modest in patient volume, suggest that TNF-alpha activity is crucial in the development and maintenance of exercise-induced hyperemia. The clinical significance of our observation may be useful as a tool to predict the response to anti-TNF therapy in patients with RA, however specific methodological designs are needed for such associations. Disclosure of Interests: None declared