Non-Steroidal Anti-Inflammatory Drugs Have An Independent Effect On Synovial Vascularity Assessed By Musculoskeletal Ultrasound In Rheumatoid Arthritis

Background Musculoskeletal ultrasound (MSUS) is useful in monitoring rheumatoid arthritis (RA) and is emphasized its high sensitivity for detecting synovitis and good correlation with clinical disease activity indices, such as Disease Activity Score (DAS28) and Simplified Disease Activity Index (SDAI). While power Doppler ultrasound (PDUS) is widely accepted for the precise assessment of synovial vascularity and the response to treatment, whether the usage of anti-rheumatic drug itself has an effect on PD signal in synovitis has been elusive. Objectives This study was undertaken to determine whether the usage of anti-rheumatic drugs correlate with the assessment of PDUS of synovitis in RA. Methods In this retrospective study, total 167 patients with RA were recruited. The patients had a mean age of 58.6 years (range 23-83) and a mean disease duration of 3.7 years (range 0.1-30.3). They were treated as follows: One hundred and five (62.9%) received non-steroidal anti-inflammatory drugs (NSAIDs), Sixty three (37.7%) received low-dose oral prednisolone (PSL), ninety nine (59.3%) received methotrexate (MTX), and thirty six (21.6%) received biologic agents. The clinical assessment parameters including DAS28, SDAI, and modified Health Assessment Questionnaire (mHAQ) as well as the usage of anti-rheumatic drugs were analyzed in this study. US assessment was performed at the bilateral wrists, MCP, and PIP joints. PDUS was graded semi-quantitatively (0 to 3) in each joint, and the sum of these gradings was estimated as PDUS score. The patient with scoring >1 for PDUS was defined as PDUS positive. The association among PDUS score, the clinical assessment parameters, and the usage of anti-rheumatic drugs was explored by multivariate linear regression analysis. In the group of patients in DAS28 remission, multivariate logistic regression analyses were performed with PDUS positive as dependent variables. Results The rate of the patients having DAS28 remission was 23.3% (39/167) and that of PDUS positive in the group was 48.7% (19/39). SDAI, mHAQ, and NSAID usage were independently associated with increased scoring of PDUS in multivariate linear regression analysis. The usage of the other anti-rheumatic drugs was not associated with PDUS score. Within the group of patients with DAS28 remission, only the usage of NSAIDs was independently associated with an increase of PDUS positive patient. Image/graph Conclusions NSAIDs usage may accelerate the PD signal and result in higher scoring despite continuing remission state. Consideration should be given to the NSAIDs effect in assessing disease activity of RA using MSUS, particularly during remission. Disclosure of Interest None Declared