Madrid Sonographic Enthesis Index (MASEI) Assessment in Radiographic Axial Spondyloarthritis (r-axSpA) Patients: Association with Clinical Activity and Outcome Scores

Background: Axial spondyloarthritis (axSpA) refers to chronic inflammatory arthritis primarily impacting the spine, resulting in pain and stiffness. It is classified as either radio-graphic axSpA (r-axSpA), previously known as ankylosing spondylitits (AS), or nonradiographic axSpA (nr-SpA). This study aimed to evaluate the validity of the ultrasound (US) en-thesis score in comparison with clinical disease outcome meas-ures for assessing disease outcome in patients with radiograph-ic axial spondyloarthritis (r-axSpA). Patients and Methods: A cross-sectional study was carried out on 84 individuals divided into 2 groups: r-axSpA patient group of 42 patients and control group of 42 healthy individu-als. Clinical scores: Bath Ankylosing Spondylitis disease activ-ity index (BASDAI), AS disease activity score (ASDAS), Bath AS metrology index (BASMI), Bath Ankylosing Spondylitis functional index (BASFI), health assessment questionnaire (HAQ), and spondyloarthritis research consortium of Canada (SPARCC) to evaluate 16 entheseal sites were assessed. Ultra-sonography was done using total and subdomains of the Madrid Sonographic Enthesitis Index (MASEI) for assessments. Results: R-axSpA patients had significantly higher abnor-mal entheses by ultrasound than control 42/504 (8.3%) vs 12 (2.3%) (p<0.001). MASEI score was 1.88±3.27 (0-12), inflam-matory MASEI score was 0.31±0.68 (0-3), and damage MASEI score was 1.57±3.16 (0-12) in r-axSpA patients. Damage MA-SEI score was significantly worse in the r-axSpA group than the control group (p=0.007). A significant correlation was observed among [total MASEI score and HAQ (p=0.036) and BASMI (p<0.001)] and between [damage MASEI score and BASMI (p=0.001), HAQ (p=0.031)]. Patients on secukinumab had significantly lower damage MASEI. There was no significant relation between total, inflammatory or damage MASEI scores with etanercept and adalimumab. Conclusions: The examination of entheses via ultrasound may serve as a valuable complement to clinical evaluation, necessitating further research to determine its diagnostic and follow-up roles in disease progression.