Clinical application of 2017 EULAR for rheumatoid arthritis ultrasound scoring: a feasible study of 62 cases

Objective To assess the clinical feasibility of the 2017 European League Against Rheumatism (EULAR) ultrasound definition and quantification system for rheumatoid arthritis (RA) ultrasound scoring system. Methods A total of 62 RA patients diagnosed in the Department of Rheumatology and Immunology of our hospital and undergoing complete small joints ultrasonography from January 2017 to February 2019 were enrolled in this cross-sectional study. The grey scale ultrasonography (GSUS) and power Doppler ultrasonography (PDUS) of synovitis in the hands, wrist and feet were retrospectively analyzed and semi-quantitatively (grades 0~3) scored twice by a physician with 10-year experience in musculoskeletal ultrasound and a junior physician with 1.5-year experience in this aspect, respectively, according to 2017EULAR. Weighted kappa test was used to evaluate intra and inter-observer consistency. The senior physician assessed the ultrasonographical data again according to the most widely used Szkudlarek scoring. Chi-square test was used to compare the 2 scoring systems. After the 2017 EULAR scores of senior physicians were taken as reference, the scores of GSUS and PDUS were summed up to an total score, and the correlation of the GSUS, PDUS and total scores with clinical parameters were analyzed with Spearman correlation analysis for non-normally distributed variables and Pearson for binormal variable. Results Compared with the results of Szkudlarek method, the distributions of 2017 EULAR GSUS grade 2 in the proximal interphalangeal and metatarsophalangeal joints were of significant differences (P < 0.05), and so were those of GSUS grade 3 in the metacarpophalangeal, proximal interphalangeal and metatarsophalangeal joints (P < 0.05). The PDUS differences of grade 1 and 2 in the wrist, metacarpophalangeal, proximal interphalangeal, and metatarsophalangeal joints were statistically significant (P < 0.05). Both GSUS and PDUS scores were positively correlated with disease activity (DAS)28 score, erythrocyte sedimentation rate (ESR), and levels of C-reactive protein (CRP) and IL-6 (P < 0.05). There was a good consistency between different observers in 2017 EULAR GSUS and PDUS scoring, with a weighted kappa value ranging from 0.494 to 1. Conclusion 2017 EULAR scoring system can relatively improve the uneven distribution of the existing semi-quantitative scoring, and the results are positively correlated with clinical indicators, such as DSA28 score, ESR, and levels of CRP and IL-6. It also has a good consistency among different observers. So it is worthy of clinical promotion.