Assessment of Disease Activity in Rheumatoid Arthritis: A Comparative Study of Clinical Evaluation with Ultrasonography


ABSTRACT: BACKGROUND: In patients with rheumatoid arthritis (RA) a poor relation on an individual joint basis, has been observed between clinical signs of synovitis and ultrasound measures of synovial disease. OBJECTIVE:To compare the traditional clinical measures of disease activity with the ultrasound (US) features of synovitis, and investigate the relationship between composite US measures and disease activity score in 28 joints (DAS28), clinical disease activity index (CDAI), their components and other variables of disease activity in RA.METHODS:Fifty patients with RA were enrolled in this study. The following 28 joints including bilateral glenohumeral, elbow, wrist, metacarpophalangeal (MCP), proximal interphalangeal (PIP) of the hands, and knee joints were assessed for tenderness and swelling. DAS28 and CDAI were determined for each patient. A systematic US examination was carried out by a radiologist for the 28 clinically examined joints. Each joint was evaluated for the presence of synovial hypertrophy (SH), power Doppler (PD) signals, and effusion. The following composite US measures of synovial disease were made: SH joint count (SHJC), effusion joint count (EJC), PD joint count (PDJC), SH index (SHI), and PD index (PDI).RESULTS: Joints with tenderness only showed significantly less PD scores than other groups. SH and PD signals were detected in 32.1% and 27.8% of the Nil group respectively. SHJC and SHI showed moderate correlation with TJC and high correlation with SJC, evaluator global assessment (EGA), patient global assessment (PGA), DAS28, CDAI, and erythrocyte sedimentation rate (ESR). PDJC and PDI showed moderate correlations with tender joint count (TJC), and high correlation with swollen joint count (SJC), EGA, DAS28, and ESR. PDI showed high correlation with PGA, and CDAI. CONCLUSION:Traditional clinical signs used in the evaluation for disease activity may bear different relation to the US features of synovitis (SH, PD signals). Composite US count and indices for SH and PD relate significantly to the DAS28-ESR, CDAI, and their components..