Background In the treatment of rheumatoid arthritis (RA), the early diagnosis and early medical treatment via tight control have become increasingly important with the advent of biological therapy. Ultrasonography (US) for the affected joints enables the evaluation of synovial hypertrophy, effusion and bone erosion in real time. US is a reliable method that can detect more erosive sites than radiography. US is now utilized widely and is a reliable tool of rheumatologists for diagnosing RA and evaluating the disease activity.
Objectives This study was conducted to clarify the relationship between the systemic disease activity, local disease activity using US and a synovial histopathological evaluation.
Methods Between March 2011 and September 2015, 668 joints were surgically treated on the whole, and synovial biopsies were performed at the time of surgery. Among them, a total of 118 toes and 21 ankles, which are not included in the 28-joint disease activity score (DAS28), were investigated. Just before surgery, the US probe was placed on the dorsal aspect of the ankle and/or the toes to evaluate the activity of local synovitis. The maximum grade of power Doppler (PD) signal was determined, ranging from 0 to 3. The serum C reactive protein (CRP), matrix metalloproteinase-3 (MMP-3) and DAS28 values were also examined just before surgery. A histopathological examination of the gathered synovium at the surgical site was performed using the Rooney score (RS). Biological disease-modifying antirheumatic drugs were used in 45 cases, namely infliximab in 7 cases, etanercept in 16, adalimumab in 7, tocilizumab in 6, abatacept in 4, certolizumab pegol in 1, and golimumab in 4.
Results The PD score was grade 0 in 82 cases, 1 in 32 cases, 2 in 20 cases and 3 in 5 cases. The total RS and its item scores except for “proliferating blood vessels” correlated well with the PD signal intensity. The systemic disease activity, as indicated by DAS28, CRP and MMP-3, had no significant correlation with the local PD signal intensity. However, the DAS28, CRP and MMP-3 values and each RS item score, except for “proliferating blood vessels”, were significantly lower in the PD grade 0 group than in the PD grades 1, 2 and 3 groups.
Conclusions No PD signal intensity in the ankle and foot indicates systemically well-controlled disease activity. US is an excellent tool for determining local synovitis as well as the systemic disease activity in patients with RA.
Disclosure of Interest None declared