Background After starting to use biological DMARDs (bDMARD), the number of small joint (SJ) arthroplasty increased as compared with large joint (LJ) at our rheumatic center. Additionally, ultrasonography (US) for the examination of the affected joints widely utilized and it became a tool by which the rheumatologist should learn to diagnose RA and to evaluate disease activity.
Objectives To clarify relationship among systemic disease activity, local disease activity using US and synovial histopathological evaluation, we examined serum CRP, MMP-3 and DAS28, and US at the surgical site before surgery. After surgery, histopathological examination of the gathered synovium at the surgical site was performed.
Methods Between March, 2011 and September, 2015, 668 joints underwent surgical treatment and synovial biopsies were performed. There were 152 LJs including 8 shoulders, 60 elbows and 84 knees, and 516 SJs including185 fingers, 118 toes, 192 wrists and 21 ankles. Male: female ratio was 1:7. The bDMARD (IFX20, ETN62, ADA17, TCZ44, ABT16, CZP4, GLM13) was used in 176 cases. Maximum power Doppler (PD) signal grade of US was determined ranging from 0 to 3. They were compared with serum CRP, MMP-3, DAS28 and local disease activity using histopathological evaluation using Rooney score (RS).
Results Systemic disease activity correlated with local PD signal intensity both in LJs and SJs. Also, total RS and its item score excepting “proliferating blood vessels” correlated well with PD signal intensity. Systemic disease activity, local synovial proliferation and lymphocyte infiltration were more severe in LJs than in SJs. Though sensitivity of synovitis at LJs lower than at SJs, there was not a significant difference in PD signal intensity and RS between at LJs and at SJs. RS reflected systemic disease activity more in LJs than in SJs.
Conclusions US is an excellent tool to reflect local synovitis as well as systemic disease activity both in LJs and SJs.
Disclosure of Interest None declared