Background/Purpose: To evaluate the efficacy of treatment with infliximab on joint inflammation and bone erosion in rheumatoid arthritis (RA) patients using ultrasonography.

Methods: 80 eligible subjects were enrolled from 7 sites. Subjects received infliximab 3 mg/kg IV infusion at 0, 2, 6 weeks, repeated every 8 weeks until 22 weeks. Endpoints included 7-joint and 12-joint ultrasound (US) synovitis scores at 22 weeks, and correlations between US scores and DAS28 (using CRP) / radiography (modified Sharp score (MSS)/van der Heijde scoring) / HAQ outcome. The 7 joints included those of the clinically dominant hand and foot: wrist, second and third metacarpophalangeal and proximal interphalangeal, and second and fifth metatarsophalangeal joints.

Results: The patients (81.25% women) had a mean age of 47.22±14.27 years (mean±SD). Baseline 7-joint and 12-joint synovitis scores were 22.35±11.67 and 42.09±29.64 in grayscale and power Doppler (GS+PD) US, 15.45±5.54 and 29.41±16.12 in GS US, and 6.90±7.26 and 12.68±15.65 in PD US. At baseline, DAS28 was 5.73±1.05, MSS was 17.75±25.27, SDAI was 187.29±55.68, CDAI was 152.16±45.82, and HAQ score was 1.36±0.79. 64 patients (80.00%) completed all visits and 66 patients (82.50%) completed treatment for 22 weeks. After 22 weeks of therapy, 7-joint GS+PD US scores significantly decreased to 18.97±10.81 and the GS US and PD US scores significantly decreased to 11.98±6.42 (P<0.01) and 3.34±4.59 (P<0.01), respectively (Figure). There were significant decreases in scores for 12-joint GS+PD US (28.47±20.93), GS US (22.65±15.19, P<0.01), PD US (5.82±8.17, P<0.01), DAS28 (3.20±1.31, P<0.01), SDAI (77.73±54.27), and CDAI (62.13±41.95). MSS increased (18.04±23.91, P>0.05) and HAQ score significantly decreased (0.56±0.61, P<0.01). There was a positive correlation between US scores and RA activity evaluation indexes, including DAS28, SDAI and CDAI (correlation coefficients 0.5535, 0.6364 and 0.5532) (Table). 14 patients experienced an adverse event and 2 patients experienced a serious adverse event.

Conclusion: In this study, treatment with TNF inhibitors relieved synovitis in patients with moderate to severe RA. US is a viable tool for examining patients with RA in daily practice because it significantly reflects therapeutic response. The 7-joint US synovitis score can be used for the evaluation of clinical efficacy in the clinic, instead of the 12-joint method. This trial showed that there is a positive correlation between US scores and DAS28. Large multicenter, prospective, randomized controlled studies are needed to confirm this preliminary observation.