Background Serum matrix metalloproteinase-3 (MMP-3) levels are useful conventional markers of synovitis associated with rheumatoid arthritis (RA). Ultrasonography (US) has recently become more popular as a method of evaluating joint synovitis.

Objectives To determine the significance of grey scale ultrasonography (GSUS) and power Doppler ultrasonography (PDUS) scores by comparison with serum biomarkers and clinical disease activity assessment.

Methods We selected 124 consecutive patients with RA who attended our hospital outpatient clinic. The patients underwent musculoskeletalultrasonography at 26 synovial sites in the following joints: bilateral first to fifth MCP (dorsal recess), first IP and second to fifth PIP (dorsal recess) joints and the wrists (dorsal radial, dorsal median and dorsal ulnar). The GS and power PD signals were scored in each joint using a scale from 0 to 3. The GSUS and PDUS scores are the sums of the scores obtained for the 26 synovial sites. Correlations among serum CRP, ESR and MMP-3 values and disease activity evaluated using the DAS-28 were analyzed along with the PDUS positive ratio in DAS-28 in patients in remission and in patients with normal MMP-3 values.

Results The clinical characteristics of the 124 patients (102 females and 22 males; mean age, 60.8±12.8 years) with RA were as follows. They received only DMARDs (n=62), and biological DMARDs (n=62). The mean number of tender (TJCs) and swollen (SJCs) joints and the ESR, CRP, DAS-28 and MMP-3 values were 7.0, 3.7, 28.5, 0.68, 4.38 and 110.7, respectively. The GSUS and PDUS scores were significantly and positively correlated with DAS-28, ESR, CRP and MMP-3. The PDUS score was positive in 19 (90.5%) of 21 patients in remission with DAS-28 (DAS-28 <2.6) and in 45 (84.9%) of 53 with normal serum MMP-3 values.

Conclusions Both GSUS and PDUS scores were closely correlated with clinical disease activity and serum biomarkers. These results indicate that US findings accurately reflect the pathogenesis of RA. However, patients in remission according to DAS-28 withnormal serum MMP-3 values also had a high rate of positive PD scores. We considered that US is more accurate for clinically evaluating patients with RA.

1. Kawashiri SY, Kawakami A, Iwamoto N, Fujikawa K, Satoh K, Tamai M, Nakamura H, Okada A, Koga T, Yamasaki S, Ida H, Origuchi T, Eguchi K. The power Doppler ultrasonography score from 24 synovial sites or 6 simplified synovial sites, including the metacarpophalangeal joints, reflects the clinical disease activity and level of serum biomarkers in patients with rheumatoid arthritis. Rheumatology (Oxford). 2011;50:962-5.

2. Naredo E, Moller I, Cruz A, Carmona L, Garrido J. Power Doppler ultrasonographic monitoring of response to anti-tumor necrosis factor therapy in patients with rheumatoid arthritis. Arthritis Rheum. 2008;58:2248-56.

3. Backhaus M, Burmester GR, Gerber T, Grassi W, Machold KP, Swen WA, Wakefield RJ, Manger B. Guidelines for musculoskeletal ultrasound in rheumatology. Ann Rheum Dis. 2001;60:641-9.

Disclosure of Interest T. Okano: None Declared, T. Koike Grant/Research support from: Takeda Pharmaceutical, Mitsubishi Tanabe Pharma Corporation, Chugai Pharmaceutical, Eisai, Abbott Japan, Teijin Pharma, Banyu Pharmaceutical and Ono Pharmaceutical, M. Tada: None Declared, Y. Sugioka: None Declared, K. Mamoto: None Declared, S. Wakitani: None Declared, H. Nakamura Grant/Research support from: Chugai Pharmaceutical, Astellas Pharma Inc.,Janssen Pharmaceutica, GlaxoSmithKline, Pfizer Inc. and Daiichi Sankyo, INC., Speakers Bureau: Ono Pharmaceutical