To evaluate by using B-mode and power Doppler ultrasonography (US) and clinical assessment the response of hand joint synovitis in patients with active rheumatoid arthritis (RA) to treatment with the anti-tumor necrosis factor-alpha agent infliximab.
Wrists, metacarpophalangeal (MCP) joints, and proximal interphalangeal (PIP) joints in 11 patients with active RA were assessed before and 6 weeks after three infliximab infusions. US assessment was performed at a single site in the MCP and PIP joints and at two sites (radiocarpal and intercarpal) in the wrists. Twenty measurements were performed in the wrists; 110 measurements, in the MCP joints; and 103 measurements, in the PIP joints. Two wrists and seven PIP joints were excluded owing to complete joint destruction. US parameters (synovial thickness, number of US-positive joints [ie, with synovial thickness > or = 1 mm], cumulative synovial thickness index, and presence of Doppler signal) and clinical parameters (swollen joint count) were independently assessed and compared with baseline values by using the McNemar chi2 and paired Student t tests.
After infliximab treatment, there was a significant decrease in the mean numbers of swollen and US-positive joints and in the cumulative synovial thickness (P <.05). The mean synovial thickness decreased in all joints swollen at baseline and in the MCP and PIP joints not swollen at baseline (P <.01). Change from baseline cumulative synovial thickness correlated significantly with change in disease activity score (r = 0.69, P <.05). The number of positive Doppler US signals decreased significantly (in 13 US-positive joints at baseline, in five after treatment; P <.05).
US is a feasible imaging modality for measurement of the response of RA small-joint synovitis to therapy.