Power Doppler ultrasound monitoring of response to anti-tumour necrosis factor alpha treatment in patients with rheumatoid arthritis

OBJECTIVES: To monitor by power Doppler US (PDUS) the short-term response to anti-TNFα therapy in six target joints of RA patients; to correlate PDUS findings with clinical assessments and laboratory indices of disease activity. METHODS: Consecutive RA patients starting anti-TNFα therapy were included and studied at baseline and 3 months later. Clinical (number of tender joints; number of swollen joints; Visual Analogue Scale; DAS28) and laboratory (ESR and CRP) assessments were performed. All patients were evaluated by PDUS at six target joints (II MCP, wrist, knee bilaterally). The components of synovitis (synovial hypertrophy, joint effusion, and power Doppler) were analysed and graded (0-3 semi-quantitative score). Moreover, by summing the PDUS findings, three different scores were calculated: a single inflammatory lesion score (0-18, for synovial hypertrophy, effusion, power Doppler), a joint score (0-18; at II MCP, wrist and knee joints) and a global score (0-54; sum of all abnormalities). RESULTS: Sixty-eight RA patients were studied. A significant decrease in the joint score in all articular sites (MCP, P = 0.003; knee, P = 0.002; wrist, P = 0.0001) as well as in the scores of the single components of synovitis (P = 0.0001-0.002) and in the global 6-joint score (P = 0.0001) was found. All clinical and laboratory parameters were significantly decreased at follow-up (P = 0.0001-0.001). A moderate significant positive correlation was observed between the global PDUS score and DAS28 (r = 0.38; P = 0.001). CONCLUSION: PDUS is a sensitive-to-change imaging modality for monitoring the short-term response to anti-TNFα treatment in RA patients. The assessment of a limited number of joints makes the evaluation feasible in rheumatology practice as a complementary tool to clinical assessment.