An important feature of rheumatoid arthritis (RA) is hypoxia-driven synovial angiogenesis, but the relationship between change in vascularity, as measured by power Doppler ultrasound (PDUS), and oxygen tensions is unaddressed.
Metacarpophalangeal (MCP) joint PDUS was assessed in 23 patients with RA, alongside arthroscopic synovitis and oxygen tension measurements, at baseline and 4 weeks after anti-tumour necrosis factor (TNF) inhibitors.
Anti-TNF reduced PDUS scores, which were negatively correlated with rise in oxygen tensions. The latter was related to good EULAR response at week 52.
Anti-TNF results in rapid reduction in synovial blood flow, with a corresponding rise in oxygen tension most marked in EULAR good responders.