Abstracto

Day-to-day variation in Doppler activity in patients on stable etanercept treatment: an exploratory cohort study

Lene Terslev, Klaus Muller, Robin Christensen, Karen Ellegaard, Soren Torp Pedersen, Sif Gudbrandsdottir and Henning Bliddal

Aim: Doppler ultrasound was used to evaluate the day-to-day variation in inflammatory activity in rheumatoid arthritis patients on stable TNF alpha blocker treatment.

Materials & methods: A total of 16 patients with rheumatoid arthritis were included in the study, according to the American College of Rheumatology criteria of unaltered etanercept dosage for the last 3 months. All patients had a stable total TNF-binding capacity during the examination period. The most swollen joint was chosen as the target joint (11 wrist joints and five metacarpophalangeal joints) and was examined by ultrasound the morning before injection of 25 mg etanercept at day 0, and the same time on days 1, 2 and 3 after the injection. Color Doppler and spectral Doppler were used to estimate the inflammation. The C reactive protein was measured at each visit.

Results: The disease activity was assessed only at baseline. Mean disease activity score 28 was 3.97. Only slight changes in ultrasound variables were seen over the 4 day period. Overall, there was no statistically significant effect of time, and all pairwise comparisons were nonsignificant (p > 0.14). No changes were found for C reactive protein and TNF-binding capacity between the individual visits (time effect: p = 0.85 and p = 0.23, respectively).

Conclusion: There was no significant day-to-day variation in Doppler parameters in patients on stable etanercept treatment. Ultrasound may therefore be performed at any time between two etanercept injections and significant alterations in Doppler activity may be a potential indicator of change in disease activity.