Method: Thirty healthy controls (15 male, 15 female, mean age 38.9 yrs, SD 11.7) underwent 2D ultrasound of 40 joints (DAS28 joint set, ankles and metatarsophalangeal joints), with imaging in greyscale and power Doppler modes, resulting in 15,480 images for analysis. Each patient had 58 power Doppler images scored (0-3 score) and recorded, resulting in a potential maximum score of 174 for power Doppler. Serum samples were analysed for an array of pro-inflammatory and anti-inflammatory cytokines using the Evidence InvestigatorTM biochip array (Randox).
Result: Power Doppler signal >1 was not generally seen in normal joints apart from the wrist (41.7%). The mean total power Doppler score was 4.8 (SEM 0.624, Range 0-13) from a potentially maximum score of 174. There was no significant difference in the power Doppler scores between male and female subjects (p=0.753) and no significant correlation between age and power Doppler score (r= 0.298, p= 0.11). Serum samples were analysed on 26/30 control patients for an array of pro-inflammatory cytokines (IL-2, IL6, IL-8, IL-1α, IL-1β, VEGF, TNFα, IFNγ) and anti-inflammatory cytokines (IL-4, IL-10). There was a significant correlation between the VEGF concentration and the power Doppler score in the normal controls (r = 0.395, p = 0.046). There was a significant inverse correlation between the TNFα concentration and the power Doppler score (r =-0.405, p=0.04). There was no correlation with any of the other cytokines and the power Doppler scores.
Conclusion: Power Doppler signals of >1 are an uncommon feature in normal joints apart from the wrist and this study supports the use of >1 score as an appropriate cut-off of clinical abnormality when performing ultrasound assessment. Power Doppler score of the 40 joint set correlated with VEGF levels in serum but not other cytokines providing further evidence of a role for VEGF in synovial neoangiogenesis.
Disclosure: J. Kitchen, None; D. Kane, None.