Color and duplex Doppler sonography to detect sacroiliitis and spinal inflammation in ankylosing spondylitis. Can this method reveal response to anti-tumor necrosis factor therapy?

OBJECTIVE: To investigate the role of color and duplex Doppler ultrasound (CDDUS) in the detection of sacroiliac (SI) and spinal inflammation, as well as response to anti-tumor necrosis factor (TNF) therapy in patients with ankylosing spondylitis (AS).

METHODS: We included 39 consecutive patients with AS followed at our center and 14 healthy controls. In the AS and control groups, blood vessels in SI joints and lumbar vertebral (LV) and thoracal vertebral (TV) paraspinal areas were investigated by CDDUS. When the artery was found, the resistive index (RI) was measured by CDDUS. Disease activity characteristics (ESR, CRP, BASDAI, and BASMI) were evaluated in patients with AS. In 11 patients for whom anti-TNF therapy was indicated, CDDUS measurements were performed before and on Week 12 of therapy.

RESULTS: In patients with AS, RI values of SI joints and of LV and TV areas were lower than in controls (all p < or = 0.01). In AS patients with active disease according to BASDAI, RI values of TV (p = 0.0013) and LV (p = 0.027) were significantly lower than in the inactive group. In the group with active AS, SI RI was nonsignificantly lower (p = 0.16). After anti-TNF therapy, there were significant increases in mean SI RI (p = 0.028) and LV RI (p = 0.039), and a nonsignificant increase in TV RI (p > 0.05).

CONCLUSION: CDDUS may be an alternative, less expensive, and easier method for detecting inflammation secondary to increased SI and spinal vascularization and in evaluating response to anti-TNF therapy in AS.