Power Doppler Ultrasonography Assessment of Entheses in Spondyloarthropathies: Response to Therapy of Entheseal Abnormalities

Abstract

Objective.To investigate the response to therapy of entheseal abnormalities assessed with power Doppler (PD) ultrasound (US) in spondyloarthropathies (SpA).Methods.A total of 327 patients with active SpA who were starting anti-tumor necrosis factor (TNF) therapy were prospectively recruited at 35 Spanish centers. A PDUS examination of 14 peripheral entheses was performed by the same investigator in each center at baseline and at 6 months. The following elementary lesions were assessed at each enthesis (presence/absence): morphologic abnormalities (hypoechogenicity and/or thickening), entheseal calcific deposits, cortical abnormalities (bone erosion and/or proliferation), adjacent bursitis and intraenthesis and perienthesis (tendon body and/or bursa) PD signal. Response to therapy of each elementary lesion was assessed by calculating change in the cumulative presence from baseline to 6 months. Intraobserver reliability of PDUS was evaluated by blindly assessing the stored baseline images 3 months after the real-time examination.Results.Complete data were obtained on 197 patients who received anti-TNF therapy for 6 months. In 91.4% of the patients there were gray-scale or PD elementary lesions at baseline and at 6 months. Cumulative entheseal morphologic abnormalities, intraenthesis PD, perienthesis PD, and bursitis showed a significant decrease from baseline to 6 months (p < 0.05). There was high intraobserver reliability for all elementary lesions (interclass correlation coefficient > 0.90, p < 0.0005).Conclusion.Entheseal morphologic abnormalities, PD signal, and bursitis were US abnormalities that were responsive to anti-TNF therapy in SpA. PDUS can be a reproducible method for multicenter monitoring of therapeutic response in enthesitis of SpA.