Abstract
Objective
To explore the sensitivity to change in power Doppler (PD) enthesitis in active spondyloarthritis (SpA) and psoriatic arthritis (PsA) patients.
Method
This was a longitudinal study in patients with SpA and PsA with active disease [patients starting or switching to biological disease-modifying anti-rheumatic drugs (bDMARDs)]. The MAdrid Sonographic Enthesitis Index (MASEI) was performed at baseline and at 3 and 6 month visits. The MASEI and Outcome Measures in Rheumatology (OMERACT) PD enthesitis definitions were checked. Reliability analysis among three readers was performed with ultrasound (US)-recorded videos.
Results
US examinations of 25 patients were included; 16 (64%) had SpA and nine (36%) PsA. The median (interquartile range, IQR) age was 49 (41–61) years, and 13 patients (52%) were female. The median (IQR) 28-joint Disease Activity Score of 3.6 (2.3–4.2), Bath Ankylosing Spondylitis Disease Activity Index of 6.7 (6.1–7.4), and C-reactive protein value of 8.2 (1.6–20) reflected moderate to high disease activity at baseline. Both MASEI and OMERACT PD enthesitis improved significantly at 3 and 6 month follow-up (p < 0.05) and showed sensitivity to change (standard error of measurement = 0.47 and 0.61, respectively). Improvement in clinical activity outcomes was significantly associated with decreases in MASEI and OMERACT PD enthesitis counts (p < 0.05). The MASEI and OMERACT PD definitions had excellent reliability (kappa = 0.918 and 0.865, respectively).
Conclusion
PD enthesitis significantly improved at 3 and 6 month follow-up in patients undergoing bDMARD therapy. Both MASEI and OMERACT PD US enthesitis reflect response to treatment.
Acknowledgements
The authors acknowledge and thank the subjects who participated in this study for their contribution.
The authors received no specific funding for this work.
Author contributions
Study design was performed by JMC and EDM. Subject recruitment and US examination were performed by JMC. Reliability analysis was performed by JMC, CMV, and EDM. CPR collected the epidemiological and clinical data. JMC and EDM performed the statistical analysis. JMC, CMV, CPR, JAG, and EDM drafted the manuscript. All coauthors revised the final manuscript.
Disclosure statement
No potential conflict of interest was reported by the authors.
Ethics approval
The research protocol has been approved by the Research Ethical Committee of Hospital Universitatrio La Paz, and all patients gave informed written consent for their participation in the study.