Responsiveness to therapy change of a global ultrasound assessment in spondyloarthritis patients

The objective of this study is to evaluate the responsiveness to therapy change of a global ultrasound (US) assessment in the short-term monitoring of spondyloarthritis (SpA) patients with peripheral involvement. Consecutive SpA patients with both clinical peripheral involvement and active disease (initiating or changing therapy) were included. All patients underwent both clinical and US assessment in day entering the study and after 3 months of follow-up. Peripheral global US assessment included the recognition of abnormal inflammatory findings at joint, tendon, and entheseal level according tostandardized scanning methods. A total of 34 patients completed both basal and 3-month follow-up assessments. Acute phase reactants, both erythrocyte sedimentation rate and C-reactive protein, tenderness (68) and swollen (66) joint counts, Bath Ankylosing Spondylitis Disease Activity Index and Health Assessment Questionnaire decreased significantly at 3-month follow-up. Total score for the global US assessment also decreased significantly between basal and 3-month follow-up assessment [mean difference, 12.33 (IC 95 %, 9.23–15.42); p < 0.0001]. All individual component, joint, tendon, and enthesis scores, also showed a significant decrease during the follow-up period. A high degree of intra-observer reliability was found for the global US assessment (ICC [95 % CI]: 0.977 [0.961–0.993]). This global US assessment, including joints, tendons, and entheses, showed a good responsiveness to clinical changes and might be useful for monitoring SpA patients with peripheral involvement.