Ultrasound for assessing disease activity and structural damage in psoriatic arthritis: the UPsA scores from a multicentre study by the Italian Society of Rheumatology

Zabotti A.;Piga M.

Co-prime

Conceptualization

;Canzoni M.;Nicola C. D.;Rozza D.;Carrara G.;Boffini N.;Picerno V.;Giovannini I.;Floris A.;Cabas N.;Farina N.;Sakellariou G.;Leccese P.;Zanframundo G.;Bortoluzzi A.;Silvagni E.;Raffeiner B.;Zanoni S.;Parisi S.;Ditto M. C.;De Lucia O.;Zandonella Callegher S.;Idolazzi L.;Figus F.;Dagna L.;Ramonda R.;D'Angelo S.;Cauli A.;Quartuccio L.;Scire C. A.;Iagnocco A.;Guiotto A.;Rossi S.;Trebo P.;Piccione F.;Maioli G.;Lorenzin M.;Gabrielli B.

2025-01-01

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Abstract

Objectives: As part of the ultrasound in psoriatic arthritis (PsA) treatment (Ultrasound in Psoriatic Arthritis Treatment-NCT03330769) study, 2 ultrasound scores for PsA (UPsA)—the UPsA activity score and the UPsA damage score—were developed and internally validated to assess musculoskeletal inflammation and structural damage in PsA. In addition, a simplified UPsA activity score (sUPsA) was also derived to enhance feasibility and applicability in routine clinical practice. Methods: Baseline and 6-month data from patients with PsA across 19 Italian centres were analysed. Clinical evaluations included joint counts, enthesitis, dactylitis, and patient-reported outcomes. Ultrasound assessments, performed by trained sonographers, covered 42 joints, 36 tendons, 12 entheses, and 2 bursae. Factor analysis was used to derive composite scores (range 0-10). Construct validity was assessed by Spearman’s correlations with clinical variables, and sensitivity to change was evaluated using the standardised response mean (SRM). Results: A total of 312 patients with PsA were enrolled. The mean UPsA activity score was 3.7 (SD 1.86), correlating with Disease Activity for Psoriatic Arthritis (rs = 0.42), 68-tender joint count (rs = 0.31), and 66-swollen joint count (rs = 0.45; all P < .001). The UPsA damage score averaged 4.1 (SD 2.26), correlating with the modified Sharp–van der Heijde score (rs = 0.36, P < .001). The UPsA activity score showed moderate sensitivity to change overall (SRM = 0.63) and high responsiveness in patients achieving minimal disease activity (SRM = 1.03). The sUPsA retained 90% of the information from the full score while substantially improving feasibility. Conclusions: The UPsA scores underwent internal validation and demonstrated responsiveness, representing valuable tools to assess PsA activity and damage