Ultrasound-Detected Synovitis in Psoriatic Arthritis Patients in Clinical Remission: Relationship with Radiographic Progression

Abstract

Introduction: Clinical remission (no swollen/tender joints) is the treatment target in psoriatic arthritis (PsA), but subclinical synovitis detected by ultrasound may predict structural damage. This review quantifies ultrasound subclinical synovitis prevalence and its association with 12-month radiographic progression.
Methods: Systematic review of longitudinal studies (≥50 PsA patients meeting clinical remission criteria, followed ≥12 months) reporting power Doppler (PD) and greyscale (GS) synovitis at baseline and subsequent modified Sharp/van der Heijde score (SHS) progression.
Results: Nine studies (n=1,203) included. Subclinical synovitis (GS grade ≥2 or any PD signal) present in 44% (95% CI 38–50%) of clinically remitted PsA patients. PD signal alone in 19%. Baseline PD signal predicted SHS progression (OR 3.4, 95% CI 2.1–5.5) over 12 months. GS synovitis without PD did not predict progression (OR 1.2, 0.8–1.7). The presence of entheseal PD signal independently predicted progression in 3 studies.
Discussion: Active (PD-positive) subclinical synovitis drives erosive progression, while chronic inactive GS changes do not. The enthesis-synovium interaction may explain residual progression. Limitations: variable ultrasound protocols and cut-offs for PD positivity.
Conclusions: PD-positive subclinical synovitis in remitted PsA predicts radiographic damage. Ultrasound-targeted treatment escalation may be considered.