Development of a preliminary US power Doppler composite score for monitoring treatment in PsA.

Objective: To develop a preliminary power Doppler (PD) US composite score for global assessment of PsA patients.
Methods: Sixteen PsA patients receiving anti-TNF-α therapy were enrolled. All patients were involved in multiple psoriatic targets, including joints, tendon, enthesis, skin and nail. The target with the highest PD signal, one for each target area, was selected to be scanned at baseline and at follow-up visit 8 weeks after. For each target, PD was graded according to semi-quantitative scoring systems. Inter- and intra-observer reliability and feasibility was also investigated. The new PD composite score for PsA was called Five Targets PD for Psoriatic Disease (5TPD).
Results: Sixty targets (16 joints, 9 tendons, 11 enthesis, 16 psoriatic plaques and 8 psoriatic onychopathies) were assessed. A significant improvement of the clinical scores was found at follow-up with respect to the baseline: HAQ modified for SpA (HAQ-S) (P = 0.0001); Psoriasis Area and Severity Index (P = 0.0001) and Nail Psoriasis Severity Index (P = 0.35). The 5TPD showed a significant change between baseline and follow-up (P = 0.0001). There was no significant correlation between HAQ-S and 5TPD findings. The inter- and intra-observer κ-values varied from good to excellent at baseline and follow-up. The time spent on baseline US examinations was mean (s.d.) 10.5 (2.0) min and no more than 7 min for follow-up assessment.
Conclusion: The present study provides a new working hypothesis that the sonographic core set may be useful to construct a PDUS composite score for the assessment of PsA. The 5TPD formula provides a feasible and reliable approach for multi-target monitoring of psoriatic disease.