DAPSA and ultrasound show different perspectives of psoriatic arthritis disease activity: results from a 12-month longitudinal observational study in patients starting treatment with biological disease-modifying antirheumatic drugs

Abstract

ObjectivesDisease Activity index for PSoriatic Arthritis (DAPSA) (sum score 68/66 tender/swollen joint counts (68TJC/66SJC), patient’s global assessment, pain and C-reactive protein (CRP)) is recommended for clinical assessment of disease activity in patients with psoriatic arthritis (PsA). Ultrasound (US) (grey scale (GS) and power Doppler (PD)) detects inflammation in joints and extra-articular structures. The present objectives were to explore the longitudinal relationships between DAPSA, clinical assessment as well as patient-reported outcome measures (PROMs) with US in patients with PsA initiating biological DMARDs and the associations between DAPSA and US remission.Methods47 patients with PsA were examined at baseline and after 3, 6, 9 and 12 months. Assessments included 68TJC/66SJC, examiner’s global assessment (EGA), PROMs, CRP, erythrocyte sedimentation rate (ESR) and US GS and PD (48 joints, 10 flexor tendons, 14 entheses, 4 bursae). Clinical composite scores and PD sum scores (0=remission) were calculated. Longitudinal associations were explored by generalised estimating equations with linear and logistic regression.ResultsDAPSA was not longitudinally associated to PD. 66SJC, ESR, 28-joint Disease Activity Score, EGA and CRP were longitudinally associated with PD (p<0.001–0.03), whereas the pain-related components of DAPSA (68TJC and pain) as well as PROMs were not associated. At 6–12 months, remission was achieved in 29%–33 % of the patients for DAPSA and 59%–70 % for PD. The association between DAPSA and PD remission was not significant (p=0.33).ConclusionsDAPSA was not associated with US inflammatory findings which indicates that DAPSA and US may assess different aspects of PsA activity.

Residual inflammation in psoriatic arthritis patients in stable minimal disease activity

“…Therefore, the US findings of synovitis and enthesitis were largely found in otherwise silent sites. This result was not surprising, as in PsA sonography examination of joints and entheses has been shown to be more sensitive than clinical assessment and the correlation between clinical and sonographic remission was, at best, moderate (7,8,26,27).…”

“…Although these indices have a good accuracy in defining disease state, they might not detect asymptomatic underlying inflammation in entheses, joints, and other related structures. Ultrasound (US) studies have actually showed that PsA patients with a good disease control as measured by DAPSA or MDA may still have smoldering synovitis and enthesitis ( 7 , 8 ). In addition, it is has been shown that a deeper assessment of disease activity by US may help to identify among patients in good disease control those who are at a greater risk of developing a flare ( 9 ).…”

Ultrasound Imaging in Psoriatic Arthritis: What Have We Learnt in the Last Five Years?

“…In the same study, the DAPSA composite scores partially reflected Boolean's remission criteria and correlated with GS and PD synovitis but not the CPDAI ( 43 ). In another longitudinal study of 47 PsA patients, the SJC66, CRP, ESR, DAS28, and the physician global assessment were associated with PD, whereas the DAPSA was not ( 44 ). Therefore, the discordance between clinical examination and US synovitis needs further research.…”

Pain in psoriatic arthritis and hand osteoarthritis

“…Furthermore, more than 30% of patients with PsA in remission or with low disease activity according to the Disease Activity Score 28 using CRP may still be experiencing pain with VAS scores for pain intensity above 4 [146]. Pain is a dominant and persistent symptom in PsA and is not uniformly correlated to routine measures of inflammatory activity [129,151,178,220] indicating that central pain mechanisms could play a role. Furthermore, several studies report that widespread pain is prevalent (23% to 35%) among patients with PsA [20,126].…”