ICYMI: How early is early in psoriatic arthritis? Save

Guidelines (ACR/EULAR/GRAPPA) for the management of psoriatic arthritis (PsA) recommend the early referral of patients with the suspected condition for early assessment and treatment. There remains a diagnostic delay of 1-2 years in PsA and ideally treatment should be commenced within 1 year of symptom onset.

How early is early in PsA and is there a window of opportunity for treatment in PsA to ensure optimal outcomes?

A Dutch study from the DEPAR cohort presented as Abstract 1641 at #ACR23 looks into this topic. It aimed to study if there is such a window of opportunity for treatment in PsA. There were 855 patients included in the study and patients were categorised into 3 groups: < 12 weeks delay (early diagnosis), 12-52 weeks (late diagnosis) and > 52 weeks. The outcome measures were the achievement of  Minimal Disease Activity (MDA) and Disease Activity in PSoriatic Arthritis (DAPSA) remission, defined as DAPSA < 5. Radiographic progression is measured with the modified Sharp van der Heijde score (mTSS), while functional impairment is measured with the Health Assessment Questionnaire–Disability Index (HAQ-DI).

In this study the median total delay was 42.0 weeks. The patients with the greatest delay of > 52 weeks were often female, had less swollen joints, lower CRP and ESR, and had more enthesitis. This group was significantly less likely to achieve MDA and DAPSA remission, and had worse HAQ-DI over 3 years of follow up compared to the early and late diagnosis groups. 

There was no significant difference in the characteristics and outcomes between the groups diagnosed within 12 (early) and within 52 (late) weeks. There was however a trend towards numerically better outcomes in the early (12 weeks) group.

This study provides some evidence that early referral and diagnosis is associated with better clinical outcomes. This should ideally be less than 1 year of symptom onset in PsA. The optimal window of opportunity will need to be an area of further study and research.

In a parallel study also from the DEPAR cohort, they looked at the use of a 3-item or 4-item VAS (3VAS/4VAS) and radiographic progression in early PsA patients. This is Abstract 1401 at #ACR23. The aim was to evaluate 3VAS/4VAS having association in terms of radiographic progression over 3 years in early PsA. The 3VAS consisted of a physician’s global VAS, the patient global VAS, and the patient skin VAS. The 4VAS comprised the physician global VAS, patient pain VAS, patient joint VAS, and patient skin VAS. Reaching low disease activity (LDA) at 6 months was determined as 3VAS(< 2.4), 4VAS(< 2.8), and DAPSA (≤14). Even though patients who achieved LDA according to 3VAS, 4VAS, and DAPSA at 6 months had fewer radiographic changes in 3 years, there were no found significant differences. This lack of association is likely attributed to the relatively low radiographic progression observed in this cohort rather than being solely influenced by the measures themselves. The articular-oriented measure DAPSA also exhibited no significant association with radiographic damage in early PsA patients. This study informs us of the pattern and rate of radiographic progression in association with the outcome scores used. Current measures such as the Psoriatic Arthritis Disease Activity Score (PASDAS) and Minimal Disease Activity (MDA) while stricter and more complex may be more stringent in assessing disease activity and radiographic progression in early PsA.