“Hey PRESTO!” – Early identification of psoriatic arthritis Save

The past decade has seen the management of psoriatic arthritis (PsA) transform, with our rich therapeutic armamentarium truly revolutionising patient outcomes.

However, despite this wealth of treatment options there remains a number of notable unmet needs in PsA, most notably the significant diagnostic delay that many patients endure. 

We are all aware that those with psoriatic skin disease are the most at risk cohort for PsA. 

However, even in this patient group, cases of established PsA may go unidentified for prolonged periods of time. Often this diagnostic delay results in significant joint damage and destruction with resultant disability. As in other inflammatory rheumatic diseases, early detection results in early intervention with resultant prevention or control of joint damage.

Identifying patients with psoriasis who have, or are at increased risk of PsA appears to be the low hanging fruit that we just can’t fully seem to grasp.

Much of the issue in PsA is the lack of an accurate diagnostic test or reliable specific disease biomarker. In an attempt to establish early and accurate PsA detection, several patient administered screening questionnaires have been developed. One such screening tool is the “Psoriasis Epidemiology Screening Tool” (PEST), which Meier et al, in abstract 0401, utilised to assess the appropriateness of patient driven PsA screening and rheumatology referral. They analysed data from 1413 patients, who were instructed to contact study staff for a rheumatology appointment if they screened positive on the PEST. Meier et al, deemed 63% of the referrals to be appropriate, however a definite diagnosis of PsA was made in only 4.7% of those reviewed. Even accounting for study recruitment and engagement being hampered by COVID-19, it appears that this novel approach to these patient administered screening tools is still falling short of the accuracy required.

Adapting an alternative approach to optimising early identification of PsA, Eder et al, in abstract 1612, propose a novel scoring system to assess PsA risk in those with newly diagnosed psoriasis at 1 and 5 year time frames, using the “Prediction of Psoriatic Arthritis Tool” (PRESTO). 

635 patients with psoriasis, but without PsA, were assessed annually by a rheumatologist for PsA as part of the prospective International Psoriasis and Arthritis Team (IPART) study. Using data from those that developed PsA during the 1- and 5- year timeframe post diagnosis of psoriasis,  prediction models for PsA were developed. These were assessed using area under the curve (AUC) and calibration plots, with an AUC of 72.3 (95% CI 65.5, 79.1) for the prediction model at 1 year, and an AUC of 74.9 (95% CI 69.3, 80.5) for the prediction model at 5 years reported. 

This risk stratification tool which demonstrates acceptable accuracy for the early prediction of PsA in those with psoriasis at 1- and 5- year time frames most definitely fosters promise for the future early identification of those with PsA, enabling early intervention and “hey PRESTO” coming closer to grasping that low hanging fruit!