Comparing Remission, Low Disease Definitions in Psoriatic Arthritis

When assessing patients with psoriatic arthritis (PsA), the definitions of minimal disease activity (MDA) and very low disease activity (VLDA) are more stringent than the Disease Activity Index for PsA (DAPSA) and the clinical (cDAPSA), according to a study published in The Journal of Rheumatology.  

Considering the lack of agreement on optimal definitions for disease state assessment in PsA, researchers in the current study investigated the prognostic value of the various definitions used by clinicians to assess disease state for patients with PsA. This was conducted using a post hoc analysis of PRESTA study data.

The remission definitions analyzed were the VLDA index (defined as 7 of 7 of the MDA cutoffs), DAPSA, and cDAPSA. The low disease activity (LDA) definitions that were analyzed were MDA (defined as 5 of 7 cutoffs); MDA of the joints with both the swollen joint count and tender joint count cutoffs mandated; MDA where  skin cutoff was mandated; MDA of the joint and skin, where skin cutoffs, swollen joint count, and tender joint count were mandated; DAPSA LDA; and cDAPSA LDA.

By 24 weeks, 10% of participants achieved VLDA remission, 35% achieved DAPSA remission, and 37% achieved cDAPSA remission. Among the patients who achieved DAPSA remission, 55% had a Psoriasis Area and Severity Index > 1 vs 56% of participants who achieved cDAPSA remission.

Forty-four percent of patients achieved the end point for MDA 5/7, 19% for MDA of the skin, 36% for MDA of the joints, and 14% for MDA of the joint and skin compared with 70% who achieved end points for DAPSA and cDAPSA LDA. Patients who had achieved disease state definitions that no longer required skin disease control had notable residual psoriasis levels.

Study investigators conclude that their “findings may assist physicians in choosing a valid composite definition that facilitates the assessment and treatment of patients with PsA and psoriasis in clinical practice.”

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Reference

Coates LC, Gottlieb AB, Merola JF, Boone C, Szumski A, Chhabra A. Comparison of different remission and low disease definitions in psoriatic arthritis and evaluation of their prognostic value. [published online October 15, 2018]J Rheumatol. doi: 10.3899/jrheum.180249