What factors correlate with residual disease activity in psoriatic arthritis?

Patients with psoriatic arthritis (PsA) may show residual disease activity (RDA), according to a study. Very low disease activity (VLDA) appears to be the most stringent criterion to identify patients in the absence of RDA.

PsA patients were eligible if they satisfied ClASsification for Psoriatic ARthritis (CASPAR) criteria with >6 months’ follow-up and achieved a status of low disease activity (LDA), minimal disease activity (MDA), or remission (Disease Activity Index for PsA [DAPSA] remission or VLDA).

The authors assessed RDA by the percentage of patients who, although in LDS or remission, had tender or swollen joints >1, Leeds Enthesitis Index >1, Health Assessment Questionnaire >0.5, Psoriasis Area Severity Index (PASI) >1, patient’s global assessment >20, physician visual analogue scale (VAS) >20, and VAS pain >15. They also evaluated the factors associated with RDA.

Among 113 eligible patients with PsA, 78 (69 percent) were in MDA while 46 (40.7 percent) had DAPSA remission and only 32 (28.3 percent) were in VLDA. The most stringent composite index was VLDA, with a minimal RDA only in the VAS physician in one patient (3.1 percent) and none in the different domains. On the other hand, patients in MDA had RDA in tender joints (14.1 percent), VAS pain (29.4 percent), and PASI >1 or body surface area (BSA) >3 percent (17.9 percent).

Notably, patients in DAPSA remission had a very low rate of RDA in almost all domains, but 12 (26 percent) of them showed a PASI >1 or BSA >3 percent. LDA also displayed RDA in higher percentages, particularly in patient-reported outcomes, tender joints, and skin domain, according to the authors.