Residual disease activity and associated factors in Psoriatic Arthritis

Objective: Remission or low disease activity should be the treatment target of Psoriatic Arthritis (PsA). However, residual disease activity (RDA) in some domains could persist. The aim of this study was to assess RDA and its associated factors in a group of PsA patients. Methods: PsA patients satisfying CASPAR criteria, with >6 months follow up and achieved a status of low disease activity (LDA), MDA or remission (DAPSA remission or VLDA) were enrolled. RDA was assessed by the percentage of patients who had, although in LDA or remission, tender and/or swollen joints>1, LEI>1, HAQ>0.5, PASI>1, PtGA>20, physician VAS>20 and VAS pain>15. Associated factors of RDA were also assessed. Results: Of 113 enrolled patients, 78 (69%) were in MDA. Moreover, DAPSA remission was observed in 46 (40.7%) while VLDA only in 32 (28.3%) of PsA patients. VLDA seems to be the most stringent criteria with a minimal RDA only in the VAS physician in one patient (3.1%) and none in the different domains, while patients in MDA had RDA in tender joints (14.1%), VAS pain (29.4%) and PASI>1 or BSA>3% (17.9%). Of note, although patients in DAPSA remission show a very low rate of RDA in almost all domains, 12 (26%) of them show a PASI>1 or BSA>3%. Finally, LDA shows RDA in higher percentage, mainly in PROs, tender joints and skin domain. Conclusion: RDA is possible to be recognized in PsA patients. VLDA seems to be the most stringent composite index to identify patients in absence of RDA