Minimal disease activity as a treatment target in psoriatic arthritis: A review of the literature

As in other inflammatory rheumatic diseases, the objective of psoriatic arthritis (PsA) treatment is the achievement of a defined target. Recent recommendations propose aiming for remission or low disease activity; however, a consensual definition of remission is lacking. A state of minimal disease activity (MDA) has been established and is defined by low activity assessed by tender/swollen joint counts, tender entheseal points, Psoriasis Area and Severity Index or body surface area, patient pain and global activity visual analog scale, and functional evaluation by Health Assessment Questionnaire. Since its development, MDA has been used increasingly in studies and clinical trials. In this article, the potential use of MDA as a treatment target in PsA is reviewed. The frequencies of MDA achievement with biologic disease-modifying antirheumatic drugs are summarized based on data from registries, observational studies, and clinical trials. Predictors and the prognostic effect of attaining MDA are also evaluated.