Epidemiology, genetics and management of psoriatic arthritis 2013: focus on developments of who develops the disease, its clinical features, and emerging treatment options

Abstract

Muhammad Haroon,1 Oliver FitzGerald,1 Robert Winchester2 1Department of Rheumatology, St Vincent's University Hospital, Dublin, Ireland; 2Division of Rheumatology, Columbia University College of Physicians and Surgeons, New York, NY, USA Abstract: The picture of elements comprising the genetic susceptibility to develop psoriatic arthritis, especially those involving human leukocyte antigen alleles, is emerging in much greater clarity because of improvements in the methods of psoriatic arthritis ascertainment and in the technology of genetic typing. This new knowledge suggests there is genetic heterogeneity in the psoriasis phenotype, and that there are several genetically and clinically different forms of psoriatic arthritis. These genetic studies on psoriatic arthritis further reinforce the relationship of psoriatic arthritis to the other spondyloarthritides, but also raise novel questions of whether the effect of certain susceptibility genes may differ among them. Considerable evidence indicates that the clinical features reflect a CD8 T lymphocyte-driven immune response is present that is characterized by clonal expansion and differentiation towards memory-effector phenotypes. With the aid of new classification criteria, the typical clinical features of psoriatic arthritis involving different joints, entheses, and their related compartments are being better defined as distinctive characteristics of psoriatic arthritis or of the spondyloarthritis group of disorders. In the evaluation of an individual with psoriatic arthritis, taking a patient-focused perspective is recommended, which has the potential to enhance their quality of life significantly. The choice of current and emerging therapeutic agents from an increasing realm of conventional and biologic agents is becoming much better rationalized and more firmly based on evidence from clinical trials. Keywords: psoriatic arthritis, genetic susceptibility, heterogeneity, classification, diagnostic criteria, treatment