GRAPPA 2013 Annual Meeting, Rheumatology Updates: Psoriatic Arthritis (PsA) Biomarker Project, Arthritis Mutilans, PsA-Peripheral Spondyloarthritis Epidemiology Project

At the 2013 annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), several key GRAPPA projects on musculoskeletal aspects of psoriatic disease were reviewed. In this article, lead investigators summarize the progress made in a multicenter study, the PsA BioDam (Psoriatic Arthritis Biomarkers for Joint Damage), to identify soluble biomarkers for joint damage, as well as developing classification criteria for arthritis mutilans. Also reviewed are concepts and rationale behind a proposal to study classification criteria for peripheral spondy-loarthritis, including PsA, reactive arthritis, inflammatory bowel disease-associated arthritis, and undifferentiated arthritis.