Biomarkers in psoriatic arthritis: recent progress.

Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis. About a quarter of patients with psoriasis of the skin will develop PsA, although it is currently challenging-if not impossible-to determine a priori which individuals will progress. Identification of biomarkers for screening, disease activity, joint damage, treatment response and comorbidities are therefore perceived as important clinical needs in the field. Over the last few years, several lines of investigation have advanced our knowledge of new markers for PsA and its outcomes, including genomic, proteomic, cellular and tissue studies. Imaging studies utilizing ultrasonography have been applied to better understand the natural history of the disease. Novel biomarkers, such as soluble proteins and microbiomics, are also being described. Although no biomarker has yet been validated for use in clinical practice, discovery studies are in progress and validation cohorts are being designed. In this report, we review the latest progress in biomarker research in PsA and its potential implications in pathogenesis, diagnosis and therapy.