Summary To gain further insight into the genetic architecture of psoriasis, we conducted a meta-analysis of three genome-wide association studies (GWAS) and two independent datasets genotyped on the Immunochip, involving 10,588 cases and 22,806 controls in total. We identified 15 new disease susceptibility regions, increasing the number of psoriasis-associated loci to 36 for Caucasians. Conditional analyses identified five independent signals within previously known loci. The newly identified shared disease regions encompassed a number of genes whose products regulate T-cell function (e.g. RUNX3, TAGAP and STAT3). The new psoriasis-specific regions were notable for candidate genes whose products are involved in innate host defense, encoding proteins with roles in interferon-mediated antiviral responses (DDX58), macrophage activation (ZC3H12C), and NF-κB signaling (CARD14 and CARM1). These results portend a better understanding of shared and distinctive genetic determinants of immune-mediated inflammatory disorders and emphasize the importance of the skin in innate and acquired host defense.

Objective To update the 2009 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) treatment recommendations for the spectrum of manifestations affecting patients with psoriatic arthritis (PsA). Methods GRAPPA rheumatologists, dermatologists, and PsA patients drafted overarching principles for the management of PsA, based on consensus achieved at face-to-face meetings and via online surveys. We conducted literature reviews regarding treatment for the key domains of PsA (arthritis, spondylitis, enthesitis, dactylitis, skin disease, and nail disease) and convened a new group to identify pertinent comorbidities and their effect on treatment. Finally, we drafted treatment recommendations for each of the clinical manifestations and assessed the level of agreement for the overarching principles and treatment recommendations among GRAPPA members, using an online questionnaire. Results Six overarching principles had ≥80% agreement among both health care professionals (n = 135) and patient research partners (n = 10). We developed treatment recommendations and a schema incorporating these principles for arthritis, spondylitis, enthesitis, dactylitis, skin disease, nail disease, and comorbidities in the setting of PsA, using the Grading of Recommendations, Assessment, Development and Evaluation process. Agreement of >80% was reached for approval of the individual recommendations and the overall schema. Conclusion We present overarching principles and updated treatment recommendations for the key manifestations of PsA, including related comorbidities, based on a literature review and consensus of GRAPPA members (rheumatologists, dermatologists, other health care providers, and patient research partners). Further updates are anticipated as the therapeutic landscape in PsA evolves

Objective. Current treatment options for psoriatic arthritis (PsA) are limited. Leflunomide, an oral pyrimidine synthesis inhibitor, is highly effective in the treatment of rheumatoid arthritis, and small studies have suggested similar efficacy in PsA. We undertook this double-blind, randomized, placebo-controlled trial to evaluate the efficacy and safety of leflunomide in patients with PsA and psoriasis.Methods. One hundred ninety patients with active PsA and psoriasis (at least 3% skin involvement) were randomized to receive leflunomide (100 mg/day loading dose for 3 days followed by 20 mg/day orally) or placebo for 24 weeks. The primary efficacy end point was the proportion of patients classified as responders by the Psoriatic Arthritis Response Criteria (PsARC). Additional efficacy (joint and skin involvement), safety, and quality-of-life assessments were performed.Results Conclusion. Leflunomide is an effective treatment for PsA and psoriasis, providing a safe and convenient alternative to current therapies.