Serum Beta-Defensin-2 is a biomarker for psoriasis but not subclinical atherosclerosis: Role of IL17a, PI-3 kinase and Rac1

Background

Beta-defensins (BDs) are antimicrobial peptides secreted upon epithelial injury. Both chemotactic and antimicrobial properties of BDs function as initial steps in host defense and prime the adaptive immune system in the body. Psoriasis, a chronic immune-mediated inflammatory disease, has both visible cutaneous manifestations as well as known associations with higher incidence of cardiometabolic complications and vascular inflammation.

Objectives

We aimed to investigate the circulating expression of beta-defensin-2 (BD2) in psoriasis at baseline compared to control subjects, along with changes in BD2 levels following biologic treatment at one-year. The contribution of BD2 to subclinical atherosclerosis is also assessed. In addition, we have sought to unravel signaling mechanisms linking inflammation with BD2 expression.

Methods

Multimodality imaging as well inflammatory biomarker assays were performed in biologic naïve psoriasis (n=71) and non-psoriasis (n=53) subjects. A subset of psoriasis patients were followed for one-year after biological intervention (anti-Tumor Necrosis Factor-α (TNFα), n=30; anti-Interleukin17A (IL17A), n=21). Measurements of circulating BD2 were completed by Enzyme-Linked Immunosorbent Assay (ELISA). Using HaCaT transformed keratinocytes, expression of BD2 upon cytokine treatment was assessed by quantitative polymerase chain reaction (qPCR) and ELISA.

Results

Herein, we confirm that human circulating BD2 levels associate with psoriasis, which attenuate upon biologic interventions (anti-TNFα, anti-IL-17A). A link between circulating BD2 and sub-clinical atherosclerosis markers was not observed. Furthermore, we demonstrate that IL-17A-driven BD2 expression occurs in a Phosphatidylinositol 3-kinase (PI3-kinase) and Rac1 GTPase-dependent manner.

Conclusions

Our findings expand on the potential role of BD2 as a tractable biomarker in psoriasis patients and describes the role of an IL-17A-PI3-kinase/Rac signaling axis in regulating BD2 levels in keratinocytes.

MP11: COMORBID DEPRESSION OR ANXIETY IS ASSOCIATED WITH AORTIC VASCULAR INFLAMMATION AND CORONARY HEART DISEASE BEYOND TRADITIONAL CARDIOVASCULAR RISK FACTORS IN PSORIASIS

Purpose of Study

Psoriasis is a chronic inflammatory disorder associated with vascular inflammation (VI), measured by 18-fluorodeoxyglucose positron emission tomography/computed tomography (18-FDG PET/CT), and increased risk of MI. Patients with psoriasis are more likely to have comorbid depression and anxiety. Whether these comorbidities accelerate the development of CVD in psoriasis is unclear. We hypothesized that aortic VI and coronary plaque burden would be increased in patients with psoriasis who have depression and/or anxiety compared to those with psoriasis who do not.

Methods Used

Patients were prospectively enrolled. Those who reported a history of depression and/or anxiety (n=40) on survey and age- and gender-matched patients who reported no history of psychiatric illness (n=40) were selected. Target-to-Background ratio from 18FDG PET/CT was used to assess aortic VI, and coronary CT angiography scans were analyzed for coronary plaque composition.

Summary of Results

Both aortic VI and coronary plaque burden were higher in psoriasis patients with comorbid depression or anxiety compared to those without (table 1). After adjustment for Framingham Risk Score, body mass index, and statin use; VI (β=0.24, p=0.02), total plaque burden (β=0.13, p=0.04), and non-calcified burden (β=0.13, p=0.04) were associated with comorbid depression and/or anxiety.

Conclusions

Patients with psoriasis who have comorbid depression or anxiety have increased aortic VI and coronary plaque burden, suggesting that identification of psychiatric diagnoses in psoriasis may be warranted for future CV risk reduction in this high risk population.

Abstract MP11 Figure 1

An integrated YAC map of the human X chromosome

The human X chromosome is associated with a large number of disease phenotypes, principally because of its unique mode of inheritance that tends to reveal all recessive disorders in males. With the longer term goal of identifying and characterizing most of these genes, we have adopted a chromosome-wide strategy to establish a YAC contig map. We have performed > 3250 inter Alu-PCR product hybridizations to identify overlaps between YAC clones. Positional information associated with many of these YAC clones has been derived from our Reference Library Database and a variety of other public sources. We have constructed a YAC contig map of the X chromosome covering 125 Mb of DNA in 25 contigs and containing 906 YAC clones. These contigs have been verified extensively by FISH and by gel and hybridization fingerprinting techniques. This independently derived map exceeds the coverage of recently reported X chromosome maps built as part of whole-genome YAC maps.