Shawn Rose

Severity of Psoriasis Associates With Aortic Vascular Inflammation Detected by FDG PET/CT and Neutrophil Activation in a Prospective Observational Study

Objective—To understand whether directly measured psoriasis severity is associated with vascular inflammation assessed by 18F-fluorodeoxyglucose positron emission tomography computed tomography. Approach—In-depth cardiovascular and metabolic phenotyping was performed in adult psoriasis patients (n=60) and controls (n=20). Psoriasis severity was measured using psoriasis area severity index. Vascular inflammation was measured using average aortic target-to-background ratio using 18F-fluorodeoxyglucose positron emission tomography computed tomography. Results—Both the psoriasis patients (28 men and 32 women, mean age 47 years) and controls (13 men and 7 women, mean age 41 years) were young with low cardiovascular risk. Psoriasis area severity index scores (median 5.4; interquartile range 2.8–8.3) were consistent with mild-to-moderate skin disease severity. Increasing psoriasis area severity index score was associated with an increase in aortic target-to-background ratio (&bgr;=0.41, P=0.001), an association that changed little after adjustment for age, sex, and Framingham risk score. We observed evidence of increased neutrophil frequency (mean psoriasis, 3.7±1.2 versus 2.9±1.2; P=0.02) and activation by lower neutrophil surface CD16 and CD62L in blood. Serum levels of S100A8/A9 (745.1±53.3 versus 195.4±157.8 ng/mL; P<0.01) and neutrophil elastase-1 (43.0±2.4 versus 30.8±6.7 ng/mL; P<0.001) were elevated in psoriasis. Finally, S100A8/A9 protein was related to both psoriasis skin disease severity (&bgr;=0.53; P=0.02) and vascular inflammation (&bgr;=0.48; P=0.02). Conclusions—Psoriasis severity is associated with vascular inflammation beyond cardiovascular risk factors. Psoriasis increased neutrophil activation and neutrophil markers, and S100A8/A9 was related to both skin disease severity and vascular inflammation.

Oxidized LDL levels are increased in HIV infection and may drive monocyte activation

Background: HIV infection is associated with increased cardiovascular risk, and this risk correlates with markers of monocyte activation. We have shown that HIV is associated with a prothrombotic monocyte phenotype, which can be partially mitigated by statin therapy. We therefore explored the relationship between oxidized low-density lipoprotein (oxLDL) particles and monocyte activation. Methods: We performed phenotypic analysis of monocytes using flow cytometry on fresh whole blood in 54 patients with HIV and 24 controls without HIV. Plasma levels of oxLDL, soluble CD14, IL-6, and soluble CD163 were measured by enzyme-linked immunosorbent assay. In vitro experiments were performed using flow cytometry. Results: Plasma levels of oxLDL were significantly increased in HIV infection compared with controls (60.1 units vs. 32.1 units, P < 0.001). Monocyte expression of the oxLDL receptors, CD36 and Toll-like receptor 4, was also increased in HIV. OxLDL levels correlated with markers of monocyte activation, including soluble CD14, tissue factor expression on inflammatory monocytes, and CD36. In vitro stimulation with oxLDL, but not to low-density lipoprotein, resulted in expansion of inflammatory monocytes and increased monocyte expression of tissue factor, recapitulating the monocyte profile we find in HIV disease. Conclusions: OxLDL may contribute to monocyte activation, and further study in the context of HIV disease is warranted.

Comprehensive Treatment of Dactylitis in Psoriatic Arthritis

Dactylitis, a hallmark clinical feature of psoriatic arthritis (PsA) and other spondyloarthropathies, may also be a severity marker for PsA and psoriasis. Traditionally, clinicians have used nonsteroidal antiinflammatory drugs and local corticosteroid injections to treat dactylitis, although conventional disease-modifying antirheumatic drugs are also used. We performed a systematic literature review to determine the most efficacious current treatment options for dactylitis in PsA. Effect sizes were greatest for the biologic agents ustekinumab, certolizumab, and infliximab, suggesting that therapy with one of these agents should be initiated in patients with dactylitis. However, the limited data highlight the need for randomized, placebo-controlled trials, with dactylitis as a primary outcome, to determine a valid, reliable, and responsive clinical outcome measure for PsA patients with dactylitis.

Psoriatic arthritis and sacroiliitis are associated with increased vascular inflammation by 18-fluorodeoxyglucose positron emission tomography computed tomography: baseline report from the Psoriasis Atherosclerosis and Cardiometabolic Disease Initiative

IntroductionPsoriasis and psoriatic arthritis (PsA) increase cardiovascular disease (CVD) risk, but surrogate markers for CVD in these disorders are inadequate. Because the presence of sacroiliitis may portend more severe PsA, we hypothesized that sacroiliitis defined by computed tomography (CT) would be associated with increased vascular inflammation defined by 18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT), which is an established measure of CVD.MethodsParticipants (n = 65) underwent whole-body FDG-PET/CT. Metabolic activity of the aorta was measured using the maximal standardized uptake value (SUVmax), a measure of atherosclerotic plaque activity. The primary outcome was aortic vascular inflammation. Linear regression (with β-coefficients (β) and P-values reported for PsA and sacroiliitis) was used to adjust for CVD risk factors to determine associations of PsA or sacroiliitis with vascular inflammation. Likelihood ratio testing was performed to evaluate the contribution of sacroiliitis to vascular disease estimation compared to the effects of PsA and traditional CVD risk factors.ResultsVascular inflammation (measured as SUVmax) was greater (P < 0.001) in patients with sacroiliitis (mean ± SD = 7.33 ± 2.09) defined by CT compared to those without sacroiliitis (6.39 ± 1.49, P = 0.038). There were associations between PsA and aortic inflammation (β = 0.124, P < 0.001) and between sacroiliitis and aortic inflammation (β = 0.270, P < 0.001) after adjusting for CVD risk factors. Sacroiliitis predicted vascular inflammation beyond PsA and CVD risk factors (χ2 = 124.6, P < 0.001).ConclusionsSacroiliitis is associated with increased vascular inflammation detected by FDG-PET/CT, suggesting that sacroiliac joint disease may identify patients at greater risk for CVD. Large, ongoing prospective studies are required to confirm these findings.

Characterization of immune cells in psoriatic adipose tissue

BackgroundAdipose tissue normally contains immune cells that regulate adipocyte function and contribute to metabolic disorders including obesity and diabetes mellitus. Psoriasis is associated with increased risk for metabolic disease, which may in part be due to adipose dysfunction, which has not been investigated in psoriasis. There is currently no standardized method for immunophenotyping human adipose tissue. In prior studies, characteristic phenotypic markers of immune cell populations identified in animal models or in other human tissues have been applied in a similar manner to human adipose tissue. Rarely have these populations been verified with confirmatory methodologies or functional studies. Thus, we performed a comprehensive phenotypic and functional analysis of immune cell populations in psoriatic adipose tissue.MethodsConventional and imaging flow cytometry were used to define immune cell populations in biopsy specimens of psoriatic adipose tissue (n = 30) including T cells, B cells, NK cells, NKT cells, neutrophils, and macrophages. Relationships between adipose immune cell types and body mass index were determined using Spearman regression analysis, and multivariate linear regression analysis was performed to adjust for cardiometabolic disease risk factors.ResultsThese analyses revealed a wide range of cell surface receptors on adipose tissue macrophages, which may serve a dual purpose in immunity and metabolism. Further, both CD16+CD56Lo and CD16-CD56Hi NK cells were found to correlate inversely with body mass index. The relationship between the predominant CD16+CD56Lo NK cell population and body mass index persisted after adjusting for age, sex, diabetes, and tobacco use.ConclusionsTogether, these studies enhance our understanding of adipose immune cell phenotype and function, and demonstrate that examination of adipose tissue may provide greater insight into cardiometabolic pathophysiology in psoriasis.

IL-17A Production in Human Psoriatic Blood and Lesions by CD146+ T Cells

To the Editor: CD146, also called melanoma cell adhesion molecule (MCAM), is a cell surface adhesion molecule on endothelial cells involved in homotypic and heterotypic cell interactions (Bardin et al, 2001). CD146 binding in endothelial cells (ECs) leads to a change in cellular permeability, actin distribution and redistribution of NF-kappa B p50 to the nucleus. CD146 has been shown to be present on 1–3% of circulating peripheral blood T cells in healthy humans (Elshal et al, 2005). CD146+ T cells have an effector memory phenotype, demonstrate up-regulation of a cluster of genes involved with adhesion, migration, homing, and inflammation, and have enhanced binding to endothelial monolayers in vitro (Elshal et al, 2007). These features of the CD146+ T cells in the peripheral circulation have led to speculation that these represent a small pool of cells primed for extravasation and/or homing of activated T cells (Elshal et al, 2007, Guezguez et al, 2007) in response to inflammatory stimuli. Circulating CD146+ T cells are elevated in several inflammatory autoimmune diseases such as sarcoidosis, inflammatory bowel disease, multiple sclerosis, connective tissue disease, and Behcets disease and produce IL-17 (Dagur et al, 2011, Dagur et al, 2010, LaRochelle et al, 2012). Whether these cells play a role at the site of active inflammation in these diseases remains unknown. Psoriasis, which is associated with increased vascular inflammation (Mehta et al, 2009) and access to both peripheral blood and the disease target tissue (e.g. skin), is ideal to study CD146+ T cell phenotype and function in an inflammatory condition. Here we present findings from a well-characterized patient population with psoriasis using peripheral blood samples and skin biopsies from psoriatic lesions and uninvolved skin. Forty-seven patients with psoriasis and sixty-seven healthy controls were included in this study. Diagnosis of psoriasis was confirmed by a dermatologist and severity was measured by percentage of body surface area (BSA) involved and the validated Psoriasis Area and Severity Index (PASI). Donor demographics and characteristics are presented in Supplemental Table 1. Skin biopsies were isolated from a representative psoriatic target lesion (6 mm) and are identified as lesional psoriatic skin. Non-lesional skin biopsies were obtained from a similar body area at least 10cm away from the nearest psoriasis skin lesion. Frozen sections were obtained from skin lesions for immunofluorescence studies and all patients provided written consent in as part of an IRB-approved study (NCT01778569). Venous blood was collected in sodium heparin vacutainers (Becton Dickinson (BD), San Jose, CA). Cells were stained and flow cytometric analysis was performed as previously described (6). Skin biopsies were digested in Collagenase IV (GIBCO BRL # 17104-019) at 5 mg/ml in RPMI 1640 for 45 min, stained, and then sorted in the same manner as peripheral blood. The following antibodies used for staining were obtained from BD: CD3, CD4, CD8, CD33, CD14, CD19, CD45, CD45-RO, CD146 (Clone P1H12). Anti-IL-17A (clone ebio64DEC17) was purchased from eBiosciences. Immunophenotyping results are expressed as means and standard errors of the mean. RNA was isolated from sorted CD146+ or CD146- T cell subpopulations using RNAquos Micro kits (Ambion) and real time PCR (QRTPCR) was performed using a 7900-sequence detector (PE-Applied Biosystems, Norwalk, CT). Data from a single specimen were considered one experiment (n). A p-value <0.05 was considered statistically significant. Statistical analysis was performed using STATA version 12.0 (StataCorp, College Station, TX, USA). To determine whether CD146+ T cells are prevalent in patients with a Th17 disorder, immunophenotyping was performed on fresh peripheral blood from patients with psoriasis. Psoriasis patients showed a significant elevation of circulating CD3+CD146+ T cells compared to healthy adults (3.91 ± 0.37% vs 2.96 ± 0.19% respectively, p =0.03) (Figure 1A). Increased CD146 expression reached statistical significance with the circulating CD4+ T cells (5.50 +/- 0.413% in PSO vs 3.55 +/− 0.213% respectively, p <0.0001), (Figure 1B), but not the CD3+CD8+CD146+ T cells (2.75 +/− 0.373% in PSO vs 2.30 +/− 0.216% respectively) (Figure 1C). CD146+ T cells were abundant within lesional skin biopsies, representing roughly 1/3 of the total CD4+ T and CD8+ T cell populations (Figures 1B, 1C). Immunofluorescence of frozen sections confirmed CD146+ T cells in lesional skin biopsies (Figure 1D). Lymphocytes, including CD146+ T cells, were rare in biopsies of non-lesional, unaffected skin from psoriasis patients. Figure 1 CD146+ T cells are significantly elevated in patients with psoriasis in the circulation and at the site of inflammation. Comparative frequencies (Mean +/− SEM) of: To determine IL-17A production from CD146- and CD146+ subsets of psoriatic T cells, cell suspensions from peripheral blood and lesional skin were stimulated for 3 hours with PMA and ionomycin, stained for cell surface markers, and then for intracellular IL-17A. CD146+ cells were the primary producers of IL-17A in lesional skin for both CD4+ (67.8± 9.5% p<0.005) and CD8+ (70.8± 11.4%, p<0.004) T cells (Figure 2A). In contrast, CD146+ cells accounted for ~20% of IL-17A producers in peripheral blood from both healthy adults and psoriatics. mRNA levels of IL-17A, RORc2, and CD146 were increased among unstimulated CD146+ T cells compared to CD146- cells, in both the blood and lesional skin, with a greater elevation in the lesions (Figure 2B). Figure 2 Figure 2A. Percentages of IL-17A -producing T cells which are CD146 positive. The T cells and T cell subsets secreting IL-17A were gated first and then the proportion of these cells expressing CD146 were determined. While previous studies have demonstrated increased circulating Th17 cells in psoriasis (Kagami et al, 2010), in this study we demonstrate that CD146+ T cells produce the majority of IL-17A at the active site of inflammation in psoriasis. Our study confirms previous reports of IL-17A production by CD146+ T cells in both healthy individuals and in patients with various autoimmune disorders and adds to those results by: 1) extending these findings to psoriasis; and 2) demonstrating that CD146+ T cells are important mediators of inflammation at the active site of disease. These findings suggest that CD146+ T cells in the circulation may represent a pool of cells with both the means to extravasate to the site of inflammation (via CD146 expression), and to mediate inflammation at a specific site. Limitations include analyzing patients with a variety of topical and systemic therapy and only studying patients with mild to moderate psoriasis. Previous studies examining this cell type in autoimmune diseases have been limited by not examining cells at the active site of inflammation – a hindrance overcome in the current work.

Chronic skin inflammation accelerates macrophage cholesterol crystal formation and atherosclerosis

Inflammation is critical to atherogenesis. Psoriasis is a chronic inflammatory skin disease that accelerates atherosclerosis in humans and provides a compelling model to understand potential pathways linking these diseases. A murine model capturing the vascular and metabolic diseases in psoriasis would accelerate our understanding and provide a platform to test emerging therapies. We aimed to characterize a new murine model of skin inflammation (Rac1V12) from a cardiovascular standpoint to identify novel atherosclerotic signaling pathways modulated in chronic skin inflammation. The RacV12 psoriasis mouse resembled the human disease state, including presence of systemic inflammation, dyslipidemia, and cardiometabolic dysfunction. Psoriasis macrophages had a proatherosclerotic phenotype with increased lipid uptake and foam cell formation, and also showed a 6-fold increase in cholesterol crystal formation. We generated a triple-genetic K14-RacV12-/+/Srb1-/-/ApoER61H/H mouse and confirmed psoriasis accelerates atherogenesis (~7-fold increase). Finally, we noted a 60% reduction in superoxide dismutase 2 (SOD2) expression in human psoriasis macrophages. When SOD2 activity was restored in macrophages, their proatherogenic phenotype reversed. We demonstrate that the K14-RacV12 murine model captures the cardiometabolic dysfunction and accelerates vascular disease observed in chronic inflammation and that skin inflammation induces a proatherosclerotic macrophage phenotype with impaired SOD2 function, which associated with accelerated atherogenesis.

DIRECTLY MEASURED INFLAMMATION IN PSORIASIS SKIN ASSOCIATES WITH VASCULAR INFLAMMATION BEYOND TRADITIONAL RISK FACTORS

Inflammation is critical to development and progression of atherosclerosis. Psoriasis, a chronic inflammatory disease characterized by skin and systemic inflammation, is associated with increased cardiovascular diseases (CVD). We have previously demonstrated increased vascular inflammation by FDG