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 (18)F-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 (18)F-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 (ß=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 (ß=0.53; P=0.02) and vascular inflammation (ß=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.

Secretion of interleukin-17 by CD8+ T cells expressing CD146 (MCAM).

Interleukin-17 (IL-17) has been associated with the pathogenesis of numerous autoimmune diseases. CD4+ T cells secreting IL-17 are termed Th17 cells. CD8+ T cells, designated Tc17 cells, are also capable of secreting IL-17. Here we describe a population of Tc17 cells characterized by the expression of surface CD146, an endothelial adhesion molecule. These cells display signatures of a human Tc17 genotype and phenotype. Circulating CD8+CD146+ T cells are present in low levels in healthy adults. Elevations in CD8+CD146+ T cells are found in Behcet's disease and birdshot retinochoroidopathy, which have been reported to have HLA class I associations. Sarcoidosis does not have a class I association and displays an increase in CD4+ CD146+ T cells but not in CD8+CD146+ T cells. CD146 on these cells may facilitate their ability to bind to, and migrate through, endothelium, as has been reported for CD4+CD146+ T cells.

Characterization of immune cells in psoriatic adipose tissue.

BACKGROUND: Adipose 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. METHODS: Conventional 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. RESULTS: These 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+CD56(Lo) and CD16-CD56(Hi) NK cells were found to correlate inversely with body mass index. The relationship between the predominant CD16+CD56(Lo) NK cell population and body mass index persisted after adjusting for age, sex, diabetes, and tobacco use. CONCLUSIONS: Together, 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.

Neutrophil Subsets, Platelets, and Vascular Disease in Psoriasis.

Psoriasis is an inflammatory skin disease associated with increased cardiovascular risk and serves as a reliable model to study inflammatory atherogenesis. Because neutrophils are implicated in atherosclerosis development, this study reports that the interaction among low-density granulocytes, a subset of neutrophils, and platelets is associated with a noncalcified coronary plaque burden assessed by coronary computed tomography angiography. Because early atherosclerotic noncalcified burden can lead to fatal myocardial infarction, the low-density granulocyte-platelet interaction may play a crucial target for clinical intervention.

B Cell Anomalies in Autoimmune Retinopathy (AIR).

Purpose: Autoimmune retinopathy (AIR) is a retinopathy associated with unexplained vision loss presumably linked to circulating antiretinal antibodies; currently, however, there are no standardized criteria regarding the diagnosis, treatment strategy, or pathogenesis of this disease. The importance of B-lymphocyte immunophenotyping in the classification of AIR is unknown. Methods: We utilized 15-color multiparametric flow cytometry to identify aberrations in B cell subsets that may contribute to the pathophysiology of AIR. Luminex cytokine analysis was also performed on plasma samples from AIR patients. Results: Significant differences in AIR patients compared to individuals with other inflammatory conditions or healthy donors were found in the B cell memory compartment, including an increase in naïve B cells and a decrease in switched and unswitched memory B cells, which correlated with alterations in immunoglobulin secretion. Conclusions: These findings suggest that the maturation process of B cells may be impaired and that B cell immunophenotyping may help in understanding disease process in AIR.

Manganese [III] Tetrakis [5,10,15,20]-Benzoic Acid Porphyrin Reduces Adiposity and Improves Insulin Action in Mice with Pre-Existing Obesity.

The superoxide dismutase mimetic manganese [III] tetrakis [5,10,15,20]-benzoic acid porphyrin (MnTBAP) is a potent antioxidant compound that has been shown to limit weight gain during short-term high fat feeding without preventing insulin resistance. However, whether MnTBAP has therapeutic potential to treat pre-existing obesity and insulin resistance remains unknown. To investigate this, mice were treated with MnTBAP or vehicle during the last five weeks of a 24-week high fat diet (HFD) regimen. MnTBAP treatment significantly decreased body weight and reduced white adipose tissue (WAT) mass in mice fed a HFD and a low fat diet (LFD). The reduction in adiposity was associated with decreased caloric intake without significantly altering energy expenditure, indicating that MnTBAP decreases adiposity in part by modulating energy balance. MnTBAP treatment also improved insulin action in HFD-fed mice, a physiologic response that was associated with increased protein kinase B (PKB) phosphorylation and expression in muscle and WAT. Since MnTBAP is a metalloporphyrin molecule, we hypothesized that its ability to promote weight loss and improve insulin sensitivity was regulated by heme oxygenase-1 (HO-1), in a similar fashion as cobalt protoporphyrins. Despite MnTBAP treatment increasing HO-1 expression, administration of the potent HO-1 inhibitor tin mesoporphyrin (SnMP) did not block the ability of MnTBAP to alter caloric intake, adiposity, or insulin action, suggesting that MnTBAP influences these metabolic processes independent of HO-1. These data demonstrate that MnTBAP can ameliorate pre-existing obesity and improve insulin action by reducing caloric intake and increasing PKB phosphorylation and expression.