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.

Application of machine learning to identify top determinants of fibrofatty plaque burden by CCTA in humans with psoriasis

Introduction

Fibrofatty plaque burden (FFB) is a high-risk, vulnerable plaque feature comprised of an atheromatous core and fibrous cap with increased risk of coronary artery disease (CAD) [1]. Psoriasis (PSO) is a chronic inflammatory disease linked with atherosclerotic risk and premature cardiovascular disease, driven in part by vulnerable plaque rupture [2,3]. Machine learning (ML) previously showed the prognostic value of FFB in predicting 5-year risk of cardiac-related mortality in patients with CAD [4]. Whether ML can predict FFB in psoriasis is understudied.

Purpose

To use ML to identify top determinants of FFB by CCTA in PSO.

Methods

320 consecutive participants with psoriasis were recruited as part of an ongoing cohort study, of whom 307 had FFB analyzed with coronary computed tomography angiography (CCTA) and quantified by QAngio CT (Medis, The Netherlands). 140 out of 182 potential determinants were subjected to ML algorithms analyzed by random forest and validated by 5-fold cross validation to select the top determinants based on R-square criteria. Lipid concentration and size were measured by nuclear magnetic resonance (NMR) and sdLDL-C was calculated by Sampson's formula.

Results

The top 21 determinants of FFB at baseline were grouped into 3 categories: cardiometabolic risk factors (BMI, sex, DBP, mean arterial pressure, exercise, heart rate, glucose, anxiety, psoriasis disease duration), clinical measurements (basophils, platelets, hemoglobin, RBC, alkaline phosphatase, ALT, creatinine, neutrophil-to-lymphocyte ratio), and lipoproteins (LDL particle size, apolipoprotein A1, apolipoprotein B-to-A1 ratio, calculated sdLDL-C).

Conclusion

ML confirmed that FFB strongly correlates with cardiometabolic risk factors, clinical measurements, and lipoproteins. Further investigations into these top determinants of FFB over time may provide insight into potential therapeutic interventions that decrease cardiovascular risk in patients with chronic inflammatory diseases and should be validated in larger studies.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This study was supported by the National Heart, Lung and Blood Institute (NHLBI) IntramuralResearch Program (ZIA-HL-06193). This research was made possible through the NIH MedicalResearch Scholars Program, a public-private partnership supported jointly by the NIH andcontributions to the Foundation for the NIH from the Doris Duke Charitable Foundation,Genentech, the American Association for Dental Research, the Colgate-Palmolive Company, andother private donors.

Chronic inflammation in psoriasis promotes visceral adipose tissue association with lipid-rich necrotic core through atherogenic myeloid score

Background/Introduction

Psoriasis is a chronic inflammatory condition associated with adipose dysfunction and high-risk coronary artery disease features, including non-calcified coronary burden (NCB) and lipid-rich necrotic core (LRNC). Visceral adipose tissue (VAT) is a metabolically-active depot that secretes inflammatory and proatherogenic factors, and is associated with increased NCB. Additionally, an atherogenic myeloid score (AMS) comprised of classical monocytes, low-density granulocytes, and platelets was shown to associate with psoriasis severity and NCB.

Purpose

To investigate the relationship between VAT and high-risk plaque features and test whether this relationship was potentially mediated by myeloid cells.

Methods

A cohort of 131 psoriasis patients were included in this study. Atherogenic myeloid score components were calculated using complete blood count data (platelets) and by flow cytometry (monocytes, LDGs). Coronary NCB and LRNC were quantified using QAngio and vascuCAP respectively. VAT was defined as intra-abdominal fat and was quantified using an automated contouring software with abdominal CT scans. Statistical analyses were performed using STATA 12.

Results

The cohort was middle-aged 50 (42–61) (median (IQR)), and predominantly male (61%). High VAT vs low VAT groups differed significantly in their NCB ((0.910±0.279) vs (1.431±0.517)); p<0.001), (mean ± SD). After adjustment for cardiovascular risk factors, VAT associated with the atherogenic myeloid score (β=0.221, p=0.044), with LRNC (β=0.128, p=0.047), and atherogenic myeloid score associated with LRNC (β=0.161, p=0.003). The relationship of VAT to LRNC was partially mediated by atherogenic myeloid score (25.14%, p=0.029) (Figure 1).

Conclusions

VAT associated with LRNC, and this relationship was partially mediated by the atherogenic myeloid score. These findings suggest that bioactive VAT may impart risk on coronary artery disease in part through myeloid cells.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Heart, Lung, and Blood Institute Intramural Research Program in Bethesda, Maryland Figure 1. Log-transformed atherogenic myeloid score partially mediates the relationship between VAT and log-transformed LRNC. Adjusted by Framingham Risk Score, PASI score, biologic therapy, statin therapy, type 2 diabetes, hyperlipidemia, and subcutaneous adipose tissue volume. Red arrow: represents indirect effect; Beta: standard regression coefficient.

Bone marrow and splenic metabolic activity by 18F-FDG PET/CT are associated with noncalcified coronary burden and lipid-rich necrotic core in psoriasis

Background/Introduction

Psoriasis is an immune-mediated inflammatory skin condition with an increased risk of myocardial infarction (MI). Elevated bone marrow (BM) and splenic hematopoiesis occurs after MI. In stable patients without chronic inflammation, higher splenic hematopoiesis predicts major adverse cardiovascular events (MACE). Nevertheless, studies in humans investigating these relationships in states of chronic inflammation on coronary artery disease features associated with MACE are limited.

Purpose

To investigate the relationships between bone marrow and splenic metabolic activity by [18]-fluorodeoxyglucose (FDG) PET/CT and subclinical cardiovascular disease in psoriasis.

Methods

Healthy participants (N=30) and psoriasis participants (N=210) were age and sex matched. All participants underwent 18FDG PET/CT and CT angiography (Toshiba 320 slice). Coronary artery plaque characteristics were assessed using QAngio CT (Medis, The Netherlands) and lipid rich necrotic core (LRNC) was assessed using vascuCAP (Elucid Bioimaging, Boston, MA). For tissue metabolic activities target-to-background ratio (TBR) was calculated as the ratio of arterial and venous standardized uptake values (SUV).

Results

The psoriasis cohort was middle aged 49.2 (±SD 11.9) years and predominantly male (64%). Those with psoriasis vs. healthy participants had higher BM (1.58 (IQR 1.35–1.89) vs. 1.23 (IQR 1.14–1.35); p<0.001) and splenic (1.40 (IQR 1.21–1.66) vs.1.17 (IQR 1.11–1.26); p<0.001) metabolic activity. After adjustment for cardiovascular risk factors bone marrow metabolic activity was associated with total burden, non-calcified burden (NCB) and LRNC (β=0.36, β=0.39, β=0.26; all p<0.001) respectively. Similar findings were observed for splenic activity (β=0.33, β=0.36, β=0.36; all p<0.001). In ROC analysis, when comparing area under the curve, BM activity better incrementally predicted non-calcified burden and lipid rich necrotic core compared to splenic activity (Figure).

Conclusions

BM and splenic metabolic activity are increased in psoriasis. Both are associated with coronary artery disease but there was a slightly stronger association with BM activity compared to splenic activity, These findings warrant further study to understand immune mechanisms underlying these observations.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Heart, Lung and Blood Institute Intramural Research Program in Bethesda, Maryland Figure 1. Median values of NCB and LRNC were used to convert these continuous variables into dichotomous variables such that values ≤ median were designated as 0 and values >median were designated 1. Bone marrow model compared to base model and splenic model added incremental value in predicting NCB (p<0.0001) and LRNC (p=0.0003). Base model: Framingham risk score, lipid treatment, biologic therapy, homeostasis model assessment as an index of insulin resistance (HOMA-IR), low density lipoprotein (LDL).

Disturbed functional brain interactions underlying deficient tactile object discrimination in Parkinson's disease

Somatosensory discrimination of cuboid objects was studied in a group of healthy volunteers and patients with Parkinson's disease using regional cerebral blood flow (rCBF) measurements obtained with positron emission tomography (PET) and 15O labeled water [H2 15O]. A 6-[18F]-fluoro-L-dopa (FDOPA) PET scan demonstrated that the patients may be grouped into those with normal and those with abnormally lowA FDOPA uptake in the caudate nucleus. The categorical group comparisons revealed that task-induced rCBF increases were deficient in bilateral motor and sensory cortical areas in the Parkinson patients. Moreover, deficient rCBF increases were evident in the mesial and right dorsolateral prefrontal cortex for patients in a more advanced disease state, who showed low FDOPA uptake in the caudate nucleus. A principal component analysis (PCA), performed on the rCBF data, identified three patterns (principal components, PCs) that differentiated patients from normals. The first PC represented a right-hemisphere dominant, bilateral group of brain areas known to be involved in tactile exploration. A second PC reflected a cortical-subcortical pattern of functional interactions, comprising cortical areas important for working memory processes. The third group-differentiating PC revealed a pattern of functional interactions involving bilateral temporo-parieto-occipital association cortices, which was consistent with a hypothesized supramodal network necessary for object discrimination. In an additional subgroup analysis, greater expression of the third PC pattern predicted greater caudate FDOPA uptake in patients. Our neuroimaging data revealed a disturbance of distinct patterns of brain functional interactions related to the sensorimotor deficit in Parkinson's disease and to deficits of cognitive information processing deficits in the more advanced stage of Parkinson's disease.

Impaired somatosensory discrimination of shape in Parkinson's disease: association with caudate nucleus dopaminergic function

Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a demanding task involving somatosensory pathways and higher cognitive processing. The objects for somatosensory discrimination, i.e., rectangular parallelepipeds differing only in oblongness, were presented in sequential pairs to normal volunteers and 12 parkinsonian patients. The performance of patients was significantly impaired compared to normal volunteers. From a biochemical point of view, the patients were characterized by a severely reduced 6-[18F]-fluoro-L-dopa (FDOPA) tracer metabolism in the basal ganglia, as measured using positron emission tomography (PET). Furthermore, reduced specific FDOPA metabolism in the putamen was consistent with the impaired motor capacities of the patients. The reduced specific FDOPA-uptake within the caudate nucleus was associated with additionally diminished somatosensory discrimination. This association, of low perception during task performance and decreased FDOPA-uptake, provides direct evidence for the role of the caudate nucleus in the cognitive part of the task. We suggest that directed attention and working memory were critically involved as a result of disturbed interactions between the head of the caudate nucleus and the dorsolateral prefrontal cortex. Furthermore, there were indications of an additional involvement of the mesolimbic system, which might be of importance during challenging situations such as forced choice. We conclude that differential effects on parts of the basal ganglia, during evolution of the degenerative process characteristic of Parkinson's disease, have profound consequences on the performance of skills, as shown here for a somatosensory discrimination task.

Prediction of angiographic carotid artery stenosis indexes by colour Doppler-assisted duplex imaging. A critical appraisal of the parameters used

The aim of our study was to establish colour Doppler-assisted duplex imaging (CDDI)-criteria to predict an angiographic internal carotid artery (ICA) stenosis of at least 70%, according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trialists (ECST) methods of measurement. In the following, we describe the findings in 79 patients who were screened for carotid endarterectomy by CDDI and further evaluated by digital subtraction angiography (DSA). In 158 carotid arteries, 107 stenoses of > 30% and nine occlusions were found. Receiver operator characteristic graphs were constructed in order to calculate sensitivities and specificities of the assessment by CDDI in the prediction of high-grade stenoses determined by angiography. Optimal cut-off points were defined by highest accuracy which reflects the combination of high sensitivity and specificity. The critical index of a high-grade ICA stenosis according to the ECST method could be predicted with an accuracy greater than 90% by a systolic peak velocitiy of 1.25 m/s or an area reduction by CDDI of 70%. Corresponding values, 1.6 m/s and 80% area reduction, predicted the stenosis indexes according to the NASCET method less reliably, with accuracies of between 80% and 90%. Flow velocity criterion was slightly less accurate than the area reduction criterion by CDDI. Finally, double-blind evaluation performed by two readers per examination modality showed that the measurement of area reduction in CDDI is at least as reliable as stenosis indexes according to ECST and NASCET methods.

Impaired somatosensory discrimination of shape in Parkinson's disease: association with caudate nucleus dopaminergic function

Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a demanding task involving somatosensory pathways and higher cognitive processing. The objects for somatosensory discrimination, i.e., rectangular parallelepipeds differing only in oblongness, were presented in sequential pairs to normal volunteers and 12 parkinsonian patients. The performance of patients was significantly impaired compared to normal volunteers. From a biochemical point of view, the patients were characterized by a severely reduced 6-[18F]-fluoro-L-dopa (FDOPA) tracer metabolism in the basal ganglia, as measured using positron emission tomography (PET). Furthermore, reduced specific FDOPA metabolism in the putamen was consistent with the impaired motor capacities of the patients. The reduced specific FDOPA-uptake within the caudate nucleus was associated with additionally diminished somatosensory discrimination. This association, of low perception during task performance and decreased FDOPA-uptake, provides direct evidence for the role of the caudate nucleus in the cognitive part of the task. We suggest that directed attention and working memory were critically involved as a result of disturbed interactions between the head of the caudate nucleus and the dorsolateral prefrontal cortex. Furthermore, there were indications of an additional involvement of the mesolimbic system, which might be of importance during challenging situations such as forced choice. We conclude that differential effects on parts of the basal ganglia, during evolution of the degenerative process characteristic of Parkinson's disease, have profound consequences on the performance of skills, as shown here for a somatosensory discrimination task.

Somatosensory discrimination of shape: prediction of success in normal volunteers and parkinsonian patients

Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a complex task including somatosensory and higher-order cognitive processing. The objects for somatosensory discrimination were rectangular parallelepipeds that differed in oblongness only. They were presented in sequential pairs to 12 normal volunteers and 13 parkinsonian patients. Owing to the dichotomy of the task, we calculated estimates of the probability of a correct answer by a binomial approach. The probability of a correct answer could be calculated on the basis of a logistic model ensuring that the probability values lie in the interval [0, 1]. The relationship between the probability of a correct answer and the difference in oblongness of the objects could be described solely by one coefficient determined by logistic regression. This coefficient summarized the effectiveness of the simultaneous and consecutive operations inherent in the task and allowed characterization of performances in groups and individuals.

[Can factors of prognostic significance be identified during rehabilitation of cardiac infarct patients?]

In a follow-up study of myocardial infarction patients who had followed the rehabilitation program at this clinic, a cardiac mortality rate of 3.8% (35 out of 930 patients) and a reinfarction rate of 2.3% (21 out of 930 patients) were observed in the 16.6 months after infarction. The relationship between 15 variables and these cardiac events was examined by cross-tabulation and then by Fischer's test of independence. No prognostic factors for reinfarction were found. However, there were 4-risk-indicators which were predictive of early mortality: diabetes, severe complications during the hospital course, congestive heart failure and exercise-induced, complex ventricular arrhythmias. While a single risk-indicator was of little prognostic significance, a combination of two or more identified patients at high risk of subsequent mortality.

Splenectomy and infection in Hodgkin's disease

The incidence of infection in 56 patients with Hodgkin's disease who had undergone staging laparotomy with splenectomy was compared with that of 28 non-splenectomized patients with Hodgkin's disease treated concurrently. The results suggest that splenectomy does not result in a major change in the incidence of infection experienced by such patients with stage II or stage III disease. Aggressive therapy may be of greater importance in increasing the susceptibility to infection in Hodgkin's disease.

Improved vascular access for patients receiving chemotherapy

Indwelling central venous catheters were used for vascular access in 25 oncology patients. The lines were used for sampling, administration of blood products, chemotherapeutic agents, parenteral nutrients and occasionally plasmapheresis. The complication rate was no higher than in reported series in which the catheters were reserved for parenteral nutrition. We believe that a central venous cannula can be safely used as the sole means of vascular access in those patients with consequent psychological and practical benefits.