Toll-Like Receptor 4-Dependent Platelet-Related Thrombosis in SARS-CoV-2 Infection.

BACKGROUND: SARS-CoV-2 is associated with an increased risk of venous and arterial thrombosis, but the underlying mechanism is still unclear. METHODS: We performed a cross-sectional analysis of platelet function in 25 SARS-CoV-2 and 10 healthy subjects by measuring Nox2 (NADPH oxidase 2)-derived oxidative stress and thromboxane B2, and investigated if administration of monoclonal antibodies against the S protein (Spike protein) of SARS-CoV-2 affects platelet activation. Furthermore, we investigated in vitro if the S protein of SARS-CoV-2 or plasma from SARS-CoV-2 enhanced platelet activation. RESULTS: Ex vivo studies showed enhanced platelet Nox2-derived oxidative stress and thromboxane B2 biosynthesis and under laminar flow platelet-dependent thrombus growth in SARS-CoV-2 compared with controls; both effects were lowered by Nox2 and TLR4 (Toll-like receptor 4) inhibitors. Two hours after administration of monoclonal antibodies, a significant inhibition of platelet activation was observed in patients with SARS-CoV-2 compared with untreated ones. In vitro study showed that S protein per se did not elicit platelet activation but amplified the platelet response to subthreshold concentrations of agonists and functionally interacted with platelet TLR4. A docking simulation analysis suggested that TLR4 binds to S protein via three receptor-binding domains; furthermore, immunoprecipitation and immunofluorescence showed S protein-TLR4 colocalization in platelets from SARS-CoV-2. Plasma from patients with SARS-CoV-2 enhanced platelet activation and Nox2-related oxidative stress, an effect blunted by TNF (tumor necrosis factor) α inhibitor; this effect was recapitulated by an in vitro study documenting that TNFα alone promoted platelet activation and amplified the platelet response to S protein via p47phox (phagocyte oxidase) upregulation. CONCLUSIONS: The study identifies 2 TLR4-dependent and independent pathways promoting platelet-dependent thrombus growth and suggests inhibition of TLR4. or p47phox as a tool to counteract thrombosis in SARS-CoV-2.

Effect of traditional or heat-not-burn cigarette smoking on circulating miRNAs in healthy subjects.

BACKGROUND: Traditional combustion cigarette (TCC) smoking is an established risk factor for several types of cancer and cardiovascular diseases. Circulating microRNAs (miRNAs) represent key molecules mediating pathogenetic mechanisms, and potential biomarkers for personalized risk assessment. TCC smoking globally changes the profile of circulating miRNAs. The use of heat-not-burn cigarettes (HNBCs) as alternative smoking devices is rising exponentially worldwide, and the circulating miRNA profile of chronic HNBC smokers is unknown. We aimed at defining the circulating miRNA profile of chronic exclusive HNBC smokers, and identifying potentially pathogenetic signatures. METHODS: Serum samples were obtained from 60 healthy young subjects, stratified in chronic HNBC smokers, TCC smokers and nonsmokers (20 subjects each). Three pooled samples per group were used for small RNA sequencing, and the fourth subgroup constituted the validation set. RESULTS: Differential expression analysis revealed 108 differentially expressed miRNAs; 72 exclusively in TCC, 10 exclusively in HNBC and 26 in both smoker groups. KEGG pathway analysis on target genes of the commonly modulated miRNAs returned cancer and cardiovascular disease associated pathways. Stringent abundance and fold-change criteria nailed down our functional bioinformatic analyses to a network where miR-25-3p and miR-221-3p are main hubs. CONCLUSION: Our results define for the first time the miRNA profile in the serum of exclusive chronic HNBC smokers and suggest a significant impact of HNBCs on circulating miRNAs.

Endothelial dysfunction, oxidative stress and low-grade endotoxemia in COVID-19 patients hospitalised in medical wards.

BACKGROUND: Endothelial dysfunction, assessed by flow-mediated dilation (FMD), is related to poor prognosis in patients with COVID-19 pneumonia (CP). In this study, we explored the interplay among FMD, NADPH oxidase type 2 (NOX-2) and lipopolysaccharides (LPS) in hospitalised patients with CP, community acquired pneumonia (CAP) and controls (CT). METHODS: We enrolled 20 consecutive patients with CP, 20 hospitalised patients with CAP and 20 CT matched for sex, age, and main cardiovascular risk factors. In all subjects we performed FMD and collected blood samples to analyse markers of oxidative stress (soluble Nox2-derived peptide (sNOX2-dp), hydrogen peroxide breakdown activity (HBA), nitric oxide (NO), hydrogen peroxide (H2O2)), inflammation (TNF-α and IL-6), LPS and zonulin levels. RESULTS: Compared with controls, CP had significant higher values of LPS, sNOX-2-dp, H2O2,TNF-α, IL-6 and zonulin; conversely FMD, HBA and NO bioavailability were significantly lower in CP. Compared to CAP patients, CP had significantly higher levels of sNOX2-dp, H2O2, TNF-α, IL-6, LPS, zonulin and lower HBA. Simple linear regression analysis showed that FMD inversely correlated with sNOX2-dp, H2O2, TNF-α, IL-6, LPS and zonulin; conversely FMD was directly correlated with NO bioavailability and HBA. Multiple linear regression analysis highlighted LPS as the only predictor of FMD. CONCLUSION: This study shows that patients with COVID-19 have low-grade endotoxemia that could activate NOX-2, generating increased oxidative stress and endothelial dysfunction.

External validation of the ADA score for predicting thrombosis among acutely ill hospitalized medical patients from the APEX Trial.

The ADA (Age-D-dimer-Albumin) score was developed to identify hospitalized patients at an increased risk for thrombosis in the coronavirus infectious disease-19 (COVID-19) setting. The study aimed to validate the ADA score for predicting thrombosis in a non-COVID-19 medically ill population from the APEX trial. The APEX trial was a multinational, randomized trial that evaluated the efficacy and safety of betrixaban vs. enoxaparin among acutely ill hospitalized patients at risk for venous thromboembolism. The study endpoints included the composite of arterial or venous thrombosis and its components. Metrics of model calibration and discrimination were computed for assessing the performance of the ADA score as compared to the IMPROVE score, a well-validated VTE risk assessment model. Among 7,119 medical inpatients, 209 (2.9%) had a thrombosis event up to 77 days of follow-up. The ADA score demonstrated good calibration for both arterial and venous thrombosis, whereas the IMPROVE score had adequate calibration for venous thrombosis (p > 0.05 from the Hosmer-Lemeshow test). For discriminating arterial and venous thrombosis, there was no significant difference between the ADA vs. IMPROVE score (c statistic = 0.620 [95% CI: 0.582 to 0.657] vs. 0.590 [95% CI: 0.556 to 0.624]; ∆ c statistic = 0.030 [95% CI: -0.022 to 0.081]; p = 0.255). Similarly, for discriminating arterial thrombosis, there was no significant difference between the ADA vs. IMPROVE score (c statistic = 0.582 [95% CI: 0.534 to 0.629] vs. 0.609 [95% CI: 0.564 to 0.653]; ∆ c statistic = -0.027 [95% CI: -0.091 to 0.036]; p = 0.397). For discriminating venous thrombosis, the ADA score was modestly superior to the IMPROVE score (c statistic = 0.664 [95% CI: 0.607 to 0.722] vs. 0.573 [95% CI: 0.521 to 0.624]; ∆ c statistic = 0.091 [95% CI: 0.011 to 0.172]; p = 0.026). The ADA score had a higher sensitivity (0.579 [95% CI: 0.512 to 0.646]; vs. 0.440 [95% CI: 0.373 to 0.507]) but lower specificity (0.625 [95% CI: 0.614 to 0.637] vs. 0.747 [95% CI: 0.737 to 0.758]) than the IMPROVE score for predicting thrombosis. Among acutely ill hospitalized medical patients enrolled in the APEX trial, the ADA score demonstrated good calibration but suboptimal discrimination for predicting thrombosis. The findings support the use of either the ADA or IMPROVE score for thrombosis risk assessment. The applicability of the ADA score to non-COVID-19 populations warrants further research.Clinical Trial Registration: http://www.clinicaltrials.gov . Unique identifier: NCT01583218.

Allergic rhinitis, microbiota and passive smoke in children: A pilot study.

BACKGROUND: Allergic rhinitis (AR) is one of the most common allergic diseases affecting children. Objective assessment of nasal obstruction is possible through active anterior rhinomanometry (AAR). Several factors, such as passive smoke exposure (PSE), are triggers for worsening nasal obstruction and chronic inflammation. PSE affects bacterial eubiosis in the upper respiratory tract. This study evaluates the influence of PSE and cotinine levels on both nasal obstruction and local microbiome composition in children with AR. METHODS: Fifty patients (aged between 6 and 16 years) with AR monosensitized grass pollen were enrolled. They underwent skin prick tests, a nasal swab to evaluate the microbial composition of the anterior nostrils, a basal AAR, a post-decongestion AAR, and spirometry. Serum cotinine levels were assessed to evaluate PSE. RESULTS: A significantly lower percentage of mean nasal flow (mNF%) was observed before and after hydrazine administration in subjects exposed to passive smoke (Exp group) compared with the non-exposed group. In contrast, higher cotinine levels were observed in the Exp group than in the controls. PSE has been associated with a decrease in biodiversity and a change in the nasal microbiome composition; instead, although to a different extent, the abundance of specific taxa resulted in being correlated to cotinine levels and nasal flow. CONCLUSION: Children with AR exposed to passive smoke with positive serum cotinine could represent a risk factor for developing nasal obstruction and microbial dysbiosis, suggesting their possible role in pathophysiological processes.

Asymptomatic and symptomatic deep venous thrombosis in hospitalized acutely ill medical patients: risk factors and therapeutic implications.

BACKGROUND: Acutely ill medical patients experience deep venous thrombosis (DVT) during the hospitalization, however the time course of DVT is still unclear. OBJECTIVES: To evaluate risk factors in acutely ill hospitalized medical patients for proximal asymptomatic DVT (ADVT) and symptomatic DVT (SDVT) at admission and discharge. PATIENTS/METHODS: In this prospective observational study, consecutive acutely ill medical patients (hospitalized mainly for acute medical disease as infections, neoplasm, anemia, heart failure) underwent compression ultrasonography (CUS) of proximal lower limb veins within 48 h from admission and at discharge to diagnose ADVT and SDVT. Covid-19 patients, anticoagulant therapy, surgical procedures, acute SDVT, and acute pulmonary embolism, were exclusion criteria. Biographical characteristics at hospitalization, D-Dimer (assessed by ELISA)) and DD-improve score. RESULTS: Of 2,100 patients (1002 females, 998 males, age 71 ± 16 years) 58 (2.7%) had proximal ADVT at admission. Logistic regression analysis showed that age, and active cancer were independently associated with ADVT at admission. The median length of hospitalization was 10 days [interquartile range: 6-15]. During the hospital stay, 6 patients (0.3%) with a negative CUS at admission experienced DVT (2 SDVT and 4 ADVT). In the subgroup of patients (n = 1118), in whom D-dimer was measured at admission, D-Dimer and IMPROVE-DD score were associated with ADVT at admission (n = 37) and with all DVT (n = 42) at discharge. ROC curve defined an IMPROVE-DD score of 2.5 as the optimal cut-off for discriminating patients with and without thrombotic events. CONCLUSIONS: We provide evidence of early development of ADVT in unselected acutely ill medical patients suggesting the need of investigating patients by CUS immediately after hospital admission (within 48 h). Advanced age, active cancer, known thrombophilia and increased IMPROVE-DD score may identify patients at risk. The benefit of anticoagulation needs to be investigated in patients with these specific risk factors and negative CUS at admission. TRIAL REGISTRATION: NCT03157843.

Impact of chronic use of heat-not-burn cigarettes on oxidative stress, endothelial dysfunction and platelet activation: the SUR-VAPES Chronic Study.

Tobacco habit still represents the leading preventable cause of morbidity and mortality worldwide. Heat-not-burn cigarettes (HNBCs) are considered as an alternative to traditional combustion cigarettes (TCCs) due to the lack of combustion and the absence of combustion-related specific toxicants. The aim of this observational study was to assess the effect of HNBC on endothelial function, oxidative stress and platelet activation in chronic adult TCC smokers and HNBC users. The results showed that both HNBC and TCC display an adverse phenotype in terms of endothelial function, oxidative stress and platelet activation. Future randomised studies are strongly warranted to confirm these data.

Features of severe COVID-19: A systematic review and meta-analysis.

BACKGROUND: To systematically review clinical and biochemical characteristics associated with the severity of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease (COVID-19). MATERIALS AND METHODS: Systematic review of observational studies from PubMed, ISI Web of Science, SCOPUS and Cochrane databases including people affected by COVID-19 and reporting data according to the severity of the disease. Data were combined with odds ratio (OR) and metanalysed. Severe COVID-19 was defined by acute respiratory distress syndrome, intensive care unit admission and death. RESULTS: We included 12 studies with 2794 patients, of whom 596 (21.33%) had severe disease. A slightly higher age was found in severe vs non-severe disease. We found that prevalent cerebrovascular disease (odds ratio [OR] 3.66, 95% confidence interval [CI] 1.73-7.72), chronic obstructive pulmonary disease (OR: 2.39, 95% CI 1.10-5.19), prevalent cardiovascular disease (OR: 2.84, 95% CI 1.59-5.10), diabetes (OR: 2.78, 95% CI 2.09-3.72), hypertension (OR: 2.24, 95% CI 1.63-3.08), smoking (OR: 1.54, 95% CI 1.07-2.22) and male sex (OR: 1.22, 95% CI 1.01-1.49) were associated with severe disease. Furthermore, increased procalcitonin (OR: 8.21, 95% CI 4.48-15.07), increased D-Dimer (OR: 5.67, 95% CI 1.45-22.16) and thrombocytopenia (OR: 3.61, 95% CI 2.62-4.97) predicted severe infection. CONCLUSION: Characteristics associated with the severity of SARS-CoV-2 infection may allow an early identification and management of patients with poor outcomes.

Oxidative stress and gut-derived lipopolysaccharides in children affected by paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections.

BACKGROUND: Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections syndrome (PANDAS) identifies patients with acute onset of obsessive-compulsive and tic disorders. The objective of this study was to evaluate serum NOX2 levels, as well as 8-iso-prostaglandin F2α (8-iso-PGF2α) and lipopolysaccharide (LPS) of PANDAS patients. METHODS: In this study we wanted to compare serum levels of soluble NOX2-dp (sNOX-2-dp), iso-PGF2α and LPS in 60 consecutive subjects, including 30 children affected by PANDAS and 30 controls (CT) matched for age and gender. Serum zonulin was used as intestinal permeability assay. RESULTS: Compared with CT, PANDAS children had increased serum levels of sNOX-2-dp, 8-iso-PGF2α and LPS. Bivariate analysis showed that serum sNOX2-dp was significantly correlated with LPS (Rs = 0.359; p = 0.005), zonulin (Rs = 0.444; p < 0.001) and 8-iso-PGF2α (Rs = 0.704; p < 0.001). Serum LPS significantly correlated with zonulin (Rs = 0.610; p < 0.001), and 8-iso-PGF2α (Rs = 0.591; p = 0.001). Finally, a multiple linear regression analysis showed that serum 8-iso-PGF2α and zonulin were the only independent variables associated with sNOX2-dp (R2 = 68%). CONCLUSION: This study shows that children affected by PANDAS have high circulating levels of sNOX2-dp, isoprostanes and of LPS that could be involved in the process of neuroinflammation.

Nasal reactivity evaluation in children with allergic rhinitis receiving grass pollen sublingual immunotherapy.

Background: The European Academy of Allergy and Clinical Immunology guidelines, strongly recommended allergen immunotherapy (AIT) as an effective treatment to achieve long-term clinical benefits and to modify the natural history of allergic diseases. Sublingual immunotherapy (SLIT) offers the possibility of home administration, which improves patient comfort and compliance. Objective: The primary outcome of this study was to assess the change in nasal reactivity after grass-pollen AIT treatment. Methods: This was a monocentric, prospective, observational study conducted in Rome from September 2016 to June 2018, in the Pediatric Department of Policlinico Umberto I. We enrolled children, ages between 6 and 12 years, with persistent allergic rhinitis (AR), sensitized to grass pollen. At the first visit (V0, September 2016), one group received the first dose of oral immunotherapy for grass-pollen spray buccal and the other group continued only standard therapy. All the patients had nasal specific immunoglobulin I (IgE) assay (Phl p1, Phl p5), active anterior rhinomanometry with a nasal provocation test (NPT), and spirometry. The patients attended two follow-up visits, in May 2017 (V1) and May 2018 (V2), with the same examinations as at V0. Results: During the treatment, we observed, in the treated group, a significant increase in the mean nasal flow compared with untreated children (p < 0.001). In the AIT group, we found an improvement of nasal function and only 21.05% of all the children in the active group with a positive NPT result at V2. In the control group, we found, at V2, a worsening of nasal function, with 89.47% of the children with a positive NPT result. Furthermore, we found a significant reduction of nasal specific IgE levels at the end of the observation period in the treated group. Conclusion: Analysis of our data provided evidence for a clinical effect of SLIT in inducing clinical changes and allergen tolerance in children with AR.

Role of NADPH oxidase-2 and oxidative stress in children exposed to passive smoking.

This study explored oxidative stress, nicotinamide adenine dinucleotide phosphate oxidase-2 (Nox2) activity and endothelial function in children exposed or not to passive smoking. Compared with controls (n=57), Nox2 activity and isoprostanes were higher in children exposed to passive smoking (n=57); conversely, nitric oxide (NO) bioavailability and flow-mediated dilation were lower in children exposed to passive smoking. A bivariate analysis showed that Nox2 activity correlated with flow-mediated dilation, NO bioavailability and isoprostanes. A multivariate analysis showed that Nox2 activity was significantly associated with serum isoprostanes and cotinine levels; flow-mediated dilation was associated with isoprostanes and carotid intima-media thickness.In children exposed to passive smoking, Nox2-derived oxidative stress is upregulated and inversely associated with impaired artery dilation.

Effects of Anticoagulants in Patients With Cirrhosis and Portal Vein Thrombosis: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Liver cirrhosis is complicated by bleeding from portal hypertension but also by portal vein thrombosis (PVT). PVT occurs in approximately 20% to 50% of patients with cirrhosis, and is a warning sign for poor outcome. It is a challenge to treat patients with cirrhosis using anticoagulants, because of the perception that the coexistent coagulopathy could promote bleeding. We performed a systematic review and meta-analysis to determine the effects of anticoagulant therapy in patients with cirrhosis and PVT. METHODS: We searched the PubMed, ISI Web of Science, SCOPUS, and Cochrane databases through February 14, 2017, for studies that assessed the effect of anticoagulant therapy vs no treatment in patients with cirrhosis and PVT. We performed a meta-analysis to estimate the effect of anticoagulant treatment vs no therapy on recanalization and progression of PVT in patients with cirrhosis. We also assessed variceal and nonvariceal bleeding. RESULTS: We analyzed data from 8 studies, comprising 353 patients, that assessed the effects of anticoagulant therapy (low-weight heparin or warfarin vs no therapy) in patients with cirrhosis and PVT; these studies reported rates of complete and partial recanalization. A significantly higher proportion of patients treated with anticoagulants underwent PVT recanalization than patients who did not receive anticoagulants (71% vs 42%, respectively; P < .0001). From 6 studies (comprising 217 patients), 53% of patients treated with anticoagulants vs 33% of patients who did not receive anticoagulants had complete PVT recanalization (P = .002). From 6 studies (comprising 225 patients), PVT progressed in 9% of patients treated with anticoagulants vs 33% of patients who did not receive these drugs (P < .0001). Six studies (257 patients) reported rates of any bleeding; there was no difference in the proportions of patients with major or minor bleeding between groups that did vs did not receive anticoagulants (11% for both groups). Four studies (comprising 158 patients) reported rates of spontaneous variceal bleeding, which occurred in a significantly lower proportion of patients who received anticoagulants vs those who did not (P = .04). CONCLUSIONS: Based on a systematic review and meta-analysis, patients with cirrhosis and PVT who receive anticoagulant therapy have increased recanalization and reduced progression of thrombosis, compared with patients who do not receive anticoagulants, with no excess of major and minor bleedings and less incidence of variceal bleeding.

Passive Smoking Exacerbates Nicotinamide-Adenine Dinucleotide Phosphate Oxidase Isoform 2-Induced Oxidative Stress and Arterial Dysfunction in Children with Persistent Allergic Rhinitis.

OBJECTIVE: To characterize nicotinamide-adenine dinucleotide phosphate oxidase isoform 2 (NOX2), oxidative stress, and endothelial function in children with and without allergic rhinitis and to ascertain the effect of passive smoke exposure on these factors, because there is an established association between allergic rhinitis and increased cardiovascular risk in adults. METHODS: We recruited 130 children-65 with persistent allergic rhinitis and 65 healthy controls. A cross-sectional study was performed to compare endothelial function by flow-mediated dilation, blood levels of isoprostanes, serum activity of soluble NOX2-dp (sNOX2-dp), and nitric oxide bioavailability, in these 2 groups of children. Serum cotinine levels were assessed to measure exposure to passive smoking. RESULTS: Compared with healthy controls, children with persistent allergic rhinitis had significantly higher sNOX2-dp and isoprostanes levels, lower flow-mediated dilation, and reduced nitric oxide bioavailability. Multivariable linear regression analysis showed that flow-mediated dilation, isoprostanes, and cotinine were independently associated with sNOX2-dp levels. Of note, sNOX2-dp serum levels were significantly higher in children with allergic rhinitis exposed to smoke, as compared with unexposed children with allergic rhinitis. CONCLUSION: NOX2 is activated in children with persistent allergic rhinitis and passive smoke exposure exacerbates this effect. We further demonstrate an association between higher sNOX2-dp and oxidative stress and endothelial dysfunction.

Oleuropein, a component of extra virgin olive oil, lowers postprandial glycaemia in healthy subjects.

AIMS: Extra virgin olive oil lowers postprandial glycaemia. We investigated if oleuropein, a component of extra virgin olive oil, exerts a similar effect on postprandial glycaemia and the underlying mechanism. METHODS: Twenty healthy subjects were randomly allocated in a cross-over design to 20 mg oleuropein or placebo immediately before lunch. Postprandial glycaemia along with blood insulin, dipeptidyl-peptidase-4 (DPP-4) and glucagon-like peptide-1 and oxidative stress, which included soluble NADPH oxidase-derived peptide activity (sNox2-dp), 8-iso-prostaglandin-2α and platelet p47phox phosphorylation, were analysed before and 2 h after meal. RESULTS: After 2 h, subjects who assumed oleuropein had significantly lower blood glucose, DPP-4 activity and higher insulin and glucagon-like peptide-1 compared to placebo. Furthermore, sNox2-dp, 8-iso-PGF2α and platelet p47phox phosphorylation were significantly lower in oleuropein- compared to placebo-treated subjects. DPP-4 significantly correlated with sNox2-dp [Spearman's rho (Rs) = 0.615; P < 0.001], p47phox phosphorylation (Rs = 0.435; P < 0.05) and 8-iso- prostaglandin-2α (Rs = 0.33; P < 0.05). In vitro study demonstrated that hydroxytyrosol, a metabolite of oleuropein, significantly reduced p47phox phosphorylation and isoprostane formation. CONCLUSIONS: These findings indicate that oleuropein improves postprandial glycaemic profile via hampering Nox2-derived oxidative stress.

NADPH Oxidase-2 and Atherothrombosis: Insight From Chronic Granulomatous Disease.

The phagocytic cell enzyme NADPH oxidase-2 (Nox2) is critical for killing micro-organisms via production of reactive oxygen species and thus is a key element of the innate immune system. Nox2 is also detectable in endothelial cells and platelets where it has vasoconstrictive and aggregating properties, respectively. Patients with X-linked chronic granulomatous disease with hereditary Nox2 deficiency not only have impaired bacterial killing but, in association with loss of Nox2 function, also have enhanced carotid artery dilation, impaired platelet-related thrombosis, and reduced carotid atherosclerotic burden. Experimental studies corroborated these reports in chronic granulomatous disease by demonstrating (1) Nox2 is upregulated in atherosclerotic plaque, and this upregulation significantly correlates with oxidative stress and (2) pharmacological inhibition of Nox2 is associated with a delayed atherosclerotic progression in animal models. Furthermore, the role of Nox2 in platelet-associated thrombosis was substantiated by experiments showing impaired platelet activation in animals treated with a Nox2 inhibitor or impaired platelet aggregation along with reduced platelet-related thrombosis in the mouse knockout model of Nox2. Interestingly, in chronic granulomatous disease patients and in the mouse knockout model of Nox2, no defects of primary hemostasis were detected. This review analyses experimental and clinical data suggesting Nox2 is a potential target for counteracting the atherothrombotic process.

Antioxidant and antiplatelet activity by polyphenol-rich nutrients: focus on extra virgin olive oil and cocoa.

Cardiovascular disease is the most common cause of death in the Western world. In the last decades nutraceutical approaches have been proposed to counteract atherosclerotic complications. In particular, polyphenols, a class of bio-active molecules prevalently contained in foods such as cocoa, fruits, vegetables, wine and tea, have been widely studied for their beneficial properties. Several epidemiological and interventional studies have shown that polyphenol-rich nutrients, as in extra virgin olive oil (EVOO) and cocoa, are associated with a risk reduction of cardiovascular events and/or modulation of cardiovascular risk factors. Definition of the mechanisms accounting for this putative cardio-protective effect is still elusive. This review focuses on the mechanisms that may be implicated in the beneficial effects of EVOO and cocoa, including down-regulation of oxidative stress and platelet aggregation, improvement of endothelial function and cardiovascular risk factor such as blood pressure, serum cholesterol and insulin sensitivity.