Thromboembolism in COVID-19: the unsolved problem.

INTRODUCTION: The recent Sars-CoV-2 pandemic (COVID-19) has led to growing research to explain the poor clinical prognosis in some patients. While early observational studies highlighted the role of the virus in lung failure, in a second moment thrombosis emerged as a possible explanation of the worse clinical course in some patients. Despite initial difficulties in management of such patients, the constant increase of literature in the field is to date clarifying some questions from clinicians. However, several other questions need answer. EVIDENCE ACQUISITION: We performed systematic research using Embase and PubMed, inserting the keywords and mesh terms relative to the new coronavirus and to VTE: "COVID-19," "SARS," "MERS," "coronavirus," "2019 n-CoV," venous thromboembolism," "pulmonary embolism," "deep vein thrombosis," "thromboembolism," "thrombosis." Boolean operators "AND," "OR," "NOT" were used where appropriate. We found 133 articles of interest but only 20 were selected, providing the most representative information. EVIDENCE SYNTHESIS: A novel disease (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) infection was responsible for thousands of hospitalizations for severe acute respiratory syndrome, with several cases of thrombotic complications due to excessive inflammation, platelet activation, endothelial dysfunction, and stasis. COVID-19 and hospitalizations for COVID-19 may carry several potential risk factors for thrombosis. Severe coagulation abnormalities may occur in almost all the severe and critical ill COVID-19 cases. CONCLUSIONS: Despite a strong pathophysiological rationale, the evidence in literature is not enough to recommend an aggressive antithrombotic therapy in COVID-19. However, it is our opinion that an early use, even at home at the beginning of the disease, could improve the clinical course.

Inhibition of Heme Oxygenase Antioxidant Activity Exacerbates Hepatic Steatosis and Fibrosis In Vitro.

The progression of non-alcoholic fatty liver disease (NAFLD) and the development of hepatic fibrosis is caused by changes in redox balance, leading to an increase of reactive oxygen species (ROS) levels. NAFLD patients are at risk of progressing to non-alcoholic steatohepatitis (NASH), associated to cardiovascular diseases (CVD), coronary heart disease and stroke. Heme Oxygenase-1 (HO-1) is a potent endogenous antioxidant gene that plays a key role in decreasing oxidative stress. The present work was directed to determine whether use of an inhibitor of HO-1 activity affects lipid metabolism and fibrosis process in hepatic cells. Oil Red assay and mRNA analysis were used to evaluate the triglycerides content and the lipid metabolism pathway in HepG2 cells. ROS measurement, RT-PCR and Soluble collagen assay were used to assess the intracellular oxidant, the fibrosis pathway and the soluble collagen in LX2 cells. The activity of HO-1 was inhibited using Tin Mesoporphyrin IX (SnMP). Our study demonstrates that a non-functional HO system results in an increased lipid storage and collagen release in hepatocytes. Consequently, an increase of HO-1 levels may provide a therapeutic approach to address the metabolic alterations associated with NAFLD and its progression to NASH.

Renal haemodynamics and coronary atherosclerotic burden are associated in patients with hypertension and mild coronary artery disease.

Intrarenal hemodynamic alterations are independent predictors of cardiovascular events in different populations. It has been hypothesized that there is an association between renal hemodynamics and coronary atherosclerotic burden in patients with hypertension. Therefore, the present study examined the associations between renal hemodynamics, coronary atherosclerotic burden and carotid atherosclerotic disease. A total of 130 patients with hypertension aged between 30-80 years who had been referred for an elective coronary angiography were enrolled in the present study. A duplex ultrasound of the intrarenal vasculature was performed to evaluate the resistive index (RI), pulsatility index (PI) and acceleration time (AT). The carotid intima-media thickness was additionally assessed. A coronary angiography was performed to detect the atherosclerotic burden using the Gensini Score (GS). Based on the GS values, subjects were divided into quintiles (I: ≤9; II: 9-17; III: 17-30; IV: 30-44; and V: GS >44) as well as in subjects with mild (GS ≤30) or severe coronary disease (GS >30). A weak significant difference in PI was identified among quintiles (P=0.041), whereas, RI and AT did not differ significantly. PI was associated with GS in the group with low coronary atherosclerotic burden (GS ≤30; P=0.047), whereas, no association was detected in subjects with GS >30. This association remained following adjustment for age and left ventricular ejection fraction (P=0.025). In conclusion, renal vascular alterations were associated with coronary atherosclerotic burden in patients with hypertension with mild coronary disease.

Computational identification of microRNAs associated to both epithelial to mesenchymal transition and NGAL/MMP-9 pathways in bladder cancer.

Bladder cancer is one of the leading cancer of the urinary tract. It is often diagnosed at advanced stage of the disease. To date, no specific and effective early detection biomarkers are available. Cancer development and progression are associated with the involvement of both epithelial-mesenchymal transition (EMT) and tumor microenvironment of which NGAL/MMP-9 complex represents the main player in bladder cancer. It is known that change in microRNAs (miRNAs) expression may result in gene modulation. Therefore, the identification of specific miRNAs associated with EMT pathway and NGAL/MMP-9 complex may be useful to detect the development of bladder cancer at early stages.On this ground, the expression levels of miRNAs in public available datasets of bladder cancer containing data of non-coding RNA profiling was evaluated. This analysis revealed a group of 16 miRNAs differentially expressed between bladder cancer patients and related healthy controls. By miRNA prediction tool (mirDIP), the relationship between the identified miRNAs and the EMT genes was established. Using the DIANA-mirPath (v.2) software, miRNAs, able to modulate the expression of NGAL and MMP-9 genes, were recognized.The results of this study provide evidence that the downregulated hsa-miR-145-5p and hsa-miR-214-3p may modulate the expression of both EMT and NGAL/MMP-9 pathways. Therefore, further validation analyses may confirm the usefulness of these selected miRNAs for predicting the development of bladder cancer at the early stage of the disease.

Increased Levels of NF-kB-Dependent Markers in Cancer-Associated Deep Venous Thrombosis.

Several studies highlight the role of inflammatory markers in thrombosis as well as in cancer. However, their combined role in cancer-associated deep vein thrombosis (DVT) and the molecular mechanisms, involved in its pathophysiology, needs further investigations. In the present study, C-reactive protein, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1ß), matrix metalloproteases-9 (MMP-9), vascular endothelial growth factor (VEGF), tissue factor (TF), fibrinogen and soluble P-selectin, were analyzed in plasma and in monocyte samples from 385 cancer patients, of whom 64 were concomitantly affected by DVT (+). All these markers were higher in cancer patients DVT+ than in those DVT-. Accordingly, significantly higher NF-kB activity was observed in cancer patients DVT+ than DVT-. Significant correlation between data obtained in plasma and monocyte samples was observed. NF-kB inhibition was associated with decreased levels of all molecules in both cancer DVT+ and DVT-. To further demonstrate the involvement of NF-kB activation by the above mentioned molecules, we treated monocyte derived from healthy donors with a pool of sera from cancer patients with and without DVT. These set of experiments further suggest the significant role played by some molecules, regulated by NF-kB, and detected in cancer patients with DVT. Our data support the notion that NF-kB may be considered as a therapeutic target for cancer patients, especially those complicated by DVT. Treatment with NF-kB inhibitors may represent a possible strategy to prevent or reduce the risk of DVT in cancer patients.

ICAM-1 and SRD5A1 gene polymorphisms in symptomatic peripheral artery disease.

The genotype distribution of two gene polymorphisms, previously associated with peripheral artery disease (PAD), has been evaluated in a population of diabetic (DPAD) and non-diabetic (NDPAD) patients affected by symptomatic PAD (stages II-IV). A decreased frequency of the AA genotype of rs5498 (ICAM-1) was observed in the PAD subjects compared to controls but this result did not reach statistical significance (p=0.06 by chi-squared test). On the contrary, a significant increase in the frequency of the GG homozygous genotype of rs248793 (SRD5A1) was observed in the PAD patient group in comparison to controls (p=0.01). These data confirm that the GG genotype of rs248793 in the SRD5A1 gene is significantly associated with symptomatic PAD and show a trend towards a stronger association with the non-diabetic status.

Proinflammatory circulating molecules in peripheral arterial disease.

Peripheral arterial disease (PAD) affects about 5% of the elderly population in the western world. It has been reported that PAD is associated with elevated plasma levels of the inflammatory markers. The goal of this review is to describe which proinflammatory molecules may play a role in PAD development, C-reactive protein, fibrinogen, pro-inflammatory cytokines, adhesion molecules and matrix metalloproteinases have been reported to be involved. High serum levels of both C-reactive protein and fibrinogen have been shown to be significantly associated with increasing severity of PAD. Among cytokines, IL-6 is one of the most studied in PAD. IL-6 is well recognized for its role in the acute phase inflammatory response which is characterized by production of a variety of hepatic proteins termed acute phase proteins. It has been shown that increased serum concentrations of several markers of the acute response, including IL-6, are elevated in patients with type 2 diabetes. These patients have a two-fold risk of PAD compared to those without type 2 diabetes. The G(-174)C IL-6 polymorphism has been suggested to influence IL-6 release, and its possible influence on PAD development among individuals with type 2 diabetes is discussed in this review. Further study of these molecules is justified as they appear to be involved in the development of PAD.

Association of high alpha2-Heremans-Schmid glycoprotein/fetuin concentration in serum and intima-media thickness in patients with atherosclerotic vascular disease and low bone mass.

OBJECTIVE: Alpha2-Heremans-Schmid glycoprotein (AHSG; fetuin), a member of the cystatin superfamily of cysteine protease inhibitors involved in vascular pathology and bone metabolism, has been reported to be reduced in patients with atherosclerosis and medial calcification related to end stage renal disease or dialysis. No data on fetuin in patients with peripheral artery disease associated with low bone mass and normal renal function are available in the literature. In the present study we evaluated serum fetuin concentrations, bone mass, and markers of bone turnover in patients with atherosclerosis of peripheral vessels and normal kidney function. PATIENTS AND METHODS: Ninety consecutive patients with evidence of atherosclerotic plaques at the common carotid or femoral artery were studied. Severity grade of disease was documented by ultrasound measurement of intima-media thickness (IMT). Fasting serum levels of fetuin were measured by sandwich enzyme immunoassay. MAIN RESULTS: The mean patient serum concentration of fetuin was 57.68+/-13.6 ng/ml, significantly higher than that of control subjects (41.6+/-7.6 ng/ml; p<0.001). The mean serum concentration of bone-specific alkaline phosphatase (BAP) were 8.4+/-2.3 microg/l, significantly lower than controls (13.6+/-1.6 microg/l; p<0.001). Fetuin was correlated with IMT (r=0.8530; p<0.0001) and inversely correlated with BAP (r=-0.5503; p<0.0001). Patients had a vertebral and femoral bone mass significantly lower than controls. CONCLUSION: This study documented for the first time that, in patients with atherosclerosis of peripheral vessels, serum fetuin levels were higher than in healthy subjects, and correlated with the severity of disease; further studies are required to analyse the role of AHSG as an independent predictor of atherosclerotic disease and low bone mass in patients with normal renal function.

Effects of antioxidant supplementation on postprandial oxidative stress and endothelial dysfunction: a single-blind, 15-day clinical trial in patients with untreated type 2 diabetes, subjects with impaired glucose tolerance, and healthy controls.

BACKGROUND: Increased generation of reactive oxygen species (ROS) and oxidative stress may be of crucial importance in the pathogenesis of endothelial damage. Furthermore, there is understood to be a relationship between endothelial damage, glycemic control, disorders of lipid metabolism, and coagulative hemostatic disorders. OBJECTIVE: This study investigated within- and between-group changes in various circulating markers of oxidation-reduction balance and endothelial function after a balanced moderate-fat meal with and without antioxidant supplementation in patients with early-stage, untreated type 2 diabetes mellitus; subjects with impaired glucose tolerance (IGT); and healthy controls. METHODS: In this single-blind, controlled clinical study, groups of patients with type 2 diabetes and subjects with IGT were identified and compared with a group of healthy controls. All groups followed a controlled, well-balanced diet for 10 days before and throughout the study. Before and after consumption of a standardized moderate-fat meal, plasma levels of oxidants (malondialdehyde, 4-hydroxynonenal, oxidized low-density lipoprotein), the antioxidant glutathione peroxidase, and markers of endothelial function (NO, endothelin-1, von Willebrand factor [vWF], vascular cell adhesion molecule-1 [VCAM-1]) were determined. These measures were then reassessed after 15 days of standard antioxidant treatment consisting of a thiol-containing antioxidant (N-acetylcysteine 600 g/d), a bound antioxidant (vitamin E 300 g/d), and an aqueous phase antioxidant (vitamin C 250 mg/d). The efficacy of antioxidant treatment in reversing abnormalities in oxidation-reduction balance after a moderate-fat meal was assessed by evaluating changes in plasma levels of ROS on the morning of the 16th day following an overnight fast. Safety was monitored in terms of adverse events, vital signs, physical findings, and laboratory values. RESULTS: The study included 46 patients with type 2 diabetes (23 men, 23 women; mean [SD] age, 41 [3] years; mean body mass index [BMI], 24 [2] kg/m(2)), 46 with IGT (23 men, 23 women; mean age, 39 [3] years; mean BMI, 23 [3] kg/m(2)), and 46 control subjects (23 men, 23 women; mean age, 40 [1] years; mean BMI, 22 [1] kg/m(2)). Before supplementation, all 3 groups had significantly increased levels of oxidants, vWF, and VCAM-1 (all, P < 0.001) and significantly decreased levels of antioxidants and NO (both, P < 0.001) after consumption of a moderate-fat meal. After 15 days of antioxidant treatment, significant improvements in these measures were seen in all groups (P < 0.05). CONCLUSIONS: This study showed changes in oxidation-reduction balance, NO bioavailability, and nonthrombogenic endothelial factors after a moderate-fat meal in patients with type 2 diabetes and those with IGT, but these postprandial changes were reverse in all subjects after 15 days of standard antioxidant supplementation. These findings suggest that the use of anti-oxidants may have decreased oxidative stress in these subjects.