Prevalence of Deep Vein Thrombosis among COVID-19 Patients using Colour Doppler Ultrasound in a Tertiary Care Centre of Central India: A Prospective Cohort Study

Introduction: Acute respiratory disease, Coronavirus Disease 2019 (COVID-19) is an infectious and potentially fatal respiratory disease. Increase in the inflammatory response, hypoxia, immobilisation are suggested mechanisms of procoagulant state. Deep Vein Thrombosis (DVT) and pulmonary emboli are common and often silent. Venous duplex ultrasound help in determination of the presence, extent, age of the thrombus and its attachment to venous wall. Aim: To evaluate the prevalence of DVT by colour doppler ultrasound in lower limbs of mild to severe clinical categories of COVID-19 patients. Materials and Methods: A time-bound, hospital-based prospective cohort study was conducted in the Department of Radiodiagnosis, MY Hospital, Indore, Madhya Pradesh, India, between March 2021 and February 2022. Study comprised 2200 cases of COVID-19 positive patients with elevated D-dimer levels i.e., >0.5 ng/mL and colour doppler imaging for lower limb. The clinical (co-morbidities, clinical severity) and radiological data (compressibility, colour flow) were studied and analysed using Statistical Package for the Social Sciences (SPSS) software version 25.0. Results: In the present study, there were 1144 (53%) males and 1056 (47%) females. Out of 2200 patients, 792 (36%) patients showed presence of DVT. The most prevalent age group was 36-55 years having 506 (63.9%) patients. Majority of DVT positive patients were suffering with hypertension and diabetes i.e., 261 (33%) and 372 (47%) patients, respectively. Most commonly affected vein in DVT was Common Femoral Vein (CFV) in 704 (88.9%) patients. Superficial veins thrombosis was also associated with DVT affecting Short Saphenous Vein (SSV) in 439 (55.4%) patients and Great Saphenous Vein (GSV) in 221 (27.9%) patients. Conclusion: There was a high prevalence of DVT among COVID-19 positive patients. Colour doppler ultrasound has provided an excellent aid in the diagnosis of DVT.

Impact of P-selectin-PSGL-1 Axis on Platelet-Endothelium-Leukocyte Interactions in Fatal COVID-19.

In critically ill patients infected with SARS-CoV-2, early leukocyte recruitment to the respiratory system was found to be orchestrated by leukocyte trafficking molecules accompanied by massive secretion of proinflammatory cytokines and hypercoagulability. Our study aimed to explore the interplay between leukocyte activation and pulmonary endothelium in different disease stages of fatal COVID-19. Our study comprised 10 COVID-19 postmortem lung specimens and 20 control lung samples (5 acute respiratory distress syndrome, 2 viral pneumonia, 3 bacterial pneumonia, and 10 normal), which were stained for antigens representing the different steps of leukocyte migration: E-selectin, P-selectin, PSGL-1, ICAM1, VCAM1, and CD11b. Image analysis software QuPath was used for quantification of positive leukocytes (PSGL-1 and CD11b) and endothelium (E-selectin, P-selectin, ICAM1, VCAM1). Expression of IL-6 and IL-1ß was quantified by RT-qPCR. Expression of P-selectin and PSGL-1 was strongly increased in the COVID-19 cohort compared with all control groups (COVID-19:Controls, 17:23, P < .0001; COVID-19:Controls, 2:75, P < .0001, respectively). Importantly, P-selectin was found in endothelial cells and associated with aggregates of activated platelets adherent to the endothelial surface in COVID-19 cases. In addition, PSGL-1 staining disclosed positive perivascular leukocyte cuffs, reflecting capillaritis. Moreover, CD11b showed a strongly increased positivity in COVID-19 compared with all controls (COVID-19:Controls, 2:89; P = .0002), indicating a proinflammatory immune microenvironment. Of note, CD11b exhibited distinct staining patterns at different stages of COVID-19 disease. Only in cases with very short disease course, high levels of IL-1ß and IL-6 mRNA were observed in lung tissue. The striking upregulation of PSGL-1 and P-selectin reflects the activation of this receptor-ligand pair in COVID-19, increasing the efficiency of initial leukocyte recruitment, thus promoting tissue damage and immunothrombosis. Our results show that endothelial activation and unbalanced leukocyte migration play a central role in COVID-19 involving the P-selectin-PSGL-1 axis.

SELP Asp603Asn and severe thrombosis in COVID-19 males.

Thromboembolism is a frequent cause of severity and mortality in COVID-19. However, the etiology of this phenomenon is not well understood. A cohort of 1186 subjects, from the GEN-COVID consortium, infected by SARS-CoV-2 with different severity was stratified by sex and adjusted by age. Then, common coding variants from whole exome sequencing were mined by LASSO logistic regression. The homozygosity of the cell adhesion molecule P-selectin gene (SELP) rs6127 (c.1807G > A; p.Asp603Asn) which has been already associated with thrombotic risk is found to be associated with severity in the male subcohort of 513 subjects (odds ratio = 2.27, 95% Confidence Interval 1.54-3.36). As the SELP gene is downregulated by testosterone, the odd ratio is increased in males older than 50 (OR 2.42, 95% CI 1.53-3.82). Asn/Asn homozygotes have increased D-dimers values especially when associated with poly Q ≥ 23 in the androgen receptor (OR 3.26, 95% CI 1.41-7.52). These results provide a rationale for the repurposing of antibodies against P-selectin as adjuvant therapy in rs6127 male homozygotes especially if older than 50 or with an impaired androgen receptor.

Implication of Neutrophils Extracellular Traps in the Pathogenesis of SARS-CoV-2 pneumonia.

Peripheral blood polymorphonuclear neutrophils (PMNs) forming extracellular traps (NETs), as well as endothelial- and platelet-derived parameters, have been analyzed in patients with SARS-CoV-2 pneumonia, and their prognostic role has been evaluated. Eighty-seven consecutive patients hospitalized with SARS-CoV-2 pneumonia were prospectively selected. A sample of 30 healthy individuals served as the control group. Clinical and oxygenation (oxygen saturation to fraction of inspired oxygen ratio-SpO2/FiO2) characteristics and PMNs forming NETs, serum levels of myeloperoxidase, E-selectin, vascular cell adhesion molecule 1-VCAM1-vascular endothelial growth factor, P-selectin, platelet factor 4 and plasma concentrations of D-dimer were evaluated at hospital admission, at discharge and 14 days after discharge. Intensive care unit admission or death was the primary composite endpoint. Patients showed a higher number of PMNs forming NETs than healthy controls. The absolute number of PMNs forming NETs was inversely correlated with oxygen status (SpO2/FiO2) and positively with inflammatory (C-reactive protein, ferritin) markers and VCAM1. A decrease in, but not a normalization of NETs and endothelial-derived parameters was observed in patients who survived. In conclusion, the formation of NETs runs parallel to that of other inflammatory and endothelial activation markers, and is inverse to the oxygenation parameters, supporting a pathogenic role for PMNs in this entity.

Role of P-Selectin in the Development of Hemostasis Disorders in COVID-19

This is a review of data on the impact of COVID-19 on blood clotting. An important feature of the pathogenesis of severe acute respiratory syndrome caused by the SARS-Co-2 coronavirus is the risk of thrombotic complications including microvascular thrombosis, venous thromboembolism, and stroke. These thrombotic complications, like thrombocytopenia, are markers of the severe form of COVID-19 and are associated with multiple organ failure and increased mortality. One of the central mechanisms of this pathology is dysregulation of the adhesive protein P-selectin. The study of the mechanisms of changes in hemostasis and vascular pathology, and the role in these processes of biomarkers of thrombogenesis, and primarily of P-selectin of various origins (platelets, endothelial cells, and plasma), can bring some clarity to the understanding of the pathogenesis and therapy of COVID-19.

Increased plasma level of soluble P-selectin in non-hospitalized COVID-19 convalescent donors.

BACKGROUND: The coronavirus disease-2019 (COVID-19) is a systemic disease with severe implications on the vascular and coagulation system. A procoagulant platelet phenotype has been reported at least in the acute disease phase. Soluble P-selectin (sP-sel) in the plasma is a surrogate biomarker of platelet activation. Increased plasma levels of sP-sel have been reported in hospitalized COVID-19 patients associated with disease severity. Here, we evaluated in a longitudinal study the sP-sel plasma concentration in blood donors who previously suffered from moderate COVID-19. METHODS: 154 COVID-19 convalescent and 111 non-infected control donors were recruited for plasma donation and for participation in the CORE research trial. First donation (T1) was performed 43-378 days after COVID-19 diagnosis. From most of the donors the second (T2) plasma donation including blood sampling was obtained after a time period of 21-74 days and the third (T3) donation after additional 22-78 days. Baseline characteristics including COVID-19 symptoms of the donors were recorded based on a questionnaire. Platelet function was measured at T1 by flow cytometry and light transmission aggregometry in a representative subgroup of 25 COVID-19 convalescent and 28 control donors. The sP-sel plasma concentration was determined in a total of 704 samples by using a commercial ELISA. RESULTS: In vitro platelet function was comparable in COVID-19 convalescent and control donors at T1. Plasma samples from COVID-19 convalescent donors revealed a significantly higher sP-sel level compared to controls at T1 (1.05 ± 0.42 ng/mL vs. 0.81 ± 0.30 ng/mL; p < 0.0001) and T2 (0.96 ± 0.39 ng/mL vs. 0.83 ± 0.38 ng/mL; p = 0.0098). At T3 the sP-sel plasma level was comparable in both study groups. Most of the COVID-19 convalescent donors showed a continuous decrease of sP-sel from T1 to T3. CONCLUSION: Increased sP-sel plasma concentration as a marker for platelet or endothelial activation could be demonstrated even weeks after moderate COVID-19, whereas, in vitro platelet function was comparable with non-infected controls. We conclude that COVID-19 and additional individual factors could lead to an increase of the sP-sel plasma level.

Endothelial Biomarkers in Patients Recovered from COVID-19 One Year after Hospital Discharge: A Cross-Sectional Study.

Background: COVID-19 is characterized by endothelial dysfunction and is presumed to have long-term cardiovascular sequelae. In this cross-sectional study, we aimed to explore the serum levels of endothelial biomarkers in patients who recovered from COVID-19 one year after hospital discharge. Methods: In this clinical follow-up study, 345 COVID-19 survivors from Huanggang, Hubei, and 119 age and gender-matched medical staff as healthy controls were enrolled. A standardized symptom questionnaire was performed, while electrocardiogram and Doppler ultrasound of lower extremities, routine blood tests, biochemical and immunological tests, serum soluble vascular cell adhesion molecule-1(VCAM-1), intercellular cell adhesion molecule-1(ICAM-1), P-selectin, and fractalkine were measured by enzyme-linked immunosorbent assays (ELISA). Results: At one year after discharge, 39% of recovers possessed post-COVID syndromes, while a few had abnormal electrocardiogram manifestations, and no deep vein thrombosis was detected in all screened survivors. There were no significant differences in circulatory inflammatory markers (leukocytes, neutrophils, lymphocytes, C-reactive protein and interleukin-6), alanine aminotransferase, estimated glomerular filtration rate, glucose, triglycerides, total cholesterol and D-dimer observed among healthy controls with previously mild or severe infected. Furthermore, serum levels of VCAM-1, ICAM-1, P-selectin, and fractalkine do not significantly differ between survivors and healthy controls. Conclusions: SARS-CoV-2 infection may not impose a higher risk of developing long-term cardiovascular events, even for those recovering from severe illness.

SERPINE1 rs6092 Variant Is Related to Plasma Coagulation Proteins in Patients with Severe COVID-19 from a Tertiary Care Hospital.

An impaired coagulation process has been described in patients with severe or critical coronavirus disease (COVID-19). Nevertheless, the implication of coagulation-related genes has not been explored. We aimed to evaluate the impact of F5 rs6025 and SERPINE1 rs6092 on invasive mechanical ventilation (IMV) requirement and the levels of coagulation proteins among patients with severe COVID-19. Four-hundred fifty-five patients with severe COVID-19 were genotyped using TaqMan assays. Coagulation-related proteins (P-Selectin, D-dimer, P-selectin glycoprotein ligand-1, tissue plasminogen activator [tPA], plasminogen activator inhibitor-1, and Factor IX) were assessed by cytometric bead arrays in one- and two-time determinations. Accordingly, SERPINE1 rs6092, P-Selectin (GG 385 pg/mL vs. AG+AA 632 pg/mL, p = 0.0037), and tPA (GG 1858 pg/mL vs. AG+AA 2546 pg/mL, p = 0.0284) levels were different. Patients carrying the CT F5-rs6025 genotype exhibited lower levels of factor IX (CC 17,136 pg/mL vs. CT 10,247 pg/mL, p = 0.0355). Coagulation proteins were also different among IMV patients than non-IMV. PSGL-1 levels were significantly increased in the late stage of COVID-19 (>10 days). The frequencies of F5 rs6025 and SERPINE1 rs6092 variants were not different among IMV and non-IMV. The SERPINE1 rs6092 variant is related to the impaired coagulation process in patients with COVID-19 severe.

Immunological insights of selectins in human disease mechanism.

Selectin enzymes are glycoproteins and are an important adhesion molecule in the mammalian immune system, especially in the inflammatory response and the healing process of tissues. Selectins play an important role in a variety of biological processes, including the rolling of leukocytes in endothelial cells, a process known as the adhesion cascade. It has recently been discovered and reported that the selectin mechanism plays a role in cancer and thrombosis disease. This process begins with non-covalent interactions-based selectin-ligand binding and the glycans play a role as a connector between cancer cells and the endothelium in this process. The selectin mechanism is critical for the immune system, but it is also involved in disease mechanisms, earning the selectins the nickname "Selectins-The Two Dr. Jekyll and Mr. Hyde Faces". As a result, the drug for selectins should have a multifaceted role and be a dynamic molecule that targets the disease mechanism specifically. This chapter explores the role of selectins in the disease mechanism at the mechanism level that provides the impact for identifying the selectin inhibitors. Overall, this chapter provides the molecular level insights on selectins, their ligands, involvement in normal and disease mechanisms.

Evaluation of admission levels of P, E and L selectins as predictors for thrombosis in hospitalized COVID-19 patients.

Thromboembolic complications are the most reported cause of death in coronavirus disease-2019 (COVID-19). Hypercoagulability, platelets activation and endotheliopathy are well-recognized features in COVID-19 patients. The aim of this work was to evaluate circulating soluble selectins P, E and L at the time of hospital admission as predictors for upcoming thrombosis. This retrospective study included 103 hospitalized COVID-19 patients and 50 healthy volunteer controls. COVID-19 patients were categorized into two groups; group 1 who developed thrombosis during hospitalization and group 2 who did not. Soluble selectins were quantitated using ELISA technique. Higher levels of sP-selectin, sE-selectin and sL-selectin were detected in COVID-19 patients compared to controls. Furthermore, significantly higher levels were found in group 1 compared to group 2. Their means were [5.86 ± 1.72 ng/mL vs. 2.51 ± 0.81 ng/mL]; [50 ± 8.57 ng/mL vs. 23.96 ± 6.31 ng/mL] and [4.66 ± 0.83 ng/mL vs. 2.95 ± 0.66 ng/mL] for sP-selectin, sE-selectin and sL-selectin respectively. The elevated selectins correlated with the currently used laboratory biomarkers of disease severity. After adjustment of other factors, sP-selectin, sE-selectin and sL-selectin were independent predictors for thrombosis. At sP-selectin ≥ 3.2 ng/mL, sE-selectin ≥ 32.5 ng/mL and sL-selectin ≥ 3.6 ng/mL thrombosis could be predicted with 97.1%, 97.6% and 96.5% sensitivity. A panel of the three selectins provided 100% clinical sensitivity. Admission levels of circulating soluble selectins P, E and L can predict thrombosis in COVID-19 patients and could be used to identify patients who need prophylactic anticoagulants. E-selectin showed a superior clinical performance, as thrombo-inflammation biomarker, to the most commonly studied P-selectin.

Unconventional CD147-dependent platelet activation elicited by SARS-CoV-2 in COVID-19.

BACKGROUND: Platelet activation and thrombotic events characterizes COVID-19. OBJECTIVES: To characterize platelet activation and determine if SARS-CoV-2 induces platelet activation. PATIENTS/METHODS: We investigated platelet activation in 119 COVID-19 patients at admission in a university hospital in Milan, Italy, between March 18 and May 5, 2020. Sixty-nine subjects (36 healthy donors, 26 patients with coronary artery disease, coronary artery disease, and seven patients with sepsis) served as controls. RESULTS: COVID-19 patients had activated platelets, as assessed by the expression and distribution of HMGB1 and von Willebrand factor, and by the accumulation of platelet-derived (plt) extracellular vesicles (EVs) and HMGB1+ plt-EVs in the plasma. P-selectin upregulation was not detectable on the platelet surface in a fraction of patients (55%) and the concentration of soluble P-selectin in the plasma was conversely increased. The plasma concentration of HMGB1+ plt-EVs of patients at hospital admission remained in a multivariate analysis an independent predictor of the clinical outcome, as assessed using a 6-point ordinal scale (from 1 = discharged to 6 = death). Platelets interacting in vitro with SARS-CoV-2 underwent activation, which was replicated using SARS-CoV-2 pseudo-viral particles and purified recombinant SARS-CoV-2 spike protein S1 subunits. Human platelets express CD147, a putative coreceptor for SARS-CoV-2, and Spike-dependent platelet activation, aggregation and granule release, release of soluble P-selectin and HMGB1+ plt-EVs abated in the presence of anti-CD147 antibodies. CONCLUSIONS: Hence, an early and intense platelet activation, which is reproduced by stimulating platelets in vitro with SARS-CoV-2, characterizes COVID-19 and could contribute to the inflammatory and hemostatic manifestations of the disease.

Further Findings Concerning Endothelial Damage in COVID-19 Patients.

Systemic vascular damage with micro/macro-thrombosis is a typical feature of severe COVID-19. However, the pathogenesis of this damage and its predictive biomarkers remain poorly defined. For this reason, in this study, serum monocyte chemotactic protein (MCP)-2 and P- and E-selectin levels were analyzed in 204 patients with COVID-19. Serum MCP-2 and P-selectin were significantly higher in hospitalized patients compared with asymptomatic patients. Furthermore, MCP-2 increased with the WHO stage in hospitalized patients. After 1 week of hospitalization, MCP-2 levels were significantly reduced, while P-selectin increased in patients in WHO stage 3 and decreased in patients in WHO stages 5-7. Serum E-selectin was not significantly different between asymptomatic and hospitalized patients. The lower MCP-2 levels after 1 week suggest that endothelial damage triggered by monocytes occurs early in COVID-19 disease progression. MCP-2 may also predict COVID-19 severity. The increase in P-selectin levels, which further increased in mild patients and reduced in severe patients after 1 week of hospitalization, suggests that the inactive form of the protein produced by the cleavage of the active protein from the platelet membrane is present. This may be used to identify a subset of patients that would benefit from targeted therapies. The unchanged levels of E-selectin in these patients suggest that endothelial damage is less relevant.

Erythrocyte, Platelet, Serum Ferritin, and P-Selectin Pathophysiology Implicated in Severe Hypercoagulation and Vascular Complications in COVID-19.

Progressive respiratory failure is seen as a major cause of death in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2)-induced infection. Relatively little is known about the associated morphologic and molecular changes in the circulation of these patients. In particular, platelet and erythrocyte pathology might result in severe vascular issues, and the manifestations may include thrombotic complications. These thrombotic pathologies may be both extrapulmonary and intrapulmonary and may be central to respiratory failure. Previously, we reported the presence of amyloid microclots in the circulation of patients with coronavirus disease 2019 (COVID-19). Here, we investigate the presence of related circulating biomarkers, including C-reactive protein (CRP), serum ferritin, and P-selectin. These biomarkers are well-known to interact with, and cause pathology to, platelets and erythrocytes. We also study the structure of platelets and erythrocytes using fluorescence microscopy (using the markers PAC-1 and CD62PE) and scanning electron microscopy. Thromboelastography and viscometry were also used to study coagulation parameters and plasma viscosity. We conclude that structural pathologies found in platelets and erythrocytes, together with spontaneously formed amyloid microclots, may be central to vascular changes observed during COVID-19 progression, including thrombotic microangiopathy, diffuse intravascular coagulation, and large-vessel thrombosis, as well as ground-glass opacities in the lungs. Consequently, this clinical snapshot of COVID-19 strongly suggests that it is also a true vascular disease and considering it as such should form an essential part of a clinical treatment regime.

The Role of P-Selectin in COVID-19 Coagulopathy: An Updated Review.

In severe COVID-19, which is characterized by blood clots and neutrophil-platelet aggregates in the circulating blood and different tissues, an increased incidence of cardiovascular complications and venous thrombotic events has been reported. The inflammatory storm that characterizes severe infections may act as a driver capable of profoundly disrupting the complex interplay between platelets, endothelium, and leukocytes, thus contributing to the definition of COVID-19-associated coagulopathy. In this frame, P-selectin represents a key molecule expressed on endothelial cells and on activated platelets, and contributes to endothelial activation, leucocyte recruitment, rolling, and tissue migration. Briefly, we describe the current state of knowledge about P-selectin involvement in COVID-19 pathogenesis, its possible use as a severity marker and as a target for host-directed therapeutic intervention.

Soluble P-selectin as a potential diagnostic and prognostic biomarker for COVID-19 disease: A case-control study.

INTRODUCTION: To our knowledge, the diagnostic value of the sP-Selectin level in the diagnosis of COVID-19 disease has not yet been investigated. In this study, we aimed to assess this by evaluating the relationship between sP-Selectin level and the clinical severity of COVID-19 infections. METHODS: A total of 80 patients (50 with mild to moderate and 30 with severe COVID-19 pneumonia), and 60 non-symptomatic healthy volunteers participated in the study. Following serum isolation, sP-Selectin levels were assessed by Enzyme-Linked Immunosorbent Assay (ELISA) method. RESULTS: The serum sP-Selectin level was 1.7 ng/ml in the control group (1-3.78); 6.24 ng/ml (5.14-7.23) in mild-to-moderate pneumonia group; and 6.72 ng/ml (5.36-8.03) in the severe pneumonia group. Serum sP-Selectin levels in both mild-to-moderate pneumonia and severe pneumonia groups were found to be higher than the control group, with statistical significance (p = 0.0001 and p = 0.0001, respectively). Receiver operating characteristic analysis (ROC) showed greater area under the curve (AUC) for the serum sP-Selectin levels of the COVID-19 patients (AUC = 0.913, 95% CI = 0.857-0.969; p = 0.0001). The serum sP-Selectin level was found to be 97.5% sensitive and 80% specific at 4.125 ng/ml level for diagnosis (p = 0.0001). The serum sP-Selectin level was found to be 76.9% sensitive and 51.9% specific at the level of 6.12 ng/ml (p = 0.005) to predict the need for intensive care treatment. CONCLUSION: This study showed that sP-Selectin can be used as a valuable biomarker in both diagnosing and predicting the need for intensive care treatment of COVID-19 infection.

Inflammatory and Prothrombotic Biomarkers Associated With the Severity of COVID-19 Infection.

Among COVID-19 hospitalized patients, high incidence of alterations in inflammatory and coagulation biomarkers correlates with a poor prognosis. Comorbidities such as chronic degenerative diseases are frequently associated with complications in COVID-19 patients. The aim of this study was to evaluate inflammatory and procoagulant biomarkers in COVID-19 patients from a public hospital in Mexico. Blood was sampled within the first 48 h after admission in 119 confirmed COVID-19 patients that were classified in 3 groups according to oxygen demand, evolution and the severity of the disease as follows: 1) Non severe: nasal cannula or oxygen mask; 2) Severe: high flow nasal cannula and 3) Death: mechanical ventilation eventually leading to fatal outcome. Blood samples from 20 healthy donors were included as a Control Group. Analysis of inflammatory and coagulation biomarkers including D-dimer, interleukin 6, interleukin 8, PAI-1, P-selectin and VWF was performed in plasma. Routine laboratory and clinical biomarkers were also included and compared among groups. Concentrations of D-dimer (14.5 ± 13.8 µg/ml) and PAI-1 (1223 ± 889.6 ng/ml) were significantly elevated in severe COVID-19 patients (P < 0.0001). A significant difference was found in interleukin-6, PAI-1 and P-selectin in non-severe and healthy donors when compared to Severe COVID-19 and deceased patients (P < 0.001). VWF levels were also significantly different between severe patients (153.5 ± 24.3 UI/dl) and non-severe ones (133.9 ± 20.2 UI/dl) (P < 0.0001). WBC and glucose levels were also significantly elevated in patients with Severe COVID-19. Plasma concentrations of all prothrombotic biomarkers were significantly higher in patients with a fatal outcome.

Elevated P-Selectin in Severe Covid-19: Considerations for Therapeutic Options.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is mainly a respiratory tract disease and acute respiratory failure with diffuse microvascular pulmonary thrombosis are critical aspects of the morbidity and mortality of this new syndrome. PURPOSE: The aim of our study was to investigate, in severe COVID-19 hospitalized patients, the P-selectin plasma concentration as a biomarker of endothelial dysfunction and platelet activation. METHODS: 46 patients with severe or critical SARS-CoV-2 infection were included in the study. Age-matched patients then were divided in those requiring admission to the intensive care unit (ICU, ICU cases) vs those not requiring ICU hospitalization (non-ICU cases). Blood samples of severe COVID-19 patients were collected at the time of hospital admission. The quantification of soluble P-selectin was performed by ELI, assay. RESULTS: Our study showed a higher P-selectin plasma concentration in patients with Covid-19, regardless of ICU admission, compared to the normal reference values and compared to ten contextually sampled healthy donors (HD); (COVID-19): median 65.2 (IQRs: 45.1-81.1) vs. HD: 40.3 (IQRs: 24.3-48.7), p=0023. Moreover, results showed a significant reduction of P-sele din after platelets removal in HD, in contrast, both ICU and non-ICU COVID-19 patients showed similar high levels of P-selectin with and without platelets. CONCLUSION: Elevation of P-selectin suggests a central role of platelet endothelium interaction as part of the multifaced pathogenic mechanism of COVID-19 leading to the local activation of hemostatic system forming pulmonary thrombi. Further work is necessary to determine the therapeutic role of antiplatelets agents or of the anti P-selectin antibody Crizanlizumab.

Design and Rationale of a Randomized, Double-Blind, Placebo-Controlled, Phase 2/3 Study Evaluating Dociparstat in Acute Lung Injury Associated with Severe COVID-19.

INTRODUCTION: The COVID-19 global pandemic caused by the novel coronavirus, SARS-CoV-2, and the consequent morbidity and mortality attributable to progressive hypoxemia and subsequent respiratory failure threaten to overrun hospital critical care units globally. New agents that address the hyperinflammatory "cytokine storm" and hypercoagulable pathology seen in these patients may be a promising approach to treat patients, minimize hospital stays, and ensure hospital wards and critical care units are able to operate effectively. Dociparstat sodium (DSTAT) is a glycosaminoglycan derivative of heparin with robust anti-inflammatory properties, with the potential to address underlying causes of coagulation disorders with substantially reduced risk of bleeding compared to commercially available heparin. METHODS: This study is a randomized, double-blind, placebo-controlled, phase 2/3 trial to determine the safety and efficacy of DSTAT added to standard of care in hospitalized adults with COVID-19 who require supplemental oxygen. Phase 2 will enroll 12 participants in each of two dose-escalating cohorts to confirm the safety of DSTAT in this population. Following review of the data, an additional 50 participants will be enrolled. Contingent upon positive results, phase 3 will enroll approximately 450 participants randomized to DSTAT or placebo. The primary endpoint is the proportion of participants who survive and do not require mechanical ventilation through day 28. DISCUSSION: Advances in standard of care, recent emergency use authorizations, and positive data with dexamethasone have likely contributed to an increasing proportion of patients who are surviving without the need for mechanical ventilation. Therefore, examining the time to improvement in the NIAID score will be essential to provide a measure of drug effect on recovery. Analysis of additional endpoints, including supportive biomarkers (e.g., IL-6, HMGB1, soluble-RAGE, D-dimer), will be performed to further define the effect of DSTAT in patients with COVID-19 infection. TRIAL REGISTRATION: ClinicalTrials.gov identifier; NCT04389840, Registered 13 May 2020.

Over time relationship between platelet reactivity, myocardial injury and mortality in patients with SARS-CoV-2-associated respiratory failure.

The aim of this study (NCT04343053) is to investigate the relationship between platelet activation, myocardial injury, and mortality in patients affected by Coronavirus disease 2019 (COVID-19). Fifty-four patients with respiratory failure due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were enrolled as cases. Eleven patients with the same clinical presentation, but negative for SARS-CoV-2 infection, were included as controls. Blood samples were collected at three different time points (inclusion [T1], after 7 ± 2 days [T2] and 14 ± 2 days [T3]). Platelet aggregation by light transmittance aggregometry and the circulating levels of soluble CD40 ligand (sCD40L) and P-selectin were measured. Platelet biomarkers did not differ between cases and controls, except for sCD40L which was higher in COVID-19 patients (p = .003). In COVID-19 patients, P-selectin and sCD40L levels decreased from T1 to T3 and were higher in cases requiring admission to intensive care unit (p = .004 and p = .008, respectively). Patients with myocardial injury (37%), as well as those who died (30%), had higher values of all biomarkers of platelet activation (p < .05 for all). Myocardial injury was an independent predictor of mortality. In COVID-19 patients admitted to hospital for respiratory failure, heightened platelet activation is associated with severity of illness, myocardial injury, and mortality.ClinicalTrials.gov number: NCT04343053.