Von Willebrand factor and the thrombophilia of severe COVID-19: in situ evidence from autopsies

Severely Ill COVID-19 Patients May Exhibit Hypercoagulability Despite Escalated Anticoagulation

Introduction: Severely ill COVID-19 patients receiving prophylactic-dose anticoagulation exhibit high rates of thrombosis and mortality. The escalation of anticoagulation also does not reduce mortality and has an uncertain impact on thrombosis rates. The reasons why escalated doses fail to outperform prophylactic doses in reducing risks of thrombosis and death in severely ill COVID-19 patients remain unclear. We hypothesized that escalated anticoagulation would not effectively prevent hypercoagulability and, consequently, would not reduce the risk of thrombosis and death in some severely ill patients. Methods: We conducted a prospective multicenter study that enrolled 3860 COVID-19 patients, including 1654 severely ill. They received different doses of low-molecular-weight or unfractionated heparin, and their blood coagulation was monitored with activated partial thromboplastin time, D-dimer, and Thrombodynamics. A primary outcome was hypercoagulability detected by Thrombodynamics. Blood samples were collected at the trough level of anticoagulation. Results: We found that escalated anticoagulation did not prevent hypercoagulability in 28.3% of severely ill patients at the trough level of the pharmacological activity. Severely ill patients with such hypercoagulability had higher levels of inflammation markers and better creatinine clearance compared to severely ill patients without it. Hypercoagulability detected by Thrombodynamics was associated with a 1.68-fold higher hazard rate for death and a 3.19-fold higher hazard rate for thrombosis. Elevated D-dimer levels were also associated with higher hazard rates for thrombosis and death, while shortened APTTs were not. The simultaneous use of Thrombodynamics and D-dimer data enhanced the accuracy for predicting thrombotic events and fatal outcomes in severely ill patients. Conclusions: Thrombodynamics reliably detects hypercoagulability in COVID-19 patients and can be used in conjunction with D-dimer to assess the risk of thrombosis and death in severely ill patients. The pharmacological effect of LMWH at the trough level might be too low to prevent thrombosis in some severely ill patients with severe inflammation and better creatinine clearance, even if escalated doses are used.

Thromboembolic Events in the Era of COVID-19: A Detailed Narrative Review

COVID-19, caused by the SARS-CoV-2 virus, is not only characterized by respiratory symptoms but is also associated with a wide range of systemic complications, including significant hematologic abnormalities. This is a comprehensive review of the current literature, using PubMed and Google Scholar, on the pathophysiology and incidence of thromboembolic events in COVID-19 patients and thromboprophylaxis. COVID-19 infection induces a prothrombotic state in patients through the dysregulation of the renin-angiotensin-aldosterone system (RAAS), endothelial dysfunction, elevated von Willebrand factor (vWF), and a dysregulated immune response involving the complement system and neutrophil extracellular traps (NETs). As a result, thromboembolic complications have emerged in COVID-19 cases, occurring more frequently in severe cases and hospitalized patients. These thrombotic events affect both venous and arterial circulation, with increased incidences of deep venous thrombosis (DVT), pulmonary embolism (PE), systemic arterial thrombosis, and myocardial infarction (MI). While DVT and PE are more common, the literature highlights the potential lethal consequences of arterial thromboembolism (ATE). This review also briefly examines the ongoing discussions regarding the use of anticoagulants for the prevention of thrombotic events in COVID-19 patients. While theoretically promising, current studies have yielded varied outcomes: Some suggest potential benefits, whereas others report an increased risk of bleeding events among hospitalized patients. Therefore, further large-scale studies are needed to assess the efficacy and safety of anticoagulants for thromboprophylaxis in COVID-19 patients.

Treatment with Sulodexide Downregulates Biomarkers for Endothelial Dysfunction in Convalescent COVID-19 Patients

INTRODUCTION

Persistent elevation of biomarkers associated with endothelial dysfunction in convalescent COVID-19 patients has been linked to an increased risk of long-term cardiovascular complications, including long COVID syndrome. Sulodexide, known for its vascular endothelial affinity, has demonstrated pleiotropic protective properties. This study aims to evaluate the impact of sulodexide on serum levels of endothelial dysfunction biomarkers in patients during the convalescent phase of COVID-19.

METHODS

We conducted a double-blind, single-center, randomized, placebo-controlled trial in Mexico, comparing sulodexide (250 LRU orally, twice daily) with placebo over 8 weeks in adult patients during early COVID-19 convalescence. Differences in serum biomarkers between the groups were analyzed using repeated measures and post hoc tests, with Thrombomodulin (TM) as the primary endpoint.

RESULTS

Among 206 analyzed patients (103 in each group), at week 8, the sulodexide group exhibited significantly lower mean levels of Thrombomodulin (TM) (25.2 ± 7.9 ng/mL vs 29.9 ± 14.7 ng/mL, P = .03), von Willebrand Factor (vWF) (232 ± 131 U/dL vs 266 ± 122 U/dL, P = .02) and Interleukin-6 (IL-6) (12.5 ± 13.2 pg/mL vs 16.2 ± 16.5 pg/mL, P = .03) compared to the placebo group. D-dimer and C reactive protein (CRP) in the sulodexide group were also lowered. No significant differences were observed for P-selectin, fibrinogen, VCAM-1, or ICAM-1 levels.

CONCLUSIONS

Patients in the convalescent phase of COVID-19 who received sulodexide for eight weeks showed a reduction in TM, vWF, D-dimer, CRP, and IL-6 serum levels compared to placebo. These findings suggest a potential protective effect of sulodexide against thromboinflammation and endothelial damage.

Cardiovascular Symposium on Perspectives in Long COVID

Significant progress has been made in treating Coronavirus disease (COVID) - an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). An ominous turn in the pandemic is the evolving public health crisis emanating from persistent SARS-CoV-2 infection and its associated long-term impact. Long COVID or post-COVID syndrome describes protean symptoms that persist at least 3 months after the onset of acute illness and last for at least 2 months in individuals with a history of confirmed SARS-CoV-2 infection. Long COVID has become a public health concern. Millions of infected individuals are now facing chronic multi-organ failures, including neuropsychiatric, cardiovascular, pulmonary, and kidney complications. In general, the cause of long COVID syndrome is unclear but factors such as prolonged activation of immune responses, and viral persistence triggering transcription dysregulation of genes associated with normal thrombotic disease may play a role in cardiovascular complications. Although inflammatory biomarkers are reported in other disorders, it remains unclear whether similar biomarkers are associated with cardiovascular manifestations following COVID. Medications such as sulodexide directed at glycocalyx and coagulation have demonstrated benefits for long COVID in smaller studies. Here, we describe the outcomes of the symposium on the underlying cardiovascular mechanisms of the long COVID.

Complex Pattern of Platelet Activation/Reactivity After SARS-CoV-2 Infection

COVID-19 and post-COVID (long COVID) are associated with thromboembolic complications; however, it is still not clear whether platelets play a leading role in this phenomenon. The platelet hyperreactivity could result from the direct interaction between platelets and viral elements or the response to inflammatory and prothrombotic factors released from blood and vessel cells following infection. The existing literature does not provide clear-cut answers, as the results determining platelet status vary according to methodology. Elevated levels of soluble markers of platelet activation (P selectin, PF4), increased platelet aggregates, and platelet-derived microparticles suggest the activation of platelets circulating in the bloodstream of COVID-19 patients. Similarly, platelets isolated from COVID-19 patients demonstrate increased reactivity in response to collagen, thrombin, and ADP. By contrast, an analysis of whole blood from COVID-19 patients indicates the reduced activation of the fibrinogen receptor. Similarly, some in vitro studies report potential targets for SARS-CoV-2 in platelets, whereas others do not indicate any direct effect of the virus on platelets. The aim of this work is to review and evaluate the reliability of the methodology for testing platelet function after contact with SARS-CoV-2. Despite the diversity of methods yielding varying results and the influence of plasma components or blood cells, it can be concluded that platelets play an important role in the development of thrombotic complications after exposure to SARS-CoV-2.

Specific and Non-specific Aspects and Future Challenges of ICU Care Among COVID-19 Patients with Obesity: A Narrative Review

PURPOSE OF REVIEW

Since the end of 2019, the coronavirus disease 2019 (COVID-19) pandemic has infected nearly 800 million people and caused almost seven million deaths. Obesity was quickly identified as a risk factor for severe COVID-19, ICU admission, acute respiratory distress syndrome, organ support including mechanical ventilation and prolonged length of stay. The relationship among obesity; COVID-19; and respiratory, thrombotic, and renal complications upon admission to the ICU is unclear.

RECENT FINDINGS

The predominant effect of a hyperinflammatory status or a cytokine storm has been suggested in patients with obesity, but more recent studies have challenged this hypothesis. Numerous studies have also shown increased mortality among critically ill patients with obesity and COVID-19, casting doubt on the obesity paradox, with survival advantages with overweight and mild obesity being reported in other ICU syndromes. Finally, it is now clear that the increase in the global prevalence of overweight and obesity is a major public health issue that must be accompanied by a transformation of our ICUs, both in terms of equipment and human resources. Research must also focus more on these patients to improve their care. In this review, we focused on the central role of obesity in critically ill patients during this pandemic, highlighting its specificities during their stay in the ICU, identifying the lessons we have learned, and identifying areas for future research as well as the future challenges for ICU activity.

Case Report: Gene expression profiling of COVID-19 vaccination-related lymphadenopathies reveals evidence of a dominantly extrafollicular immune response

mRNA-based vaccines against SARS-CoV-2 have been proven to be very efficient in preventing severe COVID-19. Temporary lymphadenopathy (LA) has been observed as a common adverse event following immunization. Here we describe a case series of three female patients with prominent local to generalized LA after SARS-CoV-2 mRNA-1273 vaccination, which led to lymph node biopsy due to the suspicion of lymphoma or metastasis. All three patients morphologically showed similar patterns of follicular hyperplasia and especially extrafollicular blast activation. Two of the three patients only had short-lasting humoral immune responses to the vaccination. Gene expression profiling (GEP) using the HTG Immune response panel revealed that all three patients clustered together and clearly differed from the GEP-patterns of COVID-19, infectious mononucleosis and non-specific follicular hyperplasia. The closest similarities were seen with lymph nodes showing extrafollicular activation of B-blasts as well as hemophagocytosis. The GEP of the vaccination-induced LA was reminiscent of an immune response with little potential of immunologic memory. mRNA-1273 vaccination-induced LA may to a certain extend reflect disordered immune response with potentially poor immunologic memory in affected individuals.

Differential Gene Expression of SARS-CoV-2 Positive Bronchoalveolar Lavages: A Case Series

BACKGROUND

Transcriptomic data on bronchoalveolar lavage (BAL) from COVID-19 patients are currently scarce.

OBJECTIVES

This case series seeks to characterize the intra-alveolar immunopathology of COVID-19.

METHOD

BALs were performed on 14 patients (5 COVID-19, of which 3 mild and 2 largely asymptomatic, 9 controls). Controls included asthma (n = 1), unremarkable BALs (n = 3), infections with respiratory syncytial virus (n = 1), influenza B (n = 1), and infections with other coronaviruses (n = 3). SARS-CoV-2 RNA load was measured by quantitative nucleic acid testing, while the detection of other pathogens was performed by immunofluorescence or multiplex NAT.

RESULTS

Gene expression profiling showed 71 significantly downregulated and 5 upregulated transcripts in SARS-CoV-2-positive lavages versus controls. Downregulated transcripts included genes involved in macrophage development, polarization, and crosstalk (LGALS3, MARCO, ERG2, BTK, RAC1, CD83), and genes involved in chemokine signaling and immunometabolism (NUPR1, CEBPB, CEBPA, PECAM1, CCL18, PPARG, ALOX5, ALOX5AP). Upregulated transcripts featured genes involved in NK-T cell signaling (GZMA, GZMH, GNLY, PRF1, CD3G). Patients with mild COVID-19 showed a significant upregulation of genes involved in blood mononuclear cell/leukocyte function (G0S2, ANXA6, FCGR2B, ADORA3), coagulation (von Willebrand factor [VWF]), interferon response (IFRD1, IL12RB2), and a zinc metalloprotease elevated in asthma (CPA3) compared to asymptomatic cases. In-silico comparison of the 5 COVID-19 BAL cases to a published cohort of lethal COVID-19 showed a significant upregulation of "antigen processing and presentation" and "lysosome" pathways in lethal cases.

CONCLUSIONS

These data underscore the heterogeneity of immune response in COVID-19. Further studies with a larger dataset are required to gain a better understanding of the hallmarks of SARS-CoV-2 immunological response.