COVID-19-associated coagulopathy: An exploration of mechanisms

A prediction model for major adverse cardiovascular events (MACE) in patients with coronavirus disease 2019 (COVID-19)

Background

Emerging evidence shows that cardiovascular injuries and events in coronavirus disease 2019 (COVID-19) should be considered. The current study was conducted to develop an early prediction model for major adverse cardiovascular events (MACE) during hospitalizations of COVID-19 patients.

Methods

This was a retrospective, multicenter, observational study. Hospitalized COVID-19 patients from Wuhan city, Hubei Province and Sichuan Province, China, between January 14 and March 9, 2020, were randomly divided into a training set (70% of patients) and a testing set (30%). All baseline data were recorded at admission or within 24 h after admission to hospitals. The primary outcome was MACE during hospitalization, including nonfatal myocardial infarction, nonfatal stroke and cardiovascular death. The risk factors were selected by LASSO regression and multivariate logistic regression analysis. The nomogram was assessed by calibration curve and decision curve analysis (DCA).

Results

Ultimately, 1206 adult COVID-19 patients were included. In the training set, 48 (5.7%) patients eventually developed MACE. Six factors associated with MACE were included in the nomogram: age, PaO₂/FiO₂ under 300, unconsciousness, lymphocyte counts, neutrophil counts and blood urea nitrogen. The C indices were 0.93 (95% CI 0.90, 0.97) in the training set and 0.81 (95% CI 0.70, 0.93) in the testing set. The calibration curve and DCA demonstrated the good performance of the nomogram.

Conclusions

We developed and validated a nomogram to predict the development of MACE in hospitalized COVID-19 patients. More prospective multicenter studies are needed to confirm our results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02143-3.

Two Years into the COVID-19 Pandemic: Lessons Learned

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and virulent human-infecting coronavirus that emerged in late December 2019 in Wuhan, China, causing a respiratory disease called coronavirus disease 2019 (COVID-19), which has massively impacted global public health and caused widespread disruption to daily life. The crisis caused by COVID-19 has mobilized scientists and public health authorities across the world to rapidly improve our knowledge about this devastating disease, shedding light on its management and control, and spawned the development of new countermeasures. Here we provide an overview of the state of the art of knowledge gained in the last 2 years about the virus and COVID-19, including its origin and natural reservoir hosts, viral etiology, epidemiology, modes of transmission, clinical manifestations, pathophysiology, diagnosis, treatment, prevention, emerging variants, and vaccines, highlighting important differences from previously known highly pathogenic coronaviruses. We also discuss selected key discoveries from each topic and underline the gaps of knowledge for future investigations.

Mortality Risk Factors Among Critically Ill Children With Acute COVID-19 in PICUs: A Multicenter Study From Turkish Pediatric Critical COVID-19 and MIS-C Study Group

BACKGROUND

During the coronavirus disease 2019 (COVID-19) pandemic, the world has a large number of reported COVID-19 cases and deaths. Information on characteristics and mortality rate of pediatric intensive care unit (PICU) cases with COVID-19 remains limited. This study aims to identify the risk factors for mortality related to COVID-19 in children admitted to PICU.

METHODS

A retrospective multicenter cohort study was conducted between March 2020 and April 2021 at 44 PICUs in Turkey. Children who were 1 month-18-year of age with confirmed COVID-19 admitted to PICU were included in the study. Children with multisystem inflammatory syndrome and asymptomatic for COVID-19 were excluded.

RESULTS

Of 335 patients with COVID-19, the median age was 6.8 years (IQR: 1.2-14) and 180 (53.7 %) were male, 215 (64.2 %) had at least one comorbidity. Age and gender were not related to mortality. Among 335 patients, 166 (49.5%) received mechanical ventilation, 17 (5.1%) received renal replacement therapy and 44 (13.1 %) died. Children with medical complexity, congenital heart disease, immunosuppression and malignancy had significantly higher mortality. On multivariable logistic regression analysis, organ failure index [odds ratio (OR): 2.1, 95 confidence interval (CI): 1.55-2.85], and having congenital heart disease (OR: 2.65, 95 CI: 1.03-6.80), were associated with mortality.

CONCLUSIONS

This study presents detailed data on clinical characteristics and outcomes of patients with COVID-19 admitted to PICU in the first pandemic year in Turkey. Our study shows that having congenital heart disease is associated with mortality. In addition, the high organ failure score in follow-up predict mortality.

Acute Myocardial Infarction From Embolized Left Ventricular Thrombus in Coronavirus Disease 2019

A 44-year-old man with a late presentation of coronavirus disease 2019 (COVID-19) pneumonia developed a left ventricular apical thrombus resulting in an asymptomatic anterior myocardial infarction due to extensive thrombosis of the left anterior descending artery. There are increasing reports of thrombotic complications in patients infected with COVID-19. This case highlights the risk of thrombotic events caused by severe acute respiratory syndrome-related corona virus-2 and the associated challenges in management. The objective of this case report is to generate primary literature and raise awareness and appreciation for cardiac manifestations of COVID-19.

The role of B cells in COVID-19 infection and vaccination

B cells secrete antibodies and mediate the humoral immune response, making them extremely important in protective immunity against SARS-CoV-2, which caused the coronavirus disease 2019 (COVID-19) pandemic. In this review, we summarize the positive function and pathological response of B cells in SARS-CoV-2 infection and re-infection. Then, we structure the immunity responses that B cells mediated in peripheral tissues. Furthermore, we discuss the role of B cells during vaccination including the effectiveness of antibodies and memory B cells, viral evolution mechanisms, and future vaccine development. This review might help medical workers and researchers to have a better understanding of the interaction between B cells and SARS-CoV-2 and broaden their vision for future investigations.

Prior Diagnosis of COVID Has No Increased Complications in Total Joint Arthroplasty

Introduction

Although a substantial portion of the United States population has been infected with and recovered from Coronavirus Disease-19 (COVID-19), many patients may have persistent symptoms and complications from disease-driven respiratory disease, arrhythmias, and venous thromboembolism (VTE). With institutions resuming elective total joint arthroplasties (TJA), it is unclear whether a prior resolved diagnosis of COVID has any implications on postoperative outcomes.

Methods

All elective TJA performed in 2021 at our institution were retrospectively reviewed and a history of prior COVID+ result recorded. Baseline demographics, days from prior COVID+ result to surgery date, preoperative methicillin-resistant Staphylococcus aureus (MRSA) nares colonization, and laboratory markers were obtained to determine baseline characteristics. Postoperative estimated blood loss (EBL), length of stay (LOS), rate of revision surgery, and discharge destination were compared between groups. Perioperative and postoperative rates of VTE, urinary tract infection (UTI), pneumonia, postoperative oxygen supplementation, cardiac arrhythmia, renal disease, sepsis, and periprosthetic joint infections within six months of surgery were recorded.

Results

Of the 155 elective TJA performed in 2021, 24 patients had a prior COVID+ diagnosis with a mean of 253 days from positive result to surgery date. There were no significant differences in baseline demographics, comorbidities, and preoperative lab markers between groups. Surgeries on patients with a prior COVID+ had a significantly higher EBL (260 vs 175cc), but postoperative outcomes of VTE, UTI, pneumonia, oxygen supplementation requirement, nares MRSA+, cardiac disease, and infection rates between groups were similar. Bivariate logistic regression revealed increased days from COVID+ diagnosis (>6 months) to surgery date were associated with a shorter LOS.

Conclusion

Although a prior COVID+ diagnosis had increased intraoperative blood loss, there were no significant differences in respiratory, infectious, cardiac, and thromboembolic complications up to six months after elective TJA. This study suggests that asymptomatic C+ patients receiving elective TJA do not require more aggressive prophylactic anticoagulation or antibiotic regimens to prevent VTE or perioperative infections. As institutions around the nation resume pre-COVID rates of arthroplasty surgeries, a prior diagnosis of COVID appears to have no effects on postoperative complications.

Association Between Previous Stroke and Severe COVID-19: A Retrospective Cohort Study and an Overall Review of Meta-Analysis

Objective

The objective of this study was to investigate the association between previous stroke and the risk of severe coronavirus disease 2019 (COVID-19).

Methods

We included 164 (61.8 ± 13.6 years) patients with COVID-19 in a retrospective study. We evaluated the unadjusted and adjusted associations between previous stroke and severe COVID-19, using a Cox regression model. We conducted an overall review of systematic review and meta-analysis to investigate the relationship of previous stroke with the unfavorable COVID-19 outcomes.

Results

The rate of severe COVID-19 in patients with previous stroke was 28.37 per 1,000 patient days (95% confidence interval [CI]: 10.65–75.59), compared to 3.94 per 1,000 patient days (95% CI: 2.66–5.82) in those without previous stroke (p < 0.001). Previous stroke was significantly associated with severe COVID-19 using a Cox regression model (unadjusted [hazard ratio, HR]: 6.98, 95% CI: 2.42–20.16, p < 0.001; adjusted HR [per additional 10 years]: 4.62, 95% CI: 1.52–14.04, p = 0.007). An overall review of systematic review and meta-analysis showed that previous stroke was significantly associated with severe COVID-19, mortality, need for intensive care unit admission, use of mechanical ventilation, and an unfavorable composite outcome.

Conclusion

Previous stroke seems to influence the course of COVID-19 infection; such patients are at high risk of severe COVID-19 and might benefit from early hospital treatment measures and preventive strategies.

A Prospective Study Evaluating Cumulative Incidence and a Specific Prediction Rule in Pulmonary Embolism in COVID-19

Rationale

Abnormal values of hypercoagulability biomarkers, such as D-dimer, have been described in Coronavirus Disease 2019 (COVID-19), which has also been associated with disease severity and in-hospital mortality. COVID-19 patients with pneumonia are at greater risk of pulmonary embolism (PE). However, the real incidence of PE is not yet clear, since studies have been limited in size, mostly retrospective, and PE diagnostic procedures were only performed when PE was clinically suspected.

Objectives

(1) To determine the incidence, clinical, radiological, and biological characteristics, and clinical outcomes of PE among patients hospitalized for COVID-19 pneumonia with D-dimer > 1,000 ng/mL. (2) To develop a prognostic model to predict PE in these patients.

Methods

Single-center prospective cohort study. Consecutive confirmed cases of COVID-19 pneumonia with D-dimer > 1,000 ng/mL underwent computed tomography pulmonary angiography (CTPA). Demographic and laboratory data, comorbidities, CTPA scores, treatments administered, and clinical outcomes were analyzed and compared between patients with and without PE. A risk score was constructed from all these variables.

Results

Between 6 April 2020 and 2 February 2021, 179 consecutive patients were included. The overall incidence of PE was 39.7% (71 patients) (CI 95%, 32–47%). In patients with PE, emboli were located mainly in segmental/subsegmental arteries (67%). Patients with PE did not differ from the non-PE group in sex, age, or risk factors for thromboembolic disease. Higher urea, D-Dimer, D-dimer-to-ferritin and D-dimer-to-lactate dehydrogenase (LDH) ratios, platelet distribution width (PDW), and neutrophil-to-lymphocyte ratio (NLR) values were found in patients with PE when compared to patients with non-PE. Besides, lymphocyte counts turned out to be lower in patients with PE. A score for PE prediction was constructed with excellent overall performance [area under the ROC curve-receiver operating characteristic (AUC-ROC) 0.81 (95% CI: 0.73–0.89)]. The PATCOM score stands for Pulmonary Artery Thrombosis in COVID-19 Mallorca and includes platelet count, PDW, urea concentration, and D-dimer-to-ferritin ratio.

Conclusion

COVID-19 patients with pneumonia and D-dimer values > 1,000 ng/mL were presented with a very high incidence of PE, regardless of clinical suspicion. Significant differences in urea, D-dimer, PDW, NLR, and lymphocyte count were found between patients with PE and non-PE. The PATCOM score is presented in this study as a promising PE prediction rule, although validation in further studies is required.

COVID-19 Infection After Total Joint Arthroplasty Is Associated With Increased Complications

BACKGROUND

The impact of a postoperative diagnosis of COVID-19 in patients undergoing total joint arthroplasty (TJA) remains unknown. The objective of this study is to characterize the effect of COVID-19 infection following TJA on perioperative complication rates.

METHODS

The Mariner database was queried for patients undergoing total hip and total knee arthroplasty from January 2018 to April 2020. TJA patients who were diagnosed with COVID-19 within 90 days postoperatively were matched in a 1:3 fashion based on age, gender, iron deficiency anemia, payer status, and Charlson Comorbidity Index with patients who were not diagnosed with COVID-19. Preoperative comorbidity profiles and complications within 3 months of surgery were compared. Statistical analysis included chi-squared tests and multivariate logistic regression with outcomes considered significant at P < .05.

RESULTS

Of the 239 COVID-19 positive patients, 132 (55.2%) underwent total hip arthroplasty. On multivariate analysis, COVID-19 diagnosis was associated with increased odds of deep vein thrombosis (odds ratio [OR] 4.86, 95% confidence interval [CI] 2.10-11.81, P < .001), pulmonary embolism (OR 6.27, 95% CI 2.57-16.71, P < .001), and all complications (OR 3.36, 95% CI 2.47-4.59, P < .001). Incidence of deep vein thrombosis/pulmonary embolism was greater the closer in time the COVID-19 diagnosis was to the surgical procedure (10.24 times at 1 month, 7.87 times at 2 months, and 1.42 times at 3 months; P < .001). A similar relationship was observed with all complications.

CONCLUSION

Postoperative COVID-19 infection is associated with higher rates of cardiopulmonary complications, thromboembolic disease, renal injury, and urinary tract infections in patients undergoing hip and knee arthroplasty. COVID-19 infection earlier in the postoperative period is associated with a higher risk of complications.

The Role of Biomarkers in Hospitalized COVID-19 Patients With Systemic Manifestations

The following article aims to review COVID-19 biomarkers used in hospital practice. It is apparent that COVID-19 is not simply a pulmonary disease but has systemic manifestations. For this reason, biomarkers must be used in the management of diagnosed patients to provide holistic care. Patients with COVID-19 have been shown to have pulmonary, hepatobiliary, cardiovascular, neurologic, and renal injury, along with coagulopathy and a distinct cytokine storm. Biomarkers can effectively inform clinicians of systemic organ injury due to COVID-19. Furthermore, biomarkers can be used in predictive models for severe COVID-19 in admitted patients. The utility of doing so is to allow for risk stratification and utilization of proper treatment protocols. In addition, COVID-19 biomarkers in the pediatric population are discussed, specifically in predicting Multisystem Inflammatory Syndrome. Ultimately, biomarkers can be used as predictive tools to allow clinicians to identify and adequately manage patients at increased risk for worse outcomes from COVID-19. Both literature review and anecdotal evidence has shown that severe COVID-19 is a systemic disease, and understanding associated biomarkers are crucial for hospitalized patients’ proper clinical decision-making. For example, the cytokine storm releases inflammatory markers in different organ systems such as the pulmonary, hepatobiliary, hematological, cardiac, neurological, and renal systems. This review summarizes the latest research of COVID-19 that can help inform healthcare professionals how to better mitigate morbidity and mortality associated with this disease and provides information about certain systemic biomarkers that can be incorporated into hospital practice to provide more comprehensive care for hospitalized COIVD-19 patients.

The Incidence of Venous Thromboembolism in Critically Ill Patients with SARS-CoV-2 Infection Compared with Critically Ill Influenza and Community-Acquired Pneumonia Patients: A Retrospective Chart Review

The rate of venous thromboembolism in COVID-19 patients has been reported to be 30% (deep vein thrombosis 20% and pulmonary embolism 18%). This has been shown to be higher in COVID-19 patients admitted to the ICU. Prophylactic anticoagulation may be sufficient at ward level, but not in intensive care. A retrospective chart review was undertaken in a large university hospital. The review included 276 patients from COVID-19 Wave 1, COVID-19 Wave 2, influenza, and community-acquired pneumonia groups. The timeframe included patients admitted between 23 February 2014 and 12 May 2021. Clinical characteristics, outcomes, blood results, rates of venous thromboembolism, and anticoagulation status were recorded. The incidence of venous thromboembolism in COVID-19 Wave 1, COVID-19 Wave 2, influenza, and community-acquired pneumonia was 10.91%, 13.69%, 13.33%, and 6.81%, respectively (p = 0.481). The incidence of pulmonary embolism was 7.27%, 10.95%, 3.33%, and 5.68%, respectively (p = 0.350). The incidence of deep vein thrombosis was 5.45%, 5.48%, 10.00%, and 1.14%, respectively (p = 0.117). Although most patients were prophylactically anticoagulated, venous thromboembolism still occurred. Venous thromboembolism remains an important differential to consider in critically ill COVID-19 patients. The current literature does not advise therapeutic anticoagulation for thromboprophylaxis in the ICU.

Is post-COVID syndrome an autoimmune disease?

INTRODUCTION

: Coronavirus disease 2019 (COVID-19) causes a long-term and persistent condition with clinical features similar to previous virulent outbreaks and other epidemics. Currently, post-COVID syndrome (PCS) is recognized as a new entity in the context of SARS-CoV-2 infection. Though its pathogenesis is not completely understood, persistent inflammation from acute illness and the development of autoimmunity play a critical role in its development. As the pandemic develops, the increasing latent and overt autoimmunity cases indicate that PCS is at the intersection of autoimmunity.

AREAS COVERED

The mechanisms involved in the emergence of PCS, their similarities with post-viral and post-care syndromes, its inclusion in the spectrum of autoimmunity and possible targets for its treatment.

EXPERT OPINION

An autoimmune phenomenon plays a major role in most causative theories explaining PCS. Due to the wide scope of symptoms and pathophysiology associated with PCS, there is a need for both PCS definition and classification criteria (including severity scores). Longitudinal and controlled studies are necessary to better understand this new entity, and to confirm that PCS is the chronic phase of COVID-19 as well as to find what additional factors participate into its development. With the high prevalence of COVID-19 cases worldwide, together with the current evidence on latent autoimmunity in PCS, we may observe an increase of autoimmune diseases (ADs) in the coming years. Vaccination's effect on the development of PCS and ADs will also receive attention in the future. Health and social care services need to develop a new framework to deal with PCS.

Venous and arterial thrombosis in COVID-19: An updated narrative review

Hospitalized patients with coronavirus disease 2019 (COVID-19), particularly those admitted to the intensive care unit (ICU) are at high risk of morbidity and mortality. Several observational studies have described hemostatic derangements and thrombotic complications in patients with COVID-19. The aim of this review article is to summarize the current evidence on pathologic findings, pathophysiology, coagulation and hemostatic abnormalities, D-dimer's role in prognostication epidemiology and risk factors of thrombotic complications, and the role of prophylactic and therapeutic anticoagulation in patients with COVID-19. While existing evidence is limited in quality, COVID-19 appears to increase micro-and macro-vascular thrombosis rates in hospitalized and critically ill patients, which may contribute to the burden of disease. D-dimer can be used for risk stratification of hospitalized patients, but its role to guide anticoagulation therapy remains unclear. Evidence of higher quality is needed to address the role of therapeutic anticoagulation or high-intensity venous thromboembolism prophylaxis in COVID-19 patients. TAKE-HOME POINTS.

Aprotinin treatment against SARS-CoV-2: A randomized phase III study to evaluate the safety and efficacy of a pan-protease inhibitor for moderate COVID-19

BACKGROUND

SARS-CoV-2 virus requires host proteases to cleave its spike protein to bind to its ACE2 target through a two-step furin-mediated entry mechanism. Aprotinin is a broad-spectrum protease inhibitor that has been employed as antiviral drug for other human respiratory viruses. Also, it has important anti-inflammatory properties for inhibiting the innate immunity contact system.

METHODS

This was a multicentre, double-blind, randomized trial performed in four Spanish hospitals comparing standard treatment versus standard treatment + aprotinin for patients with COVID-19 between 20 May 2020 and 20 October 2021. The primary efficacy outcomes were length of hospital stay and ICU admission. The secondary endpoints were each of the primary efficacy outcomes and a composite of oxygen therapy, analytical parameters and death. Safety outcomes included adverse reactions to treatment during a 30-day follow-up period. Treatment was given for 11 days or till discharge.

RESULTS

With almost identical analytical profiles, significant differences were observed in treatment time, which was 2 days lower in the aprotinin group (p = .002), and length of hospital admission, which was 5 days shorter in the aprotinin group (p = .003). The incidence of discharge was 2.19 times higher (HR: 2.188 [1.182-4.047]) in the aprotinin group than in the placebo group (p = .013). In addition, the aprotinin-treated group required less oxygen therapy and had no adverse reactions or side effects.

CONCLUSION

Inhaled aprotinin may improve standard treatment and clinical outcomes in hospitalized patients with COVID-19, resulting in a shorter treatment time and hospitalization compared with the placebo group. The administration of aprotinin was safe.

COVID-19 related thrombosis: A mini-review

Introduction

COVID-19 associated VTE is a new disease entity with high morbidity and mortality. The aim of this paper is to review contemporary emerging literature on the incidence, pathophysiology, predictive prognostic indicators, and management consensus for Covid-19 related thrombotic complications, in particular DVT and PE.

Methods

A literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All searches were done via PubMed. References of review articles were further screened according to the exclusion criteria.

Results

In total, 154 records were identified and 20 duplicates were removed. A final 68 articles were included in the qualitative analysis. COVID-19 related thrombosis can affect multiple organs of the body, presenting in the form of arterial or venous thrombosis such as ischemic stroke, myocardial infarction, mesenteric ischemia, limb ischemia, DVT, or PE. DVT and PE has an overall incidence of 6–26%, and severely ill COVID-19 patients have even higher incidence of thromboembolism. On the other hand, incidence of arterial thromboembolism is much lower with incidence of 0.7%–3.7%. D-dimer is found to be an independent risk factor, and IMPROVE score, Caprini score, and Padua score have all been used as predictors. International guidelines suggest the use of low molecular weight heparin (LMWH) or fondaparinux for prophylaxis of VTE, and therapeutic dosage of weight adjusted LMWH for treatment if confirmed diagnosis.

Conclusions

Contemporary rapidly evolving evidence shows that COVID-19 associated thrombosis was a novel clinical entity, especially in severely ill COVID-19 patients. There are multiple society-driven guidelines only, but without any level 1 evidence for management regimen. The ideal dose for prophylaxis is not established and may vary depending on balance of bleeding and thrombosis risk. The risk of bleeding may be increased in patients in intensive care unit.

The significance of surface neutrophilic MPO expression level in NETosis and NETosis-associated coagulopathies in covid-19 infected patients

INTRODUCTION

Inflammatory response-induced coagulopathy is a common complication associated with severe form of covid-19 infection. Evidences suggest that neutrophil extracellular traps (NETs) play a significant role in triggering the immunothrombosis in this condition. We aimed to evaluate the diagnostic value of surface neutrophilic myeloperoxidase (MPO) as NETosis biomarker for predicting the risk of covid-19-associated coagulopathies.

METHODS

Covid-19 infection was assessed by real-time-PCR and plasma d-dimer levels were measured by ELFA. Based on the covid-19 infection and d-dimer level outcomes, patients were categorized into four groups. Any alteration in the serum level of IL-6, H3Cit and neutrophilic surface MPO were analyzed by CLIA, ELISA, and flow cytometry, respectively.

RESULTS

H3Cit variations and different d-dimer values confirmed the association between NETosis and coagulopathies. Findings showed that the expression of neutrophilic MPO reduced in cases with NETosis, which was correlated with increased levels of H3Cit. ANC/MPO ratio was signified as a valuable marker to discriminate the covid-19 and non covid-19-associated coagulopathies and could be considered as a prognostic factor due to its noteworthy correlation with serum IL-6 concentration.

CONCLUSION

Declined levels of surface neutrophilic MPO in NETosis correlate with covid-19-associated coagulopathies and increased IL-6 levels, as a potential biomarker of covid-19 disease severity.

Screening for asymptomatic deep vein thrombosis in COVID-19 patients admitted to the medical ward: a cross-sectional study

Purpose

Patients with COVID-19 have an increased risk for venous thrombo-embolism (VTE), especially pulmonary embolism. The exact prevalence of asymptomatic DVT is not known, as is the usefulness of screening for DVT in patients admitted to ward with COVID-19. We have studied the prevalence of asymptomatic DVT.

Methods

We performed a cross-sectional observational multi-center study at four university medical centers in The Netherlands. All adult patients admitted with COVID-19 to a medical ward were eligible for inclusion, including patients who were transferred back from the ICU to the ward. The study protocol consisted of weekly cross-sectional rounds of compression ultrasound.

Results

In total, 125 patients were included in the study. A significant proportion of patients (N = 34 (27%)) had developed a VTE during their admission for COVID-19 before the study ultrasound was performed. In most VTE cases (N = 27 (79%)) this concerned pulmonary embolism. A new asymptomatic DVT was found in 5 of 125 patients (4.0%; 95% CI 1.3–9.1%) (Table 2). Nine patients (7.2%; 95% CI 3.3–13.2%) developed a VTE (all PE) diagnosed within 28 days after the screening US was performed.

Conclusion

We have shown a low prevalence (4%) of newly discovered asymptomatic DVT outside the ICU-setting in COVID-19 patients. Despite this low prevalence, nine patients developed PE (7%) within 28 days after ultrasound. This favors the hypothesis of local thrombus formation in the lungs. Based on our findings and literature, we do not recommend US-screening of asymptomatic patients with COVID-19 admitted to the ward.

The Difference Coagulopathy Factor and Interleukin-6 between Survival and Non-survival Patients COVID-19

Background: Coronavirus disease 2019 (COVID-19) was caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus. SARS-CoV-2 infection can result in coagulopathy and an increase in inflammatory responses. Numerous studies have shown a significant difference in interleukin levels and coagulopathy parameters such as platelet, aPTT, PT, and D- dimer between survivor and non-survivor patient COVID-19. Aim: The purpose of this study is to compare the age, coagulopathy characteristics, and interleukin-6 levels of non-survival versus survival patients. COVID-19. Methods: A cross-sectional retrospective study was conducted on COVID-19 patients. The diagnostic criteria are based on the Indonesian Ministry of Health's recommendations. The patient's blood was analyzed in the hospital's central laboratory. Patients are classified into two groups based on their likelihood of surviving: non-survival and survival. SPSS version 22 was used to analyze the data. Results: A total of 557 patients with COVID-19 were included in this study. Patients were categorized into 146 non-survival and 411 survival subgroups. There was a significant difference in the mean age, coagulopathy parameters, and interleukin-6 expect platelets between non-survival and survival outcomes in COVID-19 patients. Conclusion: This study demonstrated a statistically significant difference in PT, aPTT, D-Dimer, and interleukin-6 levels between the non-survival and survival groups of COVID-19.

Characteristics and outcomes among vaccinated lung transplant patients with breakthrough COVID-19

BACKGROUND

Despite multiple studies evaluating the immunological responsiveness to vaccines, the clinical effectiveness of the two-dose mRNA vaccine schedule among lung transplant (LT) patients has not been evaluated.

METHODS

We included LT patients who tested positive for SARS-CoV-2 on a nasopharyngeal swab between March 1, 2020, and August 25, 2021 (n = 70). The study group was divided based on their vaccination status.

RESULTS

During the study period, 14 fully vaccinated LT patients with one of the mRNA vaccines tested positive for COVID-19 (median age 54, range 30-62 years, M:F 9:5). The vaccinated cohort was younger with bilateral LT, have suppurative conditions as the transplant indication, and present with milder symptoms. However, pulmonary parenchymal involvement was seen among all 12 patients where computed tomography (CT) of chest was available. The laboratory profile indicated a more subdued inflammatory response among the vaccinated group. A lower proportion of vaccinated patients developed respiratory failure, needed ICU admission or ventilator support, although none of the differences achieved statistical significance. None of the vaccinated patients succumbed to COVID-19 during the study period, while the 4-week mortality among unvaccinated patients was nearly 15% (8/56).

CONCLUSIONS

In this cohort of vaccinated LT patients who developed breakthrough COVID-19, the clinical course, risk of complications, and outcomes trended better than unvaccinated patients. However, universal involvement of the allograft demonstrates the continued vulnerability of these patients to significant sequelae from COVID-19. Future studies may evaluate the incremental protection of vaccination after the completion of the third dose of mRNA vaccines among LT patients.

Longitudinal Plasma Proteomics Analysis Reveals Novel Candidate Biomarkers in Acute COVID-19

The host response to COVID-19 pathophysiology over the first few days of infection remains largely unclear, especially the mechanisms in the blood compartment. We report on a longitudinal proteomic analysis of acute-phase COVID-19 patients, for which we used blood plasma, multiple reaction monitoring with internal standards, and data-independent acquisition. We measured samples on admission for 49 patients, of which 21 had additional samples on days 2, 4, 7, and 14 after admission. We also measured 30 externally obtained samples from healthy individuals for comparison at baseline. The 31 proteins differentiated in abundance between acute COVID-19 patients and healthy controls belonged to acute inflammatory response, complement activation, regulation of inflammatory response, and regulation of protein activation cascade. The longitudinal analysis showed distinct profiles revealing increased levels of multiple lipid-associated functions, a rapid decrease followed by recovery for complement activation, humoral immune response, and acute inflammatory response-related proteins, and level fluctuation in the regulation of smooth muscle cell proliferation, secretory mechanisms, and platelet degranulation. Three proteins were differentiated between survivors and nonsurvivors. Finally, increased levels of fructose-bisphosphate aldolase B were determined in patients with exposure to angiotensin receptor blockers versus decreased levels in those exposed to angiotensin-converting enzyme inhibitors. Data are available via ProteomeXchange PXD029437.

A review of the main placenta histopathological findings reported in coronavirus disease 2019

Several studies have reported that pregnant women are more susceptible to contracting the SARS-CoV-2 disease. However, SARS-CoV-2 infection studies have limited evidence regarding its impact on pregnancy, particularly its pathological effects on the maternal-fetal interface. This review emphasized the placental structures and immunomodulatory defense mechanism against the viral infection COVID and highlighted the spectrum of reported histopathological changes from SARS-CoV-2-infected mothers' placenta to contribute to the knowledge of the nature of this placental pathology. Further studies where collaborations that seek to maximize sample numbers analyzed can be performed to improve the generalizability and reliability of the findings. This can lead to improved knowledge on the relationship between placental dysfunction and pathology from maternal SARS-CoV-2 infection. Consequently, this can help improve maternity care delivery during the pandemic.

Impaired Endothelial Function in Convalescent Phase of COVID-19: A 3 Month Follow Up Observational Prospective Study

Background: Endothelial dysfunction has a role in acute COVID-19, contributing to systemic inflammatory syndrome, acute respiratory distress syndrome, and vascular events. Evidence regarding COVID-19 middle- and long-term consequences on endothelium are still lacking. Our study aimed to evaluate if COVID-19 severity could significantly affect the endothelial function after three months from the acute phase. Methods: We assessed endothelial function in outpatients with previous COVID-19 three months after negative SARS-CoV-2 molecular test by measuring flow-mediated dilation (FMD) in patients categorized according to a four-variable COVID-19 severity scale (“home care”; “hospital, no oxygen”; “hospital, oxygen”; “hospital requiring high-flow nasal canula, non-invasive ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation”). FMD difference among COVID-19 severity categories was assessed with analysis of variance; we further clarified the relationship between FMD and previous COVID-19 severity with multivariate logistic models. Results: Among 658 consecutive COVID-19 subjects, we observed a significant linear trend of FMD reduction with the increase of the COVID-19 category (p < 0.0001). The presence of endothelial dysfunction was more frequent among hospitalized patients (78.3%) with respect to home-care patients (21.7%; p < 0.0001). COVID-19 severity was associated with increased endothelial dysfunction risk (OR: 1.354; 95% CI: 1.06−1.71; p = 0.011) at multivariate binary logistic analysis. FMD showed a significant direct correlation with PaO2 (p = 0.004), P/F ratio (p = 0.004), FEV1 (p = 0.008), and 6MWT (p = 0.0001). Conclusions: Hospitalized COVID-19 subjects showed an impaired endothelial function three months after the acute phase that correlated with pulmonary function impairment. Further studies are needed to evaluate if these subjects are at higher risk of developing pulmonary disease or future cardiovascular events.

Association between COVID-19 Diagnosis and Coronary Artery Thrombosis: A Narrative Review

Coronavirus disease 2019 is characterized by its severe respiratory effects. Data early on indicated an increased risk of mortality in patients with cardiovascular comorbidities. Early reports highlighted the multisystem inflammatory syndrome, cytokine storm, and thromboembolic events as part of the disease processes. The aim of this review is to assess the association between COVID-19 and its thrombotic complications, specifically related to the cardiovascular system. The role of neutrophil extracellular traps (NETs) is explored in the pathogenesis of the disease. The structure and anatomy of the virus are pivotal to its virulence in comparison to other α and β Coronaviridae (HCoV-229E, HCoV-OC43, HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1). In particular, the host interaction and response may explain the variability of severity in patients. Angio tensin-converting enzyme 2 (ACE2) activation may be implicated in the cardiovascular and throm bogenic potential of the disease. The virus may also have direct effects on the endothelial lining affecting hemostasis and resulting in thrombosis through several mechanisms. Dipyridamole may have a therapeutic benefit in NET suppression. Therapeutic avenues should be concentrated on the different pathophysiological steps involving the virus and the host.

Aspirin in COVID-19: Pros and Cons

Since its emergence, the COVID-19 pandemic has been ravaging the medical and economic sectors even with the significant vaccination advances. In severe presentations, the disease of SARS-CoV-2 can manifest with life-threatening thromboembolic and multi-organ repercussions provoking notable morbidity and mortality. The pathogenesis of such burdensome forms has been under extensive investigation and is attributed to a state of immune dysfunction and hyperinflammation. In light of these extraordinary circumstances, research efforts have focused on investigating and repurposing previously available agents that target the inflammatory and hematological cascades. Aspirin, due to its well-known properties and multiple molecular targets, and ought to its extensive clinical use, has been perceived as a potential therapeutic agent for COVID-19. Aspirin acts at multiple cellular targets to achieve its anti-inflammatory and anti-platelet effects. Although initial promising clinical data describing aspirin role in COVID-19 has appeared, evidence supporting its use remains fragile and premature. This review explores the notion of repurposing aspirin in COVID-19 infection. It delves into aspirin as a molecule, along with its pharmacology and clinical applications. It also reviews the current high-quality clinical evidence highlighting the role of aspirin in SARS-CoV-2 infection.

Of vascular defense, hemostasis, cancer, and platelet biology: an evolutionary perspective

We have established considerable expertise in studying the role of platelets in cancer biology. From this expertise, we were keen to recognize the numerous venous-, arterial-, microvascular-, and macrovascular thrombotic events and immunologic disorders are caused by severe, acute-respiratory-syndrome coronavirus 2 (SARS-CoV-2) infections. With this offering, we explore the evolutionary connections that place platelets at the center of hemostasis, immunity, and adaptive phylogeny. Coevolutionary changes have also occurred in vertebrate viruses and their vertebrate hosts that reflect their respective evolutionary interactions. As mammals adapted from aquatic to terrestrial life and the heavy blood loss associated with placentalization-based live birth, platelets evolved phylogenetically from thrombocytes toward higher megakaryocyte-blebbing-based production rates and the lack of nuclei. With no nuclei and robust RNA synthesis, this adaptation may have influenced viral replication to become less efficient after virus particles are engulfed. Human platelets express numerous receptors that bind viral particles, which developed from archetypal origins to initiate aggregation and exocytic-release of thrombo-, immuno-, angiogenic-, growth-, and repair-stimulatory granule contents. Whether by direct, evolutionary, selective pressure, or not, these responses may help to contain virus spread, attract immune cells for eradication, and stimulate angiogenesis, growth, and wound repair after viral damage. Because mammalian and marsupial platelets became smaller and more plate-like their biophysical properties improved in function, which facilitated distribution near vessel walls in fluid-shear fields. This adaptation increased the probability that platelets could then interact with and engulf shedding virus particles. Platelets also generate circulating microvesicles that increase membrane surface-area encounters and mark viral targets. In order to match virus-production rates, billions of platelets are generated and turned over per day to continually provide active defenses and adaptation to suppress the spectrum of evolving threats like SARS-CoV-2.

The Composition and Physical Properties of Clots in COVID-19 Pathology

Hemostasis is a finely tuned process of which dysregulation can lead either to bleeding or thrombotic complications. The latter is often caused by the hypercoagulable state as it is also seen in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, i.e., in COVID-19 patients. COVID-19 patients requiring hospitalization often suffer from thrombotic events that could not be predicted using routine coagulation assays. Recently, several studies have reported ROtational ThromboElastoMetry (ROTEM) as a promising tool to predict outcomes in COVID-19 patients. In this review we give an overview of ROTEM with a particular focus on the interpretation of the symmetrical clot formation curve in relation to coagulopathy in COVID-19 patients. Furthermore, we have introduced new parameters that might help to better distinguish between COVID-19 patients and outcomes.

Are there differences between COVID-19 and non-COVID-19 inpatient pressure injuries? Experiences in Internal Medicine Units

BACKGROUND

Pressure Injuries (PIs) are major worldwide public health threats within the different health-care settings.

OBJECTIVE

To describe and compare epidemiological and clinical features of PIs in COVID-19 patients and patients admitted for other causes in Internal Medicine Units during the first wave of COVID-19 pandemic.

DESIGN

A descriptive longitudinal retrospective study.

SETTING

This study was conducted in Internal Medicine Units in Salamanca University Hospital Complex, a tertiary hospital in the Salamanca province, Spain.

PARTICIPANTS

All inpatients ≥18-year-old admitted from March 1, 2020 to June 1, 2020 for more than 24 hours in the Internal Medicine Units with one or more episodes of PIs.

RESULTS

A total of 101 inpatients and 171 episodes were studied. The prevalence of PI episodes was 6% and the cumulative incidence was 2.9% during the first-wave of COVID-19. Risk of acute wounds was four times higher in the COVID-19 patient group (p<0.001). Most common locations were sacrum and heels. Among hospital acquired pressure injuries a significant association was observed between arterial hypertension and diabetes mellitus in patients with COVID-19 diagnosis.

CONCLUSION

During the first wave of COVID-19, COVID-19 patients tend to present a higher number of acute wounds, mainly of hospital origin, compared to the profile of the non-COVID group. Diabetes mellitus and arterial hypertension were identified as main associated comorbidities in patients with COVID-19 diagnosis.

[Computed tomography and endovascular occlusion in diagnosis and treatment of spontaneous bleeding into soft tissues of abdominal, chest wall and retroperitoneal space in patients with COVID-19]

OBJECTIVE

To investigate the results of therapeutic and prophylactic endovascular hemostasis of spontaneous bleeding into soft tissues of abdominal, chest wall and retroperitoneal space in patients with COVID-19.

MATERIAL AND METHODS

We retrospectively studied 35 patients with COVID-19 complicated by spontaneous bleeding into soft tissues of abdominal, chest wall and retroperitoneal space. According to CT data, the volume of hematoma was 1193.4±706.1 ml. In all patients, CT signs of ongoing bleeding were detected. Moreover, contrast agent extravasation in all phases of examination was established in 15 patients. In other ones, extravasation was detected in late phases or study phase was not identified. All patients underwent angiography. Ongoing bleeding was detected in 12 (34.3%) patients (group 1). They underwent embolization of the target vessel. In 23 patients, bleeding was not established during angiography. Of these, 13 ones underwent prophylactic embolization (group 2). No embolization was carried out in 10 patients (group 3). All groups differed in hematoma localization and COVID-19 severity.

RESULTS

Fourteen (40%) patients died in postoperative period. Mortality was similar in all groups. The most common cause of death was progressive respiratory failure following pneumonia. The last one was established by autopsy in 10 (71.4%) patients.

CONCLUSION

Angiography confirmed MR signs of contrast agent extravasation in 34.3% of patients. In case of extravasation in all CT phases, ongoing bleeding was confirmed in 66.7% of patients. Endovascular embolization is effective for arterial bleeding into soft tissues. However, large-scale studies are needed to assess the effect of this technique on survival.

OUP accepted manuscript

BACKGROUND

A protective antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial to decrease morbidity and mortality from severe coronavirus disease 2019 (COVID-19) disease. The effects of preexisting anti-human coronavirus (HCoV) antibodies on the SARS-CoV-2-specific immunoglobulin G (IgG) responses and severity of disease are currently unclear.

METHODS

We profiled anti-spike (S), S1, S2, and receptor-binding domain IgG antibodies against SARS-CoV-2 and 6 HCoVs using a multiplex assay (mPLEX-CoV) with serum samples from SARS-CoV-2 infected (n = 155) and pre-COVID-19 (n = 188) cohorts.

RESULTS

COVID-19 subjects showed significantly increased anti-S SARS-CoV-2 IgG levels that were highly correlated with IgG antibodies against OC43 and HKU1 S proteins. However, OC43 and HKU1 anti-S antibodies in pre-COVID-19 era sera did not cross-react with SARS-CoV-2. Unidirectional cross-reactive antibodies elicited by SARS-CoV-2 infection were distinct from the bidirectional cross-reactive antibodies recognizing homologous strains RaTG13 and SARS-CoV-1. High anti-OC43 and anti-S2 antibody levels were associated with both a rapid anti-SARS-CoV-2 antibody response and increased disease severity. Subjects with increased sequential organ failure assessment (SOFA) scores developed a higher ratio of S2- to S1-reactive antibodies.

CONCLUSIONS

Early and rapid emergence of OC43 S- and S2-reactive IgG after SARS-CoV-2 infection correlates with COVID-19 disease severity.

Prevalence and Trajectory of COVID-19-Associated Hypercoagulability Using Serial Thromboelastography in a South African Population

Introduction

The coagulation abnormalities resulting from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been attributed to inflammation and subsequent cytokine storm. Thromboelastography (TEG) is a point-of-care test used to assess clot formation and degradation in whole blood and is an indicator of the overall real-time coagulopathic state of the patient.

Methods

A single-centre, prospective, observational cohort study was conducted in South Africa, analysing the coagulation patterns of 41 patients with hypoxia related to SARS-CoV-2 using serial thromboelastography (TEG) on admission, after 48 hours, and at resolution of hypoxia/day 10. Results: Two-thirds (n = 26) were women. The median age was 61 (IQR 50–67), and the majority (88%) were Black patients. Almost half (22) of the patients were critically ill and ventilated, with median SOFA and SAPS2 scores of 3 and 22 (IQR2-4 and 18–30), respectively. The prevalence of hypercoagulability was 0.54 (95% CI 0.46–0.62), whilst 29/41 (0.71, CI 0.64–0.78)) met the definition of hypofibrinolysis. Differences between the hypercoagulable (HC) and non-hypercoagulable groups remained apparent at 48 hours after anticoagulation. At this time point, the K time was significantly lower (p ˂ 0,01), and the α-angle (p ˂ 0,01) and maximum amplitude (MA) (p ˂ 0,01) were significantly higher in the HC cohort. At resolution of hypoxia, or day 10, only MA was significantly higher in the hypercoagulable group compared to the non-hypercoagulable group (p = 0.01). The initial impairment in fibrinolysis (Ly30), α angle, and MA were significantly associated with mortality, with p values of 0.006, 0.031, and 0.04, respectively.

Conclusions

In this South African population, hypercoagulability was a highly prevalent phenomenon in COVID-19 disease. It was typified by hypofibrinolysis and a persistently elevated MA, despite anticoagulation therapy.

Indicators of Hypoxia Tolerance as Determined by Cellular Elements of Rat Blood

Although hypoxia tolerance is mainly determined genetically, it is important to study individual variability of animal organisms in order to identify the factors that underlie their tolerance to hypoxic exposure. We investigated blood cell counts and coagulograms in Wistar rats as predictors allowing the animal population to be split into hypoxia-tolerant and hypoxia-intolerant individuals. The validity of the specific predictors’ choice was proved by a coincidence between the population split in accordance with the detected individual parameters and the results of testing animals in a decompression chamber at a rarefaction corresponding to the “rise to an altitude” of 11500 m above sea level. Circulating blood cells were quantitatively assessed by eighteen indicators before and after hypoxic exposure. The differences between animals low-tolerant (LT), high-tolerant (HT), and medium-tolerant (MT) to hypoxia were determined by five indicators: white blood cell count (WBC), granulocyte count (Gran#), red blood cell count (RBC), reticulocyte count/percent (RTC), and mean corpuscular hemoglobin (MCH). The RBC, RTC, and MCH values in HT rats were significantly higher than in LT animals (by 1.4, 1.9, and 1.1 times, respectively). The WBC and Gran# values in HT rats were lower than in LT individuals. The hypoxia tolerance indices (HTI) were calculated using the original formula. It was established that in LT rats, the HTI ≤ 0.203, in HT rats ≥ 0.335, and in MT rats < 0.335 but > 0.203. After testing in a decompression chamber, the activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT) decreased, but the fibrinogen level increased. LT rats were characterized by the lowest APTT, TT, and PT values and the highest values of the fibrinogen level. Our results indicate that one of the most important mechanisms underlying a high hypoxia tolerance in rats consists in sustaining reciprocal relationships between the complex of RBC indicators, which tend to increase under hypoxia, and Gran# indicators, which tend to decrease after hypoxic exposure.

The intersection of COVID-19 and autoimmunity

Acute COVID-19, caused by SARS-CoV-2, is characterized by diverse clinical presentations, ranging from asymptomatic infection to fatal respiratory failure, and often associated with varied longer-term sequelae. Over the past 18 months, it has become apparent that inappropriate immune responses contribute to the pathogenesis of severe COVID-19. Researchers working at the intersection of COVID-19 and autoimmunity recently gathered at an American Autoimmune Related Diseases Association Noel R. Rose Colloquium to address the current state of knowledge regarding two important questions: Does established autoimmunity predispose to severe COVID-19? And, at the same time, can SARS-CoV-2 infection trigger de novo autoimmunity? Indeed, work to date has demonstrated that 10% to 15% of patients with critical COVID-19 pneumonia exhibit autoantibodies against type I interferons, suggesting that preexisting autoimmunity underlies severe disease in some patients. Other studies have identified functional autoantibodies following infection with SARS-CoV-2, such as those that promote thrombosis or antagonize cytokine signaling. These autoantibodies may arise from a predominantly extrafollicular B cell response that is more prone to generating autoantibody-secreting B cells. This Review highlights the current understanding, evolving concepts, and unanswered questions provided by this unique opportunity to determine mechanisms by which a viral infection can be exacerbated by, and even trigger, autoimmunity. The potential role of autoimmunity in post-acute sequelae of COVID-19 is also discussed.

Venous Thrombosis and SARS-CoV-2

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection is associated with high risk of venous and arterial thrombosis. Thrombotic complications, especially pulmonary embolism, lead to increased all-cause mortality in both intensive care unit and noncritically ill patients. Damage and activation of vascular endothelium, platelet activation, followed by thrombotic and fibrinolytic imbalance as well as hypercoagulability are the key pathomechanisms in immunothrombosis leading to a significant increase in thromboembolism in coronavirus disease 2019 (COVID-19) compared with other acute illnesses. In this review article, we discuss the incidence and prognosis, diagnosis, prevention, and treatment of venous thromboembolism in patients with COVID-19 disease, based on clinical experience and research available to date.

Immunopathological events surrounding IL-6 and IFN-α: A bridge for anti-lupus erythematosus drugs used to treat COVID-19

With the outbreak and rapid spread of COVID-19, the world health situation is unprecedentedly severe. Systemic lupus erythematosus (SLE) is a common autoimmune disease, which can cause multiple organ damage. Numerous studies have shown that immune factors have important roles in the pathogenesis of both COVID-19 and SLE. In the early stages of COVID-19 and SLE pathogenesis, IFN-α expression is frequently increased, which aggravates the virus infection and promotes SLE development. In addition, increased IL-6 levels, caused by different mechanisms, are observed in the peripheral blood of patients with severe COVID-19 and SLE, stimulating a series of immune cascades that lead to a cytokine storm, as well as causing B cell hyperfunction and production of numerous of antibodies, aggravating both COVID-19 and SLE. In this review, we explore the background immunopathological mechanisms in COVID-19 and SLE and analyze the advantages and disadvantages of commonly used SLE drugs for patients with COVID-19, to optimize treatment plans for patients with SLE who develop COVID-19.

State-of-the-art review - A review on snake venom-derived antithrombotics: Potential therapeutics for COVID-19-associated thrombosis?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent responsible for the Coronavirus Disease-2019 (COVID-19) pandemic, has infected over 185 million individuals across 200 countries since December 2019 resulting in 4.0 million deaths. While COVID-19 is primarily associated with respiratory illnesses, an increasing number of clinical reports indicate that severely ill patients often develop thrombotic complications that are associated with increased mortality. As a consequence, treatment strategies that target COVID-associated thrombosis are of utmost clinical importance. An array of pharmacologically active compounds from natural products exhibit effects on blood coagulation pathways, and have generated interest for their potential therapeutic applications towards thrombotic diseases. In particular, a number of snake venom compounds exhibit high specificity on different blood coagulation factors and represent excellent tools that could be utilized to treat thrombosis. The aim of this review is to provide a brief summary of the current understanding of COVID-19 associated thrombosis, and highlight several snake venom compounds that could be utilized as antithrombotic agents to target this disease.

Thrombocytopathy vs Platelet hyper-reactivity in COVID-19: diverse pathologies, disease outcomes and therapeutic implications

Coagulopathy is an evident complication of COVID-19 with predominance of a prothrombotic state. Platelet activation plays a key role. The terms "hyper-reactivity" and "hyperactivity" used in recent literature may not be clear or sufficient to explain the pathological events involved in COVID-related thrombosis (CRT). Inflammation may play a bigger role compared to thrombosis in COVID-related mortality because a smaller percentage of patients with COVID-19 die due to direct effects of thrombosis. Not all COVID-19 patients have thrombocytopenia and a few show thrombocytosis. We believe the platelet pathology is more complex than just activation or hyper-activation, particularly due to the platelets' role in inflammation. Understanding the pathology and consequences of platelets' role may help optimize management strategies and diminish CRT-associated morbidity and mortality. In this viewpoint report, we examine the published evidence of platelet hyper-reactivity in COVID-19 with a focused analysis of the key pathologies, diverse alterations, disease outcomes, and therapeutic targets. We believe that COVID-19 is a disease of inflammation and pathologic platelets, and based on the complexity and diverse pathologies, we propose the term "thrombocytopathy" as a more reflective term of the platelets' involvement in COVID-19. In our opinion, thrombocytopathy is the unpredictable pathologic alterations of platelets in function, morphology and number, caused by different factors with a variety of presentations.

Predictors and outcomes of respiratory failure among lung transplant patients with COVID-19

BACKGROUND

There is limited data on the predictors and outcomes of new or worsening respiratory failure among lung transplant (LT) patients with Coronavirus disease 2019 (COVID-19).

METHODS

We included all the LT patients diagnosed with COVID-19 during a 1-year period (March 2020 to February 2021; n = 54; median age: 60, 20-73 years; M:F 37:17). Development of new or worsening respiratory failure (ARF) was the primary outcome variable.

RESULTS

The overall incidence of ARF was 48.1% (n = 26). More than 20% of patients (n = 11) needed intubation and mechanical ventilation. Body mass index > 25 Kg/m² (adjusted OR: 5.7, .99-32.93; P = .05) and peak D-dimer levels > .95 mcg/ml (adjusted OR: 24.99, 1.77-353.8; P = .017) were independently associated with ARF while anticoagulation use prior to COVID-19 was protective (adjusted OR: .024, .001-.55; P = .02). Majority patients survived the acute illness (85.2%). Pre-infection chronic lung allograft dysfunction (CLAD) was an independent predictor of mortality (adjusted HR: 5.03, 1.14-22.25; P = .033).

CONCLUSIONS

COVID-19 is associated with significant morbidity and mortality among LT patients. Patients on chronic anticoagulation seem to enjoy favorable outcomes, while higher BMI and peak D-dimer levels are associated with development of ARF. Pre-infection CLAD is associated with an increased risk of death from COVID-19.

Lung epithelial and endothelial damage, loss of tissue repair, inhibition of fibrinolysis, and cellular senescence in fatal COVID-19

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is characterized by respiratory distress, multiorgan dysfunction, and, in some cases, death. The pathological mechanisms underlying COVID-19 respiratory distress and the interplay with aggravating risk factors have not been fully defined. Lung autopsy samples from 18 patients with fatal COVID-19, with symptom onset-to-death times ranging from 3 to 47 days, and antemortem plasma samples from 6 of these cases were evaluated using deep sequencing of SARS-CoV-2 RNA, multiplex plasma protein measurements, and pulmonary gene expression and imaging analyses. Prominent histopathological features in this case series included progressive diffuse alveolar damage with excessive thrombosis and late-onset pulmonary tissue and vascular remodeling. Acute damage at the alveolar-capillary barrier was characterized by the loss of surfactant protein expression with injury to alveolar epithelial cells, endothelial cells, respiratory epithelial basal cells, and defective tissue repair processes. Other key findings included impaired clot fibrinolysis with increased concentrations of plasma and lung plasminogen activator inhibitor-1 and modulation of cellular senescence markers, including p21 and sirtuin-1, in both lung epithelial and endothelial cells. Together, these findings further define the molecular pathological features underlying the pulmonary response to SARS-CoV-2 infection and provide important insights into signaling pathways that may be amenable to therapeutic intervention.

Isolated ovarian vein thrombosis in COVID-19 infection

COVID-19 (coronavirus disease-19) is associated with an increased risk for thrombosis due to endothelial dysfunction and hyperactivation of the immune system induced by the virus. Most cases of venous thromboembolism associated with COVID-19 are either pulmonary emboli or deep vein thromboses. Ovarian vein thrombosis is a rare condition most commonly seen in the postpartum period. This report describes a case of COVID-19-associated ovarian vein thrombosis in a nonpregnant woman with no evidence of underlying inherited coagulopathy.

Platelet extracellular vesicles in COVID-19: Potential markers and makers

Platelets and platelet extracellular vesicles (pEV) are at the crossroads of coagulation and immunity. Extracellular vesicles are messengers that not only transmit signals between cells, but also provide information about the status of their cell of origin. Thus, pEVs have potential as both biomarkers of platelet activation and contributors to pathology. Coronavirus Disease‐19 (COVID‐19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), is a complex disease affecting multiple organs and is characterized by a high degree of inflammation and risk of thrombosis in some patients. In this review, we introduce pEVs as valuable biomarkers in disease with a special focus on their potential as predictors of and contributors to COVID‐19.

Case Report: Asymptomatic COVID-19 patient with a subtle hypercoagulable state and fluctuating D-dimer level

Background: COVID-19 can infect an asymptomatic person silently without any overt symptoms despite diffuse blood clots throughout the body. Clot formation is induced by COVID-19 associated coagulopathy that can cause a high mortality rate. D-dimer, a fairly decisive marker for the coagulopathy event, is physiologically a marker of the fibrinolysis process. The increase of D-dimers in COVID-19 cases must be followed up because it relates to the initiation of a cytokine storm. Case presentation: We report an asymptomatic patient with sudden D-dimer elevation who received anticoagulant therapy. After three days of heparin administration, D-dimer results became normal and anticoagulant therapy was stopped. However, on the 12th day, the D-dimer level rebounded back and was followed by an increase of hs-C-reactive protein, erythrocyte sedimentation rate, IL-6, although SARS-CoV-2 PCR result became negative. A hyperglycaemic reaction and a sudden increase of HbA1C was observed in the patient. After three weeks D-dimer had returned to normal levels, and so did the other markers. The patient recovered fully and still no symptoms were obvious. Conclusion: COVID-19 patients without symptoms may be at risk of an asymptomatic coagulopathy process. The decreasing level of D-dimer erroneously cannot ensure that the coagulopathy process stops.

Timing of venous thromboembolism diagnosis in hospitalized and non-hospitalized patients with COVID-19

BACKGROUND

The reported incidence of venous thromboembolism (VTE) in COVID-19 patients varies widely depending on patient populations sampled and has been predominately studied in hospitalized patients. The goal of this study was to assess the evolving burden of COVID-19 and the timing of associated VTE events in a systems-wide cohort.

METHODS

COVID-19 PCR positive hospitalized and non-hospitalized patients ≥18 years of age tested between 1/1/2020 through 12/31/2020 were retrospectively analyzed using electronic medical records from multiple states across the Mayo Clinic enterprise. Radiology reports within 90 days before and after confirmed COVID-19 diagnosis were examined for VTE outcomes using validated Natural Language Processing (NLP) algorithms.

RESULTS

A 29-fold increased rate of VTE compared to the pre-COVID-19 period was noted during the first week following the first positive COVID-19 test (RR: 29.39; 95% CI 21.77-40.03). The rate of VTE steadily decreased and returned to baseline by the 6th week. Among 366 VTE events, most occurred during (n = 243, 66.3%) or after (n = 111, 30.3%) initial hospitalization. Only 11 VTE events were identified in patients who did not require hospitalization (3.0% of total VTE events). VTE and mortality increased with advancing age with a pronounced increased each decade in older patients.

CONCLUSION

We observed a profoundly increased risk of VTE within the first week after positive testing for COVID-19 that returned to baseline levels after 6 weeks. VTE events occurred almost exclusively in patients who were hospitalized, with the majority of VTE events identified within the first days of hospitalization.

Bilateral renal infarction with COVID-19 pneumonia: a case report

Acute renal infarction is a rare and often underdiagnosed condition with estimated incidence of 0.5–1.5%. Coronavirus disease 2019 (COVID-19) has been shown to cause a hypercoagulable state in patients leading to arterial and venous thromboembolism. Renal infarction as a consequence of COVID-associated coagulopathy has been reported, sometimes resulting in acute kidney injury. Most of the patients so far reported had other existing comorbidities and risk factors that compounded the risk of precipitating an infarction. Here, we present a 37-year-old, the youngest patient reported so far, with no pre-existing comorbidities or risk factors, who developed bilateral renal infarction with COVID-19 pneumonia. The patient was treated with anticoagulation for renal infarction and discharged on apixaban. Anticoagulation is an important part of current treatment strategies for COVID-19 pneumonia and should extend beyond the acute phase of the disease to prevent long-term sequelae, especially in young patients.

Association Between Periodontal Disease and the Risk of COVID-19 Complications and Mortality: A Systematic Review

AIM

The COVID-19 pandemic has strained the world's healthcare systems. Studies have identified how the COVID-19 infections are linked to several co-morbidities such as hypertension, diabetes, cardiovascular disease, renal and pulmonary disease. It is known that periodontal disease (PD) shares the same risk factors. Moreover, both diseases are characterized by an exaggerated immune response. The aim of the study was to investigate the available evidence of a potential association between PD and the risk of COVID-19 complications and mortality.

MATERIALS AND METHODS

MEDLINE/PubMed, EMBASE, Scopus, and ProQuest were searched. Studies that assess the association between PD and the risk of COVID-19 complications and mortality were eligible for inclusion. Two independent reviewers performed the selection of articles and data extraction. The New Castle Ottawa Scale was used to assess the quality of the selected studies, and the GRADE system was used to evaluate the level of confidence to support the conclusions.

RESULTS

Only two studies met the eligibility criteria. One study had a low risk of bias, whereas the other had a high risk of bias.

CONCLUSION

The level of confidence in the available evidence is very low. A close association between periodontitis and the risk of COVID-19 complications and mortality can neither be supported nor refuted.

Aeromedical Implications of Long-Term COVID-19 Sequelae

BACKGROUND: While many COVID-19 studies focus on acute effects of the infection, few examine the intermediate and long-term sequelae of the illness. Studies have shown that a good portion of patients have chronic effects in several body systems for several months or longer. Such effects can potentially adversely impact pilot performance in flight. We sought to determine the long-term effects of COVID-19 infection, how such effects can affect pilot performance, and how to best evaluate pilots for aeromedical flight clearance.METHODS: We used the PubMed literature search engine to review peer-reviewed articles that focused on the intermediate and long-term effects of COVID-19 infection. Chronic signs and symptoms were subdivided based on the particular body organ system affected. Merging information obtained from case reviews, article reviews, and aeromedical standards, we created a risk stratification guide to assist with the aeromedical disposition of affected pilots.RESULTS: Long-term effects of COVID-19 infection can last for several months or longer. The most common effects are fatigue, weakness, pulmonary diffusion defects, depression, and anxiety.DISCUSSION: This review article focuses on the most common intermediate- and long-term COVID-19 conditions of aeromedical significance and the corresponding course of actions recommended for the aeromedical examiner. Aeromedical evaluation should take into consideration factors related to the pilot, aircraft type, and specific aviation environment. Such evaluation may include diagnostic testing, medical specialist consultation, preflight simulation in an altitude chamber, human centrifuge testing, and/or a flight simulator checkride.Ko SY, Nguyen NK, Lee CL, Lee LA, Nguyen KUT, Lee EC. Aeromedical implications of long-term COVID-19 sequelae. Aerosp Med Hum Perform. 2021; 92(11):898-907.

A case of xenon inhalation therapy for respiratory failure and neuropsychiatric disorders associated with COVID-19

Acute respiratory distress syndrome (ARDS) is the main danger to the life of patients with pneumonia caused by SARS-CoV-2. At the same time, respiratory failure (RF) after ARDS can persist for a long time despite intensive therapy. Therefore, it is important to develop new effective approaches for restoring the ventilation function of the lungs after COVID-19. Here, we present a case report of effective application of short-term inhalations of xenon-oxygen (Xe/O₂) gas mixture for treatment of RF and neuropsychiatric disorders (NPD) associated with COVID-19. The patient inhaled a gas mixture of 70 % Xe and 30 % O₂. We used multispiral computed tomography, evaluated psychometry, studied hematological and biochemical blood parameters, and applied some other methods of clinical studies to assess the therapeutic effectiveness of Xe inhalation. Also, we studied the mechanism of action of xenon with computer modeling. The clinical case showed the high efficacy of Xe/O₂ mixture for treating severe RF and NPD after SARS-CoV-2 infection. Xenon inhalations dramatically increased oxygen saturation and the degree of pneumatization of the lungs. We found out that in coronavirus pneumonia, saturated phospholipids of surfactant are transferred to the solid-ordered phase, which disrupts the surface tension of the alveoli and alveolar gas exchange. Using molecular modeling methods, we demonstrated that the xenon atom increases the distance between the acyl chains of phospholipids due to the van der Waals dispersion interaction. These changes allow for the phase transition of phospholipids from the solid-ordered phase to the liquid phase and restore the functional activity of the surfactant. The findings suggest the feasibility of conducting studies on the effectiveness of Xe/O₂ inhalations for treating ARDS in SARS-CoV-2 infection.

Platelets and COVID-19

In 2019 first reports about a new human coronavirus emerged, which causes common cold symptoms as well as acute respiratory distress syndrome. The virus was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and severe thrombotic events including deep vein thrombosis, pulmonary embolism, and microthrombi emerged as additional symptoms. Heart failure, myocardial infarction, myocarditis, and stroke have also been observed. As main mediator of thrombus formation, platelets became one of the key aspects in SARS-CoV-2 research. Platelets may also directly interact with SARS-CoV-2 and have been shown to carry the SARS-CoV-2 virus. Platelets can also facilitate the virus uptake by secretion of the subtilisin-like proprotein convertase furin. Cleavage of the SARS-CoV-2 spike protein by furin enhances binding capabilities and virus entry into various cell types. In COVID-19 patients, platelet count differs between mild and serious infections. Patients with mild symptoms have a slightly increased platelet count, whereas thrombocytopenia is a hallmark of severe COVID-19 infections. Low platelet count can be attributed to platelet apoptosis and the incorporation of platelets into microthrombi (peripheral consumption) and severe thrombotic events. The observed excessive formation of thrombi is due to hyperactivation of platelets caused by the infection. Various factors have been suggested in the activation of platelets in COVID-19, such as hypoxia, vessel damage, inflammatory factors, NETosis, SARS-CoV-2 interaction, autoimmune reactions, and autocrine activation. COVID-19 does alter chemokine and cytokine plasma concentrations. Platelet chemokine profiles are altered in COVID-19 and contribute to the described chemokine storms observed in severely ill COVID-19 patients.

Mechanisms and management of prothrombotic state in COVID-19 disease

The novel severe acute respiratory syndrome viral disease outbreak due to SARS-CoV-2 is a rapidly evolving disease and represents one of the greatest medical challenges in recent times. It is believed that SARS-CoV-2 has migrated from bats to an intermediate host and then to humans. This article aims at the mechanism and management of prothrombotic state in COVID-19 positive patients. We tried to present how the SARS-CoV-2 virus can induce thromboembolic events and the incidence of these thromboembolic events. We also tried to depict anticoagulation management in these patients as well as postdischarge plan and follow-up. Invasion of type 2 pneumocytes by the SARS-CoV-2 virus is critical in the course of illness because it results in activation of immune cells leading to elevation of cytokines. The subsequent activation of T cells and macrophages infiltrates the infected myocardial cells causing direct myocardiocyte toxicity and development of arrhythmia. Hypoxia or hypotension during the clinical course causes a mismatch between myocyte oxygen supply and workload demand resulting in cardiac distress. SARS-CoV-2 affects endothelial cells and pericytes that lead to severe micro and macrovascular dysfunction, and together with oxygen supply-demand mismatch, immune hyperresponsivity can potentially cause destabilization and plaque rupture causing acute coronary syndromes. Other mechanisms of injury include myocarditis, pericarditis, stress cardiomyopathy, vasculitis, and DIC (Disseminated intravascular coagulation)/microthrombi. SARS-CoV-2 enters the cells by the Spike protein S whose surface unit, S1, binds to the ACE2 receptor on the host cell. The type II transmembrane serine proteases TMPRSS2 and histone acetyltransferases (HAT) are host cell proteases that are recruited by the virus to cleave ACE2 surface protein S which facilitates the viral entry. Therefore, TMPRSS2 and HAT could be targeted for potential drugs against SARS-CoV-2. SARS-CoV-2 uses an RNA-dependent RNA polymerase for proliferation, which is targeted by remdesivir that is currently approved for emergency use by Food and Drug Administration (FDA). We need to adopt a multifaceted approach when combating SARS-CoV-2 because it presents several challenges including medical, psychological, socioeconomic, and ethical. COVID-19 is the biggest calamity during the 21st century, we need to have a keen understanding of its pathophysiology and clinical implications for the development of preventive measures and therapeutic modalities.

Tie2 activation protects against prothrombotic endothelial dysfunction in COVID-19

Endothelial dysfunction accompanies the microvascular thrombosis commonly observed in severe COVID-19. Constitutively, the endothelial surface is anticoagulant, a property maintained at least in part via signaling through the Tie2 receptor. During inflammation, the Tie2 antagonist angiopoietin-2 (Angpt-2) is released from endothelial cells and inhibits Tie2, promoting a prothrombotic phenotypic shift. We sought to assess whether severe COVID-19 is associated with procoagulant endothelial dysfunction and alterations in the Tie2/angiopoietin axis. Primary HUVECs treated with plasma from patients with severe COVID-19 upregulated the expression of thromboinflammatory genes, inhibited the expression of antithrombotic genes, and promoted coagulation on the endothelial surface. Pharmacologic activation of Tie2 with the small molecule AKB-9778 reversed the prothrombotic state induced by COVID-19 plasma in primary endothelial cells. Lung autopsies from patients with COVID-19 demonstrated a prothrombotic endothelial signature. Assessment of circulating endothelial markers in a cohort of 98 patients with mild, moderate, or severe COVID-19 revealed endothelial dysfunction indicative of a prothrombotic state. Angpt-2 concentrations rose with increasing disease severity, and the highest levels were associated with worse survival. These data highlight the disruption of Tie2/angiopoietin signaling and procoagulant changes in endothelial cells in severe COVID-19. Our findings provide rationale for current trials of Tie2-activating therapy with AKB-9778 in COVID-19.