Resolving the developmental mechanisms of coagulation abnormalities characteristic of SARS-CoV2 based on single-cell transcriptome analysis (preprint)

The COVID-19 outbreak caused by the SARS-CoV-2 virus has developed into a global health emergency. In addition to causing respiratory symptoms following SARS-CoV-2 infection, COVID-19-associated coagulopathy (CAC) is the main cause of death in patients with severe COVID-19. In this study, we performed single-cell sequencing analysis of the right ventricular free wall tissue from healthy donors, patients who died in the hypercoagulable phase of CAC, and patients in the fibrinolytic phase of CAC. Among these, we collected 61,187 cells, which were enriched in 24 immune cell subsets and 13 cardiac-resident cell subsets. We found that in response to SARS-CoV-2 infection, CD9highCCR2high monocyte-derived mo promoted hyperactivation of the immune system and initiated the extrinsic coagulation pathway by activating CXCR-GNB/G-PI3K-AKT. This sequence of events is the main process contributing the development of coagulation disorders subsequent to SARS-CoV-2 infection. In the characteristic coagulation disorder caused by SARS-CoV-2, excessive immune activation is accompanied by an increase in cellular iron content, which in turn promotes oxidative stress and intensifies intercellular competition. This induces cells to alter their metabolic environment, resulting in an increase in sugar uptake, such as that via the glycosaminoglycan synthesis pathway, in CAC coagulation disorders. In addition, high levels of reactive oxygen species generated in response elevated iron levels promote the activation of unsaturated fatty acid metabolic pathways in endothelial cell subgroups, including vascular endothelial cells. This in turn promotes the excessive production of the toxic peroxidation by-product malondialdehyde, which exacerbates both the damage caused to endothelial cells and coagulation disorders.

IL-6 and D-Dimer at Admission Predicts Cardiac Injury and Early Mortality during SARS-CoV-2 Infection (preprint)

BACKGROUND We recently described mortality of cardiac injury in COVID-19 patients. Admission activation of immune, thrombotic biomarkers and their ability to predict cardiacinjury and mortality patterns in COVID-19 is unknown. METHODS This retrospective cohort study included 170 COVID-19 patients with cardiac injury at admission to Tongji Hospital in Wuhan from January 29–March 8, 2020. Temporal evolution of inflammatory cytokines, coagulation markers, clinical, treatment and mortality were analyzed. RESULTS Of 170 patients, 60 (35.3%) died early (<21d) and 61 (35.9%) died after prolonged stay. Admission lab work that correlated with early death were elevate levels of interleukin 6 (IL-6) (p<0.0001), Tumor Necrosis Factor-a (TNF-a) (p=0.0025), and C-reactive protein (CRP) (p<0.0001). We observed the trajectory of biomarker changes after admission, and determined that early mortality had a rapidly increasing D-dimer, gradually decreasing platelet and lymphocyte counts. Multivariate and simple linear regression models showed that death risk was determined by immune and thrombotic pathway activation. Increasing cTnI levels were associated with those of increasing IL-6 (p=0.03) and D-dimer (p=0.0021). Exploratory analyses suggested that patients that received heparin has lower early mortality compared to those who did not (p =0.07), despite similar risk profile. CONCLUSIONS In COVID-19 patients with cardiac injury, admission IL-6 and D-dimer predicted subsequent elevation of cTnI and early death, highlighting the need for early inflammatory cytokine-based risk stratification in patients with cardiac injury. Condensed Abstract COVID-19 with cardiac injury is associated with worse survival. Admission activation of immune, thrombotic biomarkers and their ability to predict cardiac injury and mortality patterns in COVID-19 is unknown. This study proved that cardiac injury in these patients is closely related to the activation of immunological and thrombotic pathways and can be predicted by admission biomarkers of these pathways. This study supports the strategy of biomarker-guided, point-of-care therapy that warrants further studies in a randomized manner to develop anti-immune and anti-thrombotic treatment regimens in severe COVID-19 patients with cardiac injury.

Identifying novel factors associated with COVID-19 transmission and fatality using the machine learning approach (preprint)

The COVID-19 virus has infected millions of people and resulted in hundreds of thousands of deaths worldwide. By using the logistic regression model, we identified novel critical factors associated with COVID19 cases, death, and case fatality rates in 154 countries and in the 50 U.S. states. Among numerous factors associated with COVID-19 risk, we found that the unitary state system was counter-intuitively positively associated with increased COVID-19 cases and deaths. Blood type B was a protective factor for COVID-19 risk, while blood type A was a risk factor. The prevalence of HIV, influenza and pneumonia, and chronic lower respiratory diseases was associated with reduced COVID-19 risk. Obesity and the condition of unimproved water sources were associated with increased COVID-19 risk. Other factors included temperature, humidity, social distancing, smoking, and vitamin D intake. Our comprehensive identification of the factors affecting COVID-19 transmission and fatality may provide new insights into the COVID-19 pandemic and advise effective strategies for preventing and migrating COVID-19 spread.

Modulation of Cardiac Injury by ACE inhibitor/ARB in Patients with Severe COVID-19 (preprint)

Introduction: Cardiac injury occurs in 7-22% of patient hospitalized with COVID-19 and an elevation in troponin is associated with a 4.2-fold increase in the risk of mortality. Preliminary data showed ACEi/ARB usage might not increase mortaily in COVID-19 patients. However, it is unknown if cardiac injury in patients with severe COVID-19 can be modulated by ACEi/ARB usage during evolution of the cardiac injury.Methods: In 154 COVID-19 patients with cardiac injury, the effect of ACEi/ARB treatment (17 patients) was compared with 137 patients without ACEi/ARB treatment. Cardiac injury was indicated by cTnI level.Results: In ACEi/ARB treatment group and no ACEi/ARB treatment group, peak cTnI level did not show significant difference (150.5 pg/ml [31.75-1179], vs 207 pg/ml [54.65-989.4], respectively, P = 0.21). Evolution of Cardiac injury (temporal change of cTnI at day 6, 9, 12, 15, 18, 21, 24, 27, 30, and 33) showed no statistical difference. Mortality (ACEi/ARB group vs no ACEi/ARB group; 52.9% vs 69.9%, P = 0.17), atrial arrhythmias (11.7% vs 24.4%, P = 0.36), requirement for invasive ventilatory support (29.4% vs 48.2%, P = 0.14) also showed no significant difference in two groups.Conclusions: ACEi/ARB usage during the COVID-19 was not associated with exacerbation of cardiac injury. These data should be interpreted as essentially hypothesis-generating due to small sample size.Clinical Trial Registration: This retrospective study was registered in Chinese clinical trial registry (ChiCTR 2000031301).