The role of the endothelium in severe acute respiratory syndrome coronavirus 2 infection and pathogenesis.

Endothelial cell (EC) dysfunction is a characteristic complication of coronavirus-19 (COVID-19). This review discusses the role of the endothelium during the pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with a focus on different vascular beds, possible routes of infectivity and the impact of EC dysfunction across multiple organ systems. It is now known that COVID-19 disease elicits a distinct transcriptomic and molecular profile that is different to other viral infections, such as Influenza A (H1N1). Interestingly, there is also a suggested interplay between the heart and lungs that promotes the amplification of inflammatory cascades, leading to an exacerbation in disease severity. Multiomic studies have informed common pathways that may be responsible for endothelial activation while also highlighting key differences in COVID-19 pathogenesis between organ systems. At a pathological level, endothelialitis is an endpoint result regardless of either a direct viral infection or via indirect effects independent of infection. Understanding if ECs are directly targeted by SARS-CoV-2 or are collaterally damaged amid a cytokine storm originating from other cells and organs can provide novel insights into disease progression and may highlight possible new therapeutic opportunities targeted at the damaged endothelium.

Severe COVID-19 and non-COVID-19 severe sepsis converge transcriptionally after a week in the intensive care unit, indicating common disease mechanisms.

Introduction: Severe COVID-19 and non-COVID-19 pulmonary sepsis share pathophysiological, immunological, and clinical features. To what extent they share mechanistically-based gene expression trajectories throughout hospitalization was unknown. Our objective was to compare gene expression trajectories between severe COVID-19 patients and contemporaneous non-COVID-19 severe sepsis patients in the intensive care unit (ICU). Methods: In this prospective single-center observational cohort study, whole blood was drawn from 20 COVID-19 patients and 22 non-COVID-19 adult sepsis patients at two timepoints: ICU admission and approximately a week later. RNA-Seq was performed on whole blood to identify differentially expressed genes and significantly enriched pathways. Results: At ICU admission, despite COVID-19 patients being almost clinically indistinguishable from non-COVID-19 sepsis patients, COVID-19 patients had 1,215 differentially expressed genes compared to non-COVID-19 sepsis patients. After one week in the ICU, the number of differentially expressed genes dropped to just 9 genes. This drop coincided with decreased expression of antiviral genes and relatively increased expression of heme metabolism genes over time in COVID-19 patients, eventually reaching expression levels seen in non-COVID-19 sepsis patients. Both groups also had similar underlying immune dysfunction, with upregulation of immune processes such as "Interleukin-1 signaling" and "Interleukin-6/JAK/STAT3 signaling" throughout disease compared to healthy controls. Discussion: Early on, COVID-19 patients had elevated antiviral responses and suppressed heme metabolism processes compared to non-COVID-19 severe sepsis patients, although both had similar underlying immune dysfunction. However, after one week in the ICU, these diseases became indistinguishable on a gene expression level. These findings highlight the importance of early antiviral treatment for COVID-19, the potential for heme-related therapeutics, and consideration of immunomodulatory therapies for both diseases to treat shared immune dysfunction.

Mitochondria and cytochrome components released into the plasma of severe COVID-19 and ICU acute respiratory distress syndrome patients.

INTRODUCTION: Proteomic analysis of human plasma by LC-ESI-MS/MS has discovered a limited number of new cellular protein biomarkers that may be confirmed by independent biochemical methods. Analysis of COVID-19 plasma has indicated the re-purposing of known biomarkers that might be used as prognostic markers of COVID-19 infection. However, multiple molecular approaches have previously indicated that the SARS-COV2 infection cycle is linked to the biology of mitochondria and that the response to infections may involve the action of heme containing oxidative enzymes. METHODS: Human plasma from COVID-19 and ICU-ARDS was analyzed by classical analytical biochemistry techniques and classical frequency-based statistical approaches to look for prognostic markers of severe COVID-19 lung damage. Plasma proteins from COVID-19 and ICU-ARDS were identified and enumerated versus the controls of normal human plasma (NHP) by LC-ESI-MS/MS. The observation frequency of proteins detected in COVID-19 and ICU-ARDS patients were compared to normal human plasma, alongside random and noise MS/MS spectra controls, using the Chi Square (χ2) distribution. RESULTS: PCR showed the presence of MT-ND1 DNA in the plasma of COVID-19, ICU-ARDS, as well as normal human plasma. Mitochondrial proteins such as MRPL, L2HGDH, ATP, CYB, CYTB, CYP, NDUF and others, were increased in COVID-19 and ICU-ARDS plasma. The apparent activity of the cytochrome components were tested alongside NHP by dot blotting on PVDF against a purified cytochrome c standard preparation for H2O2 dependent reaction with luminol as measured by enhanced chemiluminescence (ECL) that showed increased activity in COVID-19 and ICU-ARDS patients. DISCUSSION: The results from PCR, LC-ESI-MS/MS of tryptic peptides, and cytochrome ECL assays confirmed that mitochondrial components were present in the plasma, in agreement with the established central role of the mitochondria in SARS-COV-2 biology. The cytochrome activity assay showed that there was the equivalent of at least nanogram amounts of cytochrome(s) in the plasma sample that should be clearly detectable by LC-ESI-MS/MS. The release of the luminol oxidase activity from cells into plasma forms the basis of a simple and rapid test for the severity of cell damage and lung injury in COVID-19 infection and ICU-ARDS.

The role of the endothelium in SARS-CoV-2 infection and pathogenesis

Endothelial cell (EC) dysfunction is a characteristic complication of COVID-19. This review discusses the role of the endothelium during the pathogenesis of SARS-CoV-2, with a focus on different vascular beds, possible routes of infectivity and the impact of endothelial cell dysfunction across multiple organ systems. It is now known that COVID-19 disease elicits a distinct transcriptomic and molecular profile that is different to other viral infections, such as H1N1. Interestingly, there is also a suggested interplay between the heart and lungs that promotes the amplification of inflammatory cascades leading to an exacerbation in disease severity. Multiomic studies have informed common pathways that may be responsible for endothelial activation while also highlighting key differences in COVID-19 pathogenesis between organ systems. At a pathological level, endothelialitis is an endpoint result regardless of either a direct viral infection or via indirect effects independent of infection. Understanding if ECs are directly targeted by SARS-CoV-2 or are collaterally damaged amid a cytokine storm originating from other cells and organs can provide novel insights into disease progression and may highlight possible new therapeutic opportunities targeted at the damaged endothelium.

One System, Multiple Hospitals: A Unified Paediatric Healthcare System Response to the COVID-19 Pandemic.

To address severe adult in-patient capacity pressures during the COVID-19 pandemic, 15 community hospitals were mandated to close their in-patient paediatric units (167 beds) and transfer paediatric in-patients to a single paediatric tertiary hospital. The tertiary hospital increased bed capacity through a surge plan activation, while community hospitals redeployed resources to fill the gaps in adult care. Also, 530 patients were transferred solely to increase adult bed capacity during the closure. Several factors enabled the system to function collaboratively. Closures increased the potential adult in-patient capacity by 6,740 bed days and demonstrated an unprecedented system-wide approach to the provision of integrated paediatric care across the region.

(Epi)transcriptomics in cardiovascular and neurological complications of COVID-19.

Although systemic inflammation and pulmonary complications increase the mortality rate in COVID-19, a broad spectrum of cardiovascular and neurological complications can also contribute to significant morbidity and mortality. The molecular mechanisms underlying cardiovascular and neurological complications during and after SARS-CoV-2 infection are incompletely understood. Recently reported perturbations of the epitranscriptome of COVID-19 patients indicate that mechanisms including those derived from RNA modifications and non-coding RNAs may play a contributing role in the pathogenesis of COVID-19. In this review paper, we gathered recently published studies investigating (epi)transcriptomic fluctuations upon SARS-CoV-2 infection, focusing on the brain-heart axis since neurological and cardiovascular events and their sequelae are of utmost prevalence and importance in this disease.

Rapid and Low-Cost Detection and Quantification of SARS-CoV-2 Antibody Titers of ICU Patients with Respiratory Deterioration Using a Handheld Thermo-Photonic Device.

While research suggests that COVID-19 vaccines are effective in producing anti-SARS-CoV-2 antibodies that reduce the risk of COVID-19 and its potentially severe complications, how long these antibodies persist after the infection/vaccination is unknown. Longitudinal studies and rapid and scalable platforms are needed for large-scale sero-diagnosis and vaccine evaluation. In this study, we examine the efficacy of our recently-developed handheld thermo-photonic device for rapid and low-cost assessment of the adaptive immune response of COVID+ and COVID- patients admitted to the intensive care unit (ICU) at a local hospital due to respiratory deterioration. Antibody testing included detection and quantification of IgG and IgM via thermo-photonic sensing of a commercially available COVID-19 IgG/IgM rapid test as well as standard measurements with quantitative enzyme-linked immunosorbent assays (qELISA). The results demonstrate that the thermo-photonic reader in conjunction with COVID-19 IgG/IgM test cassettes can detect and quantify IgG levels in COVID-19 antibody assays within the clinically relevant range and with a high correlation to those obtained from qELISA. We also found that the IgG antibody is more reliable for detecting individuals with an adaptive immune response to SARS-CoV-2 compared to the IgM antibody. The developed reader offers a low-cost, portable, and scalable solution for accessing the antibody titer of individuals against SARS-CoV-2 and can be used in local hospital settings.

Cardiovascular signatures of COVID-19 predict mortality and identify barrier stabilizing therapies.

BACKGROUND: Endothelial cell (EC) activation, endotheliitis, vascular permeability, and thrombosis have been observed in patients with severe coronavirus disease 2019 (COVID-19), indicating that the vasculature is affected during the acute stages of SARS-CoV-2 infection. It remains unknown whether circulating vascular markers are sufficient to predict clinical outcomes, are unique to COVID-19, and if vascular permeability can be therapeutically targeted. METHODS: Prospectively evaluating the prevalence of circulating inflammatory, cardiac, and EC activation markers as well as developing a microRNA atlas in 241 unvaccinated patients with suspected SARS-CoV-2 infection allowed for prognostic value assessment using a Random Forest model machine learning approach. Subsequent ex vivo experiments assessed EC permeability responses to patient plasma and were used to uncover modulated gene regulatory networks from which rational therapeutic design was inferred. FINDINGS: Multiple inflammatory and EC activation biomarkers were associated with mortality in COVID-19 patients and in severity-matched SARS-CoV-2-negative patients, while dysregulation of specific microRNAs at presentation was specific for poor COVID-19-related outcomes and revealed disease-relevant pathways. Integrating the datasets using a machine learning approach further enhanced clinical risk prediction for in-hospital mortality. Exposure of ECs to COVID-19 patient plasma resulted in severity-specific gene expression responses and EC barrier dysfunction, which was ameliorated using angiopoietin-1 mimetic or recombinant Slit2-N. INTERPRETATION: Integration of multi-omics data identified microRNA and vascular biomarkers prognostic of in-hospital mortality in COVID-19 patients and revealed that vascular stabilizing therapies should be explored as a treatment for endothelial dysfunction in COVID-19, and other severe diseases where endothelial dysfunction has a central role in pathogenesis. FUNDING: This work was directly supported by grant funding from the Ted Rogers Center for Heart Research, Toronto, Ontario, Canada and the Peter Munk Cardiac Center, Toronto, Ontario, Canada.

MRI and CT coronary angiography in survivors of COVID-19.

OBJECTIVES: To determine the contribution of comorbidities on the reported widespread myocardial abnormalities in patients with recent COVID-19. METHODS: In a prospective two-centre observational study, patients hospitalised with confirmed COVID-19 underwent gadolinium and manganese-enhanced MRI and CT coronary angiography (CTCA). They were compared with healthy and comorbidity-matched volunteers after blinded analysis. RESULTS: In 52 patients (median age: 54 (IQR 51-57) years, 39 males) who recovered from COVID-19, one-third (n=15, 29%) were admitted to intensive care and a fifth (n=11, 21%) were ventilated. Twenty-three patients underwent CTCA, with one-third having underlying coronary artery disease (n=8, 35%). Compared with younger healthy volunteers (n=10), patients demonstrated reduced left (ejection fraction (EF): 57.4±11.1 (95% CI 54.0 to 60.1) versus 66.3±5 (95 CI 62.4 to 69.8)%; p=0.02) and right (EF: 51.7±9.1 (95% CI 53.9 to 60.1) vs 60.5±4.9 (95% CI 57.1 to 63.2)%; p≤0.0001) ventricular systolic function with elevated native T1 values (1225±46 (95% CI 1205 to 1240) vs 1197±30 (95% CI 1178 to 1216) ms;p=0.04) and extracellular volume fraction (ECV) (31±4 (95% CI 29.6 to 32.1) vs 24±3 (95% CI 22.4 to 26.4)%; p<0.0003) but reduced myocardial manganese uptake (6.9±0.9 (95% CI 6.5 to 7.3) vs 7.9±1.2 (95% CI 7.4 to 8.5) mL/100 g/min; p=0.01). Compared with comorbidity-matched volunteers (n=26), patients had preserved left ventricular function but reduced right ventricular systolic function (EF: 51.7±9.1 (95% CI 53.9 to 60.1) vs 59.3±4.9 (95% CI 51.0 to 66.5)%; p=0.0005) with comparable native T1 values (1225±46 (95% CI 1205 to 1240) vs 1227±51 (95% CI 1208 to 1246) ms; p=0.99), ECV (31±4 (95% CI 29.6 to 32.1) vs 29±5 (95% CI 27.0 to 31.2)%; p=0.35), presence of late gadolinium enhancement and manganese uptake. These findings remained irrespective of COVID-19 disease severity, presence of myocardial injury or ongoing symptoms. CONCLUSIONS: Patients demonstrate right but not left ventricular dysfunction. Previous reports of left ventricular myocardial abnormalities following COVID-19 may reflect pre-existing comorbidities. TRIAL REGISTRATION NUMBER: NCT04625075.

SARS-Cov2: a meta-analysis of symptom distribution by continent in 7310 adult COVID-19 infected patients.

There is recent evidence that suggests that there are multiple strains of coronavirus in different parts of the world. Moreover, scientist have noted multiple mutations and postulated that these changes might increase the infective rate of the virus. However literature on varying severity of disease based on these strains is absent. In this meta-analysis, we have made an attempt to correlate the symptoms in different continents with respect to various studied strains of virus. We searched three databases, PubMed, EMBASE and EMCARE to identify studies reporting symptoms of COVID-19. All articles published between December 2019 and May 2020 was included in this meta-analysis. A total of 56 studies consisted of 7310 patients were included in the meta-analysis. Mean age of patients varied from 22 to 69.8 years. The pooled proportion of male patients was 52%. Highest incidence of fever (76%) and cough (56%) was noted in Chinese population. Sore throat (29%) was most common in Asian population. Upper respiratory tract symptom like Rhinorrhoea, Anosmia and dysgeusia (32%, 47% and 39%) were well documented in European population as compared to the other continents. Nausea and diarrhoea were more common in European (17%, 19%) and Australian (12%, 16%) population. Dyspnoea and fatigue were consistently similar in all the continents. We postulate that different mutations in COVID-19 virus may vary its pathogenicity and screening symptoms across all the continents should be not be generalised but continent-specific. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13337-021-00699-y.

Anticardiolipin and other antiphospholipid antibodies in critically ill COVID-19 positive and negative patients.

BACKGROUND: Reports of severe COVID-19 being associated with thrombosis, antiphospholipid antibodies (APLA), and antiphospholipid syndrome have yielded disparate conclusions. Studies comparing patients with COVID-19 with contemporaneous controls of similar severity are lacking. METHODS: 22 COVID-19+ and 20 COVID-19- patients with respiratory failure admitted to intensive care were studied longitudinally. Demographic and clinical data were obtained from the day of admission. APLA testing included anticardiolipin (aCL), anti-ß2glycoprotien 1 (ß2GP1), antidomain 1 ß2GP1 and antiphosphatidyl serine/prothrombin complex. Antinuclear antibodies (ANAs) were detected by immunofluorescence and antibodies to cytokines by a commercially available multiplexed array. Analysis of variance was used for continuous variables and Fisher's exact test was used for categorical variables with α=0.05 and the false discovery rate at q=0.05. RESULTS: APLAs were predominantly IgG aCL (48%), followed by IgM (21%) in all patients, with a tendency towards higher frequency among the COVID-19+. aCL was not associated with surrogate markers of thrombosis but IgG aCL was strongly associated with worse disease severity and higher ANA titres regardless of COVID-19 status. An association between aCL and anticytokine autoantibodies tended to be higher among the COVID-19+. CONCLUSIONS: Positive APLA serology was associated with more severe disease regardless of COVID-19 status. TRIAL REGISTRATION NUMBER: NCT04747782.

A systematic review and meta-analysis comparing the diagnostic accuracy of initial RT-PCR and CT scan in suspected COVID-19 patients.

OBJECTIVE: To perform a systematic review and meta-analysis to compare the diagnostic accuracy of CT and initial reverse transcriptase polymerase chain reaction (RT-PCR) for detecting COVID-19 infection. METHODS: We searched three databases, PubMed, EMBASE, and EMCARE, to identify studies reporting diagnostic accuracy of both CT and RT-PCR in detecting COVID-19 infection between December 2019 and May 2020. For accurate comparison, only those studies that had patients undergoing both CT and RT-PCR were included. Pooled diagnostic accuracy of both the tests was calculated by using a bivariate random effects model. RESULTS: Based on inclusion criteria, only 11 studies consisting of 1834 patients were included in the final analysis that reported diagnostic accuracy of both CT and RT-PCR, in the same set of patients. Sensitivity estimates for CT scan ranged from 0.69 to 1.00 and for RT-PCR varied ranging from 0.47 to 1.00. The pooled estimates of sensitivity for CT and RT-PCR were 0.91 [95% CI (0.84-0.97)] and 0.84 [95% CI (0.71-0.94)], respectively. On subgroup analysis, pooled sensitivity of CT and RT-PCR was 0.95 [95% CI (0.88-0.98)] and 0.91 [95% CI (0.80-0.96), p = o.ooo1]. The pooled specificity of CT and RT-PCR was 0.31 [95% CI (0.035-0.84)] and 1.00 [95% CI (0.96-1.00)]. CONCLUSION: CT is more sensitive than RT-PCR in detecting COVID-19 infection, but has a very low specificity. ADVANCES IN KNOWLEDGE: Since the results of a CT scan are available quickly, it can be used as an adjunctive initial diagnostic test for patients with a history of positive contact or epidemiological history.

A Meta-Analysis of 67 Studies with Presenting Symptoms and Laboratory Tests of COVID-19 Patients.

OBJECTIVES/HYPOTHESIS: The objective of this meta-analysis was to look at the pooled prevalence of symptoms, laboratory tests, and imaging of all COVID-19 infected patients. This will allow better identification of potential COVID-19 patients and take appropriate precautions. STUDY DESIGN: Meta analysis. METHODS: We searched three databases, PubMed, EMBASE, and Ovid to identify studies published between Dec-2019 and May-2020. All studies reporting upper-aerodigestive symptoms of COVID-19 infection were included. The meta-analysis was conducted following meta-analyses of observational studies in epidemiology (MOOSE) guidelines, which have evaluated the pooled prevalence of 14 symptoms and nine laboratory investigations. RESULTS: Based on inclusion criteria, 67 publications consisting of 8302 patients were included. Among adults, the pooled proportion of hypertensive and diabetic patients was 18% and 7%. Cough (53% [0.46-0.61]), anosmia (38% [0.19-0.58]), loss/distortion of taste (31% [0.17-0.45]), and nasal obstruction (26% [0.12-0.39]) were the most common ear, nose & throat (ENT) symptoms. Fever (69% [0.62-0.76]) and fatigue (31% [0.26-0.37]) were the commonest generalized symptoms. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were raised in 56% (0.41-0.71) and 49% (0.21-0.77), respectively. Interestingly, lymphopenia (41% [0.30-0.53]) and leucopenia (22% [0.16-0.29]) were more common than lymphocytosis (33% [0.02-0.64]) and leucocytosis (12% [0.09-0.16]). Fever (69% vs. 44%), cough (53% vs. 33%), and dyspnea (20% vs. 4%) were more common in adults as compared to the pediatric population. Diarrhea was more common among the pediatric cases (12%) versus (9%). The pooled estimate of fatality was 4%. CONCLUSIONS: The most commonly experienced ENT symptom was cough followed by anosmia and dysguesia. Raised ESR and CRP with leukopenia and lymphopenia are common laboratory findings. Majority of the infected patients had abnormal computed tomography findings. COVID infection is less severe in pediatric patients. Laryngoscope, 131:1254-1265, 2021.