Extrapulmonary manifestations of COVID-19

SARS-CoV-2 infection: can ferroptosis be a potential treatment target for multiple organ involvement?

Since the outbreak of the new coronavirus in 2019 (SARS-CoV-2), many studies have been performed to better understand the basic mechanisms and clinical features of the disease. However, uncertainties of the underlying mechanisms of multiple organ involvement remain. A substantial proportion of severe coronavirus disease 2019 (COVID-19) patients have lymphopenia, low serum iron levels, and multiple organ involvement. Several therapeutic agents have been used for different stages of the disease, but the treatment for severe disease is still suboptimal. Understanding the mechanism of programmed cell death in COVID-19 may lead to better therapeutic strategies for these patients. On the basis of observations of basic science studies and clinical researches on COVID-19, we hypothesize that ferroptosis, a novel programmed cell death, may be an important cause of multiple organ involvement in COVID-19 and it might serve as a new treatment target. In spite of the existing findings on the involvement of ferroptosis in SARS-CoV-2 infection, there is no reported study to uncover how does ferroptosis acts in SARS-CoV-2 infection yet. Uncovering the role of ferroptosis in SARS-CoV-2 infection is essential to develop new treatment strategies for COVID-19. Intracellular cell iron depletion or new generation of ferroptosis inhibitors might be potential drug candidates for COVID-19. We hope this hypothesis may launch a new wave of studies to uncover the association of ferroptosis and SARS-CoV-2 infection in vitro and in vivo.

Quercetin and Its Metabolites Inhibit Recombinant Human Angiotensin-Converting Enzyme 2 (ACE2) Activity

Angiotensin-converting enzyme 2 (ACE2) is a host receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Inhibiting the interaction between the envelope spike glycoproteins (S-proteins) of SARS-CoV-2 and ACE2 is a potential antiviral therapeutic approach, but little is known about how dietary compounds interact with ACE2. The objective of this study was to determine if flavonoids and other polyphenols with B-ring 3',4'-hydroxylation inhibit recombinant human (rh)ACE2 activity. rhACE2 activity was assessed with the fluorogenic substrate Mca-APK(Dnp). Polyphenols reduced rhACE2 activity by 15-66% at 10 μM. Rutin, quercetin-3-O-glucoside, tamarixetin, and 3,4-dihydroxyphenylacetic acid inhibited rhACE2 activity by 42-48%. Quercetin was the most potent rhACE2 inhibitor among the polyphenols tested, with an IC50 of 4.48 μM. Thus, quercetin, its metabolites, and polyphenols with 3',4'-hydroxylation inhibited rhACE2 activity at physiologically relevant concentrations in vitro.

Management of Arrhythmias Associated with COVID-19

Purpose of Review

Cardiac arrhythmias are known complications in patients with COVID-19 infection that may persist even after recovery from infection. A review of the spectrum of cardiac arrhythmias due to COVID-19 infection and current guidelines and assessment or risk and benefit of management considerations is necessary as the population of patients infected and covering from COVID-19 continues to grow.

Recent Findings

Cardiac arrhythmias such as atrial fibrillation, supraventricular tachycardia, complete heart block, and ventricular tachycardia occur in patients infected, recovering and recovered from COVID-19.

Summary

Personalized care while balancing risk/benefit of medical or invasive therapy is necessary to improve care of patients with arrhythmias. Providers must provide thorough follow-up care and use necessary precaution while caring for COVID-19 patients.

A monoclonal antibody against staphylococcal enterotoxin B superantigen inhibits SARS-CoV-2 entry in vitro

We recently discovered a superantigen-like motif, similar to Staphylococcal enterotoxin B (SEB), near the S1/S2 cleavage site of SARS-CoV-2 Spike protein, which might explain the multisystem-inflammatory syndrome (MIS-C) observed in children and cytokine storm in severe COVID-19 patients. We show here that an anti-SEB monoclonal antibody (mAb), 6D3, can bind this viral motif, and in particular its PRRA insert, to inhibit infection by blocking the access of host cell proteases, TMPRSS2 or furin, to the cleavage site. The high affinity of 6D3 for the furin-cleavage site originates from a poly-acidic segment at its heavy chain CDR2, a feature shared with SARS-CoV-2-neutralizing mAb 4A8. The affinity of 6D3 and 4A8 for this site points to their potential utility as therapeutics for treating COVID-19, MIS-C, or common cold caused by human coronaviruses (HCoVs) that possess a furin-like cleavage site.

Frequent neurocognitive deficits after recovery from mild COVID-19

Neuropsychiatric complications associated with coronavirus disease 2019 caused by the Coronavirus SARS-CoV-2 (COVID-19) are increasingly appreciated. While most studies have focussed on severely affected individuals during acute infection, it remains unclear whether mild COVID-19 results in neurocognitive deficits in young patients. Here, we established a screening approach to detect cognitive deficiencies in post-COVID-19 patients. In this cross-sectional study, we recruited 18 mostly young patients 20-105 days (median, 85 days) after recovery from mild to moderate disease who visited our outpatient clinic for post-COVID-19 care. Notably, 14 (78%) patients reported sustained mild cognitive deficits and performed worse in the Modified Telephone Interview for Cognitive Status screening test for mild cognitive impairment compared to 10 age-matched healthy controls. While short-term memory, attention and concentration were particularly affected by COVID-19, screening results did not correlate with hospitalization, treatment, viremia or acute inflammation. Additionally, Modified Telephone Interview for Cognitive Status scores did not correlate with depressed mood or fatigue. In two severely affected patients, we excluded structural or other inflammatory causes by magnetic resonance imaging, serum and cerebrospinal fluid analyses. Together, our results demonstrate that sustained sub-clinical cognitive impairments might be a common complication after recovery from COVID-19 in young adults, regardless of clinical course that were unmasked by our diagnostic approach.

Drawing Comparisons between SARS-CoV-2 and the Animal Coronaviruses

The COVID-19 pandemic, caused by a novel zoonotic coronavirus (CoV), SARS-CoV-2, has infected 46,182 million people, resulting in 1,197,026 deaths (as of 1 November 2020), with devastating and far-reaching impacts on economies and societies worldwide. The complex origin, extended human-to-human transmission, pathogenesis, host immune responses, and various clinical presentations of SARS-CoV-2 have presented serious challenges in understanding and combating the pandemic situation. Human CoVs gained attention only after the SARS-CoV outbreak of 2002-2003. On the other hand, animal CoVs have been studied extensively for many decades, providing a plethora of important information on their genetic diversity, transmission, tissue tropism and pathology, host immunity, and therapeutic and prophylactic strategies, some of which have striking resemblance to those seen with SARS-CoV-2. Moreover, the evolution of human CoVs, including SARS-CoV-2, is intermingled with those of animal CoVs. In this comprehensive review, attempts have been made to compare the current knowledge on evolution, transmission, pathogenesis, immunopathology, therapeutics, and prophylaxis of SARS-CoV-2 with those of various animal CoVs. Information on animal CoVs might enhance our understanding of SARS-CoV-2, and accordingly, benefit the development of effective control and prevention strategies against COVID-19.

Long-Term SARS-CoV-2 Infection Associated with Viral Dissemination in Different Body Fluids Including Bile in Two Patients with Acute Cholecystitis

Our study aimed to investigate the kinetics of SARS-CoV-2 RNA in bile and in different body fluids of two SARS-CoV-2 positive patients with acute cholecystitis by innovative droplet digital PCR (ddPCR) assays. For each patient, nasopharyngeal- and rectal swabs, bile, urine, and plasma samples were collected at different time points for SARS-CoV-2 RNA quantification by two ddPCR assays. For both patients, ddPCR revealed persistent and prolonged detection of viral RNA in the nasopharyngeal swab despite triple-negative or single-positive results by qRT-PCR. In Patient 1, SARS-CoV-2 RNA dropped more rapidly in bile and rectal-swab and declined slowly in nasopharyngeal swab and plasma, becoming undetectable in all compartments 97 days after symptoms started. Conversely, in patient 2, SARS-CoV-2 RNA was detected, even if at low copies, in all body samples (with the exception of urine) up to 75 days after the onset of symptoms. This study highlights that SARS-CoV-2 RNA can persist for a prolonged time in respiratory samples and in several biological samples despite negativity to qRT-PCR, supporting SARS-CoV-2's ability to provoke persistent and disseminated infection and therefore to contribute to extra-pulmonary clinical manifestations.

Renal Carcinoma Is Associated With Increased Risk of Coronavirus Infections

Background: The current COVID-19 pandemic has affected most severely people with old age, or with comorbidities like hypertension, diabetes mellitus, and cancer. Cancer patients are twice more likely to contract the disease because of the malignancy or treatment-related immunosuppression; hence identification of the vulnerable population among these patients is essential. Method: We took a bioinformatics approach to analyze the gene and protein expression data of these coronavirus receptors (DPP4, ANPEP, ENPEP, TMPRSS2) in human normal and cancer tissues of multiple organs including the brain, liver, kidney, heart, lung, skin, GI tract, pancreas, endocrine tissues, and the reproductive organs. RNA-Seq data from The Cancer Genome Atlas (TCGA) and GTeX databases were used for extensive profiling analysis of these receptors across 9,736 tumors and 8,587 normal tissues comparing coronavirus receptors. Protein expression from immunohistochemistry data was assessed from The Human Protein Atlas database including 144 samples, corresponding to 48 different normal human tissue types, and 432 tumor samples from 216 different cancer patients. The correlations between immune cell infiltration, chemokine, and cytokines were investigated via Tumor Immune Estimation Resource (TIMER) and TCGA. Result: We found that among all, renal tumor and normal tissues exhibited increased levels of ACE2, DPP4, ANPEP, and ENPEP. Our results revealed that TMPRSS2 may not be the co-receptor for coronavirus infection in renal carcinoma patients. The other receptors DPP4, ANPEP, and ENPEP may act as the compensatory receptor proteins to help ACE2. The receptors' expression levels were variable in different tumor stage, molecular, and immune subtypes of renal carcinoma. Intriguingly, in clear cell renal cell carcinomas, coronavirus receptors were associated with high immune infiltration, markers of immunosuppression, and T cell exhaustion. Conclusion: Our study indicates that CoV receptors may play an important role in modulating the immune infiltrate and hence cellular immunity in renal carcinoma. As our current knowledge of pathogenic mechanisms will improve, it may help us in designing focused therapeutic approaches.

Severe COVID-19: understanding the role of immunity, endothelium, and coagulation in clinical practice

SARS-CoV-2 is responsible for the COVID-19 pandemic. The immune system is a determinant factor in defense against viral infections. Thus, when it acts in a balanced and effective manner the disease is self-limited and benign. Nevertheless, in a significant proportion of the population, the immune response is exaggerated. When infected, patients with diabetes, hypertension, obesity, and cardiovascular disease are more likely to progress to severe forms. These diseases are related to chronic inflammation and endothelial dysfunction. Toll-like receptors are expressed on immune cells and play an important role in the physiopathology of cardiovascular and metabolic diseases. When activated, they can induce release of inflammatory cytokines. Hypercoagulability, hyperinflammation, platelet hyperresponsiveness, and endothelial dysfunction occur in immune system hyperactivity caused by viral activity, thereby increasing the risk of arterial and venous thrombosis. We discuss the interactions between COVID-19, immunity, the endothelium, and coagulation, as well as why cardiometabolic diseases have a negative impact on COVID-19 prognosis.

D-Dimer, Fibrinogen, and IL-6 in COVID-19 Patients with Suspected Venous Thromboembolism: A Narrative Review

Coronavirus disease 2019 (COVID-19) emerged from the West District of Southern China Seafood Wholesale Market in late December 2019 and has been declared a global pandemic by the World Health Organization (WHO). Infection with severe acute respiratory syndrome coronavirus (SARS-CoV-2) presents with upper respiratory symptoms like cough, fever, and lethargy. At the same time, in later stages, critical COVID-19 patients develop acute respiratory distress syndrome (ARDS), venous thromboembolism (VTE), and multiple organ failure from cytokine storm and coagulation hyperactivity. Primary manifestations of thrombotic events include deep vein thrombosis (DVT), disseminated intravascular coagulation (DIC) and pulmonary embolism (PE). Initial coagulopathy in COVID-19 patients presents with elevated fibrin degradation products, especially D-dimers. In contrast, late presentations show evidence of prolonged prothrombin time (PT) and activated partial thromboplastin (aPTT), increased platelets, and fibrinogen levels. Diagnosis and monitoring of disease progression are done by regular screening of laboratory parameters, including D-dimer and fibrinogen. Management of coagulopathy in COVID-19 patients is like that of critically ill patients, including thromboprophylaxis. Coagulopathy is a poor prognostic factor, and optimum strategies should be developed for early diagnosis, prevention, and prompt treatment of VTE in COVID-19 patients. Thrombosis prophylaxis with low molecular weight heparin (LMWH) has shown beneficial results in preventing coagulopathy a reducing risk of mortality due to thrombotic events. We will discuss VTE in COVID-19 patients highlighting the role of D-dimer, fibrinogen, and interleukin-6 (IL-6).

Machine learning in predicting respiratory failure in patients with COVID-19 pneumonia-Challenges, strengths, and opportunities in a global health emergency

AIMS

The aim of this study was to estimate a 48 hour prediction of moderate to severe respiratory failure, requiring mechanical ventilation, in hospitalized patients with COVID-19 pneumonia.

METHODS

This was an observational prospective study that comprised consecutive patients with COVID-19 pneumonia admitted to hospital from 21 February to 6 April 2020. The patients' medical history, demographic, epidemiologic and clinical data were collected in an electronic patient chart. The dataset was used to train predictive models using an established machine learning framework leveraging a hybrid approach where clinical expertise is applied alongside a data-driven analysis. The study outcome was the onset of moderate to severe respiratory failure defined as PaO2/FiO2 ratio <150 mmHg in at least one of two consecutive arterial blood gas analyses in the following 48 hours. Shapley Additive exPlanations values were used to quantify the positive or negative impact of each variable included in each model on the predicted outcome.

RESULTS

A total of 198 patients contributed to generate 1068 usable observations which allowed to build 3 predictive models based respectively on 31-variables signs and symptoms, 39-variables laboratory biomarkers and 91-variables as a composition of the two. A fourth "boosted mixed model" included 20 variables was selected from the model 3, achieved the best predictive performance (AUC = 0.84) without worsening the FN rate. Its clinical performance was applied in a narrative case report as an example.

CONCLUSION

This study developed a machine model with 84% prediction accuracy, which is able to assist clinicians in decision making process and contribute to develop new analytics to improve care at high technology readiness levels.

Gastrointestinal involvement attenuates COVID-19 severity and mortality

Given that gastrointestinal (GI) symptoms are a prominent extrapulmonary manifestation of coronavirus disease 2019 (COVID-19), we investigated intestinal infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its effect on disease pathogenesis. SARS-CoV-2 was detected in small intestinal enterocytes by immunofluorescence staining or electron microscopy, in 13 of 15 patients studied. High dimensional analyses of GI tissues revealed low levels of inflammation in general, including active downregulation of key inflammatory genes such as IFNG, CXCL8, CXCL2 and IL1B and reduced frequencies of proinflammatory dendritic cell subsets. To evaluate the clinical significance of these findings, examination of two large, independent cohorts of hospitalized patients in the United States and Europe revealed a significant reduction in disease severity and mortality that was independent of gender, age, and examined co-morbid illnesses. The observed mortality reduction in COVID-19 patients with GI symptoms was associated with reduced levels of key inflammatory proteins including IL-6, CXCL8, IL-17A and CCL28 in circulation but was not associated with significant differences in nasopharyngeal viral loads. These data draw attention to organ-level heterogeneity in disease pathogenesis and highlight the role of the GI tract in attenuating SARS-CoV-2-associated inflammation with related mortality benefit.

ONE SENTENCE SUMMARY

Intestinal infection with SARS-CoV-2 is associated with a mild inflammatory response and improved clinical outcomes.

Clinical Features and Pathogenic Mechanisms of Gastrointestinal Injury in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the global coronavirus disease 2019 (COVID-19) outbreak. Along with the respiratory tract, the gastrointestinal (GI) tract is one of the main extra-pulmonary targets of SARS-CoV-2 with respect to symptom occurrence and is a potential route for virus transmission, most likely due to the presence of angiotensin-converting enzyme 2. Therefore, understanding the mechanisms of GI injury is crucial for a harmonized therapeutic strategy against COVID-19. This review summarizes the current evidence for the clinical features of and possible pathogenic mechanisms leading to GI injury in COVID-19.

Covid 19 and its cardiovascular effects

COVID-19 pandemic is mainly related with the pulmonary problems initially but now as the pandemic is growing it is observed that almost all organ systems of the body are affected. Up to 20-30% patients who are admitted in Covid hospitals are showing cardiovascular involvement. Severity of cardiovascular disease in a COVID-19 patient depends whether a patient is having pre-existing cardiac disease or not. Patients with pre-existing cardiac disease have more severe infection and associated mortality. Severe COVID-19 infection shows close association with myocardial damage and various arrythmias. The cardiovascular involvement occurs by either engagement directly with the angiotensin converting enzyme 2 or indirectly by the effect of inflammatory mediators which are generated as a result of viral-host response to infection. The COVID-19 disease is said to produce a wide spectrum of affliction ranging between even asymptomatic patient to Cardiovascular syndrome. Even after recovering from COVID-19 patients can reappear in the hospital with cardiomyopathies and arrythmias.

Drug Inhibition of SARS-CoV-2 Replication in Human Pluripotent Stem Cell-Derived Intestinal Organoids

BACKGROUND AND AIMS

The COVID-19 pandemic has spread worldwide and poses a severe health risk. While most patients present mild symptoms, descending pneumonia can lead to severe respiratory insufficiency. Up to 50% of patients show gastrointestinal symptoms like diarrhea or nausea, intriguingly associating with prolonged symptoms and increased severity. Thus, models to understand and validate drug efficiency in the gut of COVID-19 patients are of urgent need.

METHODS

Human intestinal organoids derived from pluripotent stem cells (PSC-HIOs) have led, due to their complexity in mimicking human intestinal architecture, to an unprecedented number of successful disease models including gastrointestinal infections. Here, we employed PSC-HIOs to dissect SARS-CoV-2 pathogenesis and its inhibition by remdesivir, one of the leading drugs investigated for treatment of COVID-19.

RESULTS

Immunostaining for viral entry receptor ACE2 and SARS-CoV-2 spike protein priming protease TMPRSS2 showed broad expression in the gastrointestinal tract with highest levels in the intestine, the latter faithfully recapitulated by PSC-HIOs. Organoids could be readily infected with SARS-CoV-2 followed by viral spread across entire PSC-HIOs, subsequently leading to organoid deterioration. However, SARS-CoV-2 spared goblet cells lacking ACE2 expression. Importantly, we challenged PSC-HIOs for drug testing capacity. Specifically, remdesivir effectively inhibited SARS-CoV-2 infection dose-dependently at low micromolar concentration and rescued PSC-HIO morphology.

CONCLUSIONS

Thus, PSC-HIOs are a valuable tool to study SARS-CoV-2 infection and to identify and validate drugs especially with potential action in the gut.

Dangerous Pathogens as a Potential Problem for Public Health

Pathogens are various organisms, such as viruses, bacteria, fungi, and protozoa, which can cause severe illnesses to their hosts. Throughout history, pathogens have accompanied human populations and caused various epidemics. One of the most significant outbreaks was the Black Death, which occurred in the 14th century and caused the death of one-third of Europe's population. Pathogens have also been studied for their use as biological warfare agents by the former Soviet Union, Japan, and the USA. Among bacteria and viruses, there are high priority agents that have a significant impact on public health. Bacillus anthracis, Francisella tularensis, Yersinia pestis, Variola virus, Filoviruses (Ebola, Marburg), Arenoviruses (Lassa), and influenza viruses are included in this group of agents. Outbreaks and infections caused by them might result in social disruption and panic, which is why special operations are needed for public health preparedness. Antibiotic-resistant bacteria that significantly impede treatment and recovery of patients are also valid threats. Furthermore, recent events related to the massive spread of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an example of how virus-induced diseases cannot be ignored. The impact of outbreaks, such as SARS-CoV-2, have had far-reaching consequences beyond public health. The economic losses due to lockdowns are difficult to estimate, but it would take years to restore countries to pre-outbreak status. For countries affected by the 2019 coronavirus disease (COVID-19), their health systems have been overwhelmed, resulting in an increase in the mortality rate caused by diseases or injuries. Furthermore, outbreaks, such as SARS-CoV-2, will induce serious, wide-ranging (and possibly long-lasting) psychological problems among, not only health workers, but ordinary citizens (this is due to isolation, quarantine, etc.). The aim of this paper is to present the most dangerous pathogens, as well as general characterizations, mechanisms of action, and treatments.

Innate immunity plays a key role in controlling viral load in COVID-19: mechanistic insights from a whole-body infection dynamics model

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pathogen of immense public health concern. Efforts to control the disease have only proven mildly successful, and the disease will likely continue to cause excessive fatalities until effective preventative measures (such as a vaccine) are developed. To develop disease management strategies, a better understanding of SARS-CoV-2 pathogenesis and population susceptibility to infection are needed. To this end, physiologically-relevant mathematical modeling can provide a robust in silico tool to understand COVID-19 pathophysiology and the in vivo dynamics of SARS-CoV-2. Guided by ACE2-tropism (ACE2 receptor dependency for infection) of the virus, and by incorporating cellular-scale viral dynamics and innate and adaptive immune responses, we have developed a multiscale mechanistic model for simulating the time-dependent evolution of viral load distribution in susceptible organs of the body (respiratory tract, gut, liver, spleen, heart, kidneys, and brain). Following calibration with in vivo and clinical data, we used the model to simulate viral load progression in a virtual patient with varying degrees of compromised immune status. Further, we conducted global sensitivity analysis of model parameters and ranked them for their significance in governing clearance of viral load to understand the effects of physiological factors and underlying conditions on viral load dynamics. Antiviral drug therapy, interferon therapy, and their combination was simulated to study the effects on viral load kinetics of SARS-CoV-2. The model revealed the dominant role of innate immunity (specifically interferons and resident macrophages) in controlling viral load, and the importance of timing when initiating therapy following infection.

A linear prognostic score based on the ratio of interleukin-6 to interleukin-10 predicts outcomes in COVID-19

BACKGROUND

Prognostic tools are required to guide clinical decision-making in COVID-19.

METHODS

We studied the relationship between the ratio of interleukin (IL)-6 to IL-10 and clinical outcome in 80 patients hospitalized for COVID-19, and created a simple 5-point linear score predictor of clinical outcome, the Dublin-Boston score. Clinical outcome was analysed as a three-level ordinal variable ("Improved", "Unchanged", or "Declined"). For both IL-6:IL-10 ratio and IL-6 alone, we associated clinical outcome with a) baseline biomarker levels, b) change in biomarker level from day 0 to day 2, c) change in biomarker from day 0 to day 4, and d) slope of biomarker change throughout the study. The associations between ordinal clinical outcome and each of the different predictors were performed with proportional odds logistic regression. Associations were run both "unadjusted" and adjusted for age and sex. Nested cross-validation was used to identify the model for incorporation into the Dublin-Boston score.

FINDINGS

The 4-day change in IL-6:IL-10 ratio was chosen to derive the Dublin-Boston score. Each 1 point increase in the score was associated with a 5.6 times increased odds for a more severe outcome (OR 5.62, 95% CI -3.22-9.81, P = 1.2 × 10-9). Both the Dublin-Boston score and the 4-day change in IL-6:IL-10 significantly outperformed IL-6 alone in predicting clinical outcome at day 7.

INTERPRETATION

The Dublin-Boston score is easily calculated and can be applied to a spectrum of hospitalized COVID-19 patients. More informed prognosis could help determine when to escalate care, institute or remove mechanical ventilation, or drive considerations for therapies.

FUNDING

Funding was received from the Elaine Galwey Research Fellowship, American Thoracic Society, National Institutes of Health and the Parker B Francis Research Opportunity Award.

Extrapulmonary Clinical Manifestations in COVID-19 Patients

COVID-19 manifestations in symptomatic patients can be in the form of pneumonia, acute respiratory syndrome, and multiple organ dysfunction as well. Renal complications, gastrointestinal dysfunctions, endocrine system disorders, myocardial dysfunction and arrhythmia, neurological dysfunctions, dermatological symptoms, hematological manifestations, and thromboinflammation are among the reported extrapulmonary complications. Moreover, the presence of coagulopathy, excessive and dysregulated immune responses, and autoimmunity by COVID-19 patients is considerable. The pathogenesis of infection entails the entry of the virus via receptors on cells, principally angiotensin-converting enzyme 2 receptors. Direct virus damage coupled with indirect effects of viral infection including thromboinflammation, dysfunction of the immune system, and dysregulation of the renin-angiotensin system leads to multiple organ failure. This review outlines the extrapulmonary organ-specific complications and their pathophysiology and epidemiology.

A network medicine approach to investigation and population-based validation of disease manifestations and drug repurposing for COVID-19

The global coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to unprecedented social and economic consequences. The risk of morbidity and mortality due to COVID-19 increases dramatically in the presence of coexisting medical conditions, while the underlying mechanisms remain unclear. Furthermore, there are no approved therapies for COVID-19. This study aims to identify SARS-CoV-2 pathogenesis, disease manifestations, and COVID-19 therapies using network medicine methodologies along with clinical and multi-omics observations. We incorporate SARS-CoV-2 virus-host protein-protein interactions, transcriptomics, and proteomics into the human interactome. Network proximity measurement revealed underlying pathogenesis for broad COVID-19-associated disease manifestations. Analyses of single-cell RNA sequencing data show that co-expression of ACE2 and TMPRSS2 is elevated in absorptive enterocytes from the inflamed ileal tissues of Crohn disease patients compared to uninflamed tissues, revealing shared pathobiology between COVID-19 and inflammatory bowel disease. Integrative analyses of metabolomics and transcriptomics (bulk and single-cell) data from asthma patients indicate that COVID-19 shares an intermediate inflammatory molecular profile with asthma (including IRAK3 and ADRB2). To prioritize potential treatments, we combined network-based prediction and a propensity score (PS) matching observational study of 26,779 individuals from a COVID-19 registry. We identified that melatonin usage (odds ratio [OR] = 0.72, 95% CI 0.56-0.91) is significantly associated with a 28% reduced likelihood of a positive laboratory test result for SARS-CoV-2 confirmed by reverse transcription-polymerase chain reaction assay. Using a PS matching user active comparator design, we determined that melatonin usage was associated with a reduced likelihood of SARS-CoV-2 positive test result compared to use of angiotensin II receptor blockers (OR = 0.70, 95% CI 0.54-0.92) or angiotensin-converting enzyme inhibitors (OR = 0.69, 95% CI 0.52-0.90). Importantly, melatonin usage (OR = 0.48, 95% CI 0.31-0.75) is associated with a 52% reduced likelihood of a positive laboratory test result for SARS-CoV-2 in African Americans after adjusting for age, sex, race, smoking history, and various disease comorbidities using PS matching. In summary, this study presents an integrative network medicine platform for predicting disease manifestations associated with COVID-19 and identifying melatonin for potential prevention and treatment of COVID-19.

Multisystem Imaging Manifestations of COVID-19, Part 2: From Cardiac Complications to Pediatric Manifestations

Infection with severe acute respiratory syndrome coronavirus 2 results in coronavirus disease 2019 (COVID-19), which was declared an official pandemic by the World Health Organization on March 11, 2020. COVID-19 has been reported in most countries, and as of August 15, 2020, there have been over 21 million cases of COVID-19 reported worldwide, with over 800 000 COVID-19-associated deaths. Although COVID-19 predominantly affects the respiratory system, it has become apparent that many other organ systems can also be involved. Imaging plays an essential role in the diagnosis of all manifestations of the disease and its related complications, and proper utilization and interpretation of imaging examinations is crucial. A comprehensive understanding of the diagnostic imaging hallmarks, imaging features, multisystem involvement, and evolution of imaging findings is essential for effective patient management and treatment. In part 1 of this article, the authors described the viral pathogenesis, diagnostic imaging hallmarks, and manifestations of the pulmonary and peripheral and central vascular systems of COVID-19. In part 2 of this article, the authors focus on the key imaging features of the varied pathologic manifestations of COVID-19, involving the cardiac, neurologic, abdominal, dermatologic and ocular, and musculoskeletal systems, as well as the pediatric and pregnancy-related manifestations of the virus. Online supplemental material is available for this article. ©RSNA, 2020.

Complement C3 vs C5 inhibition in severe COVID-19: Early clinical findings reveal differential biological efficacy

Growing clinical evidence has implicated complement as a pivotal driver of COVID-19 immunopathology. Deregulated complement activation may fuel cytokine-driven hyper-inflammation, thrombotic microangiopathy and NET-driven immunothrombosis, thereby leading to multi-organ failure. Complement therapeutics have gained traction as candidate drugs for countering the detrimental consequences of SARS-CoV-2 infection. Whether blockade of terminal complement effectors (C5, C5a, or C5aR1) may elicit similar outcomes to upstream intervention at the level of C3 remains debated. Here we compare the efficacy of the C5-targeting monoclonal antibody eculizumab with that of the compstatin-based C3-targeted drug candidate AMY-101 in small independent cohorts of severe COVID-19 patients. Our exploratory study indicates that therapeutic complement inhibition abrogates COVID-19 hyper-inflammation. Both C3 and C5 inhibitors elicit a robust anti-inflammatory response, reflected by a steep decline in C-reactive protein and IL-6 levels, marked lung function improvement, and resolution of SARS-CoV-2-associated acute respiratory distress syndrome (ARDS). C3 inhibition afforded broader therapeutic control in COVID-19 patients by attenuating both C3a and sC5b-9 generation and preventing FB consumption. This broader inhibitory profile was associated with a more robust decline of neutrophil counts, attenuated neutrophil extracellular trap (NET) release, faster serum LDH decline, and more prominent lymphocyte recovery. These early clinical results offer important insights into the differential mechanistic basis and underlying biology of C3 and C5 inhibition in COVID-19 and point to a broader pathogenic involvement of C3-mediated pathways in thromboinflammation. They also support the evaluation of these complement-targeting agents as COVID-19 therapeutics in large prospective trials.

MECHANISMS IN ENDOCRINOLOGY: Vitamin D and COVID-19

The SARS-CoV-2 virus responsible for the COVID-19 pandemic has generated an explosion of interest both in the mechanisms of infection leading to dissemination and expression of this disease, and in potential risk factors that may have a mechanistic basis for disease propagation or control. Vitamin D has emerged as a factor that may be involved in these two areas. The focus of this article is to apply our current understanding of vitamin D as a facilitator of immunocompetence both with regard to innate and adaptive immunity and to consider how this may relate to COVID-19 disease. There are also intriguing potential links to vitamin D as a factor in the cytokine storm that portends some of the most serious consequences of SARS-CoV-2 infection, such as the acute respiratory distress syndrome. Moreover, cardiac and coagulopathic features of COVID-19 disease deserve attention as they may also be related to vitamin D. Finally, we review the current clinical data associating vitamin D with SARS-CoV-2 infection, a putative clinical link that at this time must still be considered hypothetical.

Intricate interplay between Covid-19 and cardiovascular diseases

Covid-19 disease can involve any organ system leading to myriad manifestations and complications. Cardiovascular manifestations are being increasingly recognised with the improved understanding of the disease. Acute coronary syndrome, myocarditis, arrhythmias, cardiomyopathy; heart failure and thromboembolic disease have all been described. The elderly and those with prior cardiac diseases are at an increased risk of mortality. Overlapping symptomatology, ability of drugs to cause QTc interval (start of Q wave to the end of T wave) prolongation on electrocardiogram and arrhythmias, potential drug interactions, the need to recognise patients requiring urgent definitive management and provide necessary bedside interventions without increasing the risk of nosocomial spread have made the management challenging. In the background of a pandemic, non-Covid-19 cardiac patients are affected by delayed treatment and nosocomial exposure. Triaging using telemedicine and artificial intelligence along with utilization of bedside rapid diagnostic tests to detect Covid-19 could prove helpful in this aspect.

Analysis of the mechanism of Shufeng Jiedu capsule prevention and treatment for COVID-19 by network pharmacology tools

Introduction

The novel coronavirus pneumonia that broke out in 2019 has become a global epidemic. According to the diagnosis and treatment plan issued in China and the existing clinical data, Shufeng Jiedu (SFJD) Capsule can be effectively used in the treatment of COVID-19 patients. This study aimed to explore its mechanism of action by network pharmacology and molecular docking technology.

Methods

The Chinese Medicine System Pharmacology Analysis Platform (TCMSP), a Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine (BATMAN-TCM), the Encyclopedia of Traditional Chinese Medicine (ETCM) and related literature records were used to search the composition and main active compounds of SFJD, and to screen out the targets of drug components. Disease-associated genes were obtained by the Human Gene Database (GeneCards), the Human Online Mendelian Inheritance Platform (OMIM) and the DisGeNET database, and the co-targeted genes/proteins as targets of both SFJD and COVID-19 were selected by the Comparative Toxicogenomics Database (CTD). Co-targeted genes/proteins were analyzed by STRING, the Database for Annotation, Visualization and Integrated Discovery (DAVID) and Reactome for proteins to protein interaction (PPI), pathway and GO (gene ontology) enrichment, and predicted by AutoDock for their high-precision docking simulation. In addition, the therapeutic effect for SFJD treatment on COVID-19 was validated by the Chinese medicine anti-novel coronavirus pneumonia drug effect prediction and analysis platform (TCMCOVID).

Results

Screening resulted in 163 compounds and 463 targeted genes. The PPI core network contains 76 co-targeted proteins. The Reactome pathways were enriched in signaling by interleukins, immune system, etc. Finally, 6 key proteins of TNF, IL-10, IL-2, IL-6, STAT1 and CCL2 were selected and successfully docked with 4 active ingredients of quercetin, luteolin, wogonin and kaempferol.

Conclusion

SFJD may play a role in the prevention and treatment of COVID-19 through multiple active compounds acting on multiple targets and then multiple pathways.

Functional ultrasound imaging of the venous valve of the great saphenous vein in the area around the crosse using the novel vector flow technique

PURPOSE: The aim of our pilot study is to consider if the new flow presentation of the vector flow (V-flow) allows an assessment of the valve morphology of the crosses with respect to an insufficiency. MATERIAL AND METHODS: We performed a total of 50 investigations in which we documented a complete valve closure at the so called “crosse” at the valve of the large saphenous vein, a delayed valve closure or an incomplete valve closure with consecutive insufficiency at the crosse. The valve function of the crosse is crucial for the development of varicosis. For our study we recorded age and gender of the patients. One patient in the study was suffering from Covid19. For the examinations we used a 3–9 MHz probe and a high-end ultrasound device. The examination was performed in a lying position and under quiet conditions. Before examination we practiced inhalation and exhalation as well as “pressing” or coughing with the patients, which resulted in a physiological closure of the venous valves. To rule out thrombosis, we carried out compression sonography on the legs. During the examination we documented the B-scan, the Color-Coded Duplex Sonography, the HR-flow and the V-flow for 3 seconds at the estuary of the crosses and incorporated these parameters into our measurements. Via V-flow, vectors can be imaged by representing the flow of erythrocytes and visually indicate a possible insufficiency due to delayed or incomplete valve closure. RESULTS: 31 of 50 patients (age 19–81years) showed a complete valve closure of the crosses, three of them suffered from thrombosis. In eight of the 50 study participants (age 45–79 years) a delayed valve closure could be diagnosed by V-flow within 1–2 seconds. None of them had a thrombosis, but six of them suffered from cancer. In eleven patients we derived an incomplete valve closure with insufficiency (age 51–88 years). With reflux it took >2 seconds to close the valve. The patient with Covid19 also showed an incomplete valve closure with insufficiency. At the same time this patient showed a Covid19-associated deep vein thrombosis. Eight additional patients also had a thrombosis. Six of them suffered from cancer. Overall, the results were best visualized by V-Flow. CONCLUSION: The crosse as a significant venous structure can be well investigated by V-flow with respect to hemodynamic changes and a resulted reflux. Also associated changes close to the valve can be visualized well.

Coagulation Parameters: An Efficient Measure for Predicting the Prognosis and Clinical Management of Patients with COVID-19

Background. COVID-19 is an ongoing global pandemic. Since the detection of the first cases of coronavirus disease 2019 (COVID-19) in Wuhan, China, the current pandemic has affected more than 25.3 million people worldwide. The aim of this study was to evaluate the relationship between coagulation abnormalities and prognosis in a cohort of patients with COVID-19. Methods. We performed a retrospective cohort study of 3581 patients admitted to Hospital La Paz (Madrid, Spain) due to respiratory infection by severe acute respiratory syndrome coronavirus from the beginning of the current pandemic to 15 July 2020. Results. Of the 3581 study patients, 48.94% were men, and 19.80% were healthcare workers. The median age was 62 years. Compared with the survivors, the non-survivors had lower prothrombin activity (82.5 (Interquartile range—IQR, 67–95) vs. 95.25 (IQR, 87–104) for non-survivors and survivors, respectively; p < 0.001), higher fibrinogen levels (748.5—IQR, 557–960) vs. 572.75 (IQR, 417–758; p < 0.001), and notably higher D-dimer levels (2329—IQR, 1086.12–5670.40) vs. 635.5 (IQR, 325.5–1194.8); p < 0.001). Conclusions. The evaluation of coagulation parameters could be an efficient measure for predicting the prognosis and improving the clinical management of patients with COVID-19.

COVID-19 and Hematology-What Do We Know So Far?

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), the causative agent of the novel coronavirus disease 2019 (COVID 19), was reported to the World Health Organization in late 2019. This disease quickly evolved into a public health concern and was declared a pandemic on March 11, 2020. COVID-19's high transmission rate and potential to cause a spectrum of systemic diseases makes it imperative for researchers and clinicians worldwide to collaborate and develop a strategy to manage and contain this disease. Studies have shown a wide range of hematological abnormalities and virus-related coagulopathies in affected patients, resulting in an increased propensity to develop serious thrombotic complications or disseminated intravascular coagulation (DIC) in severe cases. The fatal implications of coagulopathy in the form of pulmonary embolism (PE), myocardial infarction (MI), and cerebral infarction compelled us to study in-depth the pathophysiology and treatment options related to COVID-19. This analysis reviews published reports on patients with confirmed SARS-COV-2 infection and associated coagulopathy, defined as abnormalities in the coagulation parameters prothrombin time (PT), activated partial thromboplastin time (aPTT), antithrombin time, fibrinogen, fibrin degradation products, and D-dimer. In this review, we present the hematological manifestations of COVID-19, focusing on virus-associated coagulopathy and relevant pathophysiology, clinical outcomes, and treatment.

[COVID-19 and venous thromboembolism]

La coronavirus disease 2019 (COVID-19) s’accompagne d’une incidence élevée d’événements thromboemboliques veineux (ETEV). Souvent asymptomatiques, ils ont un impact défavorable sur le pronostic des patients. En plus des facteurs de risque de thrombose veineuse auxquels les formes de COVID-19 nécessitant une hospitalisation exposent (alitement prolongée, hypoxémie, présence de matériel intraveineux), les caractéristiques des patients atteints des formes les plus sévères (âge élevé, obésité) expliquent en partie la fréquence des ETEV. De plus, la COVID-19 entraîne une maladie de l’endothélium vasculaire par une invasion directe des cellules endothéliales, à l’origine d’une endothéliite, et un état prothrombotique secondaire à l’intense réaction inflammatoire. L’ensemble de ces manifestations entraînent une immunothrombose localisée principalement au niveau du lit vasculaire pulmonaire. La stratification du risque thromboembolique veineux pour proposer aux patients un niveau d’anticoagulation adapté apparaît ainsi comme un des piliers du traitement de la COVID-19. Les recommandations émises jusqu’ici se basent sur des avis d’experts dans la mesure où les données sur l’anticoagulation au cours de la COVID-19 proviennent essentiellement d’études observationnelles. Des essais cliniques contrôlés et randomisés sont en cours et permettront d’améliorer la gestion de la maladie thromboembolique veineuse au cours de la COVID-19.

Rapid Antibody-Based COVID-19 Mass Surveillance: Relevance, Challenges, and Prospects in a Pandemic and Post-Pandemic World

The aggressive outbreak of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) as COVID-19 (coronavirus disease-2019) pandemic demands rapid and simplified testing tools for its effective management. Increased mass testing and surveillance are crucial for controlling the disease spread, obtaining better pandemic statistics, and developing realistic epidemiological models. Despite the advantages of nucleic acid- and antigen-based tests such as accuracy, specificity, and non-invasive approaches of sample collection, they can only detect active infections. Antibodies (immunoglobulins) are produced by the host immune system within a few days after infection and persist in the blood for at least several weeks after infection resolution. Antibody-based tests have provided a substitute and effective method of ultra-rapid detection for multiple contagious disease outbreaks in the past, including viral diseases such as SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome). Thus, although not highly suitable for early diagnosis, antibody-based methods can be utilized to detect past infections hidden in the population, including asymptomatic ones. In an active community spread scenario of a disease that can provide a bigger window for mass detections and a practical approach for continuous surveillance. These factors encouraged researchers to investigate means of improving antibody-based rapid tests and employ them as reliable, reproducible, sensitive, specific, and economic tools for COVID-19 mass testing and surveillance. The development and integration of such immunoglobulin-based tests can transform the pandemic diagnosis by moving the same out of the clinics and laboratories into community testing sites and homes. This review discusses the principle, technology, and strategies being used in antibody-based testing at present. It also underlines the immense prospect of immunoglobulin-based testing and the efficacy of repeated planned deployment in pandemic management and post-pandemic sustainable screenings globally.

SARS-CoV-2 Cell Entry Factors ACE2 and TMPRSS2 are Expressed in the Pancreas but are Not Enriched in Islet Endocrine Cells

Reports of new-onset diabetes and diabetic ketoacidosis in individuals with COVID-19 have led to the hypothesis that SARS-CoV-2, the virus that causes COVID-19, is directly cytotoxic to pancreatic islet β cells. This would require binding and entry of SARS-CoV-2 into host β cells via cell surface co-expression of ACE2 and TMPRSS2, the putative receptor and effector protease, respectively. To define ACE2 and TMPRSS2 expression in the human pancreas, we examined six transcriptional datasets from primary human islet cells and assessed protein expression by immunofluorescence in pancreata from donors with and without diabetes. ACE2 and TMPRSS2 transcripts were low or undetectable in pancreatic islet endocrine cells as determined by bulk or single cell RNA sequencing, and neither protein was detected in α or β cells from these donors. Instead, ACE2 protein was expressed in the islet and exocrine tissue microvasculature and also found in a subset of pancreatic ducts, whereas TMPRSS2 protein was restricted to ductal cells. The absence of significant ACE2 and TMPRSS2 co-expression in islet endocrine cells reduces the likelihood that SARS-CoV-2 directly infects pancreatic islet β cells through these cell entry proteins.

Protein-driven mechanism of multiorgan damage in COVID-19

We propose a new plausible mechanism by mean of which SARS-CoV-2 produces extrapulmonary damages in severe COVID-19 patients. The mechanism consist on the existence of vulnerable proteins (VPs), which are (i) mainly expressed outside the lungs; (ii) their perturbations is known to produce human diseases; and (iii) can be perturbed directly or indirectly by SARS-CoV-2 proteins. These VPs are perturbed by other proteins, which are: (i) mainly expressed in the lungs, (ii) are targeted directly by SARS-CoV-2 proteins, (iii) can navigate outside the lungs as cargo of extracellular vesicles (EVs); and (iv) can activate VPs via subdiffusive processes inside the target organ. Using bioinformatic tools and mathematical modeling we identifies 26 VPs and their 38 perturbators, which predict extracellular damages in the immunologic endocrine, cardiovascular, circulatory, lymphatic, musculoskeletal, neurologic, dermatologic, hepatic, gastrointestinal, and metabolic systems, as well as in the eyes. The identification of these VPs and their perturbators allow us to identify 27 existing drugs which are candidates to be repurposed for treating extrapulmonary damage in severe COVID-19 patients. After removal of drugs having undesirable drug-drug interactions we select 7 drugs and one natural product: apabetalone, romidepsin, silmitasertib, ozanezumab, procaine, azacitidine, amlexanox, volociximab, and ellagic acid, whose combinations can palliate the organs and systems found to be damaged by COVID-19. We found that at least 4 drugs are needed to treat all the multiorgan damages, for instance: the combination of romidepsin, silmitasertib, apabetalone and azacitidine.

Renal impairment and its impact on clinical outcomes in patients who are critically ill with COVID-19: a multicentre observational study

Renal impairment is common in patients who are critically ill with coronavirus disease-19 (COVID-19). We examined the association between acute and chronic kidney disease with clinical outcomes in 372 patients with coronavirus disease-19 admitted to four regional intensive care units between 10 March 2020 and 31 July 2020. A total of 216 (58%) patients presented with COVID-19 and renal impairment. Acute kidney injury and/or chronic kidney disease was associated with greater in-hospital mortality compared with patients with preserved renal function (107/216 patients (50%) (95%CI 44-57) vs. 32/156 (21%) (95%CI 15-28), respectively; p < 0.001, relative risk 2.4 (95%CI 1.7-3.4)). Mortality was greatest in patients with renal transplants (6/7 patients (86%) (95%CI 47-100)). Mortality rates increased in patients with worsening renal injury according to the Kidney Disease: Improving Global Outcomes classification: stage 0 mortality 33/157 patients (21%) (95%CI 15-28) vs. stages 1-3 mortality 91/186 patients (49%) (95%CI 42-56); p < 0.001, relative risk 2.3 (95%CI 1.7-3.3). Survivors were less likely to require renal replacement therapy compared with non-survivors (57/233 patients (24%) vs. 64/139 patients (46%), respectively; p < 0.001, relative risk 1.9 (95%CI 1.4-2.5)). One-fifth of survivors who required renal replacement therapy acutely in intensive care continued to require renal support following discharge. Our data demonstrate that renal impairment in patients admitted to intensive care with COVID-19 is common and is associated with a high mortality and requirement for on-going renal support after discharge from critical care. Our findings have important implications for future pandemic planning in this patient cohort.

Factors influencing liberation from mechanical ventilation in coronavirus disease 2019: multicenter observational study in fifteen Italian ICUs

BACKGROUND

A large proportion of patients with coronavirus disease 2019 (COVID-19) develop severe respiratory failure requiring admission to the intensive care unit (ICU) and about 80% of them need mechanical ventilation (MV). These patients show great complexity due to multiple organ involvement and a dynamic evolution over time; moreover, few information is available about the risk factors that may contribute to increase the time course of mechanical ventilation.The primary objective of this study is to investigate the risk factors associated with the inability to liberate COVID-19 patients from mechanical ventilation. Due to the complex evolution of the disease, we analyzed both pulmonary variables and occurrence of non-pulmonary complications during mechanical ventilation. The secondary objective of this study was the evaluation of risk factors for ICU mortality.

METHODS

This multicenter prospective observational study enrolled 391 patients from fifteen COVID-19 dedicated Italian ICUs which underwent invasive mechanical ventilation for COVID-19 pneumonia. Clinical and laboratory data, ventilator parameters, occurrence of organ dysfunction, and outcome were recorded. The primary outcome measure was 28 days ventilator-free days and the liberation from MV at 28 days was studied by performing a competing risks regression model on data, according to the method of Fine and Gray; the event death was considered as a competing risk.

RESULTS

Liberation from mechanical ventilation was achieved in 53.2% of the patients (208/391). Competing risks analysis, considering death as a competing event, demonstrated a decreased sub-hazard ratio for liberation from mechanical ventilation (MV) with increasing age and SOFA score at ICU admission, low values of PaO2/FiO2 ratio during the first 5 days of MV, respiratory system compliance (CRS) lower than 40 mL/cmH2O during the first 5 days of MV, need for renal replacement therapy (RRT), late-onset ventilator-associated pneumonia (VAP), and cardiovascular complications.ICU mortality during the observation period was 36.1% (141/391). Similar results were obtained by the multivariate logistic regression analysis using mortality as a dependent variable.

CONCLUSIONS

Age, SOFA score at ICU admission, CRS, PaO2/FiO2, renal and cardiovascular complications, and late-onset VAP were all independent risk factors for prolonged mechanical ventilation in patients with COVID-19.

TRIAL REGISTRATION

NCT04411459.

Microvascular dysfunction in COVID-19: the MYSTIC study

RATIONALE

Pre-clinical and autopsy studies have fueled the hypothesis that a dysregulated vascular endothelium might play a central role in the pathogenesis of ARDS and multi-organ failure in COVID-19.

OBJECTIVES

To comprehensively characterize and quantify microvascular alterations in patients with COVID-19.

METHODS

Hospitalized adult patients with moderate-to-severe or critical COVID-19 (n = 23) were enrolled non-consecutively in this prospective, observational, cross-sectional, multi-center study. Fifteen healthy volunteers served as controls. All participants underwent intravital microscopy by sidestream dark field imaging to quantify vascular density, red blood cell velocity (V_RBC), and glycocalyx dimensions (perfused boundary region, PBR) in sublingual microvessels. Circulating levels of endothelial and glycocalyx-associated markers were measured by multiplex proximity extension assay and enzyme-linked immunosorbent assay.

MEASUREMENTS AND MAIN RESULTS

COVID-19 patients showed an up to 90% reduction in vascular density, almost exclusively limited to small capillaries (diameter 4-6 µm), and also significant reductions of V_RBC. Especially, patients on mechanical ventilation showed severe glycocalyx damage as indicated by higher PBR values (i.e., thinner glycocalyx) and increased blood levels of shed glycocalyx constituents. Several markers of endothelial dysfunction were increased and correlated with disease severity in COVID-19. PBR (AUC 0.75, p = 0.01), ADAMTS13 (von Willebrand factor-cleaving protease; AUC 0.74, p = 0.02), and vascular endothelial growth factor A (VEGF-A; AUC 0.73, p = 0.04) showed the best discriminatory ability to predict 60-day in-hospital mortality.

CONCLUSIONS

Our data clearly show severe alterations of the microcirculation and the endothelial glycocalyx in patients with COVID-19. Future therapeutic approaches should consider the importance of systemic vascular involvement in COVID-19.

Automatic oxygen titration with O2matic® to patients admitted with COVID-19 and hypoxemic respiratory failure

Introduction

Patients with coronavirus disease (COVID-19) and pneumonitis often have hypoxemic respiratory failure and a need of supplementary oxygen. Guidelines recommend controlled oxygen, for most patients with a recommended interval of SpO₂ between 92 and 96%. We aimed to determine if closed-loop control of oxygen was feasible in patients with COVID-19 and could maintain SpO₂ in the specified interval.

Methods

Patients were prospectively enrolled in an observational study on a medical ward dedicated to patients with COVID-19. Closed-loop controlled oxygen was delivered by O2matic® which can deliver 0-15 liters/min and adjusts flow every second based on 15 seconds averaging of SpO₂ measured by pulse oximetry. Lung function parameters were measured at admission.

Results

Fifteen patients (six women, nine men) participated in the study. Average age was 72 years. Lung function was severely impaired with FEV₁, FVC and PEF reduced to approximately 50%. The average stay on the ward was 3.2 days and O2matic was used on average for 66 hours, providing 987 hours of observation. O2matic maintained SpO₂ in the desired interval for 82.9% of the time. Time with SpO₂ > 2% below interval was 5.1% and time with SpO₂ > 2% above interval was 0.6%.

Conclusion

Closed-loop control of oxygen to patients with COVID-19 is feasible and can maintain SpO₂ in the specified interval in the majority of time. Closed-loop automated control could be of particular benefit for patients in isolation with decreased visibility, surveillance and monitoring. Further studies must examine the clinical benefits.

Does SARS-CoV-2 Infect the Kidney?

Podcast

This article contains a podcast at https://www.asn-online.org/media/podcast/JASN/2020_11_24_JASN2020081229.mp3

Life-threatening COVID-19 presenting as stroke with antiphospholipid antibodies and low ADAMTS-13 activity, and the role of therapeutic plasma exchange: A case series

We present a case series of three patients with COVID-19 who were admitted to our intensive care unit due to acute respiratory distress syndrome, brain infarction, pulmonary embolism, and antiphospholipid antibodies. We applied therapeutic plasma exchange on all cases. On intensive care unit admission, all patients had low (<10) Glasgow Coma Scale, and central nervous imaging showed multiple brain infarctions. COVID-19 was confirmed by reverse transcriptase polymerase chain reaction assays. Patients underwent rescue therapeutic plasma exchange using the Spectra OptiaTM Apheresis System (Terumo BCT Inc., USA), which operates with acid-citrate dextrose anticoagulant as per Kidney Disease Improving Global Outcomes 2019 guidelines. A dose of 1.5 plasma volume was used for the first dose and then 1 plasma volume daily for a total of five doses. Plasma was replaced with Octaplas LG® (Octapharma AG, USA), which is an artificial fresh frozen plasma product that has undergone viral inactivation by prion reduction technology. We administered ARDS-net/prone positioning ventilation, empiric antiviral treatment, therapeutic anticoagulation, and intensive care unit supportive care. Laboratory tests showed lymphocytopenia; elevated levels of D-dimer, fibrinogen, total bilirubin, C-reactive protein, lactate dehydrogenase, and ferritin; as well as low levels of ADAMTS-13 activity and antibody. Serology tests depicted positive IgM and IgG antiphospholipid antibodies (anti-cardiolipin and anti-β2-glycoprotein I antibodies). No side effects of therapeutic plasma exchange were recorded. After the completion of therapeutic plasma exchange, patients improved clinically and gradually recovered neurologically (after 27-32 days). To conclude, in life-threatening COVID-19, especially when immune dysregulation features such as antiphospholipid antibodies exist, therapeutic plasma exchange could be an effective rescue therapy.