Spike substitution T813S increases Sarbecovirus fusogenicity by enhancing the usage of TMPRSS2.

SARS-CoV Spike (S) protein shares considerable homology with SARS-CoV-2 S, especially in the conserved S2 subunit (S2). S protein mediates coronavirus receptor binding and membrane fusion, and the latter activity can greatly influence coronavirus infection. We observed that SARS-CoV S is less effective in inducing membrane fusion compared with SARS-CoV-2 S. We identify that S813T mutation is sufficient in S2 interfering with the cleavage of SARS-CoV-2 S by TMPRSS2, reducing spike fusogenicity and pseudoparticle entry. Conversely, the mutation of T813S in SARS-CoV S increased fusion ability and viral replication. Our data suggested that residue 813 in the S was critical for the proteolytic activation, and the change from threonine to serine at 813 position might be an evolutionary feature adopted by SARS-2-related viruses. This finding deepened the understanding of Spike fusogenicity and could provide a new perspective for exploring Sarbecovirus' evolution.

Evaluation of safety, pharmacokinetics, and pharmacodynamics of apixaban in pediatric subjects at risk of venous or arterial thrombotic disorder.

Apixaban is an oral small-molecule, direct factor Xa (FXa) inhibitor approved in adults for treatment of deep vein thrombosis and pulmonary embolism, and for reducing risk of venous thromboembolism recurrence after initial anticoagulant therapy. This phase I study (NCT01707394) evaluated the pharmacokinetics (PKs), pharmacodynamics (PDs), and safety of apixaban in pediatric subjects (<18 years), enrolled by age group, at risk of venous or arterial thrombotic disorder. A single apixaban dose, targeting adult steady-state exposure with apixaban 2.5 mg, was administered using two pediatric formulations: 0.1 mg sprinkle capsule (age <28 days); 0.4 mg/ml solution (age 28 days to <18 years; dose range, 1.08-2.19 mg/m2 ). End points included safety, PKs, and anti-FXa activity. For PKs/PDs, four to six blood samples were collected ≤26 h postdosing. A population PK model was developed with data from adults and pediatric subjects. Apparent oral clearance (CL/F) included fixed maturation function based on published data. From January 2013 to June 2019, 49 pediatric subjects received apixaban. Most adverse events were mild/moderate, and the most common was pyrexia (n = 4/15). Apixaban CL/F and apparent central volume of distribution increased less than proportionally with body weight. Apixaban CL/F increased with age, reaching adult values in subjects aged 12 to <18 years. Maturation affected CL/F most notably in subjects aged <9 months. Plasma anti-FXa activity values were linearly related to apixaban concentrations, with no apparent age-related differences. Pediatric subjects tolerated single apixaban doses well. Study data and population PK model supported phase II/III pediatric trial dose selection.

ASGARD is A Single-cell Guided Pipeline to Aid Repurposing of Drugs.

Single-cell RNA sequencing technology has enabled in-depth analysis of intercellular heterogeneity in various diseases. However, its full potential for precision medicine has yet to be reached. Towards this, we propose A Single-cell Guided Pipeline to Aid Repurposing of Drugs (ASGARD) that defines a drug score to recommend drugs by considering all cell clusters to address the intercellular heterogeneity within each patient. ASGARD shows significantly better average accuracy on single-drug therapy compared to two bulk-cell-based drug repurposing methods. We also demonstrated that it performs considerably better than other cell cluster-level predicting methods. In addition, we validate ASGARD using the drug response prediction method TRANSACT with Triple-Negative-Breast-Cancer patient samples. We find that many top-ranked drugs are either approved by the Food and Drug Administration or in clinical trials treating corresponding diseases. In conclusion, ASGARD is a promising drug repurposing recommendation tool guided by single-cell RNA-seq for personalized medicine. ASGARD is free for educational use at https://github.com/lanagarmire/ASGARD .

Tissue- and cell-expression of druggable host proteins provide insights into repurposing drugs for COVID-19.

Several human host proteins play important roles in the lifecycle of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Many drugs targeting these host proteins have been investigated as potential therapeutics for coronavirus disease 2019 (COVID-19). The tissue-specific expressions of selected host proteins were summarized using proteomics data retrieved from the Human Protein Atlas, ProteomicsDB, Human Proteome Map databases, and a clinical COVID-19 study. Protein expression features in different cell lines were summarized based on recent proteomics studies. The half-maximal effective concentration or half-maximal inhibitory concentration values were collected from in vitro studies. The pharmacokinetic data were mainly from studies in healthy subjects or non-COVID-19 patients. Considerable tissue-specific expression patterns were observed for several host proteins. ACE2 expression in the lungs was significantly lower than in many other tissues (e.g., the kidneys and intestines); TMPRSS2 expression in the lungs was significantly lower than in other tissues (e.g., the prostate and intestines). The expression levels of endocytosis-associated proteins CTSL, CLTC, NPC1, and PIKfyve in the lungs were comparable to or higher than most other tissues. TMPRSS2 expression was markedly different between cell lines, which could be associated with the cell-dependent antiviral activities of several drugs. Drug delivery receptor ICAM1 and CTSB were expressed at a higher level in the lungs than in other tissues. In conclusion, the cell- and tissue-specific proteomics data could help interpret the in vitro antiviral activities of host-directed drugs in various cells and aid the transition of the in vitro findings to clinical research to develop safe and effective therapeutics for COVID-19.

Heterogeneity of neutrophils and inflammatory responses in patients with COVID-19 and healthy controls.

Severe respiratory viral infections, including SARS-CoV-2, have resulted in high mortality rates despite corticosteroids and other immunomodulatory therapies. Despite recognition of the pathogenic role of neutrophils, in-depth analyses of this cell population have been limited, due to technical challenges of working with neutrophils. We undertook an unbiased, detailed analysis of neutrophil responses in adult patients with COVID-19 and healthy controls, to determine whether distinct neutrophil phenotypes could be identified during infections compared to the healthy state. Single-cell RNA sequencing analysis of peripheral blood neutrophils from hospitalized patients with mild or severe COVID-19 disease and healthy controls revealed distinct mature neutrophil subpopulations, with relative proportions linked to disease severity. Disruption of predicted cell-cell interactions, activated oxidative phosphorylation genes, and downregulated antiviral and host defense pathway genes were observed in neutrophils obtained during severe compared to mild infections. Our findings suggest that during severe infections, there is a loss of normal regulatory neutrophil phenotypes seen in healthy subjects, coupled with the dropout of appropriate cellular interactions. Given that neutrophils are the most abundant circulating leukocytes with highly pathogenic potential, current immunotherapies for severe infections may be optimized by determining whether they aid in restoring an appropriate balance of neutrophil subpopulations.

Interpretable artificial intelligence model for accurate identification of medical conditions using immune repertoire.

Underlying medical conditions, such as cancer, kidney disease and heart failure, are associated with a higher risk for severe COVID-19. Accurate classification of COVID-19 patients with underlying medical conditions is critical for personalized treatment decision and prognosis estimation. In this study, we propose an interpretable artificial intelligence model termed VDJMiner to mine the underlying medical conditions and predict the prognosis of COVID-19 patients according to their immune repertoires. In a cohort of more than 1400 COVID-19 patients, VDJMiner accurately identifies multiple underlying medical conditions, including cancers, chronic kidney disease, autoimmune disease, diabetes, congestive heart failure, coronary artery disease, asthma and chronic obstructive pulmonary disease, with an average area under the receiver operating characteristic curve (AUC) of 0.961. Meanwhile, in this same cohort, VDJMiner achieves an AUC of 0.922 in predicting severe COVID-19. Moreover, VDJMiner achieves an accuracy of 0.857 in predicting the response of COVID-19 patients to tocilizumab treatment on the leave-one-out test. Additionally, VDJMiner interpretively mines and scores V(D)J gene segments of the T-cell receptors that are associated with the disease. The identified associations between single-cell V(D)J gene segments and COVID-19 are highly consistent with previous studies. The source code of VDJMiner is publicly accessible at https://github.com/TencentAILabHealthcare/VDJMiner. The web server of VDJMiner is available at https://gene.ai.tencent.com/VDJMiner/.

Heterogeneity of neutrophils and inflammatory responses in patients with COVID-19 and healthy controls

Severe respiratory viral infections, including SARS-CoV-2, have resulted in high mortality rates despite corticosteroids and other immunomodulatory therapies. Despite recognition of the pathogenic role of neutrophils, in-depth analyses of this cell population have been limited, due to technical challenges of working with neutrophils. We undertook an unbiased, detailed analysis of neutrophil responses in adult patients with COVID-19 and healthy controls, to determine whether distinct neutrophil phenotypes could be identified during infections compared to the healthy state. Single-cell RNA sequencing analysis of peripheral blood neutrophils from hospitalized patients with mild or severe COVID-19 disease and healthy controls revealed distinct mature neutrophil subpopulations, with relative proportions linked to disease severity. Disruption of predicted cell-cell interactions, activated oxidative phosphorylation genes, and downregulated antiviral and host defense pathway genes were observed in neutrophils obtained during severe compared to mild infections. Our findings suggest that during severe infections, there is a loss of normal regulatory neutrophil phenotypes seen in healthy subjects, coupled with the dropout of appropriate cellular interactions. Given that neutrophils are the most abundant circulating leukocytes with highly pathogenic potential, current immunotherapies for severe infections may be optimized by determining whether they aid in restoring an appropriate balance of neutrophil subpopulations.

Comparative global B cell receptor repertoire difference induced by SARS-CoV-2 infection or vaccination via single-cell V(D)J sequencing.

Dynamic changes of the paired heavy and light chain B cell receptor (BCR) repertoire provide an essential insight into understanding the humoral immune response post-SARS-CoV-2 infection and vaccination. However, differences between the endogenous paired BCR repertoire kinetics in SARS-CoV-2 infection and previously recovered/naïve subjects treated with the inactivated vaccine remain largely unknown. We performed single-cell V(D)J sequencing of B cells from six healthy donors with three shots of inactivated SARS-CoV-2 vaccine (BBIBP-CorV), five people who received the BBIBP-CorV vaccine after having recovered from COVID-19, five unvaccinated COVID-19 recovered patients and then integrated with public data of B cells from four SARS-CoV-2-infected subjects. We discovered that BCR variable (V) genes were more prominently used in the SARS-CoV-2 exposed groups (both in the group with active infection and in the group that had recovered) than in the vaccinated groups. The VH gene that expanded the most after SARS-CoV-2 infection was IGHV3-33, while IGHV3-23 in the vaccinated groups. SARS-CoV-2-infected group enhanced more BCR clonal expansion and somatic hypermutation than the vaccinated healthy group. A small proportion of public clonotypes were shared between the SARS-CoV-2 infected, vaccinated healthy, and recovered groups. Moreover, several public antibodies had been identified against SARS-CoV-2 spike protein. We comprehensively characterize the paired heavy and light chain BCR repertoire from SARS-CoV-2 infection to vaccination, providing further guidance for the development of the next-generation precision vaccine.

[Influence of COVID-19 Prevention and Control Measures on PM2.5 Concentration, Particle Size Distribution, Chemical Composition, and Source in Zhengzhou, China].

The COVID-19 lockdown was a typical occurrence of extreme emission reduction, which presented an opportunity to study the influence of control measures on particulate matter. Observations were conducted from January 16 to 31, 2020 using online observation instruments to investigate the characteristics of PM2.5 concentration, particle size distribution, chemical composition, source, and transport before (January 16-23, 2020) and during (January 24-31, 2020) the COVID-19 lockdown in Zhengzhou. The results showed that the atmospheric PM2.5 concentration decreased by 4.8% during the control period compared with that before the control in Zhengzhou. The particle size distribution characteristics indicated that there was a significant decrease in the mass concentration and number concentration of particles in the size range of 0.06 to 1.6 µm during the control period. The chemical composition characteristics of PM2.5 showed that secondary inorganic ions (sulfate, nitrate, and ammonium) were the dominant component of PM2.5, and the significant increase in PM2.5 was mainly owing to the decrease in NO3- concentration during the control period. The main sources of PM2.5 identified by the positive matrix factorization (PMF) model were secondary sources, combustion sources, vehicle sources, industrial sources, and dust sources. The emissions from vehicle sources, industrial sources, and dust sources decreased significantly during the control period. The results of analyses using the backward trajectory method and potential source contribution factor method indicated that the effects of transport from surrounding areas on PM2.5 concentration decreased during the control period. In summary, vehicle and industrial sources should be continuously controlled, and regional combined prevention and control should be strengthened in the future in Zhengzhou.

Cardiac Biomarker Abnormalities Are Closely Related to Prognosis in Patients with COVID-19

武漢大学人民医院に入院した新型コロナウイルス感染症の重症患者148例(男性67例、女性81例、平均57.2±17.7歳)を対象に、心筋バイオマーカーと予後との関連性について検討した。患者148例のうち99例(66.9%)は高血圧症、糖尿病、貧血、腎障害、肝障害、慢性閉塞性肺疾患、心血管疾患、悪性腫瘍等の基礎疾患を有していた。患者を転帰に応じて、生存群96例(男性39.6%、平均51.4±16.1歳)と死亡群52例(男性55.8%、平均68.6±14.8歳)の2群に分類した。血中NT-proBNP(基準範囲は450pg/mL未満)は死亡群(1035.46pg/mL)が生存群(81.15pg/mL)より有意に高く、CK-MBも死亡群(2.62ng/mL)が生存群(0.67ng/mL)より有意に高かった(いずれもP<0.001)。心筋トロポニンcTnIは生存群で0.000であったが、死亡群は0.131ng/mLであった。血清ミオグロビンは死亡群(101.83μg/L)が生存群(26.86μg/L)より有意に高かった(P<0.001)。心血管合併症を呈した19例のうち14例が死亡した。

Intestinal Abnormalities in Patients With SARS-CoV-2 Infection: Histopathologic Changes Reflect Mechanisms of Disease.

Approximately 20% of patients with symptomatic syndrome-associated coronavirus-2 (SARS-CoV-2) infection have gastrointestinal bleeding and/or diarrhea. Most are managed without endoscopic evaluation because the risk of practitioner infection outweighs the value of biopsy analysis unless symptoms are life-threatening. As a result, much of what is known about the gastrointestinal manifestations of coronavirus disease-2019 (COVID-19) has been gleaned from surgical and autopsy cases that suffer from extensive ischemic injury and/or poor preservation. There are no detailed reports describing any other gastrointestinal effects of SARS-CoV-2 even though >3,000,000 people have died from COVID-19 worldwide. The purpose of this study is to report the intestinal findings related to SARS-CoV-2 infection by way of a small case series including one with evidence of direct viral cytopathic effect and 2 with secondary injury attributed to viral infection. Infection can be confirmed by immunohistochemical stains directed against SARS-CoV-2 spike protein, in situ hybridization for spike protein-encoding RNA, and ultrastructural visualization of viruses within the epithelium. It induces cytoplasmic blebs and tufted epithelial cells without inflammation and may not cause symptoms. In contrast, SARS-CoV-2 infection can cause gastrointestinal symptoms after the virus is no longer detected, reflecting systemic activation of cytokine and complement cascades rather than direct viral injury. Reversible mucosal ischemia features microvascular injury with hemorrhage, small vessel thrombosis, and platelet-rich thrombi. Systemic cytokine elaboration and dysbiosis likely explain epithelial cell injury that accompanies diarrheal symptoms. These observations are consistent with clinical and in vitro data and contribute to our understanding of the protean manifestations of COVID-19.

Rapid isolation and immune profiling of SARS-CoV-2 specific memory B cell in convalescent COVID-19 patients via LIBRA-seq.

B cell response plays a critical role against SARS-CoV-2 infection. However, little is known about the diversity and frequency of the paired SARS-CoV-2 antigen-specific BCR repertoire after SARS-CoV-2 infection. Here, we performed single-cell RNA sequencing and VDJ sequencing using the memory and plasma B cells isolated from five convalescent COVID-19 patients, and analyzed the spectrum and transcriptional heterogeneity of antibody immune responses. Via linking BCR to antigen specificity through sequencing (LIBRA-seq), we identified a distinct activated memory B cell subgroup (CD11chigh CD95high) had a higher proportion of SARS-CoV-2 antigen-labeled cells compared with memory B cells. Our results revealed the diversity of paired BCR repertoire and the non-stochastic pairing of SARS-CoV-2 antigen-specific immunoglobulin heavy and light chains after SARS-CoV-2 infection. The public antibody clonotypes were shared by distinct convalescent individuals. Moreover, several antibodies isolated by LIBRA-seq showed high binding affinity against SARS-CoV-2 receptor-binding domain (RBD) or nucleoprotein (NP) via ELISA assay. Two RBD-reactive antibodies C14646P3S and C2767P3S isolated by LIBRA-seq exhibited high neutralizing activities against both pseudotyped and authentic SARS-CoV-2 viruses in vitro. Our study provides fundamental insights into B cell response following SARS-CoV-2 infection at the single-cell level.

Cardiac Biomarker Abnormalities Are Closely Related to Prognosis in Patients with COVID-19.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is erupting and spreading globally. Cardiovascular complications secondary to the infection have caught notice. This study aims to delineate the relationship of cardiac biomarkers and outcomes in severe cases of corona virus disease 2019 (COVID-19). One hundred forty-eight critically ill adult patients with COVID-19 were enrolled. From these patients, the demographic data, symptoms, cardiac biomarkers, treatments, and clinical outcomes were collected. Data were compared between survivors and non-survivors. Four patients in the non-survivor group were selected, and their cardiac biomarkers were collected and analyzed. Among the 148 patients, the incidence of cardiovascular complications was 19 (12.8%). Five of them were survivors (5.2%), and 14 of them were non-survivors (26.9%). Compared with the survivors, the non-survivors had higher levels of high-sensitivity cardiac troponin I, creatine kinase isoenzyme-MB, myoglobin, and N-terminal pro-brain natriuretic peptide (P < 0.05). The occurrence of cardiovascular events began at 11-15 days after the onset of the disease and reached a peak at 14-20 days. COVID-19 not only is a respiratory disease but also causes damage to the cardiovascular system. Cardiac biomarkers have the potential for early warning and prognostic evaluation in patients with COVID-19. It is recommended that cardiac biomarker monitoring in patients with COVID-19 should be initiated at least from the 11th day of the disease course.

Endothelial cell damage is the central part of COVID-19 and a mouse model induced by injection of the S1 subunit of the spike protein.

Neurologic complications of symptomatic COVID-19 are common. Brain tissues from 13 autopsies of people who died of COVID-19 were examined. Cultured endothelial and neuronal cells were incubated with and wild type mice were injected IV with different spike subunits. In situ analyses were used to detect SARS-CoV-2 proteins and the host response. In 13/13 brains from fatal COVID-19, pseudovirions (spike, envelope, and membrane proteins without viral RNA) were present in the endothelia of microvessels ranging from 0 to 14 positive cells/200× field (mean 4.3). The pseudovirions strongly co-localized with caspase-3, ACE2, IL6, TNFα, and C5b-9. The surrounding neurons demonstrated increased NMDAR2 and neuronal NOS plus decreased MFSD2a and SHIP1 proteins. Tail vein injection of the full length S1 spike subunit in mice led to neurologic signs (increased thirst, stressed behavior) not evident in those injected with the S2 subunit. The S1 subunit localized to the endothelia of microvessels in the mice brain and showed co-localization with caspase-3, ACE2, IL6, TNFα, and C5b-9. The surrounding neurons showed increased neuronal NOS and decreased MFSD2a. It is concluded that ACE2+ endothelial damage is a central part of SARS-CoV2 pathology and may be induced by the spike protein alone. Thus, the diagnostic pathologist can use either hematoxylin and eosin stain or immunohistochemistry for caspase 3 and ACE2 to document the endothelial cell damage of COVID-19.

Risk factors and electrocardiogram characteristics for mortality in critical inpatients with COVID-19.

BACKGROUND: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. HYPOTHESIS: The possible risk factors that lead to death in critical inpatients with coronavirus disease 2019 (COVID-19) are not yet fully understood. METHODS: In this single-center, retrospective study, we enrolled 113 critical patients with COVID-19 from Renmin Hospital of Wuhan University between February 1, 2020 and March 15, 2020. Patients who survived or died were compared. RESULTS: A total of 113 critical patients with COVID-19 were recruited; 50 (44.3%) died, and 63 (55.7%) recovered. The proportion of patients with ventricular arrhythmia was higher in the death group than in the recovery group (P = .021) and was higher among patients with myocardial damage than patients without myocardial damage (P = .013). Multivariate analysis confirmed independent predictors of mortality from COVID-19: age > 70 years (HR 1.84, 95% CI 1.03-3.28), initial neutrophil count over 6.5 × 109 /L (HR 3.43, 95% CI 1.84-6.40), C-reactive protein greater than 100 mg/L (HR 1.93, 95% CI 1.04-3.59), and lactate dehydrogenase over 300 U/L (HR 2.90, 95% CI 1.26-6.67). Immunoglobulin treatment (HR 0.39, 95% CI 0.21-0.73) can reduce the risk of death. Sinus tachycardia (HR 2.94, 95% CI 1.16-7.46) and ventricular arrhythmia (HR 2.79, 95% CI 1.11-7.04) were independent ECG risk factors for mortality from COVID-19. CONCLUSIONS: Old age (>70 years), neutrophilia, C-reactive protein greater than 100 mg/L and lactate dehydrogenase over 300 U/L are high-risk factors for mortality in critical patients with COVID-19. Sinus tachycardia and ventricular arrhythmia are independent ECG risk factors for mortality from COVID-19.

The metabolic and immunological characteristics of pregnant women with COVID-19 and their neonates.

Our aim was to investigate whether SARS-CoV-2 infection raised high risks of late pregnancy complications, and posed health problems in fetuses and neonates. We analyzed the data of COVID-19 pregnant women with COVID-19 during late pregnancy and their neonates. Eleven out of 16 (69%) pregnant women with COVID-19 had ++ or +++ of ketone body in urine. The blood uric acid of pregnant patients was 334 µmol/L (IQR, 269-452). D-dimer and FDP in pregnant patients were 3.32 mg/L (IQR, 2.18-4.21) and 9.6 mg/L (IQR, 5.9-12.4). Results of blood samples collected at birth showed that 16 neonates had leukocytes (15.7 × 109/L (IQR, 13.7-17.2)), neutrophils (11.1 × 109/L (IQR, 9.2-13.2)), CK (401 U/L (IQR, 382-647)), and LDH (445 U/L (IQR, 417-559)). Twenty-four hours after birth, a neonate from COVID-19 woman had fever and positive of SARS-CoV-2 gene. Another woman had strongly positive for SARS-CoV-2 gene (+++) for 4 weeks, and delivered one neonate who had SARS-CoV-2 IgM (46 AU/mL) and IgG (140 AU/mL) on day 1 after birth. In the third trimester, COVID-19 infection in pregnant patients raised high risks of ketonuria, hypercoagulable state, and hyperfibrinolysis, which may lead to severe complications. COVID-19 increased the inflammatory responses of placenta, and fetuses and neonates had potential organ dysregulation and coagulation disorders. There was a potential intrauterine transmission while pregnant women had high titer of SARS-CoV-2, but it is necessary to detect SARS-CoV-2 in the blood cord, placenta, and amniotic fluid to further confirm intrauterine infection of fetuses.

The Metabolic Changes and Immune Profiles in Patients With COVID-19.

To explore the metabolic changes and immune profiles in patients with COVID-19, we analyzed the data of patients with mild and severe COVID-19 as well as young children with COVID-19. Of the leukocytes, 47% (IQR, 33-59) were lymphocytes [2.5 × 109/L (IQR, 2.2-3.3)], and monocytes were 0.51 × 109/L (IQR, 0.45-0.57) in young children with COVID-19. In 32 mild COVID-19 patients, circulating monocytes were 0.45 × 109/L (IQR, 0.36-0.64). Twenty-one severe patients had low PO2 [57 mmHg (IQR, 50-73)] and SO2 [90% (IQR, 86-93)] and high lactate dehydrogenase [580 U/L (IQR, 447-696)], cardiac troponin I [0.07 ng/mL (IQR, 0.02-0.30)], and pro-BNP [498 pg/mL (IQR, 241-1,726)]. Serum D-dimer and FDP were 9.89 mg/L (IQR, 3.62-22.85) and 32.7 mg/L (IQR, 12.8-81.9), and a large number of RBC (46/µL (IQR, 4-242) was presented in urine, a cue of disseminated intravascular coagulation (DIC) in severe patients. Three patients had comorbidity with diabetes, and 18 patients without diabetes also presented high blood glucose [7.4 mmol/L (IQR, 5.9-10.1)]. Fifteen of 21 (71%) severe cases had urine glucose +, and nine of 21 (43%) had urine ketone body +. The increased glucose was partially caused by reduced glucose consumption of cells. Severe cases had extraordinarily low serum uric acid [176 µmol/L (IQR, 131-256)]. In the late stage of COVID-19, severe cases had extremely low CD4+ T cells and CD8+ T cells, but unusually high neutrophils [6.5 × 109/L (IQR, 4.8-9.6)], procalcitonin [0.27 ng/mL (IQR, 0.14-1.94)], C-reactive protein [66 mg/L (IQR, 25-114)] and an extremely high level of interleukin-6. Four of 21 (19%) severe cases had co-infection with fungi, and two of 21 (9%) severe cases had bacterial infection. Our findings suggest that, severe cases had acute respiratory distress syndrome (ARDS) I-III, and metabolic disorders of glucose, lipid, uric acid, etc., even multiple organ dysfunction (MODS) and DIC. Increased neutrophils and severe inflammatory responses were involved in ARDS, MODS, and DIC. With the dramatical decrease of T-lymphocytes, severe cases were susceptible to co-infect with bacteria and fungi in the late stage of COVID-19. In young children, extremely high lymphocytes and monocytes might be associated with the low morbidity of COVID-19. The significantly increased monocytes might play an important role in the recovery of patients with mild COVID-19.

COVID-19 pulmonary pathology: a multi-institutional autopsy cohort from Italy and New York City.

SARS-CoV-2, the etiologic agent of COVID-19, is a global pandemic with substantial mortality dominated by acute respiratory distress syndrome. We systematically evaluated lungs of 68 autopsies from 3 institutions in heavily hit areas (2 USA, 1 Italy). Detailed evaluation of several compartments (airways, alveolar walls, airspaces, and vasculature) was performed to determine the range of histologic features. The cohort consisted of 47 males and 21 females with a median age of 73 years (range 30-96). Co-morbidities were present in most patients with 60% reporting at least three conditions. Tracheobronchitis was frequently present, independent from intubation or superimposed pneumonia. Diffuse alveolar damage (DAD) was seen in 87% of cases. Later phases of DAD were less frequent and correlated with longer duration of disease. Large vessel thrombi were seen in 42% of cases but platelet (CD61 positive) and/or fibrin microthrombi were present at least focally in 84%. Ultrastructurally, small vessels showed basal membrane reduplication and significant endothelial swelling with cytoplasmic vacuolization. In a subset of cases, virus was detected using different tools (immunohistochemistry for SARS-CoV-2 viral spike protein, RNA in situ hybridization, lung viral culture, and electron microscopy). Virus was seen in airway epithelium and type 2 pneumocytes. IHC or in situ detection, as well as viable form (lung culture positive) was associated with the presence of hyaline membranes, usually within 2 weeks but up to 4 weeks after initial diagnosis. COVID-19 pneumonia is a heterogeneous disease (tracheobronchitis, DAD, and vascular injury), but with consistent features in three centers. The pulmonary vasculature, with capillary microthrombi and inflammation, as well as macrothrombi, is commonly involved. Viral infection in areas of ongoing active injury contributes to persistent and temporally heterogeneous lung damage.

Retrospective Study of Risk Factors for Myocardial Damage in Patients With Critical Coronavirus Disease 2019 in Wuhan.

BACKGROUND The novel severe acute respiratory syndrome coronavirus 2 threatens human health, and the mortality rate is higher in patients who develop myocardial damage. However, the possible risk factors for myocardial damage in patients with coronavirus disease 2019 (COVID-19) are not fully known. METHODS AND RESULTS Critical type patients were selected randomly from 204 confirmed COVID-19 cases occurring in Renmin Hospital of Wuhan University from February 1, 2020 to February 24, 2020. Univariate analyses were used to compare the 2 groups: the myocardial damage group and the non-myocardial damage group. A total of 82 critical patients with COVID-19 were recruited: 34 with myocardial damage and 48 without myocardial damage. A total of 30 patients died in the myocardial damage group, and 20 died in the non-myocardial damage group. In univariate analysis, the proportion of elderly patients (>70 years old, 70.59% versus 37.50%; P=0.003) and patients with cardiovascular disease (41.18% versus 12.50%; P=0.003) was higher among myocardial damage patients than among non-myocardial damage patients. Multivariate analysis showed that age >70 years old (hazard ratio [HR], 2.44; 95% CI, 1.01-5.40), CRP (C-reactive protein) >100 mg/L (HR, 1.92; 95% CI, 0.94-3.92), lactate dehydrogenase >300 U/L (HR, 2.67; 95% CI, 1.03-6.90), and lactic acid >3 mmol/L (HR, 3.25; 95% CI, 1.57-6.75) were independent risk factors for myocardial damage in patients with COVID-19. CONCLUSIONS Old age (>70 years old), CRP >100 mg/L, lactate dehydrogenase >300 U/L, and lactic acid >3 mmol/L are high-risk factors related to myocardial damage in critical patients with COVID-19.