SARS-CoV-2: a storm is raging

Efficacy and safety of tocilizumab in COVID-19 patients

In this retrospective study we assessed the efficacy and safety of tocilizumab in patients with critical or severe coronavirus disease 2019 (COVID-19). We enrolled 181 patients admitted to Huoshenshan Hospital (Wuhan, China) with confirmed COVID-19 between January 2020 and February 2020. Ninety-two patients were treated with tocilizumab, and 89 patients were treated conventionally. We analyzed the clinical manifestations, changes in CT scan images, and laboratory tests before and after tocilizumab treatment, and compared these results with the conventionally treated group. A significant reduction in the level of C-reactive protein was observed 1 week after tocilizumab administration. In some cases this meant the end of the IL-6-related cytokine storm. In addition, tocilizumab relieved fever, cough, and shortness of breath with no reported adverse drug reactions. These findings suggest tocilizumab improves clinical outcomes and is effective for treatment of patients with critical or severe COVID-19. However, future clinical trials are needed to better understand the impact of tocilizumab interference with IL-6 and provide a therapeutic strategy for treatment of COVID-19.

An Assessment on Impact of COVID-19 Infection in a Gender Specific Manner

Coronavirus disease 2019 (COVID-19) is caused by novel coronavirus Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first time reported in December 2019 in Wuhan, China and thereafter quickly spread across the globe. Till September 19, 2020, COVID-19 has spread to 216 countries and territories. Severe infection of SARS-CoV-2 cause extreme increase in inflammatory chemokines and cytokines that may lead to multi-organ damage and respiratory failure. Currently, no specific treatment and authorized vaccines are available for its treatment. Renin angiotensin system holds a promising role in human physiological system specifically in regulation of blood pressure and electrolyte and fluid balance. SARS-CoV-2 interacts with Renin angiotensin system by utilizing angiotensin-converting enzyme 2 (ACE2) as a receptor for its cellular entry. This interaction hampers the protective action of ACE2 in the cells and causes injuries to organs due to persistent angiotensin II (Ang-II) level. Patients with certain comorbidities like hypertension, diabetes, and cardiovascular disease are under the high risk of COVID-19 infection and mortality. Moreover, evidence obtained from several reports also suggests higher susceptibility of male patients for COVID-19 mortality and other acute viral infections compared to females. Analysis of severe acute respiratory syndrome coronavirus (SARS) and Middle East respiratory syndrome coronavirus (MERS) epidemiological data also indicate a gender-based preference in disease consequences. The current review addresses the possible mechanisms responsible for higher COVID-19 mortality among male patients. The major underlying aspects that was looked into includes smoking, genetic factors, and the impact of reproductive hormones on immune systems and inflammatory responses. Detailed investigations of this gender disparity could provide insight into the development of patient tailored therapeutic approach which would be helpful in improving the poor outcomes of COVID-19. Graphical abstract.

Ivermectin: an award-winning drug with expected antiviral activity against COVID-19

Ivermectin is an FDA-approved broad-spectrum antiparasitic agent with demonstrated antiviral activity against a number of DNA and RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite this promise, the antiviral activity of ivermectin has not been consistently proven in vivo. While ivermectin's activity against SARS-CoV-2 is currently under investigation in patients, insufficient emphasis has been placed on formulation challenges. Here, we discuss challenges surrounding the use of ivermectin in the context of coronavirus disease-19 (COVID-19) and how novel formulations employing micro- and nanotechnologies may address these concerns.

Making a case for using γδ T cells against SARS-CoV-2

Intensive worldwide efforts are underway to determine both the pathogenesis of SARS-CoV-2 infection and the immune responses in COVID-19 patients in order to develop effective therapeutics and vaccines. One type of cell that may contribute to these immune responses is the γδ T lymphocyte, which plays a key role in immunosurveillance of the mucosal and epithelial barriers by rapidly responding to pathogens. Although found in low numbers in blood, γδ T cells consist the majority of tissue-resident T cells and participate in the front line of the host immune defense. Previous studies have demonstrated the critical protective role of γδ T cells in immune responses to other respiratory viruses, including SARS-CoV-1. However, no studies have profoundly investigated these cells in COVID-19 patients to date. γδ T cells can be safely expanded in vivo using existing inexpensive FDA-approved drugs such as bisphosphonate, in order to test its protective immune response to SARS-CoV-2. To support this line of research, we review insights gained from previous coronavirus research, along with recent findings, discussing the potential role of γδ T cells in controlling SARS-CoV-2. We conclude by proposing several strategies to enhance γδ T cell's antiviral function, which may be used in developing therapies for COVID-19.

Occurrence of pulmonary embolism related to COVID-19

Recent reports have suggested an increased risk of pulmonary embolism (PE) related to COVID-19. The aim of this cohort study is to compare the incidence of PE during a 3-year period and to assess the characteristics of PE in COVID-19. We studied consecutive patients presenting with PE (January 2017-April 2020). Clinical presentation, computed tomography (CT) and biological markers were systematically assessed. We recorded the global number of hospitalizations during the COVID-19 pandemic and during the same period in 2018-2019. We included 347 patients: 326 without COVID-19 and 21 with COVID-19. Patients with COVID-19 experienced more likely dyspnea (p=0.04), had lower arterial oxygen saturation (p<0.001), higher C-reactive protein and white blood cell (WBC) count (p<0.0001 and p=0.001, respectively), and a significantly higher in-hospital mortality (14% versus 3.4%, p=0.04). Among COVID-19 patients, diagnosis of PE was performed at admission in 38% (n=8). COVID-19 patients with diagnosis of PE during hospitalization (n=13) had significantly more dyspnea (p=0.04), lower arterial oxygen saturation (p=0.01), less proximal PE (p=0.02), and higher heart rate (p=0.009), CT severity score (p=0.001), C-reactive protein (p=0.006) and WBC count (p=0.04). During the COVID-19 outbreak, a 97.4% increase of PE incidence was observed as compared to 2017-2019 and the proportion of hospitalizations related to PE was 3.7% versus 1.3% in 2018-2019 (p<0.0001). In conclusion, the COVID-19 pandemic leads to a dramatic increased incidence of PE. Physicians should be aware that PE may be diagnosed at admission, but also after several days of hospitalization, with a different clinical, CT and biological features of thrombotic disease.

Anisocytosis is Associated With Short-Term Mortality in COVID-19 and May Reflect Proinflammatory Signature in Uninfected Ambulatory Adults

BACKGROUND

Red cell distribution width (RDW), a measure of anisocytosis, is observed in chronic inflammation and is a prognostic marker in critically ill patients without COVID-19, but data in COVID-19 are limited.

METHODS

Between March 12 and April 19, 2020, 282 individuals with confirmed COVID-19 and RDW available within 7 days prior to COVID-19 confirmation were evaluated. Individuals were grouped by quartiles of RDW. Association between quartiles of RDW and mortality was assessed using the Kaplan-Meier method and statistical significance was assessed using the log-rank test. The association between RDW and all-cause mortality was further assessed using a Cox proportional hazards model. Plasma cytokine levels in uninfected ambulatory adults without cardiovascular disease (n=38) were measured and bivariate Spearman correlations and principle components analysis were used to identify relationships between cytokine concentrations with RDW.

RESULTS

After adjusting for age, sex, race, cardiovascular disease, and hemoglobin, there was an association between RDW and mortality (Quartile 4 vs Quartile 1: HR 4.04 [1.08-15.07]), with each 1% increment in RDW associated with a 39% increased rate of mortality (HR 1.39 [1.21-1.59]). Remote RDW was also associated with mortality after COVID-19 infection. Among uninfected ambulatory adults without cardiovascular disease, RDW was associated with elevated pro-inflammatory cytokines (TNF-α, IL8, IL6, IL1b), but not regulatory cytokines (TGFb).

CONCLUSIONS

Anisocytosis predicts short-term mortality in COVID-19 patients, often predates viral exposure, and may be related to a pro-inflammatory phenotype. Additional study of whether the RDW can assist in the early identification of pending cytokine storm is warranted.

Increased Metabolic Burden Among Blacks: A Putative Mechanism for Disparate COVID-19 Outcomes

Mounting evidence shows a disproportionate COVID-19 burden among Blacks. Early findings indicate pre-existing metabolic burden (eg, obesity, hypertension and diabetes) as key drivers of COVID-19 severity. Since Blacks exhibit higher prevalence of metabolic burden, we examined the influence of metabolic syndrome on disparate COVID-19 burden. We analyzed data from a NIH-funded study to characterize metabolic burden among Blacks in New York (Metabolic Syndrome Outcome Study). Patients (n=1035) were recruited from outpatient clinics, where clinical and self-report data were obtained. The vast majority of the sample was overweight/obese (90%); diagnosed with hypertension (93%); dyslipidemia (72%); diabetes (61%); and nearly half of them were at risk for sleep apnea (48%). Older Blacks (age≥65 years) were characterized by higher levels of metabolic burden and co-morbidities (eg, heart disease, cancer). In multivariate-adjusted regression analyses, age was a significant (p≤.001) independent predictor of hypertension (OR=1.06; 95% CI: 1.04-1.09), diabetes (OR=1.03; 95% CI: 1.02-1.04), and dyslipidemia (OR=0.98; 95% CI: 0.97-0.99), but not obesity. Our study demonstrates an overwhelmingly high prevalence of the metabolic risk factors related to COVID-19 among Blacks in New York, highlighting disparate metabolic burden among Blacks as a possible mechanism conferring the greater burden of COVID-19 infection and mortality represented in published data.

Evaluation of the Efficacy and Safety of Inhaled Epoprostenol and Inhaled Nitric Oxide for Refractory Hypoxemia in Patients With Coronavirus Disease 2019

OBJECTIVES

The objectives of this study were to evaluate the efficacy and safety of inhaled epoprostenol and inhaled nitric oxide in patients with refractory hypoxemia secondary to coronavirus disease 2019.

DESIGN

Retrospective single-center study.

SETTING

ICUs at a large academic medical center in the United States.

PATIENTS

Thirty-eight adult critically ill patients with coronavirus disease 2019 and refractory hypoxemia treated with either inhaled epoprostenol or inhaled nitric oxide for at least 1 hour between March 1, 2020, and June 30, 2020.

INTERVENTIONS

Electronic chart review.

MEASUREMENTS AND MAIN RESULTS

Of 93 patients screened, 38 were included in the analysis, with mild (4, 10.5%), moderate (24, 63.2%), or severe (10, 26.3%), with acute respiratory distress syndrome. All patients were initiated on inhaled epoprostenol as the initial pulmonary vasodilator and the median time from intubation to initiation was 137 hours (68-228 h). The median change in Pao₂/Fio₂ was 0 (-12.8 to 31.6) immediately following administration of inhaled epoprostenol. Sixteen patients were classified as responders (increase Pao₂/Fio₂ > 10%) to inhaled epoprostenol, with a median increase in Pao₂/Fio₂ of 34.1 (24.3-53.9). The mean change in Pao₂ and Spo₂ was -0.55 ± 41.8 and -0.6 ± 4.7, respectively. Eleven patients transitioned to inhaled nitric oxide with a median change of 11 (3.6-24.8) in Pao₂/Fio₂. A logistic regression analysis did not identify any differences in outcomes or characteristics between the responders and the nonresponders. Minimal adverse events were seen in patients who received either inhaled epoprostenol or inhaled nitric oxide.

CONCLUSIONS

We found that the initiation of inhaled epoprostenol and inhaled nitric oxide in patients with refractory hypoxemia secondary to coronavirus disease 2019, on average, did not produce significant increases in oxygenation metrics. However, a group of patients had significant improvement with inhaled epoprostenol and inhaled nitric oxide. Administration of inhaled epoprostenol or inhaled nitric oxide may be considered in patients with severe respiratory failure secondary to coronavirus disease 2019.

COVID-19 and non-alcoholic fatty liver disease: Two intersecting pandemics

BACKGROUND

Initial evidence from China suggests that most vulnerable subjects to COVID-19 infection suffer from pre-existing illness, including metabolic abnormalities. The pandemic characteristics and high-lethality rate of COVID-19 infection have raised concerns about interactions between virus pathobiology and components of the metabolic syndrome.

METHODS

We harmonized the information from the recent existing literature on COVID-19 acute pandemic and mechanisms of damage in non-alcoholic fatty liver disease (NAFLD), as an example of chronic (non-communicable) metabolic pandemic.

RESULTS

COVID-19-infected patients are more fragile with underlying metabolic illness, including hypertension, cardiovascular disease, type 2 diabetes, chronic lung diseases (e.g. asthma, chronic obstructive pulmonary disease and emphysema) and metabolic syndrome. During metabolic abnormalities, expansion of metabolically active fat ('overfat condition') parallels chronic inflammatory changes, development of insulin resistance and accumulation of fat in configuring NAFLD. The deleterious interplay of inflammatory pathways chronically active in NAFLD and acutely in COVID-19-infected patients, can explain liver damage in a subgroup of patients and might condition a worse outcome in metabolically compromised NAFLD patients. In a subgroup of patients with NAFLD, the underlying liver fibrosis might represent an additional and independent risk factor for severe COVID-19 illness, irrespective of metabolic comorbidities.

CONCLUSIONS

NAFLD can play a role in the outcome of COVID-19 illness due to frequent association with comorbidities. Initial evidences suggest that increased liver fibrosis in NAFLD might affect COVID-19 outcome. In addition, long-term monitoring of post-COVID-19 NAFLD patients is advisable, to document further deterioration of liver damage. Further studies are required in this field.

Development of multi-epitope peptide-based vaccines against SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic involving so far more than 22 million infections and 776,157 deaths. Effective vaccines are urgently needed to prevent SARS-CoV-2 infections. No vaccines have yet been approved for licensure by regulatory agencies. Even though host immune responses to SARS-CoV-2 infections are beginning to be unravelled, effective clearance of virus will depend on both humoral and cellular immunity. Additionally, the presence of Spike (S)-glycoprotein reactive CD4+ T-cells in the majority of convalescent patients is consistent with its significant role in stimulating B and CD8+ T-cells. The search for immunodominant epitopes relies on experimental evaluation of peptides representing the epitopes from overlapping peptide libraries which can be costly and labor-intensive. Recent advancements in B- and T-cell epitope predictions by bioinformatic analysis have led to epitope identifications. Assessing which peptide epitope can induce potent neutralizing antibodies and robust T-cell responses is a prerequisite for the selection of effective epitopes to be incorporated in peptide-based vaccines. This review discusses the roles of B- and T-cells in SARS-CoV-2 infections and experimental validations for the selection of B-, CD4+ and CD8+ T-cell epitopes which could lead to the construction of a multi-epitope peptide vaccine. Peptide-based vaccines are known for their low immunogenicity which could be overcome by incorporating immunostimulatory adjuvants and nanoparticles such as Poly Lactic-co-Glycolic Acid (PLGA) or chitosan.

The Pathophysiology, Diagnosis and Treatment of Corona Virus Disease 2019 (COVID-19)

Since the beginning of this century, beta coronaviruses (CoV) have caused three zoonotic outbreaks. However, little is currently known about the biology of the newly emerged SARS-CoV-2 in late 2019. There is a spectrum of clinical features from mild to severe life threatening disease with major complications like severe pneumonia, acute respiratory distress syndrome, acute cardiac injury and septic shock. The genome of SARS-CoV-2 encodes polyproteins, four structural proteins and six accessory proteins. SARS-CoV-2 tends to utilize Angiotensin-converting enzyme 2 (ACE2) of various mammals. The imbalance between ACE/Ang II/AT1R pathway and ACE2/Ang(1-7)/Mas receptor pathway in the renin-angiotensin system leads to multi-system inflammation. The early symptoms of COVID-19 pneumonia are low to midgrade fever, dry cough and fatigue. Vigilant screening is important. The diagnosis of COVID-19 should be based on imaging findings along with epidemiological history and nucleic acid detection. Isolation and quarantine of suspected cases is recommended. Management is primarily supportive, with newer antiviral drugs/vaccines under investigation.

N-Acetylcysteine: A potential therapeutic agent for SARS-CoV-2

COVID-19, a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread across the globe. Predisposing factors such as age, diabetes, cardiovascular disease, and lowered immune function increase the risk of disease severity. T cell exhaustion, high viral load, and high levels of TNF-ɑ, IL1β, IL6, IL10 have been associated with severe SARS-CoV-2. Cytokine and antigen overstimulation are potentially responsible for poor humoral response to the virus. Lower cellular redox status, which leads to pro-inflammatory states mediated by TNF-ɑ is also potentially implicated. In vivo, in vitro, and human clinical trials have demonstrated N-acetylcysteine (NAC) as an effective method of improving redox status, especially when under oxidative stress. In human clinical trials, NAC has been used to replenish glutathione stores and increase the proliferative response of T cells. NAC has also been shown to inhibit the NLRP3 inflammasome pathway (IL1β and IL18) in vitro, and decrease plasma TNF-ɑ in human clinical trials. Mediation of the viral load could occur through NAC's ability to increase cellular redox status via maximizing the rate limiting step of glutathione synthesis, and thereby potentially decreasing the effects of virally induced oxidative stress and cell death. We hypothesize that NAC could act as a potential therapeutic agent in the treatment of COVID-19 through a variety of potential mechanisms, including increasing glutathione, improving T cell response, and modulating inflammation. In this article, we present evidence to support the use of NAC as a potential therapeutic agent in the treatment of COVID-19.

Serologic Detection of SARS-CoV-2 Infections in Hemodialysis Centers: A Multicenter Retrospective Study in Wuhan, China

RATIONALE & OBJECTIVE

Patients receiving maintenance hemodialysis (MHD) are highly vulnerable to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current study was designed to evaluate the prevalence of SARS-CoV-2 infection based on both nucleic acid testing (NAT) and antibody testing in Chinese patients receiving MHD.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

From December 1, 2019, to March 31, 2020, a total of 1,027 MHD patients in 5 large hemodialysis centers in Wuhan, China, were enrolled. Patients were screened for SARS-CoV-2 infection by symptoms and initial computed tomography (CT) of the chest. If patients developed symptoms after the initial screening was negative, repeat CT was performed. Patients suspected of being infected with SARS-CoV-2 were tested with 2 consecutive throat swabs for viral RNA. In mid-March 2020, antibody testing for SARS-CoV-2 was obtained for all MHD patients.

EXPOSURE

NAT and antibody testing results for SARS-CoV-2.

OUTCOMES

Morbidity, clinical features, and laboratory and radiologic findings.

ANALYTICAL APPROACH

Differences between groups were examined using t test or Mann-Whitney U test, comparing those not infected with those infected and comparing those with infection detected using NAT with those with infection detected by positive serology test results.

RESULTS

Among 1,027 patients receiving MHD, 99 were identified as having SARS-CoV-2 infection, for a prevalence of 9.6%. Among the 99 cases, 52 (53%) were initially diagnosed with SARS-CoV-2 infection by positive NAT; 47 (47%) were identified later by positive immunoglobulin G (IgG) or IgM antibodies against SARS-CoV-2. There was a spectrum of antibody profiles in these 47 patients: IgM antibodies in 5 (11%), IgG antibodies in 35 (74%), and both IgM and IgG antibodies in 7 (15%). Of the 99 cases, 51% were asymptomatic during the epidemic; 61% had ground-glass or patchy opacities on CT of the chest compared with 11.6% among uninfected patients (P<0.001). Patients with hypertensive kidney disease were more often found to have SARS-CoV-2 infection and were more likely to be symptomatic than patients with another primary cause of kidney failure.

LIMITATIONS

Possible false-positive and false-negative results for both NAT and antibody testing; possible lack of generalizability to other dialysis populations.

CONCLUSIONS

Half the SARS-CoV-2 infections in patients receiving MHD were subclinical and were not identified by universal CT of the chest and selective NAT. Serologic testing may help evaluate the overall prevalence and understand the diversity of clinical courses among patients receiving MHD who are infected with SARS-CoV-2.

The pathophysiology of SARS-CoV-2: A suggested model and therapeutic approach

In this paper, a model is proposed of the pathophysiological processes of COVID-19 starting from the infection of human type II alveolar epithelial cells (pneumocytes) by SARS-CoV-2 and culminating in the development of ARDS. The innate immune response to infection of type II alveolar epithelial cells leads both to their death by apoptosis and pyroptosis and to alveolar macrophage activation. Activated macrophages secrete proinflammatory cytokines and chemokines and tend to polarise into the inflammatory M1 phenotype. These changes are associated with activation of vascular endothelial cells and thence the recruitment of highly toxic neutrophils and inflammatory activated platelets into the alveolar space. Activated vascular endothelial cells become a source of proinflammatory cytokines and reactive oxygen species (ROS) and contribute to the development of coagulopathy, systemic sepsis, a cytokine storm and ARDS. Pulmonary activated platelets are also an important source of proinflammatory cytokines and ROS, as well as exacerbating pulmonary neutrophil-mediated inflammatory responses and contributing to systemic sepsis by binding to neutrophils to form platelet-neutrophil complexes (PNCs). PNC formation increases neutrophil recruitment, activation priming and extraversion of these immune cells into inflamed pulmonary tissue, thereby contributing to ARDS. Sequestered PNCs cause the development of a procoagulant and proinflammatory environment. The contribution to ARDS of increased extracellular histone levels, circulating mitochondrial DNA, the chromatin protein HMGB1, decreased neutrophil apoptosis, impaired macrophage efferocytosis, the cytokine storm, the toll-like receptor radical cycle, pyroptosis, necroinflammation, lymphopenia and a high Th17 to regulatory T lymphocyte ratio are detailed.

Neurological consequences of COVID-19: what have we learned and where do we go from here?

The coronavirus disease-19 (COVID-19) pandemic is an unprecedented worldwide health crisis. COVID-19 is caused by SARS-CoV-2, a highly infectious pathogen that is genetically similar to SARS-CoV. Similar to other recent coronavirus outbreaks, including SARS and MERS, SARS-CoV-2 infected patients typically present with fever, dry cough, fatigue, and lower respiratory system dysfunction, including high rates of pneumonia and acute respiratory distress syndrome (ARDS); however, a rapidly accumulating set of clinical studies revealed atypical symptoms of COVID-19 that involve neurological signs, including headaches, anosmia, nausea, dysgeusia, damage to respiratory centers, and cerebral infarction. These unexpected findings may provide important clues regarding the pathological sequela of SARS-CoV-2 infection. Moreover, no efficacious therapies or vaccines are currently available, complicating the clinical management of COVID-19 patients and emphasizing the public health need for controlled, hypothesis-driven experimental studies to provide a framework for therapeutic development. In this mini-review, we summarize the current body of literature regarding the central nervous system (CNS) effects of SARS-CoV-2 and discuss several potential targets for therapeutic development to reduce neurological consequences in COVID-19 patients.

NFATc3 regulation of collagen V expression contributes to cellular immunity to collagen type V and hypoxic pulmonary hypertension

Chronic hypoxia (CH)-induced pulmonary hypertension (PH) results, in part, from T helper-17 (T_H17) cell-mediated perivascular inflammation. However, the antigen(s) involved is unknown. Cellular immunity to collagen type V (col V) develops after ischemia-reperfusion injury during lung transplant and is mediated by naturally occurring (n)T_H17 cells. Col5a1 gene codifies for the α1-helix of col V, which is normally hidden from the immune system within type I collagen in the extracellular matrix. COL5A1 promoter analysis revealed nuclear factor of activated T cells, cytoplasmic 3 (NFATc3) binding sites. Therefore, we hypothesized that smooth muscle NFATc3 upregulates col V expression, leading to nT_H17 cell-mediated autoimmunity to col V in response to CH, representing an upstream mechanism in PH development. To test our hypothesis, we measured indexes of PH in inducible smooth muscle cell (SMC)-specific NFATc3 knockout (KO) mice exposed to either CH (380 mmHg) or normoxia and compared them with wild-type (WT) mice. KO mice did not develop PH. In addition, COL5A1 was one of the 1,792 genes differentially affected by both CH and SMC NFATc3 in isolated intrapulmonary arteries, which was confirmed by RT-PCR and immunostaining. Cellular immunity to col V was determined using a trans vivo delayed-type hypersensitivity assay (Tv-DTH). Tv-DTH response was evident only when splenocytes were used from control mice exposed to CH but not from KO mice, and mediated by nT_H17 cells. Our results suggest that SMC NFATc3 is important for CH-induced PH in adult mice, in part, by regulating the expression of the lung self-antigen COL5A1 protein contributing to col V-reactive nT_H17-mediated inflammation and hypertension.

Potential role for tissue factor in the pathogenesis of hypercoagulability associated with in COVID-19

In December 2019, a new and highly contagious infectious disease emerged in Wuhan, China. The etiologic agent was identified as a novel coronavirus, now known as Severe Acute Syndrome Coronavirus-2 (SARS-CoV-2). Recent research has revealed that virus entry takes place upon the union of the virus S surface protein with the type I transmembrane metallo-carboxypeptidase, angiotensin converting enzyme 2 (ACE-2) identified on epithelial cells of the host respiratory tract. Virus triggers the synthesis and release of pro-inflammatory cytokines, including IL-6 and TNF-α and also promotes downregulation of ACE-2, which promotes a concomitant increase in levels of angiotensin II (AT-II). Both TNF-α and AT-II have been implicated in promoting overexpression of tissue factor (TF) in platelets and macrophages. Additionally, the generation of antiphospholipid antibodies associated with COVID-19 may also promote an increase in TF. TF may be a critical mediator associated with the development of thrombotic phenomena in COVID-19, and should be a target for future study.

Immune Correlates of COVID-19 Control

COVID-19 caused by SARS CoV2 emerged in China at the end of 2019 and soon become a pandemic. Since the virus is novel, pre-existing CoV2-specific immunity is not expected to exist in humans, although studies have shown presence of CoV2 cross-reactive T cells in unexposed individuals. Lack of effective immunity in most individuals along with high infectiousness of the virus has resulted in massive global public health emergency. Intense efforts are on to study viral pathogenesis and immune response to help guide prophylactic and therapeutic interventions as well as epidemiological assessments like transmission modeling. To develop an effective vaccine or biologic therapeutic, it is critical to understand the immune correlates of COVID-19 control. At the same time, whether immunity in recovered individuals is effective for preventing re-infection will be important for informing interventions like social distancing. Key questions that are being investigated regarding immune response in COVID-19 which will help these efforts include, investigations of immune response that distinguishes patients with severe versus mild infection or those that recover relative to those that succumb, durability of immunity in recovered patients and relevance of developed immunity in a cured patient for protection against re-infection as well as value of convalescent plasma from recovered patients as a potential therapeutic modality. This is a broad and rapidly evolving area and multiple reports on status of innate and adaptive immunity against SARS-CoV2 are emerging on a daily basis. While many questions remain unanswered for now, the purpose of this focused review is to summarize the current understanding regarding immune correlates of COVID-19 severity and resolution in order to assist researchers in the field to pursue new directions in prevention and control.

Genome-Wide Asymptomatic B-Cell, CD4 + and CD8 + T-Cell Epitopes, that are Highly Conserved Between Human and Animal Coronaviruses, Identified from SARS-CoV-2 as Immune Targets for Pre-Emptive Pan-Coronavirus Vaccines

Over the last two decades, there have been three deadly human outbreaks of Coronaviruses (CoVs) caused by emerging zoonotic CoVs: SARS-CoV, MERS-CoV, and the latest highly transmissible and deadly SARS-CoV-2, which has caused the current COVID-19 global pandemic. All three deadly CoVs originated from bats, the natural hosts, and transmitted to humans via various intermediate animal reservoirs. Because there is currently no universal pan-Coronavirus vaccine available, two worst-case scenarios remain highly possible: (1) SARS-CoV-2 mutates and transforms into a seasonal "flu-like" global pandemic; and/or (2) Other global COVID-like pandemics will emerge in the coming years, caused by yet another spillover of an unknown zoonotic bat-derived SARS-like Coronavirus (SL-CoV) into an unvaccinated human population. Determining the antigen and epitope landscapes that are conserved among human and animal Coronaviruses as well as the repertoire, phenotype and function of B cells and CD4 ⁺ and CD8 ⁺ T cells that correlate with resistance seen in asymptomatic COVID-19 patients should inform in the development of pan-Coronavirus vaccines ¹ . In the present study, using several immuno-informatics and sequence alignment approaches, we identified several human B-cell, CD4 ⁺ and CD8 ⁺ T cell epitopes that are highly conserved in: ( i ) greater than 81,000 SARS-CoV-2 human strains identified to date in 190 countries on six continents; ( ii ) six circulating CoVs that caused previous human outbreaks of the "Common Cold"; ( iii ) five SL-CoVs isolated from bats; ( iv ) five SL-CoV isolated from pangolins; ( v ) three SL-CoVs isolated from Civet Cats; and ( vi ) four MERS strains isolated from camels. Furthermore, we identified cross-reactive asymptomatic epitopes that: ( i ) recalled B cell, CD4 ⁺ and CD8 ⁺ T cell responses from both asymptomatic COVID-19 patients and healthy individuals who were never exposed to SARS-CoV-2; and ( ii ) induced strong B cell and T cell responses in "humanized" Human Leukocyte Antigen (HLA)-DR/HLA-A*02:01 double transgenic mice. The findings herein pave the way to develop a pre-emptive multi-epitope pan-Coronavirus vaccine to protect against past, current, and potential future outbreaks.

Immune transcriptomes of highly exposed SARS-CoV-2 asymptomatic seropositive versus seronegative individuals from the Ischgl community

To investigate prevalence of ongoing activation of inflammation following asymptomatic SARS-CoV-2 infection we characterized immune cell transcriptomes from 43 asymptomatic seropositive and 52 highly exposed seronegative individuals with few underlying health issues following a community superspreading event. Four mildly symptomatic seropositive individuals examined three weeks after infection as positive controls demonstrated immunological activation. Approximately four to six weeks following the event, the two asymptomatic groups showed no significant differences. Two seropositive patients with underlying genetic disease impacting immunological activation were included (Cystic Fibrosis (CF), Nuclear factor-kappa B Essential Modulator (NEMO) deficiency). CF, but not NEMO, associated with significant immune transcriptome differences including some associated with severe SARS-CoV-2 infection (IL1B, IL17A, respective receptors). All subjects remained in their usual state of health from event through five-month follow-up. Here, asymptomatic infection resolved without evidence of prolonged immunological activation. Inclusion of subjects with underlying genetic disease illustrated the pathophysiological importance of context on impact of immunological response.

COVID-19: benefits and risks of passive immunotherapeutics

Passive immunotherapeutics (PITs), including convalescent plasma, serum, or hyperimmune immunoglobulin, have been of clinical importance during sudden outbreaks since the early twentieth century for the treatment of viral diseases such as severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS) and swine flu (H1N1). With the recent SARS-CoV-2 pandemic, wherein effective antivirals and vaccines are still lacking, an interest in convalescent plasma therapy as a lifesaving option has resurfaced due to its capacity for antigenic neutralization and reducing viremia. This review summarizes convalescent blood products (CBPs) in terms of current technologies and the shortcomings related to the collection, manufacture, pathogen inactivation, and banking of CBPs, with a specific focus on their plausible applications, benefits, and risks in the COVID-19 pandemic.

A phenolic small molecule inhibitor of RNase L prevents cell death from ADAR1 deficiency

The OAS–RNase L system is an innate immunity pathway activated by viral infection. Viral dsRNA stimulates OAS enzymes to produce short 2′,5′-oligoadenylates (2-5A) that activate RNase L, resulting in cleavage of single-stranded (ss) RNA. We discovered a small-molecule inhibitor of RNase L that rescues the toxic phenotype of cells deficient in the dsRNA-editing enzyme ADAR1. ADAR1 destabilizes dsRNA to prevent OAS activity. ADAR1 mutations are responsible for a subset of cases of Aicardi-Goutières syndrome (AGS), a severe neurodevelopmental and inflammatory genetic disease of children with no effective medical therapy. We posit that an RNase L inhibitor may have utility against cases of AGS in which RNase L is activated and other indications where overactivation of RNase L is harmful.

The oligoadenylate synthetase (OAS)–RNase L system is an IFN-inducible antiviral pathway activated by viral infection. Viral double-stranded (ds) RNA activates OAS isoforms that synthesize the second messenger 2-5A, which binds and activates the pseudokinase-endoribonuclease RNase L. In cells, OAS activation is tamped down by ADAR1, an adenosine deaminase that destabilizes dsRNA. Mutation of ADAR1 is one cause of Aicardi-Goutières syndrome (AGS), an interferonopathy in children. ADAR1 deficiency in human cells can lead to RNase L activation and subsequent cell death. To evaluate RNase L as a possible therapeutic target for AGS, we sought to identify small-molecule inhibitors of RNase L. A 500-compound library of protein kinase inhibitors was screened for modulators of RNase L activity in vitro. We identified ellagic acid (EA) as a hit with 10-fold higher selectivity against RNase L compared with its nearest paralog, IRE1. SAR analysis identified valoneic acid dilactone (VAL) as a superior inhibitor of RNase L, with 100-fold selectivity over IRE1. Mechanism-of-action analysis indicated that EA and VAL do not bind to the pseudokinase domain of RNase L despite acting as ATP competitive inhibitors of the protein kinase CK2. VAL is nontoxic and functional in cells, although with a 1,000-fold decrease in potency, as measured by RNA cleavage activity in response to treatment with dsRNA activator or by rescue of cell lethality resulting from self dsRNA induced by ADAR1 deficiency. These studies lay the foundation for understanding novel modes of regulating RNase L function using small-molecule inhibitors and avenues of therapeutic potential.

Efficacy of Early Combination Therapy With Lianhuaqingwen and Arbidol in Moderate and Severe COVID-19 Patients: A Retrospective Cohort Study

Objective

Since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Wuhan City, China, coronavirus disease 2019 (COVID-19) has become a global pandemic. However, no special therapeutic drugs have been identified for COVID-19. The aim of this study was to search for drugs to effectively treat COVID-19.

Materials and Methods

We conducted a retrospective cohort study with a total of 162 adult inpatients (≥18 years old) from Ruijin Hospital (Shanghai, China) and Tongji Hospital (Wuhan, China) between January 27, 2020, and March 10, 2020. The enrolled COVID-19 patients were first divided into the Lianhuaqingwen (LHQW) monotherapy group and the LHQW + Arbidol combination therapy group. Then, these two groups were further classified into moderate and severe groups according to the clinical classification of COVID-19.

Results

The early combined usage of LHQW and Arbidol can significantly accelerate the recovery of patients with moderate COVID-19 by reducing the time to conversion to nucleic acid negativity, the time to chest CT improvement, and the length of hospital stay. However, no benefit was observed in severe COVID-19 patients treated with the combination of LHQW + Arbidol. In this study, both Arbidol and LHQW were well tolerated without serious drug-associated adverse events.

Conclusion

The early combined usage of LHQW and Arbidol may accelerate recovery and improve the prognosis of patients with moderate COVID-19.

Clinical, laboratory and radiological characteristics and outcomes of novel coronavirus (SARS-CoV-2) infection in humans: A systematic review and series of meta-analyses

New evidence on the COVID-19 pandemic is being published daily. Ongoing high-quality assessment of this literature is therefore needed to enable clinical practice to be evidence-based. This review builds on a previous scoping review and aimed to identify associations between disease severity and various clinical, laboratory and radiological characteristics. We searched MEDLINE, CENTRAL, EMBASE, Scopus and LILACS for studies published between January 1, 2019 and March 22, 2020. Clinical studies including ≥10 patients with confirmed COVID-19 of any study design were eligible. Two investigators independently extracted data and assessed risk of bias. A quality effects model was used for the meta-analyses. Subgroup analysis and meta-regression identified sources of heterogeneity. For hospitalized patients, studies were ordered by overall disease severity of each population and this order was used as the modifier variable in meta-regression. Overall, 86 studies (n = 91,621) contributed data to the meta-analyses. Severe disease was strongly associated with fever, cough, dyspnea, pneumonia, any computed tomography findings, any ground glass opacity, lymphocytopenia, elevated C-reactive protein, elevated alanine aminotransferase, elevated aspartate aminotransferase, older age and male sex. These variables typically increased in prevalence by 30-73% from mild/early disease through to moderate/severe disease. Among hospitalized patients, 30-78% of heterogeneity was explained by severity of disease. Elevated white blood cell count was strongly associated with more severe disease among moderate/severe hospitalized patients. Elevated lymphocytes, low platelets, interleukin-6, erythrocyte sedimentation rate and D-dimers showed potential associations, while fatigue, gastrointestinal symptoms, consolidation and septal thickening showed non-linear association patterns. Headache and sore throat were associated with the presence of disease, but not with more severe disease. In COVID-19, more severe disease is strongly associated with several clinical, laboratory and radiological characteristics. Symptoms and other variables in early/mild disease appear non-specific and highly heterogeneous. Clinical Trial Registration: PROSPERO CRD42020170623.

Clinical characterization and risk factors associated with cytokine release syndrome induced by COVID-19 and chimeric antigen receptor T-cell therapy

An excessive immune response during coronavirus disease (COVID-19) can induce cytokine release syndrome (CRS), which is associated with life-threatening complications and disease progression. This retrospective study evaluated the clinical characteristics of severe CRS (sCRS, grade 3–4) induced by severe COVID-19 (40 patients) or chimeric antigen receptor T-cell (CAR-T) therapy as a comparator (41 patients). Grade 4 CRS was significantly more common in the COVID-19 group (15/40 (35.7%) vs. 5/41 (12.2%), P = 0.008). The CAR-T group had more dramatic increase in cytokines, including IL-2, IL-6, IL-10, and IFN-γ. Interestingly, COVID-19 group had significantly higher levels for TNF-α (31.1 pg/ml (16.1–70.0) vs. 3.3 (1.8–9.6), P < 0.001) and lg viral loads were correlated with lg IL-6 (R² = 0.101; P < 0.001) and lg IL-10 (R² = 0.105; P < 0.001). The independent risk factor for COVID-19-related sCRS was hypertension history (OR: 4.876, 95% CI: 2.038–11.668; P < 0.001). Our study demonstrated that there were similar processes but different intensity of inflammatory responses of sCRS in COVID-19 and CAR-T group. The diagnose and management of severe COVID-19-related sCRS can learn lessons from treatment of sCRS induced by CAR-T therapy.

Platelets Can Associate with SARS-Cov-2 RNA and Are Hyperactivated in COVID-19

Rationale: In addition to the overwhelming lung inflammation that prevails in COVID-19, hypercoagulation and thrombosis contribute to the lethality of subjects infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Platelets are chiefly implicated in thrombosis. Moreover, they can interact with viruses and are an important source of inflammatory mediators. While a lower platelet count is associated with severity and mortality, little is known about platelet function during COVID-19. Objective: To evaluate the contribution of platelets to inflammation and thrombosis in COVID-19 patients. Methods and Results: Blood was collected from 115 consecutive COVID-19 patients presenting non-severe (n=71) and severe (n=44) respiratory symptoms. We document the presence of SARS-CoV-2 RNA associated with platelets of COVID-19 patients. Exhaustive assessment of cytokines in plasma and in platelets revealed the modulation of platelet-associated cytokine levels in both non-severe and severe COVID-19 patients, pointing to a direct contribution of platelets to the plasmatic cytokine load. Moreover, we demonstrate that platelets release their alpha- and dense-granule contents in both non-severe and severe forms of COVID-19. In comparison to concentrations measured in healthy volunteers, phosphatidylserine-exposing platelet extracellular vesicles were increased in non-severe, but not in severe cases of COVID-19. Levels of D-dimers, a marker of thrombosis, failed to correlate with any measured indicators of platelet activation. Functionally, platelets were hyperactivated in COVID-19 subjects presenting non-severe and severe symptoms, with aggregation occurring at suboptimal thrombin concentrations. Furthermore, platelets adhered more efficiently onto collagen-coated surfaces under flow conditions. Conclusions: Taken together, the data suggest that platelets are at the frontline of COVID-19 pathogenesis, as they release various sets of molecules through the different stages of the disease. Platelets may thus have the potential to contribute to the overwhelming thrombo-inflammation in COVID-19, and the inhibition of pathways related to platelet activation may improve the outcomes during COVID-19.

Insights on SARS-CoV-2 Molecular Interactions With the Renin-Angiotensin System

The emergence of SARS-CoV-2/human/Wuhan/X1/2019, a virus belonging to the species Severe acute respiratory syndrome-related coronavirus, and the recognition of Coronavirus Disease 2019 (COVID-19) as a pandemic have highly increased the scientific research regarding the pathogenesis of COVID-19. The Renin Angiotensin System (RAS) seems to be involved in COVID-19 natural course, since studies suggest the membrane-bound Angiotensin-converting enzyme 2 (ACE2) works as SARS-CoV-2 cellular receptor. Besides the efforts of the scientific community to understand the virus' molecular interactions with human cells, few studies summarize what has been so far discovered about SARS-CoV-2 signaling mechanisms and its interactions with RAS molecules. This review aims to discuss possible SARS-CoV-2 intracellular signaling pathways, cell entry mechanism and the possible consequences of the interaction with RAS components, including Angiotensin II (Ang II), Angiotensin-(1-7) [Ang-(1-7)], Angiotensin-converting enzyme (ACE), ACE2, Angiotensin II receptor type-1 (AT1), and Mas Receptor. We also discuss ongoing clinical trials and treatment based on RAS cascade intervention. Data were obtained independently by the two authors who carried out a search in the PubMed, Embase, LILACS, Cochrane, Scopus, SciELO and the National Institute of Health databases using Medical Subject Heading terms as "SARS-CoV-2," "COVID-19," "Renin Angiotensin System," "ACE2," "Angiotensin II," "Angiotensin-(1-7)," and "AT1 receptor." Similarly to other members of Coronaviridae family, the molecular interactions between the pathogen and the membrane-bound ACE2 are based on the cleavage of the spike glycoprotein (S) in two subunits. Following the binding of the S1 receptor-binding domain (RBD) to ACE2, transmembrane protease/serine subfamily 2 (TMPRSS2) cleaves the S2 domain to facilitate membrane fusion. It is very likely that SARS-CoV-2 cell entry results in downregulation of membrane-bound ACE2, an enzyme that converts Ang II into Ang-(1-7). This mechanism can result in lung injury and vasoconstriction. In addition, Ang II activates pro-inflammatory cascades when binding to the AT1 Receptor. On the other hand, Ang-(1-7) promotes anti-inflammatory effects through its interactions with the Mas Receptor. These molecules might be possible therapeutic targets for treating COVID-19. Thus, the understanding of SARS-CoV-2 intracellular pathways and interactions with the RAS may clarify COVID-19 physiopathology and open perspectives for new treatments and strategies.

COVID-19: An Immunopathologic Assault

When caring for patients with coronavirus disease 2019 (COVID-19), clinicians have noticed some unusual clinical presentations not observed before, such as profound hypoxia and severe hypotension. Scientists are probing the evidence to explain these issues and many other unanswered questions. Severe acute respiratory syndrome associated with coronavirus 2 presents an unchartered acute and critical care dilemma. Some of the theories and proposed interventions that will improve outcomes for these critically ill patients are explored in this article. Various testing procedures for COVID-19 are described so valid results can be obtained. Clinical presentations are discussed but continue to evolve as the pandemic ravages our society. The psychological impact of this devastation is also addressed from multiple perspectives. The health care provider is faced with an unprecedented, harrowing situation that has become an internal war that also must be confronted. Professional dedication has provided a formidable response to this destructive virus.

Preliminary report of in vitro and in vivo effectiveness of dornase alfa on SARS-CoV-2 infection

Dornase alfa, the recombinant form of the human DNase I enzyme, breaks down neutrophil extracellular traps (NET) that include a vast amount of DNA fragments, histones, microbicidal proteins and oxidant enzymes released from necrotic neutrophils in the highly viscous mucus of cystic fibrosis patients. Dornase alfa has been used for decades in patients with cystic fibrosis to reduce the viscoelasticity of respiratory tract secretions, to decrease the severity of respiratory tract infections, and to improve lung function. Previous studies have linked abnormal NET formations to lung diseases, especially to acute respiratory distress syndrome (ARDS). It is well known that novel coronavirus disease 2019 (COVID-19) pneumonia progresses to ARDS and even multiple organ failure. High blood neutrophil levels are an early indicator of COVID-19 and predict severe respiratory diseases. Also it is reported that mucus structure in COVID-19 is very similar to that in cystic fibrosis due to the accumulation of excessive NET in the lungs. In this study, we showed the recovery of three individuals with COVID-19 after including dornase alfa in their treatment. We followed clinical improvement in the radiological analysis (two of three cases), oxygen saturation (Spo₂), respiratory rate, disappearance of dyspnoea, coughing and a decrease in NET formation and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load after the treatment. Also here, we share our preliminary results suggesting that dornase alfa has an anti-viral effect against SARS-CoV-2 infection in a green monkey kidney cell line, Vero, and a bovine kidney cell line, MDBK, without determined cytotoxicity on healthy peripheral blood mononuclear cells.

Coronavirus disease 2019 (COVID-19) and immune-mediated inflammatory rheumatic diseases: at the crossroads of thromboinflammation and autoimmunity

Inflammation and coagulation are key basic mechanism of protection against all potentially pathogenic mechanical and biological factors targeting human organism from inner and outer environment. On the other hand, uncontrolled inflammation results in hypercoagulation, inhibition of anticoagulation and alteration of mechanisms responsible for resolution of inflammation, while production of “procoagulant” mediators (thrombin, tissue factor and others), activation of platelets and of vascular endothelial cells maintains inflammation. All factors taken together serve as the basis for a pathological process called thromboinflammation or immunothrombosis. Currently thromboinflammation is considered in the broad sense as a universal pathogenetic mechanism of numerous widespread acute and chronic conditions, including immune-mediated (autoimmune) inflammatory rheumatic diseases, oftentimes complicated by severe irreversible damage to vital organs. Thromboinflammation gained specific attention during СОVID-19 (coronavirus disease 2019) pandemic, caused by SARS-Cov-2 (severe acute respiratory syndrome Coronavirus-2). COVID-19 is considered currently as systemic thromboinflammation syndrome, manifesting via generalized thrombosis of arterial and venous macro- and microvasculature, termed as COVID-19-coagulopathy. The paper discusses common pathogenetic coagulopathy mechanisms in COVID-19 and immune-mediated (autoimmune) inflammatory rheumatic diseases (IMRDs), associated with overproduction of antiphospholipid antibodies, activation of the complement system, and dis-regulated synthesis of proinflammatory cytokines, etc. Delineating the autoimmune subtype of thromboinflammation, identification of genetic (i.e., genes encoding the complement system and others) and molecular-biologic biomarkers associated with higher occurrence of COVID-19-coagulopathy are the most relevant undertakings for the current practice. Gaining insights into mechanisms of thromboinflammation and converting them into potential pharmacotherapies of IMDs would facilitate and accelerate the drafting of effective therapeutic strategies for COVID-19. 

Immune transcriptomes of highly exposed SARS-CoV-2 asymptomatic seropositive versus seronegative individuals from the Ischgl community

To investigate prevalence of ongoing activation of inflammation following asymptomatic SARS-CoV-2 infection we characterized immune cell transcriptomes from 43 asymptomatic seropositive and 52 highly exposed seronegative individuals with few underlying health issues following a community superspreading event. Four mildly symptomatic seropositive individuals examined three weeks after infection as positive controls demonstrated immunological activation. Approximately four to six weeks following the event, the two asymptomatic groups showed no significant differences. Two seropositive patients with underlying genetic disease impacting immunological activation were included (Cystic Fibrosis (CF), Nuclear factor-kappa B Essential Modulator (NEMO) deficiency). CF, but not NEMO, associated with significant immune transcriptome differences including some associated with severe SARS-CoV-2 infection (IL1B, IL17A, respective receptors). All subjects remained in their usual state of health from event through five-month follow-up. Here, asymptomatic infection resolved without evidence of prolonged immunological activation. Inclusion of subjects with underlying genetic disease illustrated the pathophysiological importance of context on impact of immunological response.

A rapid, sensitive, and reproducible in vivo PBMC humanized murine model for determining therapeutic-related cytokine release syndrome

Immunotherapy is a powerful treatment strategy being applied to cancer, autoimmune diseases, allergies, and transplantation. Although therapeutic monoclonal antibodies (mAbs) have demonstrated significant clinical efficacy, there is also the potential for severe adverse events, including cytokine release syndrome (CRS). CRS is characterized by the rapid production of inflammatory cytokines following delivery of therapy, with symptoms ranging from mild fever to life-threating pathology and multi-organ failure. Overall there is a paucity of models to reliably and accurately predict the induction of CRS by immune therapeutics. Here, we describe the development of a humanized mouse model based on the NOD-scid IL2rgnull (NSG) mouse to study CRS in vivo. PBMC-engrafted NSG, NSG-MHC-DKO, and NSG-SGM3 mice were used to study cytokine release in response to treatment with mAb immunotherapies. Our data show that therapeutic-stimulated cytokine release in these PBMC-based NSG models captures the variation in cytokine release between individual donors, is drug dependent, occurs in the absence of acute xeno-GVHD, highlighting the specificity of the assay, and shows a robust response following treatment with a TGN1412 analog, a CD28 superagonist. Overall our results demonstrate that PBMC-engrafted NSG models are rapid, sensitive, and reproducible platforms to screen novel therapeutics for CRS.

Cytokine storm and COVID-19: a chronicle of pro-inflammatory cytokines

Coronavirus disease 2019 (COVID-19) has swept the world, unlike any other pandemic in the last 50 years. Our understanding of the disease has evolved rapidly since the outbreak; disease prognosis is influenced mainly by multi-organ involvement. Acute respiratory distress syndrome, heart failure, renal failure, liver damage, shock and multi-organ failure are strongly associated with morbidity and mortality. The COVID-19 disease pathology is plausibly linked to the hyperinflammatory response of the body characterized by pathological cytokine levels. The term 'cytokine storm syndrome' is perhaps one of the critical hallmarks of COVID-19 disease severity. In this review, we highlight prominent cytokine families and their potential role in COVID-19, the type I and II interferons, tumour necrosis factor and members of the Interleukin family. We address various changes in cellular components of the immune response corroborating with changes in cytokine levels while discussing cytokine sources and biological functions. Finally, we discuss in brief potential therapies attempting to modulate the cytokine storm.

Cell-based therapy to reduce mortality from COVID-19: Systematic review and meta-analysis of human studies on acute respiratory distress syndrome

Severe cases of COVID-19 infection, often leading to death, have been associated with variants of acute respiratory distress syndrome (ARDS). Cell therapy with mesenchymal stromal cells (MSCs) is a potential treatment for COVID-19 ARDS based on preclinical and clinical studies supporting the concept that MSCs modulate the inflammatory and remodeling processes and restore alveolo-capillary barriers. The authors performed a systematic literature review and random-effects meta-analysis to determine the potential value of MSC therapy for treating COVID-19-infected patients with ARDS. Publications in all languages from 1990 to March 31, 2020 were reviewed, yielding 2691 studies, of which nine were included. MSCs were intravenously or intratracheally administered in 117 participants, who were followed for 14 days to 5 years. All MSCs were allogeneic from bone marrow, umbilical cord, menstrual blood, adipose tissue, or unreported sources. Combined mortality showed a favorable trend but did not reach statistical significance. No related serious adverse events were reported and mild adverse events resolved spontaneously. A trend was found of improved radiographic findings, pulmonary function (lung compliance, tidal volumes, PaO2 /FiO2 ratio, alveolo-capillary injury), and inflammatory biomarker levels. No comparisons were made between MSCs of different sources.

Persistent Viral Presence Determines the Clinical Course of the Disease in COVID-19

BACKGROUND

The clinical management of coronavirus disease 2019 (COVID-19) is dependent on understanding the underlying factors that contribute to the disease severity. In the absence of effective antiviral therapies, other host immunomodulatory therapies such as targeting inflammatory response are currently being used without clear evidence of their effectiveness. Because inflammation is an essential component of host antiviral mechanisms, therapies targeting inflammation may adversely affect viral clearance and disease outcome.

OBJECTIVE

To understand whether the persistent presence of the virus is a key determinant in the disease severity during COVID-19 and to determine whether the viral reactivation in some patients is associated with infectious viral particles.

METHODS

The data for patients were available including the onset of the disease, duration of viral persistence, measurements of inflammatory markers such as IL-6 and C-reactive protein, chest imaging, disease symptoms, and their durations among others. Follow-up tests were performed to determine whether the viral negative status persists after their recovery.

RESULTS

Our data show that patients with persistent viral presence (>16 days) have more severe disease outcomes including extensive lung involvement and requirement of respiratory support. Two patients who died of COVID-19 were virus-positive at the time of their death. Four patients demonstrated virus-positive status on the follow-up tests, and these patient samples were sent to viral culture facility where virus culture could not be established.

CONCLUSIONS

These data suggest that viral persistence is the key determining factor of the disease severity. Therapies that may impair the viral clearance may impair the host recovery from COVID-19.

Management of childhood-onset autoinflammatory diseases during the COVID-19 pandemic

Concerns regarding the comorbidity as a significant risk factor for Coronavirus Disease-2019 (COVID-19), gave rise to an urgent need for studies evaluating patients with chronic conditions such as autoinflammatory diseases (AIDs). We prepared a web-based survey investigating the clinical findings and contact histories among pediatric patients with AIDs. Confirmed COVID-19 cases, patients with contact history and those with symptoms which were highly suggestive of COVID-19 were called via phone or recruited to a video or face to face appointment. Data of AIDs were obtained from their medical records, retrospectively. Laboratory and screening findings were confirmed by our national health registry website. There were 404 patients (217 female) eligible for the enrollment. During pandemic, 375 (93%) were on colchicine treatment and 48 (11.8%) were receiving biologic treatment. Twenty-four out of 404 patients were admitted to hospital due to COVID-19 suspicion. Severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) was identified through rhinopharyngeal swabs in seven patients, six of whom were only on colchicine treatment. Only one patient with no finding of any severe respiratory complications was hospitalized. All of seven patients recovered completely. Among patients on biologic drugs, neither a symptom nor a positive polymerase chain reaction test for COVID 19 was detected. In conclusion, pediatric patients with AIDs, those receiving biologic treatment and/or colchicine, may not be at increased risk for neither being infected nor the severe disease course.

The potential effects of DPP-4 inhibitors on cardiovascular system in COVID-19 patients

With the outbreak of a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the public healthcare systems are facing great challenges. Coronavirus disease 2019 (COVID-19) could develop into severe pneumonia, acute respiratory distress syndrome and multi-organ failure. Remarkably, in addition to the respiratory symptoms, some COVID-19 patients also suffer from cardiovascular injuries. Dipeptidyl peptidase-4 (DPP-4) is a ubiquitous glycoprotein which could act both as a cell membrane-bound protein and a soluble enzymatic protein after cleavage and release into the circulation. Despite angiotensin-converting enzyme 2 (ACE2), the recently recognized receptor of SARS-CoV and SARS-CoV-2, which facilitated their entries into the host, DPP-4 has been identified as the receptor of middle east respiratory syndrome coronavirus (MERS-CoV). In the current review, we discussed the potential roles of DPP-4 in COVID-19 and the possible effects of DPP-4 inhibitors on cardiovascular system in patients with COVID-19.

Bone Metabolism in SARS-CoV-2 Disease: Possible Osteoimmunology and Gender Implications

Even though inflammatory conditions are known to exert adverse effects on bone metabolism, there are no published data regarding SARS-CoV-2 infection and subsequent fracture risk. We present a brief review of the molecular mechanisms linking inflammatory diseases to increased fracture risk/osteoporosis and of the therapeutic strategies that can prevent bone resorption in patients with inflammatory disease, focusing on the RANK-RANKL system. We also make some considerations on gender differences in infection response and on their implications for survival and for the consequences of COVID-19. Several inflammatory cytokines, especially IL-1, IL-6, and TNF-α, stimulate osteoclast activity, favoring bone resorption through the RANK-RANKL system. Data from the previous SARS-CoV outbreak suggest that the present disease also has the potential to act directly on bone resorption units, although confirmation is clearly needed. Even though the available data are limited, the RANK-RANKL system may provide the best therapeutic target to prevent bone resorption after COVID-19 disease. Vitamin D supplementation in case of deficiency could definitely be beneficial for bone metabolism, as well as for the immune system. Supplementation of vitamin D in case of deficiency could be further advantageous. In COVID-19 patients, it would be useful to measure the bone metabolism markers and vitamin D. Targeting the RANK-RANKL system should be a priority, and denosumab could represent a safe and effective choice. In the near future, every effort should be made to investigate the fracture risk after SARS-CoV-2 infection.

Natural Killer Cell Dysfunction and Its Role in COVID-19

When facing an acute viral infection, our immune systems need to function with finite precision to enable the elimination of the pathogen, whilst protecting our bodies from immune-related damage. In many instances however this "perfect balance" is not achieved, factors such as ageing, cancer, autoimmunity and cardiovascular disease all skew the immune response which is then further distorted by viral infection. In SARS-CoV-2, although the vast majority of COVID-19 cases are mild, as of 24 August 2020, over 800,000 people have died, many from the severe inflammatory cytokine release resulting in extreme clinical manifestations such as acute respiratory distress syndrome (ARDS) and hemophagocytic lymphohistiocytosis (HLH). Severe complications are more common in elderly patients and patients with cardiovascular diseases. Natural killer (NK) cells play a critical role in modulating the immune response and in both of these patient groups, NK cell effector functions are blunted. Preliminary studies in COVID-19 patients with severe disease suggests a reduction in NK cell number and function, resulting in decreased clearance of infected and activated cells, and unchecked elevation of tissue-damaging inflammation markers. SARS-CoV-2 infection skews the immune response towards an overwhelmingly inflammatory phenotype. Restoration of NK cell effector functions has the potential to correct the delicate immune balance required to effectively overcome SARS-CoV-2 infection.

Immunoregulation with mTOR inhibitors to prevent COVID-19 severity: A novel intervention strategy beyond vaccines and specific antiviral medicines

Coronavirus disease 2019 (COVID-19) has become a major global public health concern. The mortality rate for critically ill patients is up to 60%, and, thus, reducing the disease severity and case mortality is a top priority. Currently, cytokine storms are considered as the major cause of critical illness and death due to COVID-19. After a systematical review of the literature, we propose that cross-reactive antibodies associated with antibody-dependent enhancement (ADE) may actually be the cause of cytokine storms. It would be more difficult to develop vaccines for highly pathogenic human coronaviruses (CoVs) if ADE characteristics are taken into consideration. Therefore, it is urgent to find an effective way to prevent the occurrence of severe illness as severe acute respiratory syndrome CoV-2 specific drugs or vaccines are still in development. If the activation of memory B cells can be selectively inhibited in high-risk patients at an early stage of COVID-19 to reduce the production of cross-reactive antibodies against the virus, we speculate that ADE can be circumvented and severe symptoms can be prevented. The mammalian target of rapamycin (mTOR) inhibitors satisfy such needs and it is recommended to conduct clinical trials for mTOR inhibitors in preventing the severity of COVID-19.

The role of IL-6 and other mediators in the cytokine storm associated with SARS-CoV-2 infection

The coronavirus disease 2019 pandemic caused by severe acute respiratory syndrome coronavirus 2 presents with a spectrum of clinical manifestations from asymptomatic or mild, self-limited constitutional symptoms to a hyperinflammatory state ("cytokine storm") followed by acute respiratory distress syndrome and death. The objective of this study was to provide an evidence-based review of the associated pathways and potential treatment of the hyperinflammatory state associated with severe acute respiratory syndrome coronavirus 2 infection. Dysregulated immune responses have been reported to occur in a smaller subset of those infected with severe acute respiratory syndrome coronavirus 2, leading to clinical deterioration 7 to 10 days after initial presentation. A hyperinflammatory state referred to as cytokine storm in its severest form has been marked by elevation of IL-6, IL-10, TNF-α, and other cytokines and severe CD4+ and CD8+ T-cell lymphopenia and coagulopathy. Recognition of at-risk patients could permit early institution of aggressive intensive care and antiviral and immune treatment to reduce the complications related to this proinflammatory state. Several reports and ongoing clinical trials provide hope that available immunomodulatory therapies could have therapeutic potential in these severe cases. This review highlights our current state of knowledge of immune mechanisms and targeted immunomodulatory treatment options for the current coronavirus disease 2019 pandemic.

Diabetes, infection risk and COVID-19

BACKGROUND

Individuals with diabetes are at a greater risk of hospitalization and mortality resulting from viral, bacterial, and fungal infections. The coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has spread quickly to more than 213 countries and claimed 395,779 lives as of June 7, 2020. Notably, in several studies, diabetes is one of the most reported comorbidities in patients with severe COVID-19.

SCOPE OF REVIEW

In this review, I summarize the clinical data on the risk for infectious diseases in individuals with diabetes while highlighting the mechanisms for altered immune regulation. The focus is on coronaviruses. Based on the new clinical data obtained from COVID-19 patients, a discussion of mechanisms, such as cytokine storm, pulmonary and endothelial dysfunction, and hypercoagulation, that may render individuals with diabetes more vulnerable to COVID-19 is provided.

MAJOR CONCLUSIONS

Epidemiological studies show that poorly controlled diabetes is a risk factor for various infectious diseases. Given the global burden of diabetes and the pandemic nature of coronaviruses, understanding how diabetes affects COVID-19 severity is critical to designing tailored treatments and clinical management of individuals affected by diabetes.

Statistical design of Phase II/III clinical trials for testing therapeutic interventions in COVID-19 patients

BACKGROUND

Because of unknown features of the COVID-19 and the complexity of the population affected, standard clinical trial designs on treatments may not be optimal in such patients. We propose two independent clinical trials designs based on careful grouping of patient and outcome measures.

METHODS

Using the World Health Organization ordinal scale on patient status, we classify treatable patients (Stages 3-7) into two risk groups. Patients in Stages 3, 4 and 5 are categorized as the intermediate-risk group, while patients in Stages 6 and 7 are categorized as the high-risk group. To ensure that an intervention, if deemed efficacious, is promptly made available to vulnerable patients, we propose a group sequential design incorporating four factors stratification, two interim analyses, and a toxicity monitoring rule for the intermediate-risk group. The primary response variable (binary variable) is based on the proportion of patients discharged from hospital by the 15^th day. The goal is to detect a significant improvement in this response rate. For the high-risk group, we propose a group sequential design incorporating three factors stratification, and two interim analyses, with no toxicity monitoring. The primary response variable for this design is 30 day mortality, with the goal of detecting a meaningful reduction in mortality rate.

RESULTS

Required sample size and toxicity boundaries are calculated for each scenario. Sample size requirements for designs with interim analyses are marginally greater than ones without. In addition, for both the intermediate-risk group and the high-risk group, the required sample size with two interim analyses is almost identical to analyses with just one interim analysis.

CONCLUSIONS

We recommend using a binary outcome with composite endpoints for patients in Stage 3, 4 or 5 with a power of 90% to detect an improvement of 20% in the response rate, and a 30 day mortality rate outcome for those in Stage 6 or 7 with a power of 90% to detect 15% (effect size) reduction in mortality rate. For the intermediate-risk group, two interim analyses for efficacy evaluation along with toxicity monitoring are encouraged. For the high-risk group, two interim analyses without toxicity monitoring is advised.

Statistical design of Phase II/III clinical trials for testing therapeutic interventions in COVID-19 patients

BACKGROUND

Because of unknown features of the COVID-19 and the complexity of the population affected, standard clinical trial designs on treatments may not be optimal in such patients. We propose two independent clinical trials designs based on careful grouping of patient and outcome measures.

METHODS

Using the World Health Organization ordinal scale on patient status, we classify treatable patients (Stages 3-7) into two risk groups. Patients in Stages 3, 4 and 5 are categorized as the intermediate-risk group, while patients in Stages 6 and 7 are categorized as the high-risk group. To ensure that an intervention, if deemed efficacious, is promptly made available to vulnerable patients, we propose a group sequential design incorporating four factors stratification, two interim analyses, and a toxicity monitoring rule for the intermediate-risk group. The primary response variable (binary variable) is based on the proportion of patients discharged from hospital by the 15th day. The goal is to detect a significant improvement in this response rate. For the high-risk group, we propose a group sequential design incorporating three factors stratification, and two interim analyses, with no toxicity monitoring. The primary response variable for this design is 30 day mortality, with the goal of detecting a meaningful reduction in mortality rate.

RESULTS

Required sample size and toxicity boundaries are calculated for each scenario. Sample size requirements for designs with interim analyses are marginally greater than ones without. In addition, for both the intermediate-risk group and the high-risk group, the required sample size with two interim analyses is almost identical to analyses with just one interim analysis.

CONCLUSIONS

We recommend using a binary outcome with composite endpoints for patients in Stage 3, 4 or 5 with a power of 90% to detect an improvement of 20% in the response rate, and a 30 day mortality rate outcome for those in Stage 6 or 7 with a power of 90% to detect 15% (effect size) reduction in mortality rate. For the intermediate-risk group, two interim analyses for efficacy evaluation along with toxicity monitoring are encouraged. For the high-risk group, two interim analyses without toxicity monitoring is advised.

SARS-CoV-2 Spike 1 Protein Controls Natural Killer Cell Activation via the HLA-E/NKG2A Pathway

Natural killer cells are important in the control of viral infections. However, the role of NK cells during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has previously not been identified. Peripheral blood NK cells from SARS-CoV and SARS-CoV-2 naïve subjects were evaluated for their activation, degranulation, and interferon-gamma expression in the presence of SARS-CoV and SARS-CoV-2 spike proteins. K562 and lung epithelial cells were transfected with spike proteins and co-cultured with NK cells. The analysis was performed by flow cytometry and immune fluorescence. SARS-CoV and SARS-CoV-2 spike proteins did not alter NK cell activation in a K562 in vitro model. On the contrary, SARS-CoV-2 spike 1 protein (SP1) intracellular expression by lung epithelial cells resulted in NK cell-reduced degranulation. Further experiments revealed a concomitant induction of HLA-E expression on the surface of lung epithelial cells and the recognition of an SP1-derived HLA-E-binding peptide. Simultaneously, there was increased modulation of the inhibitory receptor NKG2A/CD94 on NK cells when SP1 was expressed in lung epithelial cells. We ruled out the GATA3 transcription factor as being responsible for HLA-E increased levels and HLA-E/NKG2A interaction as implicated in NK cell exhaustion. We show for the first time that NK cells are affected by SP1 expression in lung epithelial cells via HLA-E/NKG2A interaction. The resulting NK cells' exhaustion might contribute to immunopathogenesis in SARS-CoV-2 infection.