Cytokine storm and leukocyte changes in mild versus severe SARS-CoV-2 infection: Review of 3939 COVID-19 patients in China and emerging pathogenesis and therapy concepts

Does COVID-19 infection increase the risk of pressure injury in critically ill patients?: A narrative review

ABSTRACT

Patients with severe COVID-19 may have endothelial dysfunction and a hypercoagulable state that can cause skin damage. In the presence of external pressure on the tissues, the local inflammatory process regulated by inflammatory cytokines can increase and prolong itself, contributing to the formation of pressure injury (PI). PI is defined as localized damage to the skin or underlying tissues. It usually occurs as a result of intense and/or prolonged pressure in combination with shear. The aim of the study is to perform a narrative review on the physiological evidence of increased risk in the development of PI in critically ill patients with COVID-19.In patients with severe COVID-19 a pattern of tissue damage consistent with complement-mediated microvascular injury was found in the lungs and skin of critically ill COVID-19 patients, suggesting sustained systemic activation of complement pathways. Theoretically, the same thrombogenic vascular changes related to COVID-19 that occur in the skin also occur in the underlying tissues, making patients less tolerant to the harmful effects of pressure and shear. Unlike the syndromes typical of acute respiratory illnesses and other pathologies that commonly lead to intensive care unit admission, COVID-19 and systemic viral spread show that local and systemic factors overlap. This fact may be justified by current epidemiological data showing that the prevalence of PI among intensive care unit patients with COVID-19 was 3 times higher than in those without COVID-19. This narrative review presents physiological evidence to suggesting an increased risk of developing PI in critically ill patients with COVID-19.

Depletion and Dysfunction of Dendritic Cells: Understanding SARS-CoV-2 Infection

Uncontrolled severe acute respiratory syndrome-coronavirus (SARS-CoV)-2 infection is closely related to disorders of the innate immune and delayed adaptive immune systems. Dendritic cells (DCs) “bridge” innate immunity and adaptive immunity. DCs have important roles in defending against SARS-CoV-2 infection. In this review, we summarize the latest research concerning the role of DCs in SARS-CoV-2 infection. We focus on the complex interplay between DCs and SARS-CoV-2: pyroptosis-induced activation; activation of the renin–angiotensin–aldosterone system; and activation of dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin. We also discuss the decline in DC number, the impaired antigen-presentation capability, and the reduced production of type-I interferon of DCs in severe SARS-CoV-2 infection. In addition, we discuss the potential mechanisms for pathological activation of DCs to understand the pattern of SARS-CoV-2 infection. Lastly, we provide a brief overview of novel vaccination and immunotherapy strategies based on DC targeting to overcome SARS-CoV-2 infection.

Interleukin-6-Production Is Responsible for Induction of Hepatic Synthesis of Several Chemokines as Acute-Phase Mediators in Two Animal Models: Possible Significance for Interpretation of Laboratory Changes in Severely Ill Patients

Simple Summary

The release of acute-phase proteins and cytokine storms are considered critical parameters for the progression of COVID-19 disease. The increase in the serum levels of cytokines such as IL6 and IL8 observed in patients primarily infected with the SARS-CoV-2 virus has been used to determine the severity of clinical conditions resulting from infection and for prognostic purposes. Animal models have been used to understand the mechanisms of the changes in homeostasis observed under pathological conditions. In the present study, we therefore report the changes in serum levels and hepatic gene expression of cytokines and chemokines in two different animal models of acute-phase responses. The acute-phase response is a transient emergency response aimed at preserving life and bringing about the changes necessary to reduce and repair tissue damage after the removal of damaging noxious agents. Our data suggest that the liver may be responsible for the increase in the serum levels of cytokines and chemokines as part of the body’s defense response to tissue damage. It is therefore doubtful that inhibiting this response at any stage after infection could improve the prognosis of patients. These results may help to interpret the laboratory changes observed in critically ill patients, as may be the case following SARS-CoV-2 infection.

Abstract

A mild to moderate increase in acute-phase proteins (APPs) and a decrease in serum albumin levels are detected in hospitalized COVID-19 patients. A similar trend is also observed for acute-phase cytokines (APC), mainly IL6, besides chemokines (e.g., CXCL8 and CCL2). However, the source of the chemokines in these patients at different stages of disease remains to be elucidated. We investigated hepatic gene expression of CXC- and CC-chemokines in a model of a localized extrahepatic aseptic abscess and in a model of septicemia produced by the intramuscular injection of turpentine oil (TO) into each hindlimb or lipopolysaccharide (LPS) intraperitoneally (i.p.) in rats and mice (wild-type (WT) and IL6-KO). Together with a striking increase in the serum IL6 level, strong serum CXCL2 and CXCL8 concentrations were detected. Correspondingly, rapid (2 h) upregulation of CXCL1, CXCL2, CXCL5, and CXCL8 was observed in rat liver after intramuscular TO injection. The induction of the gene expression of CXCL1 and CXCL8 was the fastest and strongest. The hepatic CXC-chemokines behaved like positive APPs that depend on IL6 production by activated macrophages recruited to extrahepatic damaged tissue. Chemokine upregulation was greatly reduced in IL6-KO mice. However, IL6 was dispensable in the LPS–APR model, as massive induction of hepatic chemokines studied was measured in IL6-KO mice.

Antioxidant, anti-inflammatory and immunomodulatory roles of vitamins in COVID-19 therapy

oxidative stress is caused by an abundant generation of reactive oxygen species, associated to a diminished capacity of the endogenous systems of the organism to counteract them. Activation of pro-oxidative pathways and boosting of inflammatory cytokines are always encountered in viral infections, including SARS-CoV-2. So, the importance of counteracting cytokine storm in COVID-19 pathology is highly important, to hamper the immunogenic damage of the endothelium and alveolar membranes. Antioxidants prevent oxidative processes, by impeding radical species generation. It has been proved that vitamin intake lowers oxidative stress markers, alleviates cytokine storm and has a potential role in reducing disease severity, by lowering pro-inflammatory cytokines, hampering hyperinflammation and organ failure. For the approached compounds, direct antiviral roles are also discussed in this review, as these activities encompass secretion of antiviral peptides, modulation of angiotensin-converting enzyme 2 receptor expression and interaction with spike protein, inactivation of furin protease, or inhibition of pathogen replication by nucleic acid impairment induction. Vitamin administration results in beneficial effects. Nevertheless, timing, dosage and mutual influences of these micronutrients should be carefullly regarded.

A Comprehensive Biological and Synthetic Perspective on 2-Deoxy-d-Glucose (2-DG), A Sweet Molecule with Therapeutic and Diagnostic Potentials

Glucose, the primary substrate for ATP synthesis, is catabolized during glycolysis to generate ATP and precursors for the synthesis of other vital biomolecules. Opportunistic viruses and cancer cells often hijack this metabolic machinery to obtain energy and components needed for their replication and proliferation. One way to halt such energy-dependent processes is by interfering with the glycolytic pathway. 2-Deoxy-d-glucose (2-DG) is a synthetic glucose analogue that can inhibit key enzymes in the glycolytic pathway. The efficacy of 2-DG has been reported across an array of diseases and disorders, thereby demonstrating its broad therapeutic potential. Recent approval of 2-DG in India as a therapeutic approach for the management of the COVID-19 pandemic has brought renewed attention to this molecule. The purpose of this perspective is to present updated therapeutic avenues as well as a variety of chemical synthetic strategies for this medically useful sugar derivative, 2-DG.

Serum from COVID-19 patients early in the pandemic shows limited evidence of cross-neutralization against variants of concern

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) results in a variety of clinical symptoms ranging from no or mild to severe disease. Currently, there are multiple postulated mechanisms that may push a moderate to severe disease into a critical state. Human serum contains abundant evidence of the immune status following infection. Cytokines, chemokines, and antibodies can be assayed to determine the extent to which a patient responded to a pathogen. We examined serum and plasma from a cohort of patients infected with SARS-CoV-2 early in the pandemic and compared them to negative-control sera. Cytokine and chemokine concentrations varied depending on the severity of infection, and antibody responses were significantly increased in severe cases compared to mild to moderate infections. Neutralization data revealed that patients with high titers against an early 2020 SARS-CoV-2 isolate had detectable but limited neutralizing antibodies against the emerging SARS-CoV-2 Alpha, Beta and Delta variants. This study highlights the potential of re-infection for recovered COVID-19 patients.

The Immune Response to SARS-CoV-2: Mechanisms, Aging, Sequelae and Vaccines

This review seeks to clarify the factors involved in the various immune responses to SARS-CoV-2 infection and the mechanisms that influence the development of COVID-19 with severe evolution. The innate immune response that evolves against SARS-CoV-2 in a complex way is highlighted, integrating multiple pathways by coronaviruses to evade it, in addition to characterizing the adaptive immune response, which can lead to an effective immune response or can contribute to immunopathological imbalance. In turn, host-dependent biomarkers such as age, gender, ABO blood group, and risk factors that contribute to the critical and varied progress of COVID-19 immunopathogenesis were analyzed. Finally, the potential vaccine candidates are presented, capable of generating immune protection with humoral and/or cellular neutralizing responses, in favor of blocking and destroying both the new human coronavirus and its variants, which cause the current pandemic.

重症COVID–19患者における侵襲的人工呼吸管理中のステロイドの投与終了と28日死亡率の関連の検討，後方視的コホート研究(Association between corticosteroid treatment termination during invasive mechanical ventilation and 28–day mortality in severe COVID–19 patients, a retrospective cohort study)

Aims: To investigate the association between corticosteroid treatment termination during invasive mechanical ventilation and 28–day mortality in severe COVID–19 patients.

Methods: The study was a single–center, retrospective cohort study of COVID–19 patients undergoing invasive mechanical ventilation on their scheduled corticosteroid termination day between March 1, 2020, and June 30, 2021. The scheduled corticosteroid termination day was scheduled 10 days after initiation of dexamethasone 6mg orally or 6.6mg intravenously. Patients who terminated corticosteroids during the ventilatory period and did not receive corticosteroids thereafter were defined as the termination group, whereas patients who continued to receive corticosteroids in some form after the scheduled corticosteroid termination day were defined as the continuation group. The primary endpoint was 28–day mortality, and the difference was evaluated using the log–rank test.

Results: The 28–day mortality was found to be 61% (14 of 23 patients) in the termination group, which was significantly higher than the 28–day mortality of 22% (5 of 23 patients) in the continuation group (Hazard Ratio: 3.82, 95% CI: 1.37–10.68; p=0.005).

Conclusions: In severe COVID–19 patients, corticosteroid termination during invasive ventilation is associated with an increased 28–day mortality.

Pathological effects of SARS-CoV-2 on hematological and immunological cells: Alterations in count, morphology, and function

The novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19 outbreak, spread rapidly and infected more than 140 million people with more than three million victims worldwide. The SARS-CoV-2 causes destructive changes in the immunological and hematological system of the host. These alterations appear to play a critical role in disease pathology and the emerging of clinical manifestations. In this review, we aimed to discuss the effect of COVID-19 on the count, function and morphology of immune and blood cells and the role of these changes in the pathophysiology of the disease. Knowledge of these changes may help with better management and treatment of COVID-19 patients.

Jing Si Herbal Drink as a prospective adjunctive therapy for COVID-19 treatment: Molecular evidence and mechanisms

Background

SARS-CoV-2 has led to a sharp increase in the number of hospitalizations and deaths from pneumonia and multiorgan disease worldwide; therefore, SARS-CoV-2 has become a global health problem. Supportive therapies remain the mainstay treatments against COVID-19, such as oxygen inhalation, antiviral drugs, and antibiotics. Traditional Chinese medicine (TCM) has been shown clinically to relieve the symptoms of COVID-19 infection, and TCMs can affect the pathogenesis of SARS-CoV-2 infection in vitro. Jing Si Herbal Drink (JSHD), an eight herb formula jointly developed by Tzu Chi University and Tzu Chi Hospital, has shown potential as an adjuvant treatment for COVID-19 infection. A randomized controlled trial (RCT) of JSHD as an adjuvant treatment in patients with COVID-19 infection is underway

Objectives

This article aims to explore the efficacy of the herbs in JSHD against COVID-19 infection from a mechanistic standpoint and provide a reference for the rational utilization of JSHD in the treatment of COVID-19.

Method

We compiled evidence of the herbs in JSHD to treat COVID-19 in vivo and in vitro.

Results

We described the efficacy and mechanism of action of the active ingredients in JSHD to treat COVID-19 based on experimental evidence. JSHD includes 5 antiviral herbs, 7 antioxidant herbs, and 7 anti-inflammatory herbs. In addition, 2 herbs inhibit the overactive immune system, 1 herb reduces cell apoptosis, and 1 herb possesses antithrombotic ability.

Conclusion

Although experimental data have confirmed that the ingredients in JSHD are effective against COVID-19, more rigorously designed studies are required to confirm the efficacy and safety of JSHD as a COVID-19 treatment.

Circulating B10 regulatory cells are decreased in severe and critical COVID-19

The contribution of B cells in COVID‐19 pathogenesis, beyond the production of specific antibodies against SARS‐CoV‐2, is still not well understood. Since one of their most relevant functional roles includes their immune‐suppressive mechanisms, we decided to evaluate one of the most recognized human B regulatory subpopulations: the IL‐10⁺ B10 cells, during COVID‐19 onset. After stimulation of PBMCs for IL‐10 induction, we employed multiparametric flow cytometry to determine B10 frequencies in severe and critical COVID‐19 patients and then correlated those with clinical and laboratory parameters. Compared with healthy individuals, we detected a significant reduction in the B10 subset in both patient groups, which correlates with some inflammatory parameters that define the disease severity. This evidence suggests an aberrant role of B10 cells in immune responses against SARS‐CoV‐2 that needs to be further explained.

Molecular and Physiological Aspects of SARS-CoV-2 Infection in Women and Pregnancy

Whilst scientific knowledge about SARS-CoV-2 and COVID-19 is rapidly increasing, much of the effects on pregnant women is still unknown. To accommodate pregnancy, the human endometrium must undergo a physiological transformation called decidualization. These changes encompass the remodeling of endometrial immune cells leading to immunotolerance of the semi-allogenic conceptus as well as defense against pathogens. The angiotensin converting enzyme 2 (ACE2) plays an important regulatory role in the renin-angiotensin-system (RAS) and has been shown to be protective against comorbidities known to worsen COVID-19 outcomes. Furthermore, ACE2 is also crucial for decidualization and thus for early gestation. An astounding gender difference has been found in COVID-19 with male patients presenting with more severe cases and higher mortality rates. This could be attributed to differences in sex chromosomes, hormone levels and behavior patterns. Despite profound changes in the female body during pregnancy, expectant mothers do not face worse outcomes compared with non-pregnant women. Whereas mother-to-child transmission through respiratory droplets during labor or in the postnatal period is known, another question of in utero transmission remains unanswered. Evidence of placental SARS-CoV-2 infection and expression of viral entry receptors at the maternal-fetal interface suggests the possibility of in utero transmission. SARS-CoV-2 can cause further harm through placental damage, maternal systemic inflammation, and hindered access to health care during the pandemic. More research on the effects of COVID-19 during early pregnancy as well as vaccination and treatment options for gravid patients is urgently needed.

Cyclosporine A Inhibits Viral Infection and Release as Well as Cytokine Production in Lung Cells by Three SARS-CoV-2 Variants

In December 2019, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started spreading worldwide causing the coronavirus disease 2019 (COVID-19) pandemic. The hyperactivation of the immune system has been proposed to account for disease severity and death in COVID-19 patients. Despite several approaches having been tested, no therapeutic protocol has been approved. Given that Cyclosporine A (CsA) is well-known to exert a strong antiviral activity on several viral strains and an anti-inflammatory role in different organs with relevant benefits in diverse pathological contexts, we tested its effects on SARS-CoV-2 infection of lung cells. We found that treatment with CsA either before or after infection of CaLu3 cells by three SARS-CoV-2 variants: (i) reduces the expression of both viral RNA and proteins in infected cells; (ii) decreases the number of progeny virions released by infected cells; (iii) dampens the virus-triggered synthesis of cytokines (including IL-6, IL-8, IL1α and TNF-α) that are involved in cytokine storm in patients. Altogether, these data provide a rationale for CsA repositioning for the treatment of severe COVID-19 patients.

IMPORTANCE SARS-CoV-2 is the most recently identified member of the betacoronavirus genus responsible for the COVID-19 pandemic. Repurposing of available drugs has been a “quick and dirty” approach to try to reduce mortality and severe symptoms in affected patients initially, and can still represent an undeniable and valuable approach to face COVID-19 as the continuous appearance and rapid diffusion of more “aggressive”/transmissible variants, capable of eluding antibody neutralization, challenges the effectiveness of some anti-SARS-CoV-2 vaccines. Here, we tested a known antiviral and anti-inflammatory drug, Cyclosporine A (CsA), and found that it dampens viral infection and cytokine release from lung cells upon exposure to three different SARS-CoV-2 variants. Knock down of the main intracellular target of CsA, Cyclophilin A, does not phenocopy the drug inhibition of viral infection. Altogether, these findings shed new light on the cellular mechanisms of SARS-CoV-2 infection and provide the rationale for CsA repositioning to treat severe COVID-19 patients.

Association Between Lymphocyte Level and Severity of Coronavirus Disease 2019 Patients: A Cross-sectional Study in Indonesia

BACKGROUND: Coronavirus disease 2019 (COVID-19) pandemic has caused significant health problems globally. COVID-19 should be considered a systemic disease since it involves multiple systems, including the hematopoietic system and the immune system. AIM: This study sought to determine the relationship between the lymphocyte levels and the severity of COVID-19 patients in Indonesia. METHODS: A cross-sectional study was conducted among COVID-19 patients at Dr. Zainoel Abidin Hospital Banda Aceh Indonesia from August 27, to September 20, 2021. The subjects were recruited using consecutive sampling method and the data were obtained at their admission to the hospital. Chi-squared test was used to assess the association between lymphocyte levels and the severity of patients. RESULTS: A total of 280 COVID-19 patients included of which 56.9% (91/160) of the patients with moderate severity, 76.1% (51/67) with a severe condition, and 84.9% (45/53) with critical severity had lymphopenia. There were no patients with lymphocytosis found in this study (0%). The Chi-squared test suggested that the lymphocyte level was significant associated with the severity of COVID-19 patients with p < 0.001. CONCLUSION: Our study suggests that the lower the lymphocyte level, the higher the severity of COVID-19 patients. The level of lymphocyte is therefore potentially to be used as predictor for the disease severity and needs to be monitored regularly in COVID-19 patients.

Cytokine producing ability of peripheral blood cells from COVID-19 patients after unspecific in vitro stimulation

Objective and design

Subjects and methods

Results

Conclusion

Galectin-3 as a potential prognostic biomarker of severe COVID-19 in SARS-CoV-2 infected patients

Severe COVID-19 is associated with a systemic hyperinflammatory response leading to acute respiratory distress syndrome (ARDS), multi-organ failure, and death. Galectin-3 is a ß-galactoside binding lectin known to drive neutrophil infiltration and the release of pro-inflammatory cytokines contributing to airway inflammation. Thus, we aimed to investigate the potential of galectin-3 as a biomarker of severe COVID-19 outcomes. We prospectively included 156 patients with RT-PCR confirmed COVID-19. A severe outcome was defined as the requirement of invasive mechanical ventilation (IMV) and/or in-hospital death. A non-severe outcome was defined as discharge without IMV requirement. We used receiver operating characteristic (ROC) and multivariable logistic regression analysis to determine the prognostic ability of serum galectin-3 for a severe outcome. Galectin-3 levels discriminated well between severe and non-severe outcomes and correlated with markers of COVID-19 severity, (CRP, NLR, D-dimer, and neutrophil count). Using a forward-stepwise logistic regression analysis we identified galectin-3 [odds ratio (OR) 3.68 (95% CI 1.47-9.20), p < 0.01] to be an independent predictor of severe outcome. Furthermore, galectin-3 in combination with CRP, albumin and CT pulmonary affection > 50%, had significantly improved ability to predict severe outcomes [AUC 0.85 (95% CI 0.79-0.91, p < 0.0001)]. Based on the evidence presented here, we recommend clinicians measure galectin-3 levels upon admission to facilitate allocation of appropriate resources in a timely manner to COVID-19 patients at highest risk of severe outcome.

Clinical and antibody characteristics reveal diverse signatures of severe and non-severe SARS-CoV-2 patients

Background

COVID-19 pandemic continues, clarifying signatures in clinical characters and antibody responses between severe and non-severe COVID-19 cases would benefit the prognosis and treatment.

Methods

In this study, 119 serum samples from 37 severe or non-severe COVID-19 patients from the First People's Hospital of Yueyang were collected between January 25 and February 18 2020. The clinical features, antibody responses targeting SARS-CoV-2 spike protein (S) and its different domains, SARS-CoV-2-specific Ig isotypes, IgG subclasses, ACE2 competitive antibodies, binding titers with FcγIIa and FcγIIb receptors, and 14 cytokines were comprehensively investigated. The differences between severe and non-severe groups were analyzed using Mann–Whitney U test or Fisher’s exact test.

Results

Severe group including 9 patients represented lower lymphocyte count, higher neutrophil count, higher level of LDH, total bile acid (TBA) (P < 1 × 10^–4), r-glutaminase (P = 0.011), adenosine deaminase (P < 1 × 10^–4), procalcitonin (P = 0.004), C-reactive protein (P < 1 × 10^–4) and D-dimer (P = 0.049) compared to non-severe group (28 patients). Significantly, higher-level Igs targeting S, different S domains (RBD, RBM, NTD, and CTD), FcγRIIa and FcγRIIb binding capability were observed in a severe group than that of a non-severe group, of which IgG1 and IgG3 were the main IgG subclasses. RBD-IgG were strongly correlated with S-IgG both in severe and non-severe group. Additionally, CTD-IgG was strongly correlated with S-IgG in a non-severe group. Positive RBD-ACE2 binding inhibition was strongly associated with high titers of antibody (S-IgG1, S-IgG3, NTD-IgG, RBD-IgA, NTD-IgA, and CTD-IgA) especially RBD-IgG and CTD-IgG in the severe group, while in the non-severe group, S-IgG3, RBD-IgG, NTD-IgG, and NTD-IgM were correlated with ACE2 blocking rate. S-IgG1, NTD-IgM and S-IgM were negatively associated with illness day in a severe group, while S-IgG3, RBD-IgA, CTD-IgA in the severe group (r = 0.363, P = 0.011) and S-IgG1, NTD-IgA, CTD-IgA in the non-severe group were positively associated with illness day. Moreover, GRO-α, IL-6, IL-8, IP-10, MCP-1, MCP-3, MIG, and BAFF were also significantly elevated in the severe group.

Conclusion

Antibody detection provides important clinical information in the COVID-19 process. The different signatures in Ig isotypes, IgG subclasses, antibody specificity between the COVID-19 severe and non-severe group will contribute to future therapeutic and preventive measures development.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-00940-w.

Immunological Biomarkers in Blood to Monitor the Course and Therapeutic Outcomes of COVID-19

BACKGROUND

The COVID-19 pandemic has posed a great challenge to the medical community because little is known about its clinical course, therapeutic options, and laboratory monitoring tools for diagnosis, prognosis, and surveillance. This review focuses on immune biomarkers that can be measured in peripheral blood in a clinical laboratory under routine conditions to monitor the innate immune system response in the acute phase, as well as the adaptive immune response established both after infection and vaccination.

METHODS

A PubMed search was performed covering January 2020 to June 2021 to extract biomarkers suitable for monitoring the immune response and outcome of COVID-19 and therapeutic interventions, including vaccination.

RESULTS

To monitor the innate immune response, cytokines such as interleukin-6 or acute phase reactants such as C-reactive protein or procalcitonin can be measured on autoanalyzers complemented by automated white blood cell differential counts. The adaptive immune response can be followed by commercially available enzyme-linked immune spot assays to assess the specific activation of T cells or by monitoring immunoglobulin A (IgA), IgM, and IgG antibodies in serum to follow B-cell activation. As antigens of the SARS-CoV-2 virus, spike and nucleocapsid proteins are particularly suitable and allow differentiation between the immune response after infection or vaccination.

CONCLUSIONS

Routine immune monitoring of COVID-19 is feasible in clinical laboratories with commercially available instruments and reagents. Strategies such as whether biomarkers reflecting the response of the innate and adaptive immune system can be used to make predictions and assist in individualizing therapeutic interventions or vaccination strategies need to be determined in appropriate clinical trials. Promising preliminary data are already available based on single-center reports and completed or ongoing vaccination trials.

Blood transcriptomes of SARS-CoV-2 infected kidney transplant recipients demonstrate immune insufficiency

BACKGROUND

Kidney transplant recipients (KTRs) with COVID-19 have poor outcomes compared to non-KTRs. To provide insight into management of immunosuppression during acute illness, we studied immune signatures from the peripheral blood during and after COVID-19 infection from a multicenter KTR cohort.□.

METHODS

Clinical data were collected by chart review. PAXgene blood RNA was poly-A selected and RNA sequencing was performed to evaluate transcriptome changes.

RESULTS

A total of 64 cases of COVID-19 in KTRs were enrolled, including 31 acute cases (< 4 weeks from diagnosis) and 33 post-acute cases (>4 weeks). In the blood transcriptome of acute cases, we identified differentially expressed genes (DEGs) in positive or negative association COVID-19 severity scores. Functional enrichment analyses showed upregulation of neutrophil and innate immune pathways, but downregulation of T-cell and adaptive immune-activation pathways proportional to severity score. This finding was independent of lymphocyte count and despite reduction in immunosuppression (IS) in most KTRs. Comparison with post-acute cases showed "normalization" of these enriched pathways after >4 weeks, suggesting recovery of adaptive immune system activation despite reinstitution of IS. The latter analysis was adjusted for COVID-19 severity score and lymphocyte count. DEGs associated with worsening disease severity in a non-KTR cohort with COVID-19 (GSE152418) showed significant overlap with KTRs in these identified enriched pathways.

CONCLUSION

Blood transcriptome of KTRs affected by COVID-19 shows decrease in T-cell and adaptive immune activation pathways during acute disease that associate with severity despite IS reduction and show recovery after acute illness.

SIGNIFICANCE STATEMENT

Kidney transplant recipients (KTRs) are reported to have worse outcomes with COVID-19, and empiric reduction of maintenance immunosuppression is pursued. Surprisingly, reported rates of acute rejection have been low despite reduced immunosuppression. We evaluated the peripheral blood transcriptome of 64 KTRs either during or after acute COVID-19. We identified transcriptomic signatures consistent with suppression of adaptive T-cell responses which significantly associated with disease severity and showed evidence of recovery after acute disease, even after adjustment for lymphocyte number. Our transcriptomic findings of immune-insufficiency during acute COVID-19 provide an explanation for the low rates of acute rejection in KTRs despite reduced immunosuppression. Our data support the approach of temporarily reducing T -cell-directed immunosuppression in KTRs with acute COVID-19.

SARS-CoV-2 treatment effects induced by ACE2-expressing microparticles are explained by the oxidized cholesterol-increased endosomal pH of alveolar macrophages

Exploring the cross-talk between the immune system and advanced biomaterials to treat SARS-CoV-2 infection is a promising strategy. Here, we show that ACE2-overexpressing A549 cell-derived microparticles (AO-MPs) are a potential therapeutic agent against SARS-CoV-2 infection. Intranasally administered AO-MPs dexterously navigate the anatomical and biological features of the lungs to enter the alveoli and are taken up by alveolar macrophages (AMs). Then, AO-MPs increase the endosomal pH but decrease the lysosomal pH in AMs, thus escorting bound SARS-CoV-2 from phago-endosomes to lysosomes for degradation. This pH regulation is attributable to oxidized cholesterol, which is enriched in AO-MPs and translocated to endosomal membranes, thus interfering with proton pumps and impairing endosomal acidification. In addition to promoting viral degradation, AO-MPs also inhibit the proinflammatory phenotype of AMs, leading to increased treatment efficacy in a SARS-CoV-2-infected mouse model without side effects. These findings highlight the potential use of AO-MPs to treat SARS-CoV-2-infected patients and showcase the feasibility of MP therapies for combatting emerging respiratory viruses in the future.

Identification of SARS-CoV-2 Variants and Their Clinical Significance in Hefei, China

The ongoing coronavirus disease 2019 (COVID-19) pandemic represents one of the most exigent threats of our lifetime to global public health and economy. As part of the pandemic, from January 10 to March 10, 2020, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) began to spread in Hefei (Anhui Province, China) with a total of 174 confirmed cases of COVID-19. During this period, we were able to gather critical information on the transmission and evolution of pathogens through genomic surveillance. Particularly, the objective of our study was to track putative variants of SARS-CoV-2 circulating in Hefei for the first time and contribute to the global effort toward elucidating the molecular epidemic profile of the virus. Patients who showed symptoms of COVID-19 were routinely tested for SARS-CoV-2 infections via RT-PCR at the First Affiliated Hospital of Anhui Medical University. Whole-genome sequencing was performed on 97 clinical samples collected from 29 confirmed COVID-19 patients. As a result, we identified a local novel single-nucleotide polymorphism site (10,380) harboring a G → T mutation (Gly → Val) in Hefei. Further phylogenetic network analysis with all the sequences of SARS-CoV-2 deposited in GenBank collected in East and Southeast Asia revealed a local subtype of S-type SARS-CoV-2 (a1) harboring a C → T synonymous mutation (Leu) at position 18,060 of ORF1b, likely representing a local SARS-CoV-2 mutation site that is obviously concentrated in Hefei and the Yangtze River Delta region. Moreover, clinical investigation on the inflammatory cytokine profile of the patients suggested that mutations at positions 18,060 (the shared variable site of subtype a1) and 28,253(harboring a C → T synonymous mutation, Phe) were associated with milder immune responses in the patients.

Bulbus Fritillariae Cirrhosae as a Respiratory Medicine: Is There a Potential Drug in the Treatment of COVID-19?

Bulbus fritillariae cirrhosae (BFC) is one of the most used Chinese medicines for lung disease, and exerts antitussive, expectorant, anti-inflammatory, anti-asthmatic, and antioxidant effects, which is an ideal therapeutic drug for respiratory diseases such as ARDS, COPD, asthma, lung cancer, and pulmonary tuberculosis. Through this review, it is found that the therapeutic mechanism of BFC on respiratory diseases exhibits the characteristics of multi-components, multi-targets, and multi-signaling pathways. In particular, the therapeutic potential of BFC in terms of intervention of “cytokine storm”, STAT, NF-κB, and MAPK signaling pathways, as well as the renin-angiotensin system (RAS) that ACE is involved in. In the “cytokine storm” of SARS-CoV-2 infection there is an intense inflammatory response. ACE2 regulates the RAS by degradation of Ang II produced by ACE, which is associated with SARS-CoV-2. For COVID-19, may it be a potential drug? This review summarized the research progress of BFC in the respiratory diseases, discussed the development potentiality of BFC for the treatment of COVID-19, explained the chemical diversity and biological significance of the alkaloids in BFC, and clarified the material basis, molecular targets, and signaling pathways of BFC for the respiratory diseases. We hope this review can provide insights on the drug discovery of anti-COVID-19.

Factors associated with prolonged length of hospital stay among COVID-19 cases admitted to the largest treatment center in Eastern Ethiopia

INTRODUCTION

The hospital admissions load and how long each patient will stay in the hospital should be known to prevent the overwhelming of the health system during coronavirus disease 2019 era. Even though the length of hospital stay could vary due to different factors, the factors that affect the stay are not well characterized yet, particularly in the resource-limited settings. Knowing the time spent by the coronavirus disease 2019 patients in the hospital and its associated factors are important to prioritize mobilizing resources, such as beds, pharmacological and non-pharmacological supplies, and health personnel. Therefore, this study was intended to determine the median and identify factors associated with the length of hospital stay among coronavirus disease 2019 cases.

METHODS

A facility-based cross-sectional study design was implemented on 394 randomly selected hospitalized patients. Epidata Version 3.1 software was used for data entry, and further analysis was done using Stata version 14.2 software. Frequencies, median with interquartile range, and chi-square test were performed. A logistic regression model was used to identify the association between outcome and explanatory variables. The statistical significance was declared at p-value of less than 0.05 at 95% confidence interval.

RESULTS

The analysis was done for a total of 394 cases admitted for coronavirus disease 2019. The median age of the study participants was 40 years with interquartile range of 28-60 years. The median length of hospital stay was 12 days with the interquartile range of 8-17 days. The patients presented with shortness of breathing (AOR = 2.74, 95% confidence interval: 1.33-5.66), incident organ failure (AOR = 3.65, 95% confidence interval: 1.15-11.58), increased leukocyte count (AOR = 0.95; 95% confidence interval: 0.91-0.99), and blood urea nitrogen (AOR = 0.98, 95% confidence interval: 0.97-0.99) had a significant association with prolonged hospital stay.

CONCLUSION

This study demonstrated that the proportion of patients stayed above the median hospital stay of the total patients was 185 (46.9%) with the median length of 12 (interquartile range = 8-17) days. Patients presented with difficulty of breathing, had incident organ failure, had decreased leukocyte, and blood urea nitrogen level should be estimated to stay longer in the hospital. Hence, patients with prolonged hospital length of stay associating factors should be expected to consume more pharmacological and non-pharmacological resources during hospital care receiving.

Postmortem high-dimensional immune profiling of severe COVID-19 patients reveals distinct patterns of immunosuppression and immunoactivation

A complete diagnostic autopsy is the gold-standard to gain insight into Coronavirus disease 2019 (COVID-19) pathogenesis. To delineate the in situ immune responses to SARS-CoV-2 viral infection, here we perform comprehensive high-dimensional transcriptional and spatial immune profiling in 22 COVID-19 decedents from Wuhan, China. We find TIM-3-mediated and PD-1-mediated immunosuppression as a hallmark of severe COVID-19, particularly in men, with PD-1+ cells being proximal rather than distal to TIM-3+ cells. Concurrently, lymphocytes are distal, while activated myeloid cells are proximal, to SARS-CoV-2 viral antigens, consistent with prevalent SARS-CoV-2 infection of myeloid cells in multiple organs. Finally, viral load positively correlates with specific immunosuppression and dendritic cell markers. In summary, our data show that SARS-CoV-2 viral infection induces lymphocyte suppression yet myeloid activation in severe COVID-19, so these two cell types likely have distinct functions in severe COVID-19 disease progression, and should be targeted differently for therapy.

Innate immune deficiencies are associated with severity and poor prognosis in patients with COVID-19

COVID-19 can cause acute respiratory distress syndrome, leading to death in many individuals. Evidence of a deleterious role of the innate immune system is accumulating, but the precise mechanisms involved remain unclear. In this study, we investigated the links between circulating innate phagocytes and severity in COVID-19 patients. We performed in-depth phenotyping of neutrophil and monocyte subpopulations and measured soluble activation markers in plasma. Additionally, anti-microbial functions (phagocytosis, oxidative burst, and NETosis) were evaluated on fresh cells from patients. Neutrophils and monocytes had a strikingly disturbed phenotype, and elevated concentrations of activation markers (calprotectin, myeloperoxidase, and neutrophil extracellular traps) were measured in plasma. Critical patients had increased CD13^low immature neutrophils, LOX-1 + and CCR5 + immunosuppressive neutrophils, and HLA-DR^low downregulated monocytes. Markers of immature and immunosuppressive neutrophils were strongly associated with severity. Moreover, neutrophils and monocytes of critical patients had impaired antimicrobial functions, which correlated with organ dysfunction, severe infections, and mortality. Together, our results strongly argue in favor of a pivotal role of innate immunity in COVID-19 severe infections and pleads for targeted therapeutic options.

Innate immune deficiencies are associated with severity and poor prognosis in patients with COVID-19

COVID-19 can cause acute respiratory distress syndrome, leading to death in many individuals. Evidence of a deleterious role of the innate immune system is accumulating, but the precise mechanisms involved remain unclear. In this study, we investigated the links between circulating innate phagocytes and severity in COVID-19 patients. We performed in-depth phenotyping of neutrophil and monocyte subpopulations and measured soluble activation markers in plasma. Additionally, anti-microbial functions (phagocytosis, oxidative burst, and NETosis) were evaluated on fresh cells from patients. Neutrophils and monocytes had a strikingly disturbed phenotype, and elevated concentrations of activation markers (calprotectin, myeloperoxidase, and neutrophil extracellular traps) were measured in plasma. Critical patients had increased CD13^low immature neutrophils, LOX-1 + and CCR5 + immunosuppressive neutrophils, and HLA-DR^low downregulated monocytes. Markers of immature and immunosuppressive neutrophils were strongly associated with severity. Moreover, neutrophils and monocytes of critical patients had impaired antimicrobial functions, which correlated with organ dysfunction, severe infections, and mortality. Together, our results strongly argue in favor of a pivotal role of innate immunity in COVID-19 severe infections and pleads for targeted therapeutic options.

Potential and Possible Therapeutic Effects of Melatonin on SARS-CoV-2 Infection

The absence of effective drugs for COVID-19 prevention and treatment requires the search for new candidates among approved medicines. Fundamental studies and clinical observations allow us to approach an understanding of the mechanisms of damage and protection from exposure to SARS-CoV-2, to identify possible points of application for pharmacological interventions. In this review we presented studies on the anti-inflammatory, antioxidant, and immunotropic properties of melatonin. We have attempted to present scientifically proven mechanisms of action for the potential therapeutic use of melatonin during SARS-CoV-2 infection. A wide range of pharmacological properties allows its inclusion as an effective addition to the methods of prevention and treatment of COVID-19.

Quadruple-negative RT-PCR assay for COVID-19, but clinically and radiologically COVID pneumonia with POTS: Case report and case-based review

A 25-year-old woman with a background history of bronchial asthma and intellectual disability presented to hospital with progressively worsening dyspnoea. Despite testing negative four times for coronavirus disease infection by nasopharyngeal swab reverse-transcriptase polymerase chain reaction, her clinical symptoms of hypoxaemic respiratory failure and radiological findings on computed tomography pulmonary angiogram were consistent with coronavirus disease pneumonia. Although she made a quick recovery in the intensive care unit with a combination of empirical antibiotics, corticosteroids, high flow nasal oxygen, therapeutic anticoagulation and awake semi proning, her protracted hospital course due to persistent sinus tachycardia remained challenging. A diagnosis of potential postural orthostatic tachycardia syndrome was explored during the acute phase of illness following an active stand test and exclusion of other causes. She was treated with beta blockers as she failed to improve with non-pharmacological measures. We searched for similar cases by analysing the literature databases. Our case aims to stress the importance of recognising and treating patients with negative nasal reverse-transcriptase polymerase chain reaction swabs as coronavirus disease infection, especially if there is strong evidence of clinical and radiological findings where diagnosis is often under recognised in asthmatics with intellectual disability.

Experimental Models of COVID-19

COVID-19 is the most consequential pandemic of the 21st century. Since the earliest stage of the 2019-2020 epidemic, animal models have been useful in understanding the etiopathogenesis of SARS-CoV-2 infection and rapid development of vaccines/drugs to prevent, treat or eradicate SARS-CoV-2 infection. Early SARS-CoV-1 research using immortalized in-vitro cell lines have aided in understanding different cells and receptors needed for SARS-CoV-2 infection and, due to their ability to be easily manipulated, continue to broaden our understanding of COVID-19 disease in in-vivo models. The scientific community determined animal models as the most useful models which could demonstrate viral infection, replication, transmission, and spectrum of illness as seen in human populations. Until now, there have not been well-described animal models of SARS-CoV-2 infection although transgenic mouse models (i.e. mice with humanized ACE2 receptors with humanized receptors) have been proposed. Additionally, there are only limited facilities (Biosafety level 3 laboratories) available to contribute research to aid in eventually exterminating SARS-CoV-2 infection around the world. This review summarizes the most successful animal models of SARS-CoV-2 infection including studies in Non-Human Primates (NHPs) which were found to be susceptible to infection and transmitted the virus similarly to humans (e.g., Rhesus macaques, Cynomolgus, and African Green Monkeys), and animal models that do not require Biosafety level 3 laboratories (e.g., Mouse Hepatitis Virus models of COVID-19, Ferret model, Syrian Hamster model). Balancing safety, mimicking human COVID-19 and robustness of the animal model, the Murine Hepatitis Virus-1 Murine model currently represents the most optimal model for SARS-CoV-2/COVID19 research. Exploring future animal models will aid researchers/scientists in discovering the mechanisms of SARS-CoV-2 infection and in identifying therapies to prevent or treat COVID-19.

Subclinical myocardial injury, coagulopathy, and inflammation in COVID-19: A meta-analysis of 41,013 hospitalized patients

Background

Infection with the SARS-CoV-2 virus can lead to myocardial injury, evidenced by increases in specific biomarkers and imaging.

Objective

To quantify the association between biomarkers of myocardial injury, coagulation, and severe COVID-19 and death in hospitalized patients.

Methods

Studies were identified through a systematic search of indexed articles in PubMed, Embase, CINAHL, Cochrane, Web of Science, and Scopus, published between December 2019 to August 2021. Effect estimates from individual studies for association between markers of myocardial injury (Troponin), myocardial stretch (N-terminal-pro hormone BNP, NT-proBNP), and coagulopathy (D-Dimer) and death or severe/critical COVID-19 were pooled using inverse variance weighted random-effects model. Odds Ratios (OR), Hazard Ratios (HR), and 95% Confidence Intervals (CI) were pooled separately and reported by outcomes of critical/severe COVID-19 and death. A meta-analysis of proportions was also performed to summarize the pooled prevalence of co-morbidities in patients hospitalized with COVID-19.

Results

We included 62 articles, with a total of 41,013 patients. The pooled proportion of patients with history of hypertension was 39% (95% CI: 34-44%); diabetes, 21% (95% CI: 18%-24%); coronary artery disease, 13% (95% CI: 10-16%); chronic obstructive pulmonary disease, 7% (95% CI: 5-8%), and history of cancer, 5% (95% CI: 4-7%). Elevated troponin was associated with higher pooled odds of critical/severe COVID-19 and death [Odds Ratio (OR: 1.76, 95% CI: 1.42-2.16)]; and also separately for death (OR: 1.72, 95% CI: 1.32-2.25), and critical/severe COVID-1919 (OR: 1.93, 95% CI: 1.45-2.40). Elevations in NT-proBNP were also associated with higher severe COVID-19 and death (OR: 3.00, 95% CI: 1.58-5.70). Increases in D-dimer levels was also significantly associated with critical/severe COVID-19 and death (pooled OR: 1.38, 95% CI: 1.07-1.79).

Conclusions

This meta-analysis synthesizes existing evidence showing that myocardial injury, and coagulopathy are complications of COVID-19. The durability of these complications and their contributions to long-term cardiac implications of the disease is still being investigated. Patients who have recovered from COVID-19 may benefit from minimally invasive assessment for markers of myocardial injury, stretch and coagulopathy for early risk stratification purposes.

The Predictive Value of Cell Blood Count Parameters to Diagnose Pulmonary Embolism in Patients with SARS-CoV-2 Infection: A Case Control Study

Introduction: Acute pulmonary embolism (aPE) is frequently associated with coronavirus infectious disease-2019 (COVID-19) with an incidence of more than 16%. Among the new promising biomarkers of aPE, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) showed correlations with aPE prognosis. The aim of this study was to conduct an exploratory analysis to check the possible role of cell blood count (CBC) parameters as diagnostic and prognostic biomarkers of aPE in COVID-19 patients. Materials and Methods: A case control study was conducted. Two populations were compared: (i) patients hospitalised from 31 January 2020 to 30 June 2021 with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection and aPE confirmed at angio computed tomography (aCT) or pulmonary scintigraphy (COVID-19 aPE group); (ii) patients hospitalised from 31 January 2017 to 30 June 2021 without SARS-CoV-2 infection whose suspicion of aPE was excluded by aCT or pulmonary scintigraphy (no-aPE group). Results: Overall, 184 patients were included in the study, 83 in COVID-19 aPE group and 101 in no-aPE group. At the univariate analysis, COVID-19 patients with aPE had higher NLR, PLR, neutrophil and lymphocyte counts than patients without aPE (p < 0.05). No significant difference was found in mean platelet volume and platelet counts. No difference in mortality rate was detected. At the multivariate analysis, neutrophil and lymphocyte counts were both associated with diagnostic of aPE while no CBC parameters were associated with mortality at day#7. Conclusions: Neutrophiland lymphocyte counts could be predictors of the early detection of aPE in COVID-19 patients. The value of CBC indices as biomarkers of aPE in daily clinical practice needs to be investigated in further studies.

Monoclonal antibodies for COVID-19 therapy and SARS-CoV-2 detection

The coronavirus disease 2019 (COVID-19) pandemic is an exceptional public health crisis that demands the timely creation of new therapeutics and viral detection. Owing to their high specificity and reliability, monoclonal antibodies (mAbs) have emerged as powerful tools to treat and detect numerous diseases. Hence, many researchers have begun to urgently develop Ab-based kits for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Ab drugs for use as COVID-19 therapeutic agents. The detailed structure of the SARS-CoV-2 spike protein is known, and since this protein is key for viral infection, its receptor-binding domain (RBD) has become a major target for therapeutic Ab development. Because SARS-CoV-2 is an RNA virus with a high mutation rate, especially under the selective pressure of aggressively deployed prophylactic vaccines and neutralizing Abs, the use of Ab cocktails is expected to be an important strategy for effective COVID-19 treatment. Moreover, SARS-CoV-2 infection may stimulate an overactive immune response, resulting in a cytokine storm that drives severe disease progression. Abs to combat cytokine storms have also been under intense development as treatments for COVID-19. In addition to their use as drugs, Abs are currently being utilized in SARS-CoV-2 detection tests, including antigen and immunoglobulin tests. Such Ab-based detection tests are crucial surveillance tools that can be used to prevent the spread of COVID-19. Herein, we highlight some key points regarding mAb-based detection tests and treatments for the COVID-19 pandemic.

Outcomes associated with different vaccines in individuals with bipolar disorder and impact on the current COVID-19 pandemic- a systematic review

Bipolar disorder (BD) might be associated with higher infection rates of coronavirus disease (COVID-19) which in turn could result in worsening the clinical course and outcome. This may be due to a high prevalence of somatic comorbidities and an increased risk of delays in and poorer treatment of somatic disease in patients with severe mental illness in general. Vaccination is the most important public health intervention to tackle the ongoing pandemic. We undertook a systematic review regarding the data on vaccinations in individuals with BD. Proportion of prevalence rates, efficacy and specific side effects of vaccinations and in individuals with BD were searched. Results show that only five studies have investigated vaccinations in individuals with BD, which substantially limits the interpretation of overall findings. Studies on antibody production after vaccinations in BD are very limited and results are inconsistent. Also, the evidence-based science on side effects of vaccinations in individuals with BD so far is poor.

Lab-on-a-Chip Immunoassay for Prediction of Severe COVID-19 Disease

Most people infected by the SARS-CoV-2 virus which causes COVID-19 disease experience mild or no symptoms. Severe forms of the disease are often marked by a hyper-inflammatory response known as a cytokine storm. Thus, biomarker tests which can identify these patients and place them on the appropriate treatment regime at the earliest possible phase would help to improve outcomes. Here we describe an automated microarray-based immunoassay using the Fraunhofer lab-on-a-chip platform for analysis of C-reactive protein due to its role in the hyper-inflammatory response.

Combined Use of ECMO, Prone Positioning, and APRV in the Management of Severe COVID-19 Patients

Background

Severe COVID-19-associated Acute Respiratory Distress Syndrome (ARDS) may warrant extracorporeal membrane oxygenation (ECMO). We evaluated the safety and physiologic changes in oxygenation and hemodynamic profile during ECMO, prone positioning, and the two modalities combined in patients receiving veno-venous (VV) ECMO.

Methods

Cohort study of consecutive adult patients with COVID-19-associated ARDS requiring VV-ECMO, classified into three groups: ECMO support only; Prone positioning only; and Prone positioning during ECMO. We collected hemodynamic, respiratory and ventilation variables as follows: pre-treatment, 1, 6, and 24 h post-treatment, and documented treatment-related complications. On-treatment variables were compared with pre-treatment using one-sample paired t-test with Bonferroni correction.

Results

Fourteen patients (mean age 48.1 [SD 9.3] years, male [100%]) received VV-ECMO. Of those, 10 patients had data during prone positioning alone and seven had data while proned on ECMO. While on ECMO, patients had improvement in oxygen saturation, PaO₂/FiO₂ ratio, and minute ventilation up to 24 h post-treatment. Vasopressor requirements increased with ECMO at 1 h and 24 h post-treatment. Prone positioning was not associated with clinically significant hemodynamic or respiratory changes, either alone or during ECMO support. All patients sustained deep tissue injuries, but only those on the face or chest were related to prone positioning. Three patients required cannula replacement. In-hospital mortality was 43%.

Conclusions

VV-ECMO and prone positioning in patients with COVID-19 ARDS was overall well-tolerated; however, physiologic improvements were marginal, and patients sustained deep tissue injuries. Although this was a selected population with high mortality, our data call into question the benefits of these management modalities in this severe COVID-19 population.

COVID-19 associated symmetrical peripheral gangrene: A case series

BACKGROUND AND AIMS

The novel coronavirus disease (COVID-19) caused by SARS-CoV-2 has turned the world topsy-turvy since its onset in 2019. The thromboinflammatory complications of this disease are common in critically ill patients and associated with poor prognosis. Symmetrical peripheral gangrene (SPG) is characterized by symmetrical distal gangrene in absence of any large vessel occlusion or vasculitis and it is usually associated with critical illness. Our aim was to report the clinical profile and outcome of patients diagnosed with SPG associated with COVID-19. To the best of our knowledge, no such similar cases have been reported till date.

METHODS

In this case series, we have discussed the clinical presentation, laboratory parameters and outcome in a series of two patients of SPG associated with COVID-19 and also compared those findings. Due to paucity of data, we also reviewed the literature on this under-diagnosed and rarely reported condition and association.

RESULTS

Two consecutive patients (both males, age range: 37-42 years, mean: 39.5 years) were admitted with the diagnosis of COVID-19 associated SPG. Both patients had clinical and laboratory evidence of disseminated intravascular coagulation (DIC). Leucopenia was noted in both patients. Despite vigorous therapy, both patients succumbed to their illness within a fortnight of admission.

CONCLUSION

SPG in the background of COVID-19 portends a fatal outcome. Physicians should be aware of its grim prognosis.

Point-of-Care Device for Assessment of Blood Coagulation Status in COVID-19 Patients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent driving the current COVID-19 pandemic. The acute respiratory distress that occurs in some severe COVID-19 cases has been linked with hypercoagulation or thrombotic events as well as a worse prognosis and increased risk of death. Thus, point-of-care devices that can be used for early detection of coagulation abnormalities would assist in COVID-19 management. This chapter describes the use of the Roche Diagnostics CoaguChek^® XS test kit for potential use in COVID-19 personalized medicine approaches.

Osteoclast-mediated bone loss observed in a COVID-19 mouse model

The consequences of SARS-CoV-2 infection on the musculoskeletal system represent a dangerous knowledge gap. Aging patients are at added risk for SARS-CoV-2 infection; therefore, a greater understanding of the resulting musculoskeletal sequelae of SARS-CoV-2 infection may help guide clinical strategies. This study examined fundamental bone parameters among mice treated with escalating viral loads. Male C57BL/6J (WT, n = 17) and B6.Cg-Tg(K18-ACE2)2Prlmn/J mice (K18-hACE2 transgenic mice, n = 21) expressing human ACE2 (TG) were divided into eight groups (n = 4-6/group) and subjected to intranasal dosing of 0, 1 × 10³, 1 × 10⁴, and 1 × 10⁵ PFU (plaque forming units) of human SARS-CoV-2. Animal health was assessed daily by veterinary staff using established and validated scoring criteria (activity, posture, body condition scores and body weight). We report here that mock and WT infected mice were healthy and completed the study, surviving until 12-14 days post infection (dpi). In contrast, the TG mice infected with 1 × 10⁵ PFU all experienced severe health declines that necessitated early euthanasia (6-7 dpi). For TG mice infected with 1 × 10⁴ PFU, 2 mice were also euthanized after 7 dpi, while 3 mice showed signs of moderate disease at day 6 dpi, but recovered fully by day 11 dpi. Four of the 5 TG mice that were infected with 1 × 10³ PFU remained healthy throughout the study. This suggests that our study mimics what is seen during human disease, where some patients develop severe disease resulting in death, while others have moderate to severe disease but recover, and others are asymptomatic. At necropsy, femurs were extracted and analyzed by μCT. No difference was found in μCT determined bone parameters among the WT groups. There was, however, a significant 24.4% decrease in trabecular bone volume fraction (p = 0.0009), 19.0% decrease in trabecular number (p = 0.004), 6.2% decrease in trabecular thickness (p = 0.04), and a 9.8% increase in trabecular separation (p = 0.04) among surviving TG mice receiving any viral load compared to non-infected controls. No differences in cortical bone parameters were detected. TRAP staining revealed surviving infected mice had a significant 64% increase in osteoclast number, a 27% increase in osteoclast surface, and a 38% increase in osteoclasts per bone surface. While more studies are needed to investigate the long-term consequences of SARS-CoV-2 infection on skeletal health, this study demonstrates a significant reduction in several bone parameters and corresponding robust increases in osteoclast number observed within 2 weeks post-infection in surviving asymptomatic and moderately affected mice.

Maternal Immune Activation and Interleukin 17A in the Pathogenesis of Autistic Spectrum Disorder and Why It Matters in the COVID-19 Era

Autism spectrum disorder (ASD) is the commonest neurodevelopmental disability. It is a highly complex disorder with an increasing prevalence and an unclear etiology. Consensus indicates that ASD arises as a genetically modulated, and environmentally influenced condition. Although pathogenic rare genetic variants are detected in around 20% of cases of ASD, no single factor is responsible for the vast majority of ASD cases or that explains their characteristic clinical heterogeneity. However, a growing body of evidence suggests that ASD susceptibility involves an interplay between genetic factors and environmental exposures. One such environmental exposure which has received significant attention in this regard is maternal immune activation (MIA) resulting from bacterial or viral infection during pregnancy. Reproducible rodent models of ASD are well-established whereby induction of MIA in pregnant dams, leads to offspring displaying neuroanatomical, functional, and behavioral changes analogous to those seen in ASD. Blockade of specific inflammatory cytokines such as interleukin-17A during gestation remediates many of these observed behavioral effects, suggesting a causative or contributory role. Here, we review the growing body of animal and human-based evidence indicating that interleukin-17A may mediate the observed effects of MIA on neurodevelopmental outcomes in the offspring. This is particularly important given the current corona virus disease-2019 (COVID-19) pandemic as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy is a potent stimulator of the maternal immune response, however the long-term effects of maternal SARS-CoV-2 infection on neurodevelopmental outcomes is unclear. This underscores the importance of monitoring neurodevelopmental outcomes in children exposed to SARS-CoV-2-induced MIA during gestation.

Roles of the gut microbiota in severe SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. The pathophysiological mechanisms linking gut dysbiosis and severe SARS-CoV-2 infection are poorly understood, although gut microbiota disorders are related to severe SARS-CoV-2 infections. The roles of the gut microbiota in severe SARS-CoV-2 infection were compared with those in respiratory viral infection, which is an easily understood and enlightening analogy. Secondary bacterial infections caused by immune disorders and antibiotic abuse can lead to dysregulation of the gut microbiota in patients with respiratory viral infections. The gut microbiota can influence the progression of respiratory viral infections through metabolites and the immune response, which is known as the gut–lung axis. Angiotensin-converting enzyme 2 is expressed in both the lungs and the small intestine, which may be a bridge between the lung and the gut. Similarly, SARS-CoV-2 infection has been shown to disturb the gut microbiota, which may be the cause of cytokine storms. Bacteria in the gut, lung, and other tissues and respiratory viruses can be considered microecosystems and may exert overall effects on the host. By referencing respiratory viral infections, this review focused on the mechanisms involved in the interaction between SARS-CoV-2 infections and the gut microbiota and provides new strategies for the treatment or prevention of severe SARS-CoV-2 infections by improving gut microbial homeostasis.

Micronutrient Level Is Negatively Correlated with the Neutrophil-Lymphocyte Ratio in Patients with Severe COVID-19

AIM

To explore the potential relationship between NLR and micronutrient deficiency in patients with severe COVID-19 infection.

METHODS

Sixteen patients were categorized into the mild group (mild COVID-19) and severe group (severe COVID-19) based on the guideline of the management of COVID-19. The lactate dehydrogenase (LDH); superoxide dismutase (SOD), the inflammatory markers (neutrophil lymphocyte ratio (NLR)), erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), selenium (Se), iron (Fe), zinc (Zn), nickel (Ni), copper (Cu), chromium (Cr), cadmium (Cd), arsenic (As), and manganese (Mn) were measured in the blood.

RESULTS

Compared to the mild group, the NLR (P < 0.05) and the level of Se (P < 0.01), Fe (P < 0.05), and Zn (P < 0.05) were significantly decreased in the severe group. The level of Se, Fe, and Zn was significantly correlated to NLR levels. Furthermore, close positive correlation was found between NLR and severity of COVID-19.

CONCLUSION

The micronutrient deficiency in the blood is associated with NLR in the severity of COVID-19 patients.

COVID-19-associated opportunistic infections: a snapshot on the current reports

Treatment of the novel Coronavirus Disease 2019 (COVID-19) remains a complicated challenge, especially among patients with severe disease. In recent studies, immunosuppressive therapy has shown promising results for control of the cytokine storm syndrome (CSS) in severe cases of COVID-19. However, it is well documented that immunosuppressive agents (e.g., corticosteroids and cytokine blockers) increase the risk of opportunistic infections. On the other hand, several opportunistic infections were reported in COVID-19 patients, including Aspergillus spp., Candida spp., Cryptococcus neoformans, Pneumocystis jiroveci (carinii), mucormycosis, Cytomegalovirus (CMV), Herpes simplex virus (HSV), Strongyloides stercoralis, Mycobacterium tuberculosis, and Toxoplasma gondii. This review is a snapshot about the main opportunistic infections that reported among COVID-19 patients. As such, we summarized information about the main immunosuppressive agents that were used in recent clinical trials for COVID-19 patients and the risk of opportunistic infections following these treatments. We also discussed about the main challenges regarding diagnosis and treatment of COVID-19-associated opportunistic infections (CAOIs).

NLRP3 inflammasome activation and SARS-CoV-2-mediated hyperinflammation, cytokine storm and neurological syndromes

Despite the introduction of vaccines and drugs for SARS-CoV-2, the COVID-19 pandemic continues to spread throughout the world. In severe COVID-19 patients, elevated levels of proinflammatory cytokines have been detected in the blood, lung cells, and bronchoalveolar lavage, which is referred to as a cytokine storm, a consequence of overactivation of the NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome and resultant excessive cytokine production. The hyperinflammatory response and cytokine storm cause multiorgan impairment including the central nervous system, in addition to a detriment to the respiratory system. Hyperactive NLRP3 inflammasome, due to dysregulated immune response, is the primary cause of COVID-19 severity. The severity could be enhanced due to viral evolution leading to the emergence of mutated variants of concern, such as delta and omicron. In this review, we elaborate on the inflammatory responses associated with the NLRP3 inflammasome activation in COVID-19 pathogenesis, the mechanisms for the NLRP3 inflammasome activation and pathway involved, cytokine storm, and neurological complications as long-term consequences of SARS-CoV-2 infection. Also discussed is the therapeutic potential of NLRP3 inflammasome inhibitors for the treatment of COVID-19.

Perspectives Concerning Various Symptoms of SARS-CoV-2 Detected Individuals

After exposure to SARS-CoV-2, varying symptoms of COVID-19 ranging from asymptomatic symptoms to morbidity and mortality have been exhibited in each individual. SARS-CoV-2 requires various cellular molecules for penetration into a target host cell. Angiotensin-converting enzyme2 (ACE2) acts as the viral receptor molecule. After attachment, SARS-CoV-2 also requires the transmembrane protease serine-2 (TMPRSS-2) and furin molecules, which serve as co-receptors for penetration into the target cell and for subsequent replication. In the meantime, a major histocompatibility complex (MHC) is required for the induction of adaptive immune cells, especially cytotoxic T cells and helper T cells, to clear the virally infected cells. This perspective review article proposes different aspects to explain the varying symptoms of the individuals who have been exposed to SARS-CoV-2, which relates to the polymorphisms of these involved molecules.