Early preemptive immunomodulators (corticosteroids) for severe pneumonia patients infected with SARS-CoV-2

Common immunopathogenesis of central nervous system diseases: the protein-homeostasis-system hypothesis

There are hundreds of central nervous system (CNS) diseases, but there are few diseases for which the etiology or pathogenesis is understood as well as those of other organ-specific diseases. Cells in the CNS are selectively protected from external and internal insults by the blood–brain barrier. Thus, the neuroimmune system, including microglia and immune proteins, might control external or internal insults that the adaptive immune system cannot control or mitigate. The pathologic findings differ by disease and show a state of inflammation that reflects the relationship between etiological or inflammation-inducing substances and corresponding immune reactions. Current immunological concepts about infectious diseases and infection-associated immune-mediated diseases, including those in the CNS, can only partly explain the pathophysiology of disease because they are based on the idea that host cell injury is caused by pathogens. Because every disease involves etiological or triggering substances for disease-onset, the protein-homeostasis-system (PHS) hypothesis proposes that the immune systems in the host control those substances according to the size and biochemical properties of the substances. In this article, I propose a common immunopathogenesis of CNS diseases, including prion diseases, Alzheimer’s disease, and genetic diseases, through the PHS hypothesis.

Etiological and pathophysiological enigmas of severe coronavirus disease 2019, multisystem inflammatory syndrome in children, and Kawasaki disease

During the coronavirus disease 2019 (COVID-19) pandemic, a novel multisystem inflammatory syndrome in children (MIS-C) has been reported worldwide since the first cases were reported in Europe in April 2020. MIS-C is temporally associated with severe acute respiratory syndrome coronavirus 2 infection and shows Kawasaki disease (KD)-like features. The epidemiological and clinical characteristics in COVID-19, KD, and MIS-C differ, but severe cases of each disease share similar clinical and laboratory findings such as a protracted clinical course, multiorgan involvement, and similar activated biomarkers. These findings suggest that a common control system of the host may act against severe disease insult. To solve the enigmas, we proposed the protein-homeostasis-system hypothesis in that every disease involves etiological substances and the host's immune system controls them by their size and biochemical properties. Also, it is proposed that the etiological agents of KD and MIS-C might be certain strains in the microbiota of human species and etiological substances in severe COVID-19, KD, and MIS-C originate from pathogen-infected cells. Since disease severity depends on the amounts of inflammation-inducing substances and corresponding immune activation in the early stage of the disease, an early proper dose of corticosteroids and/or intravenous immunoglobulin (IVIG) may help reduce morbidity and possibly mortality among patients with these diseases. Corticosteroids are low cost and an analogue of host-origin cortisol among immune modulators. This study's findings will help clinicians treating severe COVID-19, KD, and MIS-C, especially in developing countries, where IVIG and biologics supplies are insufficient.

Immune response and potential therapeutic strategies for the SARS-CoV-2 associated with the COVID-19 pandemic

Following onset of the first recorded case of Coronavirus disease 2019 (COVID-19) in December 2019, more than 269 million cases and over 5.3 million deaths have been confirmed worldwide. COVID-19 is a highly infectious pneumonia, caused by a novel virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, it poses a severe threat to human health across the globe, a trend that is likely to persist in the foreseeable future. This paper reviews SARS-CoV-2 immunity, the latest development of anti-SARS-CoV-2 drugs as well as exploring in detail, immune escape induced by SARS-CoV-2. We expect that the findings will provide a basis for COVID-19 prevention and treatment.

Infection, Inflammation and Immunity in Covid-19 Infection

The COVID-19 pandemic caused by the SARS-CoV-2 has increased the burden on healthcare system. Despite some progress in its diagnostics has been made, effective prevention and treatment are still insufficient. Since SARS-CoV-2 infections often cause systemic inflammation and multiple organ failure, the therapeutic options aimed at modulating the host immune responses to prevent subsequent systemic complications are demanding. The review provides a summary of the SARS-CoV-2 virus infection and underlines the current perception of pulmonary host’s immune response and its contributions to disease severity and systemic inflammation. Signaling pathways which have the potential to manipulate host immunity and improve clinical outcomes are also presented.

Biomaterials-Based Opportunities to Engineer the Pulmonary Host Immune Response in COVID-19

The COVID-19 pandemic caused by the global spread of the SARS-CoV-2 virus has led to a staggering number of deaths worldwide and significantly increased burden on healthcare as nations scramble to find mitigation strategies. While significant progress has been made in COVID-19 diagnostics and therapeutics, effective prevention and treatment options remain scarce. Because of the potential for the SARS-CoV-2 infections to cause systemic inflammation and multiple organ failure, it is imperative for the scientific community to evaluate therapeutic options aimed at modulating the causative host immune responses to prevent subsequent systemic complications. Harnessing decades of expertise in the use of natural and synthetic materials for biomedical applications, the biomaterials community has the potential to play an especially instrumental role in developing new strategies or repurposing existing tools to prevent or treat complications resulting from the COVID-19 pathology. Leveraging microparticle- and nanoparticle-based technology, especially in pulmonary delivery, biomaterials have demonstrated the ability to effectively modulate inflammation and may be well-suited for resolving SARS-CoV-2-induced effects. Here, we provide an overview of the SARS-CoV-2 virus infection and highlight current understanding of the host's pulmonary immune response and its contributions to disease severity and systemic inflammation. Comparing to frontline COVID-19 therapeutic options, we highlight the most significant untapped opportunities in immune engineering of the host response using biomaterials and particle technology, which have the potential to improve outcomes for COVID-19 patients, and identify areas needed for future investigations. We hope that this work will prompt preclinical and clinical investigations of promising biomaterials-based treatments to introduce new options for COVID-19 patients.

Severe COVID-19 in pediatric age: an update on the role of the anti-rheumatic agents

BACKGROUND

SARS-CoV-2 can induce an immune impairment and dysregulation, finally resulting in the massive release of inflammatory mediators (cytokine storm), strongly contributing to the pulmonary and systemic manifestations in severe coronavirus disease 2019 (COVID-19). As a consequence, different drugs active on the immune system have been proposed for the treatment of the disease in adults.

ROLE OF THE ANTI-RHEUMATIC AGENTS IN CHILDREN

Children are more likely to develop a mild disease course, as the severe form of COVID-19 is identified in less than 5% of the pediatric patients. Moreover, in children a peculiar disease phenotype, defined as multisystem inflammatory syndrome in children (MIS-C) is observed, representing the most severe expression of the inflammatory dysregulation caused by SARS-CoV-2. The limited experience with the severe pediatric COVID-19 and MIS-C does not allow conclusions about the role of the immune pharmacological approach, and therefore the treatment of these conditions represents a considerable clinical challenge. The use of chloroquine, hydroxychloroquine, and colchicine in the early disease stages is not sufficiently supported by evidence, and there is an increasing interest in the role of biologic agents, including anti-IL-1 and anti-IL-6 agents, in the prevention and treatment of the severe manifestations of COVID-19.

CONCLUSION

The therapeutic approach to pediatric COVID-19 is multidisciplinary, and anti-rheumatic agents have a prominent role in severe disease. This paper reviews the rationale for the use of anti-rheumatic agents in pediatric COVID-19 and MIS-C and the clinical experience with the single drugs. Finally, the areas of potential improvement in the use of anti-rheumatic agents, including the optimization of the drug choice and the timing of administration, are discussed.

The proportion and effect of corticosteroid therapy in patients with COVID-19 infection: A systematic review and meta-analysis

Objectives

Coronavirus disease 2019 (COVID-19) remains a global challenge. Corticosteroids constitute a group of anti-inflammatory and immunosuppressive drugs that are widely used in the treatment of COVID-19. Comprehensive reviews investigating the comparative proportion and efficacy of corticosteroid use are scarce. Therefore, we conducted a systematic review and meta-analysis of clinical trials to evaluate the proportion and efficacy of corticosteroid use for the treatment of COVID-19.

Methods

We conducted a comprehensive literature review and meta-analysis of research articles, including observational studies and clinical trials, by searching the PubMed, EMBASE, Cochrane Controlled Trials Registry, and China Academic Journal Network Publishing databases. Patients treated between December 1, 2019, and January 1, 2021, were included. The outcome measures were the proportion of patients treated with corticosteroids, viral clearance and mortality. The effect size with the associated 95% confidence interval is reported as the weighted mean difference for continuous outcomes and the odds ratio for dichotomous outcomes.

Results

Fifty-two trials involving 15710 patients were included. The meta-analysis demonstrated that the proportion of COVID-19 patients who received corticosteroids was significantly lower than that of patients who did not receive corticosteroids (35.19% vs. 64.49%). In addition, our meta-analysis demonstrated no significant difference in the proportions of severe and nonsevere cases treated with corticosteroids (27.91% vs. 20.91%). We also performed subgroup analyses stratified by whether patients stayed in the intensive care unit (ICU) and found that the proportion of patients who received corticosteroids was significantly higher among those who stayed in the ICU than among those who did not. The results of our meta-analysis indicate that corticosteroid treatment significantly delayed the viral clearance time. Finally, our meta-analysis demonstrated no significant difference in the use of corticosteroids for COVID-19 between patients who died and those who survived. This result indicates that mortality is not correlated with corticosteroid therapy.

Conclusion

The proportion of COVID-19 patients who received corticosteroids was significantly lower than that of patients who did not receive corticosteroids. Corticosteroid use in subjects with severe acute respiratory syndrome coronavirus 2 infections delayed viral clearance and did not convincingly improve survival; therefore, corticosteroids should be used with extreme caution in the treatment of COVID-19.

Benefits of early aggressive immunomodulatory therapy (tocilizumab and methylprednisolone) in COVID-19: Single center cohort study of 685 patients

INTRODUCTION

A growing evidence suggests that immune dysregulation and thrombotic phenomena are key features in the pathophysiology of COVID-19. Apart from antivirals and respiratory support, anticoagulants, corticoids and immunomodulators are increasingly being prescribed, especially for more severe cases. We describe the clinical outcome of a large cohort of patients preferentially treated with glucocorticoids and interleukin inhibitors.

METHODS

Single center and retrospective case series. Adult patients admitted with COVID-19 related respiratory insufficiency were included. Patients who died within 2 days after admission and those testing positive but asymptomatic were excluded. We defined two study periods: from March 3rd to March 31 st, 2020 (beginning of epidemic until peak of incidence) and April 1 st to May 7 th, 2020 (second half of epidemic). The majority of patients received respiratory support, combinations of antimicrobials, anticoagulants, corticoids and interleukin inhibitors. Antivirals were preferentially given in the first period. The clinical outcome (death and ventilator dependency) of both periods was compared.

RESULTS

From March 3 rd to May 7 th, 685 patients were included for analysis (58.4% males, mean age 68.9 years). Patients in the first period (n ​= ​408) were younger (66.6 vs 71.1 years, p ​= ​0.003), presented lower mean P a O 2/F i O2 ratio at admission (256.5 vs 270.4 ​mm Hg,p ​= ​0.0563), higher ferritin (1520 vs 1221 ​ng/ml, p ​= ​0.01), higher IL-6 (679 vs 194 ​pg/ml, p ​< ​0.0001) and similar D-dimer levels (3.59 vs 3.39 ​μg/mL, p ​= ​0.65) compared to the second period (n ​= ​277). Lopinavir/ritonavir and interferon were preferentially given in the first period (23.8% and 32% vs 1.8% and 11.9%, p ​< ​0.0001). Use of corticoids (88.2% vs 87.4%, p ​= ​0,74) and tocilizumab (26.29 vs 20.22% p ​= ​0.06) were similarly administered in both periods. Patients in the second period needed less mechanical ventilation (4.9% vs 16.9%, p ​< ​0.0001), fewer ICU admission (6.1% vs 20.1%,p ​< ​0.0001) and showed similar mortality (17.7% vs 15.4%, p ​= ​0.43). Infectious and thrombotic complications were comparable in both periods (both around 8%, with no statistical difference). Patients treated with tocilizumab (n ​= ​163) had lower mortality rate compared to those untreated under the same indication (7.9% vs 24.2%, p ​< ​0.0001).

CONCLUSIONS

In this large retrospective COVID-19 in-hospital cohort, lopinavir/ritonavir and interferon showed no significant impact on survival. Extensive use of corticosteroids and tocilizumab resulted in good overall outcome and showed acceptable complication rates.

Immunity, endothelial injury and complement-induced coagulopathy in COVID-19

In December 2019, a novel coronavirus was isolated from the respiratory epithelium of patients with unexplained pneumonia in Wuhan, China. This pathogen, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causes a pathogenic condition that has been termed coronavirus disease 2019 (COVID-19) and has reached pandemic proportions. As of 17 September 2020, more than 30 million confirmed SARS-CoV-2 infections have been reported in 204 different countries, claiming more than 1 million lives worldwide. Accumulating evidence suggests that SARS-CoV-2 infection can lead to a variety of clinical conditions, ranging from asymptomatic to life-threatening cases. In the early stages of the disease, most patients experience mild clinical symptoms, including a high fever and dry cough. However, 20% of patients rapidly progress to severe illness characterized by atypical interstitial bilateral pneumonia, acute respiratory distress syndrome and multiorgan dysfunction. Almost 10% of these critically ill patients subsequently die. Insights into the pathogenic mechanisms underlying SARS-CoV-2 infection and COVID-19 progression are emerging and highlight the critical role of the immunological hyper-response - characterized by widespread endothelial damage, complement-induced blood clotting and systemic microangiopathy - in disease exacerbation. These insights may aid the identification of new or existing therapeutic interventions to limit the progression of early disease and treat severe cases.

COVID-19-Associated Coagulopathy and Inflammatory Response: What Do We Know Already and What Are the Knowledge Gaps?

Patients with coronavirus disease 2019 (COVID-19) frequently experience a coagulopathy associated with a high incidence of thrombotic events leading to poor outcomes. Here, biomarkers of coagulation (such as D-dimer, fibrinogen, platelet count), inflammation (such as interleukin-6), and immunity (such as lymphocyte count) as well as clinical scoring systems (such as sequential organ failure assessment [SOFA], International Society on Thrombosis and Hemostasis disseminated intravascular coagulation [ISTH DIC], and sepsis-induced coagulopathy [SIC] score) can be helpful in predicting clinical course, need for hospital resources (such as intensive care unit [ICU] beds, intubation and ventilator therapy, and extracorporeal membrane oxygenation [ECMO]) and patient's outcome in patients with COVID-19. However, therapeutic options are actually limited to unspecific supportive therapy. Whether viscoelastic testing can provide additional value in predicting clinical course, need for hospital resources and patient's outcome or in guiding anticoagulation in COVID-19-associated coagulopathy is still incompletely understood and currently under investigation (eg, in the rotational thromboelastometry analysis and standard coagulation tests in hospitalized patients with COVID-19 [ROHOCO] study). This article summarizes what we know already about COVID-19-associated coagulopathy and-perhaps even more importantly-characterizes important knowledge gaps.

Overview of management of children with COVID-19

The widespread and contagious coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 has become a burden in the global health domain. The subsequent discovery of the virus features and pathogenesis, and prompt and adequate management are still lacking and remain inconclusive. Children usually present milder symptoms than adults, and management focuses on providing symptomatic and respiratory supports. Several treatment modalities, including the utilization of mechanical ventilation (MV), antivirals, immune-modulating drugs, or other agents, may present promising results in reducing the symptoms of COVID-19, particularly in severe cases. Although no randomized clinical trials have been published to date, it is interesting to explore potential modalities for treating COVID-19 in children, based on review articles, case reports, and recent guidelines.

The solution on enigmas in COVID-19: the protein-homeostasis-system hypothesis

Infectious diseases, including coronavirus disease 2019 (COVID-19), are representative, of which etiology is known in all human diseases. However, many enigmas persist in relation to COVID-19, including different clinical phenotypes and incubation periods across individuals, species-specificity, appearance of cytokine storm and lymphopenia, and the mechanism of damage to organ cells. Current immunological concepts have limitations to explain these unsolved issues. Meanwhile, results of clinical, pathological, and animal studies have suggested that the virus itself is not a direct cause of acute injury to the lung or other organ cells. For better understanding of COVID-19, a presumed immunopathogenesis of COVID-19 is presented under the protein-homeostasis-system hypothesis; every disease, including COVID-19, has associated etiological substances, and the host immune system controls these diverse substances according to the size and biochemical property. These etiological substances, inducing inflammation and subsequent tissue injury, are smaller substances derived from virus-infected cells. Initially acting nonspecific adaptive immune reaction with cytokine imbalance may be responsible for target cell injury. Furthermore, substances from initial target cell injury and secondary bacterial invasion can induce further inflammation if released from local or systemic circulation. COVID-19 patients with pneumonia show hypercytokinemia with lymphocytopenia corresponding to the severity of pneumonia at early stages. Thus, early immune-modulator treatment, including corticosteroids and intravenous immunoglobulin, has an immunological rationale. It could help reduce the morbidity and possibly mortality of older patients with underlying conditions.

Immunopathogenesis of COVID-19 and early immunomodulators

The novel coronavirus disease 2019 (COVID-19) is spreading globally. Although its etiologic agent is discovered as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), there are many unsolved issues in COVID-19 and other infectious diseases. The causes of different clinical phenotypes and incubation periods among individuals, species specificity, and cytokine storm with lymphopenia as well as the mechanism of damage to organ cells are unknown. It has been suggested that in viral pneumonia, virus itself is not a direct cause of acute lung injury; rather, aberrant immune reactions of the host to the insults from viral infection are responsible. According to its epidemiological and clinical characteristics, SARS-CoV-2 may be a virus with low virulence in nature that has adapted to the human species. Current immunological concepts have limited ability to explain such unsolved issues, and a presumed immunopathogenesis of COVID-19 is presented under the proteinhomeostasis-system hypothesis. Every disease, including COVID-19, has etiological substances controlled by the host immune system according to size and biochemical properties. Patients with severe pneumonia caused by SARS-CoV-2 show more severe hypercytokinemia with corresponding lymphocytopenia than patients with mild pneumonia; thus, early immunomodulator treatment, including corticosteroids, has been considered. However, current guidelines recommend their use only for patients with advanced pneumonia or acute respiratory distress syndrome. Since the immunopathogenesis of pneumonia may be the same for all patients regardless of age or severity and the critical immune-mediated lung injury may begin in the early stage of the disease, early immunomodulator treatment, including corticosteroids and intravenous immunoglobulin, can help reduce morbidity and possibly mortality rates of older patients with underlying conditions.

Immunology of COVID-19: Current State of the Science

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people worldwide, igniting an unprecedented effort from the scientific community to understand the biological underpinning of COVID19 pathophysiology. In this Review, we summarize the current state of knowledge of innate and adaptive immune responses elicited by SARS-CoV-2 infection and the immunological pathways that likely contribute to disease severity and death. We also discuss the rationale and clinical outcome of current therapeutic strategies as well as prospective clinical trials to prevent or treat SARS-CoV-2 infection.