COVID-19 in two severe asthmatics receiving benralizumab: busting the eosinophilia myth

Comprehensive overview of COVID-19-related respiratory failure: focus on cellular interactions

The pandemic outbreak of coronavirus disease 2019 (COVID-19) has created health challenges in all parts of the world. Understanding the entry mechanism of this virus into host cells is essential for effective treatment of COVID-19 disease. This virus can bind to various cell surface molecules or receptors, such as angiotensin-converting enzyme 2 (ACE2), to gain cell entry. Respiratory failure and pulmonary edema are the most important causes of mortality from COVID-19 infections. Cytokines, especially proinflammatory cytokines, are the main mediators of these complications. For normal respiratory function, a healthy air-blood barrier and sufficient blood flow to the lungs are required. In this review, we first discuss airway epithelial cells, airway stem cells, and the expression of COVID-19 receptors in the airway epithelium. Then, we discuss the suggested molecular mechanisms of endothelial dysfunction and blood vessel damage in COVID-19. Coagulopathy can be caused by platelet activation leading to clots, which restrict blood flow to the lungs and lead to respiratory failure. Finally, we present an overview of the effects of immune and non-immune cells and cytokines in COVID-19-related respiratory failure.

Eosinophils and eosinophilic immune dysfunction in health and disease

The functions ascribed to eosinophils have classically been limited to host defence against certain parasitic infections and potentially deleterious effects in the setting of specific diseases that are associated with elevated eosinophil counts in blood and/or tissue. The ability to induce eosinophil depletion either experimentally in animal models or through targeted therapies in humans has extended our understanding of the roles played by eosinophils in health and homeostasis as well as in disease pathogenesis. When associated with human disease aetiology, the eosinophil takes on a pathogenic rather than a protective role. This maladaptive response, called "eosinophilic immune dysfunction" herein, appears central to exacerbation pathogenesis and disease control in severe asthma and may be involved in the aetiology of other eosinophil-related conditions ranging from organ-system-limited diseases such as phenotypic subsets of chronic obstructive pulmonary disease and chronic rhinosinusitis with nasal polyposis to more broadly systemic diseases such as eosinophilic granulomatosis with polyangiitis and hypereosinophilic syndrome. In this review, we describe the evidence supporting eosinophilic functions related to health and homeostasis and explore the contribution of eosinophilic immune dysfunction to human disease.

Asthma and COVID-19 Associations: Focus on IgE-Related Immune Pathology

Management of patients with asthma during the coronavirus disease 2019 (COVID-19) pandemic is a concern, especially since asthma predisposes patients to respiratory problems. Interestingly, asthma characterized by type 2 inflammation, also known as T-helper type 2-high endotype, displays a cellular and molecular profile that may confer protective effects against COVID-19. The results of experimental and clinical studies have established the actions of immunoglobulin E (IgE) in inducing airway hyperreactivity and weakening an interferon-mediated antiviral response following respiratory viral infection. Robust evidence supports the beneficial effect of the anti-IgE biologic treatment omalizumab on reducing respiratory virus-induced asthma exacerbations and reducing the frequency, duration, and severity of respiratory viral illness in patients with asthma. Indeed, accumulating reports of patients with severe asthma treated with omalizumab during the pandemic have reassuringly shown that continuing omalizumab treatment during COVID-19 is safe, and in fact may help prevent the severe course of COVID-19. Accordingly, guidance issued by the Global Initiative for Asthma recommends that all patients with asthma continue taking their prescribed asthma medications, including biologic therapy, during the COVID-19 pandemic. The impact of biologic treatments on patients with asthma and COVID-19 will be better understood as more evidence emerges.

Severe asthma in the era of COVID-19: A narrative review

INTRODUCTION AND OBJECTIVES

Severe asthma management during the coronavirus disease 2019 (COVID-19) pandemic is a challenge and will continue to be, at least in the next few months, as herd immunity is still a mirage. A lot has to be learned about how COVID-19 affects underlying diseases, and severe asthma is no exception.

METHODS

Narrative review of papers available until February 2021 in PubMed and Google Scholar, relating severe asthma and COVID-19. Four main research topics were reviewed: SARS-CoV-2 infection: immunology and respiratory pathology; interrelationship of severe asthma endotypes and COVID-19 disease mechanisms; severe asthma epidemiology and COVID-19; and biologics for severe asthma in the context of COVID-19.

RESULTS

COVID-19 disease mechanisms start with upper respiratory cell infection, and afterwards several immunological facets are activated, contributing to disease severity, namely cell-mediated immunity and antibody production. Although infrequent in the COVID-19 course some patients develop a cytokine storm that causes organ damage and may lead to acute respiratory distress syndrome or multiorgan failure. Regarding severe asthma endotypes, type2-high might have a protective role both in infection risk and disease course. There is conflicting data regarding the epidemiological relationship between COVID-19 among severe asthma patients, with some studies reporting increased risk of infection and disease course, whereas others the other way round. Biologics for severe asthma do not seem to increase the risk of infection and severe COVID-19, although further evidence is needed.

CONCLUSIONS

Globally, in the era of COVID-19, major respiratory societies recommend continuing the biologic treatment, preferably in a self-home administration program.

COVID-19 in a Patient With Severe Eosinophilic Asthma on Benralizumab Therapy: A Case Report and Review of Literature

Patients with coronavirus disease 2019 (COVID-19) can develop eosinopenia. Eosinophils have various functions, including immunoregulation and antiviral activity, in addition to modulation of an inflammatory reaction. Benralizumab is an anti-interleukin-5Rα monoclonal antibody that selectively depletes eosinophils through enhanced antibody-dependent cell-mediated cytotoxicity. Whether eosinophil depletion affects COVID-19 prognosis is yet to be elucidated. Here, we present a case of a 60-year-old patient with severe asthma on benralizumab therapy, who tested positive for an acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The patient experienced an asymptomatic COVID-19 course without deterioration of asthma control. Eosinophil depletion did not contribute to a deterioration of the clinical status. Comorbidities play a major role in the severity of COVID-19 in patients with asthma. The findings of our case and a literature review revealed that benralizumab therapy is not associated with a significant negative impact on the disease course in COVID-19 patients.

Understanding and Managing Severe Asthma in the Context of COVID-19

Coronavirus disease 2019 (COVID-19) continues to spread across the world. Since the beginning of the pandemic, the question of whether asthma is a risk factor for getting the infection or for poor outcomes motivated a great debate. In the field of severe asthma and its treatment during COVID-19 pandemic, several issues are also pending. A literature review focused on the management of severe asthma patients in the context of COVID-19 is performed. The available evidence suggests that severe asthma patients do not have an increased risk of poor COVID-19 outcomes and that it is safe to treat asthmatic patients with inhaled corticosteroids (ICS) and biologics during the pandemic, even though some studies indicate that high doses of ICS may predispose to COVID-19. The chronic use of oral corticosteroid (OCS) might be associated with poor COVID-19 outcomes, although there is no complete agreement. There is very limited evidence concerning the use of triple therapy for asthma in the context of this pandemic. Ultimately, severe asthma patients should maintain their medication during the COVID-19 pandemic, including biologic agents. More studies are needed to address the role of asthma medications and asthma’s different phenotypes on the incidence and course of COVID-19.

Impact of Anti-Type 2 Inflammation Biologic Therapy on COVID-19 Clinical Course and Outcome

SARS-CoV-2 pandemic had a general and deep impact on the clinical management of chronic diseases, including respiratory and allergic disorders. At the beginning of the pandemic, one of the main concerns was the potential impact of immunosuppressive/immunomodulatory drugs on COVID-19 clinical course. In this review, we aim to summarize and analyze the available clinical evidence from patients treated with anti-type 2 inflammation biologics (including anti-IgE, anti-IL-5 and anti-IL-4 agents), who developed COVID-19. Overall, the treatment with anti-Th2 biologics can be considered safe during COVID-19. It does not worsen the clinical course and outcome of COVID-19, and it may be actually protective somehow from developing severe forms. Moreover, patients treated with these biological agents do not seem to be more prone to get infected by SARS-CoV-2.

Biological therapies, asthma and coronavirus disease 2019

PURPOSE OF REVIEW

As of June 2021, coronavirus disease 2019 (COVID-19) exceeded 180 million reported cases and was responsible for almost 4 million deaths globally. Asthma affects approximately 262 million people worldwide and is an important cause of morbidity and mortality. Presently, it appears asthma is neither associated with an increased risk of contracting COVID-19 nor with a risk of severe COVID-19 or COVID-19 related death. Regarding the severe asthma patients on biologics, questions remain. The purpose of this review is to discuss the evidence regarding the relationship between asthma, biologics and COVID-19.

RECENT FINDINGS

The available evidence does not suggest that severe asthmatics on treatment with biologics have a higher risk of severe acute respiratory syndrome coronavirus 2 infection compared to the general population. It does not appear that they have a higher risk of severe disease or COVID-19 related death either.

SUMMARY

This review suggests that treatment with biologics for severe asthma is safe and should be maintained during the COVID-19 pandemic. However, more studies are needed to address this question and the role of biological therapy on different asthma phenotypes.

Asthma and COVID-19: a dangerous liaison?

The coronavirus disease 2019 (COVID-19) pandemic, caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), provoked the most striking international public health crisis of our time. COVID-19 can cause a range of breathing problems, from mild to critical, with potential evolution to respiratory failure and acute respiratory distress syndrome. Elderly adults and those affected with chronic cardiovascular, metabolic, and respiratory conditions carry a higher risk of severe COVID-19. Given the global burden of asthma, there are well-founded concerns that the relationship between COVID-19 and asthma could represent a "dangerous liaison".Here we aim to review the latest evidence on the links between asthma and COVID-19 and provide reasoned answers to current concerns, such as the risk of developing SARS-CoV-2 infection and/or severe COVID-19 stratified by asthmatic patients, the contribution of type-2 vs. non-type-2 asthma and asthma-COPD overlap to the risk of COVID-19 development. We also address the potential role of both standard anti-inflammatory asthma therapies and new biological agents for severe asthma, such as mepolizumab, reslizumab, and benralizumab, on the susceptibility to SARS-CoV-2 infection and severe COVID-19 outcomes.

Emerging Evidence for Pleiotropism of Eosinophils

Eosinophils are complex granulocytes with the capacity to react upon diverse stimuli due to their numerous and variable surface receptors, which allows them to respond in very different manners. Traditionally believed to be only part of parasitic and allergic/asthmatic immune responses, as scientific studies arise, the paradigm about these cells is continuously changing, adding layers of complexity to their roles in homeostasis and disease. Developing principally in the bone marrow by the action of IL-5 and granulocyte macrophage colony-stimulating factor GM-CSF, eosinophils migrate from the blood to very different organs, performing multiple functions in tissue homeostasis as in the gastrointestinal tract, thymus, uterus, mammary glands, liver, and skeletal muscle. In organs such as the lungs and gastrointestinal tract, eosinophils are able to act as immune regulatory cells and also to perform direct actions against parasites, and bacteria, where novel mechanisms of immune defense as extracellular DNA traps are key factors. Besides, eosinophils, are of importance in an effective response against viral pathogens by their nuclease enzymatic activity and have been lately described as involved in severe acute respiratory syndrome coronavirus SARS-CoV-2 immunity. The pleiotropic role of eosinophils is sustained because eosinophils can be also detrimental to human physiology, for example, in diseases like allergies, asthma, and eosinophilic esophagitis, where exosomes can be significant pathophysiologic units. These eosinophilic pathologies, require specific treatments by eosinophils control, such as new monoclonal antibodies like mepolizumab, reslizumab, and benralizumab. In this review, we describe the roles of eosinophils as effectors and regulatory cells and their involvement in pathological disorders and treatment.

Administration of benralizumab in a patient with severe asthma admitted to the intensive care unit with COVID-19 pneumonia: case report

A patient with severe asthma on benralizumab therapy was admitted to the intensive care unit (ICU) for a coronavirus disease 2019 (COVID-19) infection. At the end of the 8 week benralizumab dosing interval, discussion arose as to whether benralizumab should be administered or if treatment should be discontinued, due to the lack of experience with benralizumab in this situation. Severe broncho-obstruction developed, and the next injection of benralizumab was administered during ICU admission without detrimental symptoms. With this case report, we would like to share our experience with the safe administration of benralizumab during COVID-19 pneumonia, guiding doctors in future decision making.

Immunological Aspects Related to Viral Infections in Severe Asthma and the Role of Omalizumab

Viral respiratory infections are recognized risk factors for the loss of control of allergic asthma and the induction of exacerbations, both in adults and children. Severe asthma is more susceptible to virus-induced asthma exacerbations, especially in the presence of high IgE levels. In the course of immune responses to viruses, an initial activation of innate immunity typically occurs and the production of type I and III interferons is essential in the control of viral spread. However, the Th2 inflammatory environment still appears to be protective against viral infections in general and in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections as well. As for now, literature data, although extremely limited and preliminary, show that severe asthma patients treated with biologics don't have an increased risk of SARS-CoV-2 infection or progression to severe forms compared to the non-asthmatic population. Omalizumab, an anti-IgE monoclonal antibody, exerts a profound cellular effect, which can stabilize the effector cells, and is becoming much more efficient from the point of view of innate immunity in contrasting respiratory viral infections. In addition to the antiviral effect, clinical efficacy and safety of this biological allow a great improvement in the management of asthma.

Anti-IL5 Drugs in COVID-19 Patients: Role of Eosinophils in SARS-CoV-2-Induced Immunopathology

SARS-CoV-2 infection stimulates a complex activation of the immune system. Eosinophils belong to the host’s defense equipment against respiratory viruses. In the first phase of the infection, eosinophils contribution is probably appropriate and beneficial, as they facilitate the suppression of the viral replication. However, in severe COVID-19 patients, during the second and third phases of the disease, eosinophils may participate in a maladaptive immune response and directly contribute to immunopathology. In fact, in severe patients, the immune response is prevalently T helper 1 type, but T helper 2 is also present. Eosinophils’ expansion and activation are stimulated by Type 2 cytokines, especially IL-5. Moreover, bronchial asthma, in which eosinophils play a central role, seems not to be a major risk factor for severe COVID-19. Among possible explanations, asthmatic patients are often treated with corticosteroids, which have been demonstrated to reduce the progression to critical COVID-19 in hospitalized patients. In addition to steroids, severe asthmatic patients are currently treated with biological drugs that target Type 2 immune response. Because IL-5 is necessary for the growth, survival, and activation of eosinophils, IL-5 inhibitors, such as mepolizumab, decrease the peripheral blood count of eosinophils, but do not influence eosinophils activation in the airway. In severe COVID-19 patients, the blockade of eosinophils’ activation might contrast harmful immunity.