Asthma and severe acute respiratory syndrome coronavirus 2019: current evidence and knowledge gaps.

PURPOSE OF REVIEW: Although respiratory viruses are common triggers of asthma exacerbation, it is unknown whether this also applies to infection with SARS-CoV-2. Indeed, patients with asthma and allergy appear underrepresented in large reports of COVID-19 cases worldwide. In this review, we evaluate existing literature on this topic and potential underlying mechanisms for any interrelationship between asthma and COVID-19. RECENT FINDINGS: Data from several preclinical and clinical reports suggest a lower susceptibility for COVID-19 in patients with underlying type 2 airway inflammation including asthma that may be related to a reduced expression of ACE2 and TMPRSS2 receptors for SARS-CoV-2. Corticosteroids further decrease expression of the ACE2 and TMPRSS2 receptors, hence may also have a protective effect against infection with SARS-CoV-2. In addition, some studies suggest that the reported improvement in asthma control and a reduction in asthma exacerbations during the COVID-19 pandemic may be related to improvement in adherence to controller therapy and reduced exposure to triggers, such as other respiratory viruses and air pollutants. Recent data point towards differential susceptibility for COVID-19 among asthma patients based on their phenotype and/or endotype. On the basis of existing evidence, continuation with controller therapies is recommended for all patients with asthma. For patients with severe uncontrolled asthma infected by SARS-CoV-2, adjustment of controllers and biologics should be based on a multidisciplinary decision. SUMMARY: Underrepresentation of SARS-CoV-2-infected patients with asthma and related allergic diseases may be based on potentially protective underlying mechanisms, such as type 2 airway inflammation, downregulation of ACE2/TMPRSS2 receptors, reduced exposures to triggers and improved adherence to controller medications. Although it is imperative that control should be maintained and asthma medications be continued in all patients, management of patients with severe uncontrolled asthma infected by SARS-CoV-2 including adjustment of controllers and biologics should be discussed on an individual basis.

Biological treatments for severe asthma.

PURPOSE OF REVIEW: Asthma is a heterogenous disease associated with different phenotypes and endotypes. The unmet needs with severe asthma have led to the emergence of potential therapeutic targets beyond the existing therapies. Recently, several biologics were examined and some have now been approved to target T2 airway inflammation in patients with severe disease. We provide an overview of recently approved biologic, those which are emerging and highlight unmet needs in this area. RECENT FINDINGS: Multiple biologics targeting T2 high asthma are now available for clinical use in the appropriate groups of severe asthma. These target overlapping phenotypes, which include allergic and eosinophilic asthma. Available biologics were shown to improve outcomes that include the reduction of exacerbations and improvement of lung function. Some have also demonstrated improvement in patient-reported outcomes. Some of these biologics have also demonstrated beneficial effects on associated asthma comorbidities. Biomarkers help predict response to certain biologics, although only few currently exist. Emerging biologics blocking other pathways of airway inflammation are under development. Several small molecule antagonists and inhibitors are also in development. Biologics and therapies targeting T2 low or non-T2 asthma are needed. SUMMARY: Recently approved biologic therapies improve asthma outcomes in subset of patients. Future research to uncover better predictors of response can improve the precise approach to therapy of patients with severe disease.