Pathological Differences Between Allergic Asthma and Nonallergic Asthma
Transcript: Thomas Casale, MD: Hi, and welcome to this HCPLive® Peer Exchange titled “Biomarkers in Shifting the Treatment Paradigm of Asthma.” I’m Dr Tom Casale from the University of South Florida in Tampa. It’s my pleasure to host this meeting with 4 distinguished colleagues. Joining me today are Dr Geoffrey Chupp from Yale School of Medicine, Dr Stanley Goldstein from Allergy and Asthma Care of Long Island, Dr Shahzad Mustafa from Rochester Regional Health, and Dr Michael Wechsler from National Jewish Health in Denver.
In today’s discussion, we’re going to provide an overview of recent advances in patient assessments and treatment, with a focus on biomarkers in the management of patients with asthma, especially severe asthma.
We’ll also try to cover a few of the areas that are on everybody’s mind, and that [includes] the complexity of dealing with a patient right now during the COVID-19 [coronavirus disease 2019] pandemic.
Let’s go ahead and get started, and we’ll talk first to Stan and ask him a question about allergic asthma. Stan, how do you define allergic asthma, and what’s the difference between that and nonallergic asthma?
Stanley Goldstein, MD: Thank you for that question, Tom. Allergic asthma is created by a host immunologic interaction with the environment that results in sensitization to aeroallergen. It results in an overproduction of specific IgE [immunoglublin E] antibodies, which results in activation of mast cells; also, production of TH2 cytokines and eventually eosinophils lining up the airways because of inhalation of specific allergens. Once you have sensitization, inhalation of the allergen will result in symptoms, and it also would result in inflammation of the airway. Therefore, if you have a patient who has allergic asthma, when they inhale an allergen, what you’d expect to see is an immediate result in bronchospasm and mucus production, the early phases of the asthmatic response. Then you would expect to get, hours later, an influx of inflammatory cells, resulting in airway inflammation.
Thomas Casale, MD: Geoff or Mike, do you have any comments or anything you’d like to add about the issue of allergic versus nonallergic asthma?
Michael E. Wechsler, MD, MMSc: I think that certainly asthma is a very heterogeneous disease. We recognize that there are both allergic and nonallergic factors that play a role. One of the issues that often gets dismissed or isn’t recognized is how dynamic asthma is and how dynamic the components that may be causing asthma may be occurring are. You can have allergic asthma one day mediated by a specific aeroallergen, then, on a different day, you may be exposed to a virus and have a different type of asthma. I think recognizing the different patterns is critical in terms of the overall treatment plan and treatment paradigm that one is going to engage in. Geoff, what are your thoughts?
Geoffrey L. Chupp, MD: I think that these are all really interesting comments. I have 2 thoughts, 1 related to asthma and COVID-19, and 1 relates to kind of our classic constructs that we’ve been talking about here. In terms of how we look at asthma and allergic versus nonallergic, this is the classic paradigm of how we group patients. Now we have entered into this in our current era, eosinophilic asthma, as well. That is, I think, a newer definition or way of looking at the disease, and we need to make sure that we integrate this into our classic construct of allergic and nonallergic, because I think for clinicians, there can be some confusion about how these different subtypes of disease overlap and the fact that patients with eosinophilic asthma may or may not have allergic disease, as well. So, we need to make sure that we come to kind of a new understanding of how we subtype the disease in these different ways.
Dr Goldstein was talking about sputum phenotyping, in terms of pauci-immune and neutrophilic and eosinophilic. This is one way of looking at the disease, but I think we have to come to some new paradigm here of how to subgroup the diseases.
In terms of the COVID-19, I totally agree. I think there’s definitely concern about susceptibility to viral infections, including coronavirus. Very important in my view is for all patients to continue their medications and maintain control, because this will help their mucosal immunity and, I think, help their susceptibility on balance compared with the risk of being on an inhaled steroid, which in vitro studies have actually shown in some cases to be beneficial in terms of viral replication.
Transcript Edited for Clarity
