Asthma and viral infections

Abstract

Key MessagesViral infections in infancy, particularly with rhinovirus (RV) or respiratory syncytial virus (RSV), are important risk factors for wheezing episodes, asthma, and asthma exacerbations.RV infection is a more important risk factor for the development of atopic asthma, likely through a mechanism that relies on allergic sensitization.RSV infection is a more important risk factor for the development of nonatopic asthma, likely through a different mechanism than RV.Neutrophils and dendritic cell responses to viral infection appear to be important contributors to the T H 2 response that defines atopic asthma.Understanding the association among viral infections, atopy, and asthma can help guide appropriate treatment strategies for viralinduced or exacerbated asthma. A B S T R A C TObjective: To synthesize available data related to the complex associations among viral infections, atopy, and asthma. Data Sources: Key historical articles, articles highlighted in our recent review of most significant recent asthma advancements, and findings from several birth cohorts related to asthma and viral infections were reviewed. In addition, PubMed was searched for review articles and original research related to the associations between viral infection and asthma, using the search words asthma, viral infections, atopy, development of asthma, rhinovirus (RV), and respiratory syncytial virus (RSV). Study Selections: Articles were selected based on novelty and relevance to our topic of interest, the role of asthma and viral infections, and possible mechanisms to explain the association. Results: There is a large body of evidence demonstrating a link between early viral infections (especially RV and RSV) and asthma inception and exacerbations. RV-induced wheezing is an important risk factor for asthma only when atopy is present, with much evidence supporting the idea that sensitization is a risk factor for early RV-induced wheezing, which in turn is a risk factor for asthma. RSV, on the other hand, is a more important risk factor for nonatopic asthma, with severe infections conferring greater risk. Conclusion: There are important differences in the development of atopic and nonatopic asthma, with several proposed mechanisms explaining the association between viral infections and the development of asthma and asthma exacerbations. Understanding these complex associations is important for developing asthma prevention strategies and targeted asthma therapies.

Interrelations between COVID-19 and other disorders

“…Allergic asthma patients are at higher risk of developing a more severe disease upon viral infection [ 112 ]. Immunologically, asthma patients tend to have a slower response to viral infections as they show reduced and slow production of Type 1 interferons; the production of neutrophils increases in asthmatic patients, which indicates the presence of viral infections [ 113 ].…”

The “envirome” and what the practitioner needs to know about it

“…The role of viral infections in asthma has been recently reviewed in the Annals by Mikhail and Grayson. 38 Respiratory syncytial virus clearly induces lower airway disease and is frequently associated with asthma development. Rhinovirus (RV) is likely the leading viral cause of asthma exacerbation and also is linked with disease development.…”

Chronic Inflammatory Diseases, Anti-Inflammatory Agents and Their Delivery Nanosystems

“…can be based on an infectious or autoimmune basis, with the body always trying to eradicate harmful substances and restore tissue homeostasis [ 12 , 21 ]. Bacterial infections are often associated with serious inflammatory diseases such as bronchial asthma [ 22 , 23 , 24 ], gingivitis, periodontitis [ 25 ], systemic lupus erythematosus [ 26 ], and even cancer [ 27 ]. As bacterial infections can cause inflammation, which can cause consequent damage to surrounding tissue [ 16 , 18 , 28 ], anti-inflammatory drugs are very often combined with drugs that have antimicrobials effects, at least for the first time to control an attack ( Figure 1 ).…”