Mechanisms of virus‐induced asthma exacerbations: state‐of‐the‐art. A GA²LEN and InterAirways document

Abstract

Viral infections of the respiratory tract are the most common precipitants of acute asthma exacerbations. Exacerbations are only poorly responsive to current asthma therapies and new approaches to therapy are needed. Viruses, most frequently human rhinoviruses (RV), infect the airway epithelium, generate local and systemic immune responses, as well as neural responses, inducing inflammation and airway hyperresponsiveness. Using in vitro and in vivo experimental models the role of various proinflammatory or anti-inflammatory mediators, antiviral responses and molecular pathways that lead from infection to symptoms has been partly unravelled. In particular, mechanisms of susceptibility to viral infection have been identified and the bronchial epithelium appeared to be a key player. Nevertheless, additional understanding of the integration between the diverse elements of the antiviral response, especially in the context of allergic airway inflammation, as well as the interactions between viral infections and other stimuli that affect airway inflammation and responsiveness may lead to novel strategies in treating and/or preventing asthma exacerbations. This review presents the current knowledge and highlights areas in need of further research.

Important research questions in allergy and related diseases: nonallergic rhinitis: a GA2LEN paper

“…Infectious rhinitis, most often caused by respiratory viruses and characterized as a Ôcommon coldÕ, may trigger both allergic (114,115) and NAR in addition to asthma (116). However, the role of viruses in the development of persistent rhinitis has not been adequately assessed.…”

Nachweis von Atemwegsviren – Wie, warum, wann und wo?

“…Die Mehrheit aller akuten Asthma−Exazerbationen wird durch Infekte der oberen Atemwege ausgelöst [30]. Dies wurde in epi− demiologischen Studien sowohl bei Kindern (Nachweis bei bis zu 80 % der Exazerbationen) [31] als auch bei Erwachsenen (Nachweis bei ca.…”

Activation of eosinophils via Toll-like receptor (TLR)3, TLR7 and TLR9: link between viral infection and asthma?

“…A hallmark of the virus-recognising TLRs is that they are located intracellularly in endosomes and that they respond to nucleic acids from viruses, such as double-stranded RNA (TLR3), single-stranded RNA (TLR7/8) and unmethylated CpG DNA (TLR9). In the context of the respiratory tract, rhinovirus, influenza virus, coronavirus and respiratory syncytial virus are common causes of infection [5]. The work presented in the award-winning abstract is from my latest study, in which this question was addressed.…”