Characterizing the early and late asthmatic responses in the allergen inhalation challenge

Allergen inhalation challenges (AICs) are widely used in research to assess airway responses to allergen exposure and predict the therapeutic effectiveness of various medications. 1 Cockcroft D.W. Hargreave F.E. O’Byrne P.M. Boulet L.P. Understanding allergic asthma from allergen inhalation tests. Can Respir J. 2007; 14: 414-418 Crossref PubMed Scopus (24) Google Scholar The characteristics of early asthmatic response (EAR) and late asthmatic response (LAR) are often described in general terms. 2 O’Byrne P.M. Dolovich J. Hargreave F.E. Late asthmatic responses. Am Rev Respir Dis. 1987; 136: 740-751 Crossref PubMed Scopus (433) Google Scholar , 3 Boulet L.P. Gauvreau G. Boulay M.E. O’Byrne P. Cockcroft D.W. Clinical Investigative Collaboration, Canadian Network of Centers of Excellence AllerGen. The allergen bronchoprovocation model: an important tool for the investigation of new asthma anti-inflammatory therapies. Allergy. 2007; 62: 1101-1110 Crossref PubMed Scopus (56) Google Scholar , 4 Diamant Z. Gauvreau G.M. Cockcroft D.W. et al. Inhaled allergen bronchoprovocation tests. J Allergy Clin Immunol. 2013; 132: 1045-1055.e6 Abstract Full Text Full Text PDF PubMed Scopus (77) Google Scholar Original research findings focus on mean data. We are not aware of any data objectively documenting the responses of individual participants, and it is important to acknowledge that mean data do not accurately reflect the range of individual responses and the relevant safety implications of performing AICs. We therefore sought to directly characterize the timing, magnitude, and recovery characteristics of the EAR and LAR with an emphasis on individual responses.