Allergen bronchoprovocation test: an important research tool supporting precision medicine

Abstract

Purpose of reviewAllergen bronchoprovocation test (ABT) has been used to study asthma pathophysiology and as a diseasemodelling tool to assess the properties and efficacy of new asthma drugs. In view of the complexity and heterogeneity of asthma, which has driven the definition of several phenotypes and endotypes, we aim to discuss the role of ABT in the era of precision medicine and provide guidance for clinicians how to interpret and use available data to understand the implications for the benefits of asthma treatment. Recent findingsIn this review, we summarize background knowledge and applications of ABT and provide an update with recent publications on this topic. In the past years, several studies have been published on ABT in combination with non-invasive and invasive airway samplings and innovative detection techniques allowing to study several inflammatory mechanisms linked to Th2-pathway and allergen-induced pathophysiology throughout the airways. SummaryABT is a valuable research tool, which has strongly contributed to precision medicine by helping to define allergen-triggered key inflammatory pathways and airway pathophysiology, and thus helped to shape our understanding of allergen-driven asthma phenotypes and endotypes. In addition, ABT has been instrumental to assess the interactions and effects of new-targeted asthma treatments along these pathways.

Organ‐specific allergen challenges in airway allergy: Current utilities and future directions

“…Unlike the NAC and CAC, classical BAC protocols are tailored to research needs and are hardly applicable in the clinic due to both safety and cost‐efficiency matters 73 . A positive BAC is determined by the occurrence of an early asthmatic response (EAR) within the 3 h following allergen inhalation 74 . Some patients testing positive also experience a late asthmatic response (LAR) that can persist longer than 7 h 70 .…”

“…73 A positive BAC is determined by the occurrence of an early asthmatic response (EAR) within the 3 h following allergen inhalation. 74 Some patients testing positive also experience a late asthmatic response (LAR) that can persist longer than 7 h. 70 Indeed, allergen-induced bronchoconstriction can be more profound than that triggered by mannitol or methacholine. 53 Thus, the BAC requires a long observation period in the clinic, sometimes including overnight stay.…”

EAACI position paper on the clinical use of the bronchial allergen challenge: Unmet needs and research priorities

“…Research BAC aims to alter lung function to study the mechanisms of airway allergy, 16 or analyse the effect of asthma medication. 17 Published studies mostly include mild asthmatics with a clinical history indicative of AA who maintain asthma control without ICS for a period long enough to achieve the required washout. Upon BAC, these subjects experience an early asthmatic response (EAR, see section 5 for definition).…”

“…BAC is currently a standard tool for translational studies. Research BAC aims to alter lung function to study the mechanisms of airway allergy, 16 or analyse the effect of asthma medication 17 . Published studies mostly include mild asthmatics with a clinical history indicative of AA who maintain asthma control without ICS for a period long enough to achieve the required washout.…”

Editorial: Dealing with asthma during the turbulent times of coronavirus disease-2019

“…Apart from specific indications within the field of occupational exposure, Boulet et al [3] point out that an allergen bronchoprovocation test (ABT) is mainly a research tool, which should not be applied for 'per default' diagnostic purposes and which is well tolerated and reproducible in expert settings only. Over the past decades, combined with noninvasive airway sampling methods, such as induced sputum and exhaled air analysis, ABT has helped precision medicine allowing to study several mechanisms linked to the T-helper 2 (Th2) pathway and the effects on airway pathophysiology [4].…”