Which patients with asthma are most likely to benefit from allergen immunotherapy?

If allergen immunotherapy (AIT) is to be considered as a treatment option for allergic asthma, it must undergo the same developmental steps as other antiasthmatic drugs. The bronchial allergen challenge model has demonstrated excellent negative predictive value for the development of new therapies for asthma. Subcutaneous immunotherapy appears to have a clinical and significant effect on the early asthmatic response to mite, cat, and birch and grass pollens in children and adults. Use of AIT in children with asthma is widely practiced but not supported by as strong a level of evidence as in adults. House dust mite sublingual immunotherapy tablets demonstrate efficacy in asthma exacerbations and other outcomes when used as add-on therapy in adult patients. Using a biologic to improve the patient's lung functions and asthma control before initiating AIT can transform unsuitable candidates for AIT into appropriate candidates. Because AIT is a form of personalized medicine, phenotyping the most suitable patient is necessary. Field studies of adults and children have suggested that polysensitized patients with rhinitis and Global Initiative for Asthma class 2 to class 4 asthma appear the most likely to be good responders. We hypothesized that AIT responders are those who demonstrate a high eosinophilic response to natural or experimental exposure.