Allergen immunotherapy: effective on lung function?

PURPOSE OF REVIEW: This review evaluates the evidence on the effects of allergen immunotherapy (AIT) on lung function in asthma, with a focus on long-term outcomes. The topic is timely given the increasing interest in disease-modifying strategies that may alter asthma's natural course, particularly through interventions targeting type 2 inflammation. RECENT FINDINGS: Previous long-term observational and randomized studies suggest that sublingual immunotherapy (SLIT) can sustain clinical benefits and may positively impact lung function. However, while improvements in asthma control and exacerbation reduction are consistent, recent and robust evidence for lung function preservation remains limited. Real-world prospective studies from European and Chinese cohorts, point to possible allergen-independent benefits on forced expiratory volume in one second. SUMMARY: While AIT is a proven disease-modifying intervention for allergic diseases, its role in preventing or slowing lung function decline in asthma is underexplored. Future research should prioritize longitudinal spirometry data across diverse allergens and patient populations to clarify AIT's potential to alter asthma progression.