The study was a real-world, population-based cohort study that comprised healthcare data of patients from Germany (aged ≥14 years) between the years of 2005 and 2014. Patients with incident asthma during this period were identified and included in the analysis (n=39,167). The primary outcome was the progression of disease severity over time. Asthma severity was classified based on each patient’s prescribed asthma medication and according to the Global Initiative for Asthma classification system. The researchers compared the effects of allergy immunotherapy vs no allergy immunotherapy on asthma severity progression.
Approximately 10.5% (n=4111) of patients who had incident asthma during the observation period received ≥1 allergy immunotherapy prescription. Exposure to allergy immunotherapy correlated with a reduced likelihood of asthma progression, according to the Global Initiative for Asthma classification step 1 to step 3 (hazard ratio [HR], 0.87; 95% CI, 0.80-0.95) and step 3 to Global Initiative for Asthma step 4 (HR, 0.66; 95% CI, 0.60-0.74). The effect of allergy immunotherapy on the progression of asthma severity was more pronounced in adolescents (HR, 0.72; 95% CI, 0.58-0.88), followed by young adults between the ages of 18 and 49 years in 2005 (HR, 0.89; 95% CI, 0.80-0.98). There was no observable risk reduction in patients aged ≥50 years (HR, 1.09; 95% CI, 0.87-1.38).
A limitation of the study was the lack of data on spirometry, peak expiratory flow, or bronchial challenge testing results for the objective measurement of asthma severity progression.
The researchers suggest that their findings support “the assumption that treatment with [allergy immunotherapy] may prevent the progression from mild to more severe asthma.”
Schmitt J, Wüstenberg E, Küster D, Mücke V, Serup-Hansen, Tesch F. The moderating role of allergy immunotherapy in asthma progression. Results of a population-based cohort study [published online August 13, 2019]. Allergy. doi:10.1111/all.14020