Phenotypic characteristics of exacerbations in severe asthmatics receiving biological agent treatment

Identifying the eosinophilic, neutrophilic, or infectious phenotypes of exacerbations, particularly those occurring during biologic agent therapy, may provide valuable guidance for determining maintenance therapy for patients and preventing recurrent exacerbations. Our study primarily aimed to evaluate the clinical phenotypic features of exacerbations in patients with severe asthma receiving biologic agent therapy.

The first asthma exacerbation experienced by the patients after the 16th week of biological agent treatment was evaluated in terms of inflammatory phenotype and clinical features. White blood cell counts and C-reactive protein levels, related season, antibiotic use, and hospitalization during the exacerbation were recorded from patients' medical file records.

Data of 75 patients with severe asthma receiving biological treatment were analyzed. Subjects were aged 48.0 (mean) ± 11.0 (standard deviation), and 52 (69.3%) of them were female. Biological agent used in treatment was omalizumab in 53 (70.7%) subjects and mepolizumab in 22 (29.3%) subjects. The majority of exacerbations in asthmatics treated with either biologic agent were eosinophilic. In patients using omalizumab, the median eosinophil count was significantly higher compared to those using mepolizumab (p=0.032).

Phenotyping of asthma exacerbations that persist in spite of biologic therapy will guide treatment adjustments and decisions to switch biologic agents to improve outcomes.