Baseline inflammation patterns in severe asthma patients receiving biologic therapy

Photo by Joshua Chehov / Unsplash

Frontiers in Medicine Published April 9, 2026 Medically reviewed May 26, 2026 DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Note that most neutrophilic severe asthma patients exhibit elevated T2 biomarkers and lower FVC in this observational cohort.

This retrospective observational cohort study evaluated clinical and inflammatory outcomes in 103 patients with severe asthma who received biologic therapy. The analysis stratified patients based on baseline bronchial inflammation patterns observed at the start of treatment. No comparator group was defined, and the study setting was not reported. The primary focus was on characterizing inflammatory phenotypes rather than testing therapeutic efficacy against a control arm.

Among the 103 subjects analyzed, 62.8% exhibited an eosinophilic pattern, 13.3% a mixed granulocytic pattern, and 15.0% a neutrophilic pattern. Notably, 82.7% of the neutrophilic patients presented elevated type 2 biomarkers, such as FeNO and blood eosinophils. Additionally, forced vital capacity was lower in neutrophilic patients compared with other groups, and these patients had higher frequencies of obstructive sleep apnea but lower frequencies of chronic rhinosinusitis with nasal polyps.

During the 6 and 12-month follow-up period, all patients demonstrated a significant reduction in their ability to produce sputum (p < 0.05). The study did not report data on adverse events, serious adverse events, discontinuations, or overall tolerability. Key limitations include the retrospective observational design, which precludes causal inference, and the lack of reported funding or conflict of interest information. Consequently, the certainty of these findings is low, and generalizability to other populations or specific biologic agents remains uncertain.

Study Details

Study typeCohort

EvidenceLevel 3

PublishedApr 2026

View Original Abstract ↓

IntroductionPatients with severe asthma have new therapeutic opportunities with biologic agents, reducing exacerbation rates, symptom scores, and oral corticosteroid use; however, their effects on lung function appear to be variable. The aim of this study is to evaluate the clinical and inflammatory outcomes of biologic therapy in patients with severe asthma, stratified according to baseline bronchial inflammation.MethodsThis was a retrospective observational study in patients with severe asthma at 6 and 12 months after initiation of biologic therapy. Patients were categorized according to their baseline airway inflammatory profile. The inflammatory biomarkers evaluated included induced sputum, fractional exhaled nitric oxide (FeNO), and peripheral blood leukocyte counts. Lung function, comorbidities, exacerbation rate, and asthma control (assessed by ACQ-6 and ACT) were also recorded.ResultsA total of 113 patients with severe asthma were analyzed. Patients with a paucigranulocytic pattern were excluded from further analyses due to their small number (n = 10). Among the remaining subjects (n = 103), 62.8% exhibited an eosinophilic pattern, 13.3% a mixed granulocytic pattern, and 15.0% a neutrophilic pattern. Most neutrophilic patients (82.7%) presented elevated type 2 (T2) biomarkers (FeNO and/or blood eosinophils). Differences in baseline biomarkers and comorbidities reflected the underlying airway inflammatory patterns; forced vital capacity (FVC, L) was lower in neutrophilic patients compared with the other groups. Neutrophilic patients had higher frequencies of obstructive sleep apnea and lower chronic rhinosinusitis with nasal polyps than eosinophilic subjects. During follow-up, all patients showed a significant reduction in their ability to produce sputum (p