High Serum IgE Predicts Severe Exacerbations in Non-Eosinophilic Bronchiectasis: Study
A new study published in the journal of Lung found bronchiectasis to show significantly high blood IgE levels independently predicted severe exacerbations necessitating hospitalization in individuals with non-eosinophilic bronchiectasis.
Bronchiectasis is usually thought to be largely a neutrophil-driven condition, although up to 40% of patients have type 2 inflammation, which is characterized by high blood eosinophils and immunoglobulin E. While both are important indicators, they represent very different immunopathological processes.
Even in the absence of asthma or allergic bronchopulmonary aspergillosis, more than one-third of individuals with bronchiectasis had increased IgE levels. Previous study has linked increased IgE to more widespread lung involvement and mucus plugging during imaging.
However, the exact therapeutic significance of these many endotypes—specifically, how they affect patient symptoms, total lung function, sputum pathogen distribution, and exacerbation rates—is uncertain. To fill this clinical vacuum, this study explicitly analyzes the predictive impact of serum IgE levels in predicting bad outcomes, with a focus on patients with non-eosinophilic bronchiectasis.
From 2017 to 2020, this multicenter prospective cohort research at 16 Taiwanese universities recruited participants with bronchiectasis but no allergic bronchopulmonary aspergillosis. Patients were classified based on their baseline absolute eosinophil count (cutoff 300/uL) and serum IgE level (≤100, 100-500, >500 IU/mL). The primary outcome was severe exacerbations that required hospitalization within one year. Secondary objectives were all-cause mortality, bacterial distribution in sputum, imaging pattern, and lung function.
A total of 579 people were registered. The most prevalent microbes identified from sputum were nontuberculous mycobacteria (10.7%) and Pseudomonas aeruginosa (9.0%).
Low-eosinophil bronchiectasis was diagnosed in 493 individuals (85.1%), with 41 (7.1%) having blood IgE levels more than 500 IU/ml.
Acute exacerbation hospitalization rates were significantly greater in this group compared to those with lower IgE levels (9.8% vs. 0.9% and 2.3%; P = 0.009).
In multivariate analysis, IgE levels over 500 IU/mL were the largest independent predictor of hospitalization (adjusted odds ratio, 7.38; 95% confidence interval, 2.40-22.7; P < 0.001).
The connection was stronger in female patients and those with concomitant asthma. All-cause mortality was not substantially different between IgE strata.
Overall, in individuals with low-eosinophil bronchiectasis, dramatically high blood IgE predicted severe exacerbations that required hospitalization. These findings supported the use of IgE testing in routine bronchiectasis assessments to identify a high-risk subgroup that might benefit from focused therapies.
Source:
Kao, T.-W., Wang, Y.-H., Chang, C.-L., Sheu, C.-C., Wang, P.-H., Hsieh, M.-H., Hsu, W.-H., Chen, M.-T., Ou, W.-F., Wei, Y.-F., Yang, T.-M., Lan, C.-C., Wang, C.-Y., Lin, C.-B., Lin, M.-S., Wang, Y.-T., Lin, C.-H., Liu, S.-F., Cheng, M.-H., … Taiwan Bronchiectasis Research Collaboration (TBARC). (2026). High serum IgE is associated with risk of severe exacerbations among non-eosinophilic bronchiectasis. Lung, 204(1). https://doi.org/10.1007/s00408-026-00874-2
