Type 2-high severe asthma is often co-existent with bronchiectasis, according to a multicenter Italian study.¹ High-Resolution Chest Tomography (HRCT) can help in the identification of this group of patients.

The prospective, observational study recruited 113 patients, aged 55 years (mean), with type 2-high severe asthma (T2-SA). Women comprised almost 60% of the study population. All patients were on high-dose inhaled corticosteroids/long-acting β-agonists (LABAs). Inclusion criteria were “blood eosinophils count ≥150 cells/μL and/or fraction of exhaled nitric oxide (FeNO)≥20 ppb and/or sputum eosinophils ≥2%, and/or asthma clinically allergen-driven and/or need oral corticosteroids for maintenance”. Patients with immunological deficits, allergic bronchopulmonary aspergillosis, alpha-1-deficiency, vasculitis, cystic fibrosis, primary ciliary dyskinesia, T2-Low SA and patients with past history of pneumonia were excluded.

Fifty (44.2%) out of the 113 patients had co-existing bronchiectasis (T2-SA+BE group). These patients also had higher incidence of chronic rhinosinusitis (CRS) (84% vs 58.7% and chronic rhinosinusitis with nasal polyps (CRSwNP) (54% vs 42.9%), compared to patients who did not have bronchiectasis.

Fifty-eight percent of patients in the T2-SA+BE group reported chronic mucus hypersecretion, which was often purulent or muco-purulent in nature compared to 23.8% patients in the T2-SA alone group.

More T2-SA patients with bronchiectasis reported episodes of asthma exacerbations in the past year (10 vs 6) and required maintenance with oral corticosteroids (56% vs 34.9%). On multivariate analysis, the presence of chronic rhinosinusitis, chronic sputum production and dependence on oral steroids were all strongly predictive of the presence of underlying BE in T2-SA patients with a 78% accuracy.

On HRCT, 76% patients had mild bronchiectasis and 24% had moderate bronchiectasis.

Twelve percent of patients i.e., six out of the 50 patients with bronchiectasis had a Bronchiectasis Severity Index (BSI) score of 9 or higher. The number of lobes with bronchiectasis ranged from 2 to 4 with involvement of mainly lower lobes (52%) and peripheral areas (72%); 96% had cylindrical bronchiectasis. The median Bhalla score was 18.3 suggesting mild radiological severity. Sputum culture was negative in 88%, while 10% showed Pseudomonas aeruginosa. An inverse association was observed between the BSI score and levels of asthma control, but not with duration of asthma or the risk of asthma exacerbations.

Type 2 asthma has allergic and/or eosinophilic phenotypes. Raised eosinophils, FeNO and IgE levels point to type 2 inflammation.  This study reported in the Journal of Asthma and Allergy has characterized the presentation of T2-SA patients with and without bronchiectasis. It has red flagged chronic rhinosinusitis with/without nasal polyposis, excess mucus production, long-term steroid use and a higher exacerbations rate as indicative of co-existing bronchiectasis and recommends chest HRCT for early diagnosis to improve clinical outcomes and quality of life of these patients.

Reference

1. Crimi C, et al. Type 2-high severe asthma with and without bronchiectasis: a prospective observational multicentre study. J Asthma Allergy. 2021 Nov 30;14:1441-1452. doi: 10.2147/JAA.S332245.