Near-fatal asthma phenotype in the ENFUMOSA Cohort

Near-fatal asthma (NFA) is characterized by severe asthma attacks usually requiring intensive care unit admission. This phenotype of asthma has been studied mainly in acute conditions.

The aim of our study was to compare the clinical, functional and inflammatory characteristics of NFA patients with mild to severe asthmatics in stable conditions. We recruited 155 asthmatic patients from five centres of the European Network for Understanding Mechanisms of Severe Asthma: 67 patients with mild-to-moderate asthma controlled by low/medium doses of inhaled corticosteroids; 64 with severe asthma that, despite treatment with high doses of inhaled corticosteroids, long-acting beta2-agonists and for 1/3 also with regular oral corticosteroids, had at least one asthma exacerbation in the previous year; 24 with an NFA episode in the previous 5 years in the absence of inclusion criteria for the previous groups. All the patients were examined in stable conditions.

NFA patients were taking less corticosteroids and were less compliant to prescribed asthma medications than the other two groups of patients. Lung function, blood gases, atopic status, sputum and blood inflammatory cell count of NFA patients were similar to mild-to-moderate, but not severe, asthmatic patients.

In stable conditions patients with an NFA attack in the previous 5 years cannot be distinguished from patients with mild-to-moderate asthma, while they are different from severe asthmatics both in terms of lung function and of airway inflammation. The risk factor that characterizes this group of patients is reduced usage of prophylactic corticosteroids.