Elevated serum IgE, oral corticosteroid dependence and IL-17/22 expression in highly neutrophilic asthma

Information on the clinical traits associated with bronchial neutrophilia in asthma is scant, preventing its recognition and adequate treatment. We aimed to assess the clinical, functional and biological features of neutrophilic asthma and identify possible predictors of bronchial neutrophilia. The inflammatory phenotype of 70 mild-to-severe asthma patients was studied cross-sectionally based on the eosinophilic/neutrophilic counts in their bronchial lamina propria. Patients were classified as neutrophilic or non-neutrophilic. Neutrophilic asthma patients (neutrophil count cut-off: 47.17 neutrophils·mm–2; range: 47.17–198.11 neutrophils·mm–2; median: 94.34 neutrophils·mm–2) were further classified as high (≥94.34 neutrophils·mm–2) or intermediate (47.17– <94.34 neutrophils·mm–2). The effect of smoking ≥10 pack-years was also assessed. Neutrophilic asthma patients (n=38; 36 mixed eosinophilic/neutrophilic) had greater disease severity, functional residual capacity, inhaled corticosteroid (ICS) dose and exacerbations, and lower forced vital capacity (FVC) % pred and forced expiratory volume in 1 s (FEV1) reversibility than non-neutrophilic asthma patients (n=32; 28 eosinophilic and four paucigranulocytic). Neutrophilic asthma patients had similar eosinophil counts, increased bronchial CD8+, interleukin (IL)-17-F+ and IL-22+ cells, and decreased mast cells com...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Lung biology and experimental studies, Asthma and allergy Original Articles: Asthma and basic science Source Type: research