Abstract
The U-BIOPRED consortium aims to sub phenotype adult and paediatric patients with severe asthma using an innovative systems medicine approach. The adult study included a bronchoscopy sub-study to collect a range of samples and the objective of the present study was to characterise the immunopathology in GMA embedded bronchial biopsies. Two severe asthma groups, one never smoked and one current/ex-smokers, and a mild-moderate asthma group classified and treated according to the GINA guidelines plus a healthy control group were included (see table).
Subjects
Sections were stained immunohistochemically for mast cells, eosinophils, neutrophils, macrophages, CD3, CD4, CD8 and CD25 lymphocytes, and smooth muscle actin. Positive cells were counted in the submucosa, epithelium and airway smooth muscle (ASM). The thickness of the lamina reticularis and the volume fraction of the ASM were also assessed. There were significantly more mast cells in submucosa of the healthy control group (33.56mm-2) compared with both severe asthma groups (never smoker: 17.44mm-2, p<0.001, smokers / ex-smokers: 22.19mm-2, p=0.01) and to the mild-moderate asthma group (21.30mm-2, p=0.01). The number of CD4 lymphocytes was decreased in the smoking severe asthma group (4.73mm-2) compared with the never smoking severe group (11.6mm-2,p=0.002) and to the healthy controls (10.59mm-2, p<0.001). No other differences were observed across the groups. We conclude that bronchial immunopathology is associated with asthma severity, treatment and smoking status. Sponsored by IMI.
- © 2014 ERS
