Cited 15 times since 2013 (1.4 per year) source: EuropePMC Respiratory medicine, Volume 107, Issue 7, 30 5 2013, Pages 959-966 CD8(+) T cells characterize early smoking-related airway pathology in patients with asthma. Ravensberg AJ, Slats AM, van Wetering S, Janssen K, van Wijngaarden S, de Jeu R, Rabe KF, Sterk PJ, Hiemstra PS
Background
Smoking in asthma occurs frequently and is associated with increased symptom severity, an impaired response to corticosteroids, and accelerated lung function decline. Airway pathology in smoking asthmatics is characterized by neutrophilia and epithelial changes such as goblet cell hyperplasia and increased proliferation. Bronchial CD8(+) T cells are implicated in lung function decline in asthma and COPD. We hypothesized that smoking modifies airway inflammation in asthma by increasing the number of CD8(+) T cells at an early stage.
Objectives & methods
To study effects of smoking on airway pathology in bronchial biopsies from atopic patients with controlled intermittent or mild persistent asthma (12 smokers, 9.7 py and 11 never-smokers, 0.0 py; 20-50 yrs; FEV1 > 70% predicted; PC20MCh < 8 mg/mL, no ICS) using immunohistochemistry.
Results
Smoking asthmatics showed higher numbers of bronchial CD8(+) T cells (55.8 vs 23.9 cells/0.1 mm(2); p = 0.001) and CD68(+) macrophages (7.5 vs 4.6 cells/0.1 mm(2), p = 0.012), and a lower CD4(+)/CD8(+) cell ratio (0.16 vs 0.40; p = 0.007) compared with non-smoking asthmatics, but no difference in neutrophils. Furthermore, the % intact epithelium was higher in smoking asthmatics (49.3 vs 23.3, p = 0.001).
Conclusion
Smoking asthmatics with a limited smoking history show a distinct pattern of airway pathology characterized by a bronchial infiltrate of CD8(+) T cells and CD68(+) macrophages, and epithelial remodelling resembling COPD-like features. This raises the hypothesis that early presence of CD8(+) T cells contributes to disease progression in smoking asthmatics.
