TY - JOUR
T1 - Alveolar T-helper type-2 immunity in atopic asthma is associated with poor clinical control
AU - Bergqvist, Anders
AU - Andersson, Cecilia
AU - Mori, Michiko
AU - Walls, Andrew F.
AU - Bjermer, Leif
AU - Erjefält, Jonas
PY - 2015
Y1 - 2015
N2 - Real-world evaluation studies have shown that many patients with asthma remain symptomatic despite treatment with inhaled corticosteroids (ICSs). As conventional ICSs have poor access to the peripheral airways, the aim of the present paper was to study the relationship between peripheral airway inflammation and clinical control in allergic asthma. Consequently, bronchial and transbronchial biopsies were obtained from patients with poorly controlled asthma [n=12, asthma control test (ACT) score < 20], patients with well-controlled asthma (n= 12, ACT score >= 20) and healthy controls (n= 8). Tissue sections were immunostained to assess multiple leucocyte populations. To determine the degree of T-helper type-2 (Th2) immunity, the logarithmic value of the ratio between Th2 cells/mm(2) and Th1 cells/mm(2) was used as a surrogate score for Th2-skewed immunity. In the bronchi, the leucocyte infiltration pattern and the Th2-score were similar between patients with well-controlled asthma and those with poorly controlled asthma. In contrast, in the alveolar parenchyma, the expression of T-helper cells was significantly higher in patients with poorly controlled asthma than in patients with well-controlled asthma (P < 0.01). Furthermore, the alveolar Th2-score was significantly higher in patients with poorly controlled asthma (median 0.4) than in the controlled patients (median -0.10, P < 0.05). In addition, in contrast with bronchial Th2-score, the alveolar Th2-score correlated significantly with ACT score (r(s)=-0.62, P < 0.01) in the pooled asthma group. Collectively, our data reveal an alveolar Th2-skewed inflammation, specifically in asthmatic patients who are poorly controlled with ICSs, and suggest that pharmacological targeting of the peripheral airways may be beneficial in this large patient category.
AB - Real-world evaluation studies have shown that many patients with asthma remain symptomatic despite treatment with inhaled corticosteroids (ICSs). As conventional ICSs have poor access to the peripheral airways, the aim of the present paper was to study the relationship between peripheral airway inflammation and clinical control in allergic asthma. Consequently, bronchial and transbronchial biopsies were obtained from patients with poorly controlled asthma [n=12, asthma control test (ACT) score < 20], patients with well-controlled asthma (n= 12, ACT score >= 20) and healthy controls (n= 8). Tissue sections were immunostained to assess multiple leucocyte populations. To determine the degree of T-helper type-2 (Th2) immunity, the logarithmic value of the ratio between Th2 cells/mm(2) and Th1 cells/mm(2) was used as a surrogate score for Th2-skewed immunity. In the bronchi, the leucocyte infiltration pattern and the Th2-score were similar between patients with well-controlled asthma and those with poorly controlled asthma. In contrast, in the alveolar parenchyma, the expression of T-helper cells was significantly higher in patients with poorly controlled asthma than in patients with well-controlled asthma (P < 0.01). Furthermore, the alveolar Th2-score was significantly higher in patients with poorly controlled asthma (median 0.4) than in the controlled patients (median -0.10, P < 0.05). In addition, in contrast with bronchial Th2-score, the alveolar Th2-score correlated significantly with ACT score (r(s)=-0.62, P < 0.01) in the pooled asthma group. Collectively, our data reveal an alveolar Th2-skewed inflammation, specifically in asthmatic patients who are poorly controlled with ICSs, and suggest that pharmacological targeting of the peripheral airways may be beneficial in this large patient category.
KW - alveolar parenchyma
KW - asthma control asthma
KW - peripheral inflammation
KW - T-helper type-2 (Th2)
U2 - 10.1042/CS20140309
DO - 10.1042/CS20140309
M3 - Article
C2 - 25059741
SN - 1470-8736
VL - 128
SP - 47
EP - 56
JO - Clinical Science
JF - Clinical Science
IS - 1
ER -