Rationale: Airway remodeling and inflammation are characteristic features of adult asthma that are still poorly investigated in childhood asthma. Objectives: To examine epithelial and vascular changes as well as the inflammatory response in airways of children with asthma. Methods: We analyzed bronchial biopsies obtained from 44 children undergoing bronchoscopy for appropriate clinical indications other than asthma: 17 with mild/moderate asthma (aged 2-15 yr), 12 with atopy without asthma (1-11 yr), and 15 control children without atopy or asthma (1-14 yr). By histochemistry and immunohistochemistry, we quantified epithelial loss, basement membrane thickness, number of vessels, and inflammatory cells in subepithelium. Results: Epithelial loss and basement membrane thickness were increased in children with asthma compared with control subjects (p ϭ 0.005 and p ϭ 0.0002, respectively) and atopic children (p ϭ 0.002 and p ϭ 0.005, respectively). The number of vessels and eosinophils was increased not only in asthmatic children (p ϭ 0.03 and p ϭ 0.0002, respectively) but also in atopic children without asthma (p ϭ 0.03 and p ϭ 0.008, respectively) compared with control subjects. When we stratified the analysis according to age, we observed that children with asthma younger than 6 yr had increased epithelial loss, basement membrane thickening, and eosinophilia compared with control subjects of the same age. Conclusions: Epithelial damage and basement membrane thickening, which are pathologic features characteristic of adult asthma, are present even in childhood asthma. Other changes, such as airway eosinophilia and angiogenesis, were also observed in atopic children without asthma. These observations suggest that pathologic changes occur early in the natural history of asthma and emphasize the concept that some of these lesions may characterize atopy even in the absence of asthmatic symptoms.

CXCR3 is a chemokine receptor preferentially expressed on lymphocytes, particularly on type-1 T-lymphocytes. Smokers who develop chronic obstructive pulmonary disease (COPD) have a chronic bronchopulmonary inflammation that is characterized by an increased infiltration of T-lymphocytes, particularly CD8(+), in the airways and lung parenchyma. To investigate the expression of CXCR3 and its ligand interferon-induced protein 10/CXCL10 in COPD, we counted the number of CXCR3(+) cells and analyzed the expression of CXCL10 in the peripheral airways of 19 patients undergoing lung resection for localized pulmonary lesions. We examined lung specimens from seven smokers with fixed airflow limitation (COPD), five smokers with normal lung function, and seven nonsmoking subjects with normal lung function. The number of CXCR3(+) cells was immunohistochemically quantified in the epithelium, in the submucosa, and in the adventitia of peripheral airways. The number of CXCR3(+) cells in the epithelium and submucosa was increased in smokers with COPD as compared with nonsmoking subjects, but not as compared with smokers with normal lung function. Immunoreactivity for the CXCR3-ligand CXCL10 was present in the bronchiolar epithelium of smokers with COPD but not in the bronchiolar epithelium of smoking and nonsmoking control subjects. Most CXCR3(+) cells coexpressed CD8 and produced interferon gamma. These findings suggest that the CXCR3/CXCL10 axis may be involved in the T cell recruitment that occurs in peripheral airways of smokers with COPD and that these T cells may have a type-1 profile.

Inflammation, oxidative stress and apoptosis, which are involved in chronic obstructive pulmonary disease (COPD) pathogenesis, may activate the p38 subgroup of mitogenactivated protein kinases (MAPKs). Therefore, the aim of the present study was to evaluate the expression of the phosphorylated, active form of p38 MAPK (phospho-p38) in the lungs of COPD patients.Surgical specimens were obtained from 18 smokers with COPD at different stages of disease severity, plus nine smoking and eight nonsmoking subjects with normal lung function. Phosphop38+ cells were quantified by immunohistochemistry in both alveolar spaces and alveolar walls. Moreover, a Western blot analysis of phospho-p38 and total p38a isoform expressed by alveolar macrophages was performed.Phospho-p38+ alveolar macrophages and phospho-p38+ cells in alveolar walls were increased in patients with severe and mild/moderate COPD, compared with smoking and nonsmoking controls. Moreover, they were inversely correlated to values of forced expiratory volume in one second (FEV1) and FEV1/forced vital capacity. Western blot analysis showed that phosphorylated p38, but not the total p38a isoform, was specifically increased in alveolar macrophages from COPD patients.Activation of the p38 mitogen-activated protein kinase pathway appears to be involved in the pathogenesis of chronic obstructive pulmonary disease. The present findings suggest that this protein may be a suitable pharmacological target for therapeutic intervention.

Airway pathology has been extensively investigated in adulthood asthma, whereas only few studies examined bronchial biopsies in childhood asthma. To evaluate the airway pathology in children with asthma, we analyzed bronchial biopsies obtained from 23 children undergoing bronchoscopy for clinical indications other than asthma. Nine had mild/moderate asthma. Six had atopy without asthma, and eight had no atopy or asthma. We measured basement membrane thickness and quantified the number of eosinophils, mast cells, neutrophils, macrophages, T lymphocytes, and positive cells for transforming growth factor-beta1 (TGF-beta1) and its receptors I and II (TGFbeta-RI and TGFbeta-RII) in subepithelium. Children with asthma had an increase in basement membrane thickness and in the number of eosinophils compared with control subjects, but not compared with children with atopy. They also had a decreased expression of TGFbeta-RII compared with both those with atopy and control subjects. In children with asthma, the number of eosinophils correlated negatively with TGFbeta-RII and positively with symptom duration. In conclusion, airway eosinophilia and basement membrane thickening, which are the pathologic features that are characteristic of adulthood asthma, are already present in children with mild asthma, and even in children with atopy without asthma. Moreover, in children with asthma but not in children with atopy without asthma, there is a downregulation of TGFbeta-RII.