Relationship between airway wall thickness assessed by high-resolution computed tomography and lung function in patients with asthma and chronic obstructive pulmonary disease.

Airway remodeling in asthma and chronic obstructive pulmonary disease (COPD) results in thickening of bronchial walls and may affect lung function. In the present study we set out to evaluate the relationship between small airway wall thickness and the lung function parameters in patients with asthma and COPD. The study was performed in 10 patients with asthma (4M/6F, the mean age 37+/-13 yr) and 12 patients with COPD (7M/5F, the mean age 57+/-9 yr) with stable, mild to moderate disease. The study group characteristics were based on clinical assessment and lung function testing (spirometry, body plethysmography, methacholine challenge test). All patients underwent chest high resolution computerized tomography with small bronchi (external diameter 1-5 mm) cross section measurements at five selected lung levels. The following parameters were measured in end-inspiratory scans: external (D) and internal (L) diameters, wall area (WA), percentage of the wall area (WA%), wall thickness (WT), and WT/D ratio (BWT). We found no significant correlations between airway wall thickness and spirometric parameters in either group. In the asthma group, the relationships between WA% and BWT, on the one side, and postbronchodilator residual volume, on the other, were noted (r=0.72; P<0.05 and r=0.72; P<0.05, respectively). In the COPD group, WA% related with airway resistance (r=0.72; P<0.05). The correlations between WA% and PC(20) (r=-0.61; P<0.05) and BWT and PC(20) (r=-0.72; P<0.05) were found in the COPD group. There was also a relationship between WA% and airway resistance (Raw) (r=0.72; P<0.05) and BWT and Raw (r=0.45; P=0.1). The number of pack-years correlated with WA and WT in COPD patients. In conclusion, the study shows that the thickening of airway wall in asthma is reflected by an increase in the indices of air trapping and in COPD this thickening results in a higher airway resistance and responsiveness. In COPD, the thickening of airway wall also is related to exposure to tobacco smoke.

Relationship between airway inflammation and remodeling in patients with asthma and chronic obstructive pulmonary disease.

UNLABELLED: Despite a number of important differences in the pathogenesis, course and prognosis of asthma and chronic obstructive pulmonary disease (COPD), these two entities also have common features with airway inflammation being one of them. Airway remodeling is a characteristic feature of asthma, but data on the bronchial wall thickening in COPD patients are still scarce. AIM: To assess the relation between the inflammatory cell count in the bronchoalveolar lavage fluid (BALF) and thickness of bronchial walls assessed by high resolution computed tomography (HRCT) in asthma and COPD patients. MATERIAL AND METHODS: The study was conducted in 9 patients with mild-to-moderate asthma (M/F 4/5, mean age 35 +/- 10 years) and 11 patients with mild-to-moderate COPD (M/F 7/4, mean age 57 +/- 9 years). In all subjects lung function tests and HRCT scanning of the chest were performed. External (D) and internal (L) diameters of the airways were assessed at five selected lung levels. The lumen area (A(L)), wall area (WA), wall thickness (WT) and bronchial wall thickness (WT/D ratio) were calculated. Eight patients with asthma and 8 patients with COPD underwent fiberoptic bronchoscopy and bronchoalveolar lavage (BAL). Total and differential cell counts were assessed in the BAL fluid. RESULTS: Mean FEV(1)% pred was 80 +/- 19%, and 73 +/- 20% in asthma and COPD patients, respectively (NS). No significant differences in the total and differential cell counts in BALF were found in patients with asthma and COPD. There were no significant differences in the airway diameter or airway wall thickness. The mean inner airway diameter was 1.4 +/- 0.3 and 1.2 +/- 0.3 mm and the mean lumen area was 1.8 +/- 0.7 and 1.6 +/- 0.7 mm(2) in asthma and COPD, respectively (NS). Negative correlations between the eosinophil count in BALF and inner airway diameter (r=-0.7, P<0.05) and lumen area (r=-0.7, P<0.05) were found in asthmatics. There was no significant relationship between the BALF cell count and airway wall thickness in COPD patients. - CONCLUSIONS: In mild-to-moderate asthma and COPD the airway diameter and thickness are similar. In asthmatics, the airway diameter might be associated with eosinophil count in BAL fluid.

Eosinophilic airway inflammation in chronic obstructive pulmonary disease and asthma.

Eosinophilic airway inflammation is regarded as a typical feature of asthma, while in chronic obstructive pulmonary disease (COPD) neutrophils seem predominant inflammatory airway cells. The aim of the present study was to compare the cellular components of airway inflammation in patients with newly diagnosed mild or moderate COPD and asthma. Seventeen patients with COPD (M/F 10/7, aged 57 +/-11 yr) and 22 patients with asthma (M/F 12/10, aged 36 +/-14 yr) were enrolled into the study. None of the patients has been treated with steroids for at least 3 months. All patients underwent clinical examination, laboratory examinations, skin-prick tests, pulmonary function tests, methacholine challenge test, and sputum induction with the total and differential cell count assessments. We found increased number of eosinophils in both study groups. However, there were no significant differences in the cellular composition of induced sputum between the asthma and COPD patients. We conclude that eosinophils are important inflammatory cells not only in asthma, but also in COPD.

Comparison of cellular and biochemical markers of airway inflammation in patients with mild-to-moderate asthma and chronic obstructive pulmonary disease: an induced sputum and bronchoalveolar lavage fluid study.

Although the clinical pictures of asthma and chronic obstructive pulmonary disease (COPD) may be similar, the pathogenesis differs in many aspects. The aim of the present study was to compare the cellular and biochemical features of airway inflammation in patients with asthma and COPD. The study was conducted in 22 patients with asthma (M/F 12/10, mean age 36 +/-14 years) and 17 patients with COPD (M/F 10/7, mean age 57 +/-11 years). Each patient underwent sputum induction followed by bronchoscopy, and bronchoalveolar lavage. Total and differential cell counts and the concentration of interleukin-8 (IL-8) and myeloperoxidase (MPO) were measured in induced sputum (IS) and BALF. We found no significant differences in the total and differential cell counts in IS between asthma and COPD patients. However, COPD patients showed an increased total macrophage count in BALF compared with asthma patients. The relative eosinophil count in BALF was significantly higher in patients with asthma vs. COPD. The concentration of IL-8 in IS and BALF was significantly higher in patients with COPD vs. asthma patients. The BALF concentration of MPO was significantly higher in patients with COPD compared with asthma patients. We conclude that the comparison of cellular composition and the concentration of inflammatory mediators in IS does not differentiate between asthma and COPD. The evaluation of BALF reveals more differences in the cellular and biochemical features of airways inflammation in patients with asthma and COPD than that of IS.