Asthma and lower airway diseaseThe outer wall of small airways is a major site of remodeling in fatal asthma
Section snippets
Methods
This study was approved by the review board for human studies of the School of Medicine, São Paulo University.
Twenty-four patients who died of asthma and were autopsied between 1996 and 2003 were included in the study. All individuals had a previous history of asthma (information provided by a next of kin before autopsy). Further clinical data (smoking habits, treatment history, medical follow-up, and previous hospital admission caused by asthma) were obtained during a later interview with the
Results
The characteristics of the subjects are shown in Table II. The mean ages of asthmatic patients and control subjects were 40.9 and 48.7 years, respectively. Among the asthmatic patients, 7 were current smokers, and 1 was a former smoker. Only 9 asthmatic patients had a regular medical follow-up, and 9 patients had a previous hospital admission caused by asthma. All had been using inhaled β-agonists. Only 6 patients had been treated with corticosteroids: 1 had received beclomethasone regularly, 1
Discussion
In the present study we quantified structural (collagens I and III) and adhesive (fibronectin) ECM proteins, as well as MMPs and their inhibitors, in the large and small airways and alveolar parenchyma of subjects who had died of asthma and compared the results with those obtained from nonsmoking control subjects. The main finding of our study was the identification of the outer wall of small airways as the major site of airway remodeling in patients with fatal asthma, which presented
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2021, Current Opinion in PhysiologyCitation Excerpt :However, the thicker mucosal geometry and raised levels of forces due to smooth muscle thickening thought to cause the stiffer airways diminishes this effect [45]. Linking the mechanotransductive structural changes observed in the diseased airway to actual quantifiable decline of pulmonary mechanics and function is nontrivial [46,31••]. Some studies suggest that the thickening of the airway wall in asthma is not the fundamental issue but a beneficial mechanism to facilitate structural integrity and to counterbalance the increased constricting force of the thicker smooth muscle [25,32].
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2019, Immunology and Allergy Clinics of North AmericaCitation Excerpt :Airway inflammation is a consistent feature of asthma. The dominant cell type found in the airways can be used to characterize airway inflammation, and in adults with severe asthma, the distinction between eosinophilic, neutrophilic, and paucigranulocytic disease may inform treatment response.41 Although some studies have shown associations between the dominant cell type in bronchoalveolar lavage fluid and endobronchial biopsies in children and a particular phenotype of severe asthma,42,43 others have not.42,44
Supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and Laboratório de Investigação Médica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (LIM-05 HCFMUSP).
Disclosure of potential conflict of interest: J. H. Lindeman has received research support from Abbott. The rest of the authors have declared that they have no conflict of interest.