Seminars in respiratory and critical care medicine
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Bronchiolar pathologic lesions result from the interplay between inflammatory and mesenchymal cells following injury to bronchioles. Offending agents include viruses, bacteria, fungi, cigarette smoke, toxic inhalants, inorganic dusts, allergens, and systemic or localized autoimmune or inflammatory processes. Bronchiolar pathologic lesions also arise in the context of allograft transplantation and pathology of the large airways and in the setting of an idiopathic disorder. ⋯ After a survey of the normal histology of bronchioles, we present a pragmatic classification that reflects the spectrum of bronchiolar pathology, illustrating the intimate interdependence of clinical, radiological, and pathologic findings in assessing the significance of bronchiolar lesions. This classification is intended to be applicable to surgical pathology material that can be correlated with clinical disease syndromes. It includes asthma-associated bronchiolar changes, chronic bronchitis/emphysema-associated bronchiolar changes, cellular bronchiolitis, respiratory bronchiolitis, bronchiolitis obliterans with intraluminal polyps/ BOOP, constrictive bronchiolitis, mineral dust small airway disease, peribronchiolar fibrosis and bronchiolar metaplasia, and bronchiolocentric nodules.
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Semin Respir Crit Care Med · Oct 2003
Bronchiolar disorders: classification and diagnostic approach.
Bronchiolitis is a process in which inflammatory cells and mesenchymal tissue are both present, mainly centered in and around membranous and/or respiratory bronchioles, with sparing of a considerable portion of the other parenchymal structures. The distribution and amounts of the cellular and mesenchymal components vary from case to case, which accounts for the variety of histopathologic, radiographic, and clinical aspects of bronchiolitis. The clinical classification of bronchiolar diseases considers the causes or the clinical settings in which bronchiolitis develops: inhalation of toxic fumes, irritant gases or organic dusts, infectious and postinfectious bronchiolitis, collagen-vascular disease-associated bronchiolitis, posttransplant bronchiolitis, or rarer associations. ⋯ High-resolution computed tomographic scanning (HRCT) is currently the best imaging technique for the evaluation of patients suspected of having bronchiolitis. HRCT findings in bronchiolar diseases with a good correlation with histopathologic changes are classified as follows: centrilobular tubular branching or nodular opacities; ground-glass attenuation or consolidation; mosaic perfusion; a mixed pattern. This article presents and briefly discusses the diagnostic approach to these diseases.
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Semin Respir Crit Care Med · Aug 2003
Fibrotic idiopathic interstitial pneumonia: high-resolution computed tomography considerations.
The fibrotic idiopathic interstitial pneumonias comprise usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP). The characteristic high-resolution computed tomography findings of UIP are reticular abnormality and honeycombing with basal and peripheral predominance. Honeycombing is the strongest predictor of UIP. ⋯ The CT finding of extensive ground-glass abnormality and some reticular abnormality, with basal and peripheral predominance, is strongly suggestive of NSIP. However, the CT appearances of NSIP overlap with those of UIP, organizing pneumonia (OP), and desquamative interstitial pneumonia (DIP), and biopsy may be necessary to sort this out. Other idiopathic pneumonias that may be associated with CT evidence of lung fibrosis include DIP, OP, acute interstitial pneumonia, and lymphoid interstitial pneumonia.
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Bronchiectasis is an abnormal dilation of bronchi, consequent to the destruction of their walls. It is included in the category of obstructive pulmonary diseases, along with chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis. In approximately 50% of cases, bronchiectasis is associated with underlying conditions; in the remainder, known causes are not ascertainable (idiopathic bronchiectasis). ⋯ The cystic fibrosis gene is also associated with bronchiectasis due to rheumatoid arthritis and allergic bronchopulmonary aspergillosis. A few other genes have been investigated in idiopathic bronchiectasis, with negative results. Idiopathic bronchiectasis is, therefore, to be considered as an obstructive multifactorial disorder belonging to the category of cystic fibrosis monosymptomatic diseases (or CFTR-opathies), whose pathogenesis is influenced by environmental factors and other undetermined genes.
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Semin Respir Crit Care Med · Apr 2003
Genetics of acute respiratory distress syndrome: challenges, approaches, surfactant proteins as candidate genes.
There are challenges "inherent" in studying the genetics of a complex disease, such as acute respiratory distress syndrome (ARDS). It is necessary to define each ARDS subgroup using considerably narrower definitions that better reflect the particular subgroup. ⋯ This article presents the findings of a small pilot case-control association study where the surfactant proteins were used as candidate genes in the study of ARDS. This article discusses the relevance of surfactant protein genes in ARDS as well as the significance of genetic variants associated with ARDS subgroups.