Adult bone marrow contains a number of discrete populations of progenitor cells, including endothelial, mesenchymal, and epithelial progenitor cells and fibrocytes. In the context of a range of diseases, endothelial progenitor cells have been reported to promote angiogenesis, mesenchymal stem cells are potent immunosuppressors but can also contribute directly to tissue regeneration, and fibrocytes have been shown to induce tissue fibrosis. This article provides an overview of the basic biology of these different subsets of progenitor cells, reporting their distinct phenotypes and functional activities. The differences in their secretomes are highlighted, and the relative role of cellular differentiation vs paracrine effects of progenitor cells is considered. The article reviews the literature examining the contribution of progenitor cells to the pathogenesis of respiratory disease, and discusses recent studies using bone marrow progenitor cells as stem cell therapies in the context of pulmonary hypertension, COPD, and asthma.

The American Thoracic Society and European Respiratory Society guidelines for the diagnosis and treatment of idiopathic pulmonary fibrosis (IPF) have been published recently. However, the influence, practical application, and utility of the prior consensus statement for IPF have never been evaluated. Demographics, diagnostic criteria, pulmonary function data, and disposition of patients with IPF evaluated at an interstitial lung disease center between 2000 and 2009 were analyzed. Enrollment in clinical drug trials, lung transplantation, and mortality also were assessed. A total of 521 patients with IPF were evaluated, with pulmonary function testing available in 446. In the 64% of patients without surgical lung biopsy, the most common major criterion not fulfilled was bronchoscopy. Lung transplantation was performed in 16.1% of patients, whereas 27.4% of prescreened patients were enrolled in a prospective drug study. Patients with mild, moderate, and severe disease categorized by FVC % predicted had median survivals of 55.6, 38.7, and 27.4 months, respectively. The attrition rate of patients who survived beyond 5 years was attenuated in subsequent years. IPF remains a deadly disease with a poor prognosis. Bronchoscopy does not appear to be required for an accurate diagnosis. A minority of patients were accommodated within a clinical trial or with transplantation. Categorization by baseline FVC % predicted effectively discriminates groups with different long-term outcomes. Our analysis supports the view that the value of statements also can be realized in the subsequent demonstration of their impact on patient management, which might enable further refinements in a continuous, iterative rediscovery process.

Stress-Induced Respiratory Pattern Changes in Asthma.

Psychosom Med. 2011 Jun 28;

Authors: Ritz T, Simon E, Trueba AF

Objectives To build upon prior research on stress-related breathing pattern changes in asthma. Previous research has considered a limited set of respiratory parameters and has remained equivocal. Emotions and stress are known to change the respiratory pattern. In asthma, certain breathing patterns have adverse effects on the airways and lead to symptom exacerbation. Methods We studied respiration during resting conditions and an acute psychosocial stressor (a free speech and mental arithmetic task) in participants with asthma (n = 20) and healthy controls (n = 19). The respiratory pattern was recorded with respiratory inductance plethysmography. Partial pressure of end-tidal carbon dioxide (PCO(2)) was measured with capnometry before and after stress. Results The overall minute ventilation was higher in asthma (mean [standard deviation] = 9.0 [4.0] L versus 6.8 [4.1] L, p < .05), but levels of the PCO(2) were comparable (34.6 [3.5] mm Hg versus 35.0 [3.7] mm Hg, p = .667) to healthy controls during prestress and poststress phases. Participants with asthma also showed a significant lengthening of inspiration, expiration, and the total respiratory cycle during stress compared with healthy controls (p < .05). During stress tasks, all participants showed marked increases in tidal volume, inspiratory flow, minute ventilation, tidal volume instability, ribcage contribution to tidal volume, and ribcage-abdominal asynchrony. A significant increase in tidal volume instability and a tendency toward lengthening of expiration and the total respiratory cycle were observed in quiet-sitting periods at prestress to poststress in asthma. Conclusions Expiratory lengthening and variable tidal volumes are characteristic for individuals with asthma during psychosocial stress. The function and possible association of these changes with symptom exacerbations require further study.

PMID: 21715298 [PubMed - as supplied by publisher]