BACKGROUND: Exacerbation of asthma has a negative impact on quality of life and increases the risk of fatal asthma. One of the known risk factors for patients with a history of near-fatal asthma is reduced sensitivity to dyspnea. OBJECTIVE: We aimed to identify patients with such risk before they experienced severe exacerbation of asthma. METHODS: We analyzed asthma symptoms and peak expiratory flow rate (PEFR) values of 53 patients recorded daily in a diary over a mean period of 274 days. Patients matched their symptoms to one of eight categories ranging in severity from 'absent' to 'severe attack'. We then analyzed the relationship between PEFR and asthma symptoms by dividing the PEFR value by the values of clinical parameters, including asthma symptom level.
Asthma ; Dyspnea ; Forced Expiratory Volume ; Humans ; Peak Expiratory Flow Rate ; Quality of Life ; Risk Factors

BACKGROUND: Asthma is characterized by a chronic inflammatory process involving high numbers of inflammatory cells and mediators which have multiple inflammatory effects on the airway. Interferon (IFN)-alpha, which is used widely for treating chronic hepatitis C, is reported to have an effect on patients with Churg-Strauss syndrome. Therefore, it may also be suitable for patients with severe asthma. OBJECTIVE: We studied the effect of IFN-alpha on airway eosinophilia in a guinea pig model of asthma and the expression of adhesion molecules on human eosinophils and vascular endothelial cells. METHODS: After antigen challenge, airway hyperresponsiveness and airway eosinophilia were measured in a guinea pig asthma model with or without airway IFN-alpha administration. Expression of adhesion molecules on eosinophils and cultured human umbilical vein endothelial cells (HUVECs) was also evaluated with or without IFN-alpha. RESULTS: IFN-alpha inhibited eosinophil recruitment into the tracheal wall and improved airway hyperresponsiveness in sensitized guinea pigs. IFN-alpha also significantly suppressed IL-1 beta-induced intercellular adhesion molecule-1 (ICAM-1) expression on HUVECs. However, IFN-alpha did not suppress platelet-activating factor-induced macrophage antigen-1 expression on human eosinophils. IFN-alpha significantly inhibited eosinophil adhesion to IL-1 beta-induced HUVECs and migration through IL-1 beta induced HUVECs. CONCLUSION: The findings suggest that the modulation of ICAM-1 in lung with pre-existing inflammation following treatment with IFN-alpha may be a novel and selective treatment for control of chronic airway inflammation and hyperresponsiveness associated with asthma.
Animals ; Asthma ; Churg-Strauss Syndrome ; Endothelial Cells ; Eosinophilia ; Eosinophils ; Guinea Pigs ; Hepatitis C, Chronic ; Human Umbilical Vein Endothelial Cells ; Humans ; Inflammation ; Intercellular Adhesion Molecule-1 ; Interferon-alpha ; Interferons ; Interleukin-1 ; Interleukin-1beta ; Lung ; Macrophages

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