Roles of hyperresponsiveness and airway inflammation in bronchial asthma

Bronchial hyperresponsiveness is one important feature of bronchial asthma, and evidence has been accumulated that airway inflammation contributes to the specific airway response in asthmatic patients. Increase in airway responsiveness following viral infection, exposure to allergen, ozone or chemical sensitizers supports the evidence for a link between hyperresponsiveness and airway inflammation. However, as only some respiratory tract infections induce an increase in hyperresponsiveness, and patients with chronic bronchitis and cystic fibrosis have less airway hyperresponsiveness than asthmatics, airway inflammation is considered to be only one of many factors contributing to the hyperresponsiveness of asthmatic airways.