Persistence of Airway Obstruction and Hyperresponsiveness in Subjects With Asthma Remission
Bronchial asthma is characterized by variable airflow obstruction and airway hyperresponsiveness. Its underlying mechanism is considered to be an airway inflammatory process with bronchial epithelial damage and mucus secretion, and in which eosinophils and lymphocytes seem to play a key role.2 There is still no cure for asthma. We may, however, observe remissions, either spontaneously, after withdrawal of exposure to a sensitizing agent, or following bronchial anti-inflammatory therapy. Remissions are mostly observed in children, being quite rare in adults. Relapses of asthma after remission, however, are frequent in children. Blair reported a 20 percent recurrence of wheezing after a period of 3 years without symptoms in asthmatic children. Ryssing reported that in 36 percent of asthmatics who remitted from their asthma, wheezing resumed after a 13-year follow-up. In another study, 31 percent of young adults free of wheezing at 21 years old had recurrent wheezing at 28 years. mycanadianpharmacy.com
Brewster et al has described deposition of collagen, in relation to the presence of myofibroblasts beneath the basement membrane, suggesting a repair process in asthma, which may lead to chronic morphologic changes. Other observations suggest that subjects with a history of asthma with no or minimal respiratory symptoms often show marked inflammatory changes on bronchial biopsy specimens as shown by activated inflammatory cells in the bronchial mucosa. This suggests that the underlying asthmatic inflammation or hyperresponsiveness may persist for prolonged periods of time, even when symptoms have disappeared.
The present study was designed to determine if subjects who consider themselves to be in remission of their asthma, with neither asthma symptom nor any asthma medication use in the last 2 years, show persistence of airflow obstruction and hyperresponsiveness, and if these abnormalities are in relation with the age at the onset of asthma or remission or with their duration.