Persistence of Airway Obstruction and Hyperresponsiveness in Subjects With Asthma Remission: Comment
Medication may influence symptoms and airway responsiveness. It has been shown that prolonged use of inhaled steroids may reduce airway responsiveness and “induce” remission in some subjects. In our study, only two subjects “in remission” previously took inhaled steroids or prednisone, most subjects using a /82-agonist on demand, in some of them in association with a theophylline. Some subjects took no antiasthma medication.
There was no significant correlation between PC20 and duration of asthma or of remission. This suggests that it is not necessarily the duration of asthma that determines the persistence of airflow obstruction or airway hyperresponsiveness. However, in the study of Chan-Yeung33 on occupational asthma to red cedar, the longer the duration of symptoms and the more intense the antigenic contact, the less likely the remission. Subjects who became asymptomatic following withdrawal from the sensitizing agent had at the time of diagnosis a PC20 and an FEVi much higher than those that remained symptomatic, even after cessation of work Link http://birthcontroltab.com. They also had an early diagnostic of occupational asthma and a shorter exposure period to a sensitizing agent.
We found a significant correlation between actual PC20 and age at the time of diagnosis, a higher PC20 being observed in subjects whose conditions were diagnosed at an earlier age. Twelve subjects had remission of their asthma at youth. We also showed a significant correlation between PC20 and the age at the time of remission, the subjects being in remission at a younger age having the weaker airway responsiveness.
Definition of remission of asthma should be reconsidered as usually asthma is considered to be inactive (ex-asthma) if the subject denies medication use, asthmatic attacks, and “frequent” attacks of shortness of breath with wheezing during the preceding year.4 The present study suggests that these patients may still have asthma and that studies looking at factors inducing remission of asthma should not only be based on symptoms but also should ideally include measurements of expiratory flows and airway responsiveness.
Presently, asthma treatment is mainly based on symptoms and expiratory flows assessment. Further studies are needed to determine if we should treat more aggressively airway hyperresponsiveness and inflammation in order to reduce the underlying basic process and not only its clinical manifestations.
In conclusion, this study shows that airway hyperresponsiveness with or without airflow obstruction persists in many subjects who consider themselves to be in remission of asthma. This suggests that in those subjects, there may be ongoing airway inflammation or that they developed irreversible airway changes even if symptoms have disappeared or markedly decreased. The definition of “remission” of asthma has to be reconsidered and studies on remission should include measurements of airflow obstruction and airway responsiveness.