THEOPHYLLINES EFFECT ON NEUTROPHIL FUNCTION AND THE LATE ASTHMATIC RESPONSE

Background: The decrement in lung function associated with the late as thmatic response after allergen challenge is believed to be mediated b y an inflammatory response in the airways. Theophylline has been shown to inhibit the late asthmatic response, but the mechanisms are not cl ear. Objective: The study was designed to determine whether theophylli ne would inhibit the late asthmatic response by reducing neutrophil ac tivation and subsequent superoxide production. Methods: Twelve subject s with asthma underwent treatment in this double-blind, randomized, cr ossover study. Each subject received theophylline and placebo in rando m order in two treatment periods of 3 weeks each. Each treatment perio d was followed by an allergen challenge and blood neutrophil function analysis.Results: At therapeutic levels theophylline increased FEV(1) at baseline and during the allergen challenge and increased the percen tage suppression of neutrophil superoxide production by adenosine. Con clusion: Theophylline improved pulmonary function at baseline and duri ng an allergen challenge, in part perhaps, by increasing the neutrophi l's response to feedback inhibition by adenosine. However, theophyllin e did not decrease the severity and duration of the late asthmatic res ponse.