Exercise-Induced Late Asthmatic Reactions with Neutrophil Chemotactic Activity

Abstract

Two adults and 13 children with exercise-induced asthma had both immediate and late reductions in forced expiratory volume in one second (FEV₁) after treadmill exercise. The late reactions developed 4 to 10 hours after exercise and in each instance were associated with wheezing or chest tightness (or both). Increases in neutrophil chemotactic activity, measured in the 2 adults and in 11 of the children, accompanied the reductions in FEV₁ in all these subjects. In contrast, four other adults with only an immediate fall in FEV₁ after exercise had only an initial elevation in neutrophil chemotactic activity, with no subsequent increase for the remaining 24-hour period. The agent responsible for the neutrophil chemotactic activity released during exercise-induced late reactions appeared to be identical to that released during immediate reactions. These observations suggest that some patients with exercise-induced asthma have late reactions that, as in the case of antigen-induced bronchoconstriction, are accompanied by the release of neutrophil chemotactic activity. (N Engl J Med 1983; 308:1502–5.)