NONSPECIFIC REFRACTORINESS TO ADENYLYL-CYCLASE STIMULATION IN ALVEOLAR MACROPHAGES FROM INFANTS WITH RECURRENT BRONCHIOLITIS

Epidemiologic studies suggest an association between recurrent bronchi olitis in children younger than 3 years of age and diagnosis of asthma later in life. Bronchoalveolar lavages from 20 infants with recurrent wheezing and 18 nonwheezy control subjects were analyzed to determine whether alveolar macrophages of wheezy infants present abnormalities similar to those described in adults with asthma. Alveolar macrophages from both groups responded in vitro, in a concentration-dependent man ner, to prostaglandin E(2), salbutamol, and forskolin, drugs that incr ease cyclic adenosine monophosphate levels. However, alveolar macropha ges from infants with recurrent wheezing accumulated less cyclic adeno sine monophosphate than those from control subjects in response to all three stimulations. These results are in agreement with the reduced c yclic adenosine monophosphate response to different agonists demonstra ted in leukocytes from patients with asthma, and suggest that this ref ractoriness could be one of the precipitating events in the developmen t of asthma observed in a large proportion of infants who have had bro nchiolitis.