Soluble proteins of bronchopulmonary secretions from patients with cystic fibrosis, asthma, and bronchitis.

The concentrations of nine plasma proteins were determined by quantitative immunoelectrophoresis in 
sputum specimens from 29 patients with cystic fibrosis (CF) and from 
24 patients with severe asthma and chronic bronchitis. The results suggested 
that the population of CF patients could be divided into two 
groups in spite of an absence of difference in clinical status 
between the groups. Average concentrations of seven plasma proteins in sputum 
of group I CF patients were identical with those in sputum 
of patients with bronchitis, but the average concentrations of six of 
these proteins in sputum from group II CF patients were higher 
than those in specimens from the bronchitic patients and were similar 
to corresponding concentrations in sputum from patients with asthma, all of 
whom were examined while in status asthmaticus. The average concentrations of 
14 secretory proteins were the same in all sputum specimens whether 
or not they were produced by patients with cystic fibrosis, asthma 
or bronchitis. It was concluded that the concentrations in the bronchopulmonary 
secretions of proteins associated with host defence were not diminished in 
patients with cystic fibrosis, and failure to produce adequate concentrations of 
proteins with antimicrobial activity was unlikely to be responsible for the 
above average susceptibility to chest infection in cystic fibrosis. It is 
suggested that there exists a group of CF patients in whom 
a pulmonary allergic reaction generates an inflammatory response as severe as 
that characterizing status asthmaticus and that this response could be detrimental. 
