Pseudomonas aeruginosa infection in cystic fibrosis. Occurrence of precipitating antibodies against pseudomonas aeruginosa in relation to the concentration of sixteen serum proteins and the clinical and radiographical status of the lungs.

The significance of Pseudomonas aeruginosa infection in the respiratory tract of 9 
cystic fibrosis patients have been studied by means of immunoelectrophoretical analysis 
of patients' sera for the number of precipitins against Pseudomonas aeruginosa 
and the concentrations of 16 serum proteins. In addition, the clinical 
and radiographical status of the lungs have been evaluated using 2 
scoring systems. Precipitins against Pseudomonas aeruginosa were demonstrated in all sera, 
the maximum number in one serum was 22. The concentrations of 
12 of the serum proteins were significantly changed compared with matched 
control persons. Notably IgG and IgA were elevated and the "acute 
phase proteins" were changed, the latter suggesting active tissue damage. The 
concentrations of 3 of the acute phase proteins, notably haptoglobin, were 
correlated to the number of precipitins suggesting that the respiratory tract 
infection in patients with many precipitins is accompanied by more tissue 
damage than the infection in patients with few precipitins. The results 
indicate no protective value of the many precipitins on the tissue 
of the respiratory tract. 