Pseudomonas aeruginosa infection in cystic fibrosis. Diagnostic and prognostic significance of Pseudomonas aeruginosa precipitins determined by means of crossed immunoelectrophoresis.

A total of 133 patients with cystic fibrosis have been followed for 
up to 5 years with monthly examinations including bacteriological examinations of 
sputum. Sera from the patients were examined by means of crossed 
immunoelectrophoresis for the occurence and number of precipitating antibody specificites against 
Pseudomonas aeruginosa. Poor prognosis in cystic fibrosis was associated with chronic 
colonization (9 months - more than 5 years) of the respiratory 
tract with mucoid Pseudomonas aeruginosa, and with an onset of the 
chronic colonization before puberty. Among the patients with chronic Pseudomonas aeruginosa 
colonization, poor prognosis was associated with high numbers of precipitins against 
antigens from these bacteria (up to 61). The number of Pseudomonas 
aeruginosa precipitins increased on an average with five per year in 
chronically colonized patients. Rapidly increasing number of precipitins was associated with 
poor prognosis. Patients with any degree of impairment of the ventilatory 
function and any changes on the chest radiographs could contract chronic 
Pseudomonas aeruginosa colonization. Poor ventilatory function and severe changes on the 
chest radiographs was associated with high numbers of Pseudomonas aeruginosa precipitins 
and with poor prognosis. Although many O groups of Pseudomonas aeruginosa 
were found in the chronically colonized group of patients, 53% of 
the patients harboured strains belonging to O group 3 or 3/9, 
and the highest numbers of precipitins were found in serum from 
these patients. 