Role of chronic Pseudomonas aeruginosa infection in airway mucosal permeability

The role of Pseudomonas aeruginosa infection in airway mucosal permeability was studied in 16 patients with chronic bronchitis by measuring the amounts of radiolabeled albumin in sputum. One group (A) consisted of six patients (two female, four male, 53 +/- 6 years, SEM) with chronic P aeruginosa infection for 5 +/- 0.9 years. Another group (B) consisted of ten patients (five female, five male, 67 +/- 4 years) without P aeruginosa infection for at least two years. No significant differences between groups A and B were found in the volume of sputum (63 +/- 21 ml/day in group A and 45 +/- 8 ml/day in group B, p = 0.44), the obstructive changes (FEV1 of 57 +/- 6 percent in group A and 51 +/- 4 percent in group B), or the duration of disease (19 +/- 4 years in group A and 14 +/- 4 years in group B). Saliva, sputum, and serum samples were collected at intervals of 2 h over an 8-h period, and at 24 h after intravenous administration of 131I-labeled human albumin. For counting, free 131I was removed by dialysis. Radiocounts (cpm) of saliva were significantly smaller than those of sputum or serum. The cpm from each sputum sample was divided by serum cpm at the time of each sampling. Group A showed significantly higher values in the ratio of sputum- to serum-cpm than did group B at all sampling times. Furthermore, the ratios at 2 and 4 h after 131I-albumin injection significantly correlated with sputum volume per day, whereas they did not correlate with any other factors (age, obstructive impairment, and duration of disease). These findings suggest that chronic P aeruginosa infection produces an increase in airway mucosal permeability to albumin.