Role of chronic Pseudomonas aeruginosa infection in the development of bronchiectasis.

To understand the role of Pseudomonas aeruginosa infection in the development of bronchiectasis, we investigated by CT the presence of bronchiectasis in two groups of chronic bronchitis patients and in a control group. There were no differences in clinical or laboratory findings between groups A and B. Three observers without any knowledge of these patients reported bronchiectasis on a scale of 0 to 3 and bronchial wall thickness on a scale of 0 to 3 in each lobe of both lungs. Bronchiectasis and wall thickness scores in group A (chronic bronchitis with P aeruginosa infection) were significantly higher than bronchiectasis scores and wall thickness in group B (chronic bronchitis without P aeruginosa infection). Both scores in group B were higher than those in group C (control group). These findings support the idea that chronic P aeruginosa infection plays a role in the development of bronchiectasis.