Effect of aerosolized rhDNase (Pulmozyme®) on pulmonary colonization in patients with cystic fibrosis

Background: Aerosolized recombinant human deoxyribonuclease ( rhDNase I ( Pulmozyme (R))) has previously been shown to increase pulmonary function and reduce exacerbations of respiratory symptoms in cystic fibrosis ( CF) patients with moderate to severe reduction in pulmonary function. Aim: To analyse whether aerosolized Pulmozyme (R) could reduce the number of bacterial infections in the lower respiratory airways of CF patients without chronic pulmonary infection. Methods: Patients were randomized either to aerosolized Pulmozyme (R) 2 1/2 mg once daily or to no rhDNase treatment. The study period was 1 y, and the study was blinded for the Department of Clinical Microbiology. Results: Overall, the number of positive cultures was significantly higher in the untreated group ( 82%) compared with the treated group ( 72%) ( p < 0.05). The most striking difference was found for Staphylococcus aureus, with a prevalence of 30% in the untreated group compared with 16% in the treated group ( chi(2) test, p < 0.0001). Pulmonary function ( FEV1) in the treated group showed a significant increase of 7.3% compared to 0.9% in the untreated group ( p < 0.05). Conclusion: Long-term DNase treatment was beneficial to CF patients without chronic lower respiratory tract infection, leading to reduced demand for antibiotics and to improved lung function.