EFFECT OF RBDNASE ON AIR-FLOW OBSTRUCTION AND MUCOILIARY CLEARANCE INCYSTIC-FIBROSIS

We tested the hypothesis that recombinant human deoxyribonuclease 1 (r hDNase) reduces airflow obstruction and improves mucociliary clearance in patients with cystic fibrosis (CF), and that improvements seen in FEV(1) and NC after rhDNase treatment are independent of chest physica l therapy (CPT). CF patients inhaled placebo (10 patients) or 2.5 mg r hDNase aerosol (10 patients) twice a day for six consecutive days. Com pared with baseline, there were no statistically significant differenc es between the two study groups by Day 6 for indices of airflow obstru ction obtained from gamma-camera images of the right lung following in halation of Tc-99m aerosol, or for mucociliary clearance or the rate o f clearance of the radioaerosol, quantified over a 6-h period. By Day 6, FEV(1) and NC were significantly higher in the rhDNase-treated grou p than in the placebo group, increasing by an average of 9.4 +/- 3.5% and 12.7 +/- 2.6%, respectively, as compared with a decrease of 1.8 +/ - 1.7% and an increase of 0.4 +/- 1.1%, respectively (p < 0.05). There was no significant change in the FEV(1)/FVC ratio on Day 6 (0.68 +/- 0.05) compared with baseline (0.70 +/- 0.05) in the rhDNase group. On Day 6, FEV(1) and FVC decreased after CPT in both study groups, but th e decreases were not significant. Our results indicate that aerosolize d rhDNase improves FEV(1) and FVC independent of CPT. We were unable t o demonstrate that rhDNase reduces airflow obstruction or improves muc ociliary clearance.