AIRWAY INFLAMMATION AFTER TREATMENT WITH AEROSOLIZED DEOXYRIBONUCLEASE IN CYSTIC-FIBROSIS

Recombinant human deoxyribonuclease (rhDNase) has been shown to reduce sputum viscoelasticity and to improve lung function in patients with cystic fibrosis (CF). The aim of this study was to determine whether a irway inflammation would decrease after administration of rhDNase. Twe nty patients with CF and chronic suppurative lung disease inhaled 2.5 mg of rhDNase daily for 1 month. Before and after the 1-month trial, l ung function was measured and sputum was obtained, either after sponta neous expectoration or after sputum induction with hypertonic saline. Sputum total cell and differential counts were measured using techniqu es previously described. The mean age of the patients was 16.8 years ( range, 6.7-27.5). After 1 month of rhDNase, mean FEV1 increased from a baseline of 62.3% predicted to 70.8% (P = 0.02, paired t test); and F VC increased from 74.4% to 83.9% predicted (P = 0.007). No significant differences were found in sputum cytology before or after rhDNase (me dian total cell counts 16.0 x 10(6)/ml vs. 19.3 x 10(6)/ml, P = 0.68). Thirteen patients had a 10% or greater increase in FEV1 after rhDNase (responders). Initial lung function was less in responders than in no nresponders (53.5% vs. 78.6%, P = 0.007). There was no significant cha nge in total cell count and neutrophil count after rhDNase in either r esponders or nonresponders. We conclude that airway inflammation, as m easured by total cell counts in sputum, was a prominent feature in cys tic fibrosis, and neutrophils were the dominant inflammatory cells. Al though the administration of rhDNase resulted in significant improveme nts in FEV1, there was no evidence of accompanying changes in airway i nflammation. Pediatr Pulmonol. 1998; 26:97-100. ( C) 1998 Wiley-Liss, Inc.