Myeloperoxidase (MPO), antiproteases and interleukin (IL)-8 in sputum from controls and cystic fibrosis (CF) patients

Free NE activity µg·mL−10.01 (0.01–0.02)23.4 (15.2–50.1)<0.001
Surface-bound NE activity D/A ratio0.09 (0.04–0.12)0.80 (0.56–1.07)<0.001
MPO µg·mL−10.4 (0.3–0.6)29.7 (18.4–51.8)<0.001
SLPI ng·mL−11211.5 (923.3–1811.7)180.8 (87.3–474.1)<0.001
AAT–NE ng·mL−124.8 (15.6–33.2)82.6 (40.4–183.1)<0.001
IL-8 ng·mL−10.6 (0.3–0.8)11.2 (8.2–16.6)<0.001

Data are presented as median (interquartile range), unless otherwise stated. NE: neutrophil elastase; D/A: donor/acceptor fluorescence; MPO: myeloperoxidase; SLPI: secretory leukocyte protease inhibitor; AAT–NE: α1-antitrypsin–NE complexes.