1989 Volume 63 Issue 4 Pages 369-375
We tested blood neutrophil functions in the patients with chronic respiratory tract diseases to study the mechanism of susceptibility to bacterial infections. Peripheral blood neutrophils were obtained from 15 healthy subjects and 14 patients including diffuse panbronchiolitis, bronchiectasis, chronic emphysema and chronic bronchitis. Seven patients suffered from the chronic. P. aeruginosa infection.
Firstly, neutrophil chemotaxis was determined by the method of Boyden Chamber assays using FMLP as a neutropil chemoattractant. The number of migrated neutrophils were 239.2 ± 65.6 cells/50 HPF in the patients group and 256.6 ± 49.0 cells/50 HPF in the control group.
Secondly, neutrophil phagocytosis against P. aeruginosa, E. coli and K. pneumoniae was determined by phagocytic activity (PA) and phagocytic index (PI).PA against each bacteria was 44.1 ± 13.2%(P. aeruginosa), 44.8 ± 12.3%(E. colt) and 35.8 ± 13.6%(K. pneumoniae) in the patients group and 42.3 ± 10.6%(P. aeruginosa), 43.0 ± 11.9%(E. coli) and 36.3 ± 16.0%(K. pneumoniae) in the control group. PI against each bacteria was 2.2 ± 0.6 (P. aeruginosa), 2.1 ± 0.3 (E. colt) and 2.6 ± 0.9 (K. pneumoniae) in the patients group and 2.2 ± 0.6 (P. aeruginosa), 2.2 ± 0.4 (E. colt) and 2.5 ± 0.6 (K. pneumoniae) in the control group.
Thirdly, neutrophil bacteriocidal activity was determined by superoxide production and intracellular kiling efficiency. Superoxide produced from OPZ-triggered neutrophils was 17.8 ± 6.5 nmol/3.5 × 106 cells/20 min in the patients group and 20.2 ± 5.8 nmol/3.5 × 106 cells/20 min in the control group, respectively. Intracellular killing against each bacteria was 89.1 ± 10.2%(P. aeruginosa), 57.9 ± 23.2%(E. coli) and-46.5 ± 93.1%(K. pneumoniae) in the patients group and 92.1 ± 12.3%(P. aeruginosa), 62.2± 21.6 (E. colt) and-44.7 ± 66.0%(K. pneumoniae) in the control group.
These results suggest that neutrophil functions determined by chemotaxis, phagocytosis and bacteriocidal activity were not inhibited in the patients with chronic respiratory tract diseases. Probably, the susceptibility to bacterial infections in these patients could be attributed to other factors enhancing bacterial adherence and growth in the respiratory tracts.
