Article

Original Article

Korean J Clin Pathol 1996; 16(5): 723-735

Published online October 1, 1996

Copyright © Korean Society for Laboratory Medicine.

Respiratory Burst Activity and Surface Expression of Neutral Endopeptidase (CDlO) and Aminopeptidase (CD13) of Circulating Neutrophils in Pneumonia Patients

박찬정 강경령 조현찬 ·이규만 ·정기석 ·모은경 ·이재명 ·김동환

Abstract

Background :The surface peptidases of neutrophils modulate the neutrophil activation, so this is considered as a part of control mechanism which limits the intensity of the inflammatory reactions by neutrophils. We studied the respiratory burst activity and the surface expession of peptidases (CDlO/neutral endopeptidase and CDlS/aminopeptidase) of neutrophils in patients with pneumonia, in which neutrophils play a major role. Method :EDTA anticoagulated peripheral blood was drawn from forty normal controls and sixty four patients with pneumonia. The respiratory burst activity (with the proudction of Hz02 which changes nonfluorescent DCF-DA to green fluorescent DCF) in non-stimulated and PMA-stimulated states and the surface expression of CD10 and CD13 (with binding of PE-conjugated anti-CD10 or anti-CD13) of neutrophils were simultaneously measured by flowcytometry. Result :Compared with the neutophils of normal controls, those of Pseudomonas pneumonia patients showed lower respiratory burst activity in the non-stimulated state. The neutrophils of Staphylococcus pneumonia patients and Tuberculosis pneumonia patients showed higher activity in the PMA-stimulated state, whereas the neutrophils of Gram (-) bacterial (Enterobacter and Pseudomonas) pneumonia patients showed lower activity. The surface CD10 positivity of neutrophils was lower in pneumonia patients, whereas the surface CD13 positivity was very high, near 100% in both of normal controls and pneumonia patients. The binding of neutrophils with isotypic control immunoglobulin (IgG1) caused increased respiratory burst activity, but the binding with anti-CD10 did not. Conclusion :The respiratory burst activity of neutrophils in pneumonia patients showed variable results according to the pathogenic bacteria. The CD10 (+) neutrophils are considered to modulate the respiratory burst activity, and the surface expression of CD10 was decreased in pneumonia neutrophils. These features might contribute to the effective microbial killing of neutrophils, but also could cause a damage of the adjacent tissue by reducing the control mechanism of neutrophil activation.

Keywords: Pneumonia, Neutrophil, Respiratory burst activity, Neutral Endopeptidase (CD10), Aminopeptidase (CD13)