Age-Related Decrease and a Simple Flow Cytometric Assay of Neutrophil Function / 대한진단검사의학회지

ABSTRACT

BACKGROUND: We intended to confirm a decline in neutrophil function with aging and to devise a simple neutrophil function test protocol for use in a clinical setting. Reversely, the reliability of this protocol was to be verified by detectability of a decline in neutrophil function with aging. METHODS: Whole blood samples from young (thirties, N=32) and old (sixties, N=32) healthy subjects were incubated with the 7-aminoactinomycin D stained Escherichia coli. The mixture was stained by dihydrorhodamine 123 as an oxidative probe. Two kinds of fluorescence were measured by flow cytometry. RESULTS: Phagocytosis was declined with aging as indicated by a decrease in the percentage (form 28.2+/-9.5% to 21.9+/-10.9%, P<0.05) and the mean fluorescence intensity (MFI) ratio (from 1.67+/-0.27 to 1.51+/-0.27, P<0.05). Oxidative burst had a trend toward a decrease with aging, but the differences were not significant (percentage from 35.3+/-13.2% to 32.1+/-14.1%, P=0.36; MFI ratio from 5.26+/-3.23 to 5.08+/-3.55, P=0.84). CONCLUSIONS: The devised protocol in this study could detect a significant decline in neutrophil function with aging, and this protocol may be useful for the assessment of neutrophil function in a clinical setting.