Non-myeloperoxidase-mediated system activity of neutrophil in newborn infants.
- Author:
Xiao-dong ZHU
1
;
Tong-xin CHEN
;
Ruo-xu JI
;
Xiao-ling ZHOU
;
Lian-wen WANG
;
Jian-xing ZHU
Author Information
- Publication Type:Journal Article
- MeSH: Escherichia coli; immunology; Fetal Blood; immunology; Flow Cytometry; Humans; Infant, Newborn; Neutrophils; enzymology; immunology; Peroxidase; metabolism; Staphylococcus aureus; immunology
- From: Chinese Journal of Pediatrics 2003;41(4):286-289
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo evaluate the variety of non-myeloperoxidase-mediated system activity of neutrophils in newborns during bacterial infection and the effect of cord plasma on the activation of non-myeloperoxidase-mediated system.
METHODSAn infection model with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) and a non-infection model with phorbol-12-myristate-13-acetate (PMA) were established to investigate the activation of non-myeloperoxidase-mediated system in neutrophils. According to the intensity of fluorescence, the activation of non-myeloperoxidase-mediated system of neutrophils was detected by flow cytometry (FCM). The blood cells and plasma were separated from cord blood and adult blood and cross-mixed in order to investigate the opsonic activity.
RESULTSIn the non-infection model, the activation of non-myeloperoxidase-mediated system with PMA stimulation in cord blood was lower compared with that in adult blood, the statistical difference was significant (t = 3.378, P < 0.01). In the infection model, the activations of non-myeloperoxidase-mediated system in cord blood were also lower compared with those in adult blood, while the statistical difference could only be found in the model with E. coli stimulation (t = 12.150, P < 0.001). Furthermore the experiments demonstrated that cord plasma could deeply depress the non-myeloperoxidase-mediated system activity with E. coli stimulation. On the contrary, adult plasma could successfully recruit the potential of non-myeloperoxidase-mediated system activity of neutrophils in newborns.
CONCLUSIONThe function of neonatal neutrophils might not developed very well. As a stimulant, E. coli failed to induce the non-myeloperoxidase-mediated system activity in neonates, which might be related to the lower level of immunoglobulins in cord blood. This result indicated that immunoglobulins played a more important modulating role in bacterial killing during gram-negative bacterial infections.