新生儿脐血中性粒细胞吞噬功能降低的研究

Study on the decreased phagocytosis of neutrophils in neonatal cord blood

目的探讨新生儿脐血中性粒细胞(PMN)吞噬功能的变化及其影响因素。方法收集2021年6—8月来自本院的健康成人血和脐血标本各13例,分离新鲜PMN,流式细胞仪检测PMN吞噬大肠杆菌的情况,ELISA法检测成人外周血和新生儿脐血血清中前列腺素E2(PGE2)的含量。应用不同浓度的PGE2(0-500 ng/ml)刺激PMN株HL-60细胞及PGE2(100 ng/ml)刺激新鲜分离的成人PMN 48小时后,流式细胞术观察HL-60细胞和PMN吞噬大肠杆菌的情况。结果与成人PMN相比,新生儿PMN吞噬大肠杆菌百分率明显降低(P<0.01),但脐血PGE2的浓度较成人外周血明显升高(P<0.01);PGE2(100-500 ng/ml)刺激组HL-60细胞吞噬细菌百分率明显低于0 ng/ml组(P<0.01);成人PMN受PGE2(100 ng/ml)刺激后吞噬百分率明显降低(P<0.05)。结论新生儿脐血PMN吞噬功能降低,这可能是由于PGE2对PMN的抑制作用引起。

Objective To investigate the changes in phagocytic function of polymorphonuclearneutrophils(PMN)in neonatal cord blood and its influencing factors.Methods From June to August 2021,13 blood samples from healthy adults and 13 umbilical cord blood samples were collected,and fresh PMN was isolated.Flow cytometry was used to observe the phagocytosis of PMN to Escherichia coli.The content of prostaglandin E2(PGE2)in adult peripheral blood and neonatal cord blood were tested by ELISA.HL-60 cells were stimulated with different concentrations of PGE2(0-500 ng/ml),and freshly isolated PMN from adults were treated with PGE2(100 ng/ml)for 48 hours,then flow cytometry was used to observe the phagocytosis of E.coli by HL-60 cells and neutrophils.Results The results showed that compared with adult PMN,the phagocytic percentage of neonatal PMNto E.coliwas significantly decreased(P<0.01),however,the concentration of PGE2 in cord blood was significantly higher than that in adult peripheral blood(P<0.01).The phagocytic function of HL-60 cells in the PGE2(100-500 ng/ml)stimulation group was significantly lower than that in the 0 ng/ml group(P<0.01).The phagocytic percentage of adult PMN stimulated by PGE2(100 ng/ml)was significantly reduced(P<0.05).Conclusions This study suggests that the phagocytic function of PMN in neonatal cord blood is reduced,which may be caused by the inhibitory effect of PGE2 on PMN.