血中性粒细胞胞外诱捕网在系统性红斑狼疮中表达及杀菌功能的变化

The expression and antibacterial function of neutrophii extracellular traps in systemic lupus erythe-matosus

目的观察外周血中性粒细胞胞外诱捕网（NETs）在稳定期系统性红斑狼疮（SLE）患者中的表达及杀菌功能变化情况，探讨其可能的发生机制。方法选择30例稳定期SLE患者及30例健康对照者（NC）。采用系统性红斑狼疮活动指数（SLEDAI）评分评估SLE病情活动度，密度梯度离心法分离外周血中性粒细胞；Picogreen试剂盒测定NETs数量，菌落计数法比较金黄色葡萄球菌诱导的NETs对金黄色葡萄球菌的杀灭效率，ELISA测定诱导生成的NETs上弹性蛋白酶（NE）、过氧化物酶（MPO）的表达及活性。结果与NC组相比，SLE组血浆中NETs数目无明显变化（P〉0．05），但由金黄色葡萄球菌诱导中性粒细胞生成的NETs明显增多（P〈0．05），总体杀菌活性明显降低（P〈0．05），NETs相关杀菌蛋白MPO活性明显降低（P〈0．05）。结论稳定期SLE外周血中性粒细胞体外更易诱导NETs表达，但表达的NETs杀菌功能明显下降，提示SLE患者中性粒细胞胞外诱捕网存在杀菌功能缺陷，可能与杀菌蛋白MPO活性降低有关。

Objective To investigate the expression and antibacterial function of Neutrophil extracellular traps （NETs） in systemic lupus erythematosus （SLE） patients. Methods Thirty stable SLE pa-tients and thirty normal controls （NC） were recruited to this study. The acitivity of SLE was assessed by SLE Disease Activity Index （SLEDA1）. Density gradient centrifugation was uesd to isolate neutrophilic granulocytes. Picogreen assay was used to quantify NETs formation. Colony counting method was used to compare the antibacterial rate of NETs between two groups. Variation of quantity and activities of neutrophil elastase （NE） and myeloperoxidase （MPO） on induced NETs was tested by enzyme linked immunosorbent assay （ELISA）. Results There was no significant difference in the number of NETs between SLE and NC. Compared to the control group, more NETs were induced from neutrophils in SLE, the antibacterial rate of induced NETs was significantly lower, with the activities of antibacterial protein MPO decreased. Conclusions Stable SLE patients are more easily to induce NETs, and the antibacterial function of induced NETs are truely defective, may be related to the decreased activity of the antibacterial protein MPO.