重症AP患者外周血中单个核细胞Toll样受体4的表达及与血浆内毒素的关系

The expression of toll-like receptor 4 on peripheral blood mononuclear cells and its relation with endotoxin levels in severe acute pancreatitis

目的动态观察重症急性胰腺炎(SAP)患者外周血中单个核细胞Toll样受体4(TLR4)表达的变化,并探讨其与内毒素血症的关系。方法收集31例SAP患者和25例轻型急性胰腺炎(MAP)患者,SAP患者于入院后1、3、5、7、14、21d,MAP患者于入院后1、3、5、7d分别抽取外周静脉血,用RT-PCR法检测TLR4基因表达水平,同时用鲎试剂测定血浆内毒素水平。结果所有患者的血浆中均检出内毒素,与MAP组比较,SAP组内毒素在各个时期浓度都明显升高,差异有统计学意义(P<0.05)。与正常对照组比较,SAP患者在入院后1d外周血单个核细胞TLR4基因水平显著升高(P<0.05),达正常对照组的1.55倍,并持续较长时间。相关分析显示,SAP患者在入院后第3、5、7天TLR4mRNA与血浆内毒素水平变化趋势一致,两者呈正相关(P<0.05)。结论 TLR4通路的异常可能在SAP的发病及炎性反应中均发挥一定作用,其诱生与内毒素刺激密切相关。

Objective To investigate the significance of changes of expression of toll-like receptor 4（TLR4） on peripheral blood mononuclear cells（PMBCs） and its relationship with endotoxemia in severe acute pancreatitis（SAP）.Methods 31 patients with SAP and 25 patients with mild acute pancreatitis（MAP） were included in this study,and 16 healthy volunteers served as normal controls.The PMBCs expression levels of TLR4 mRNA were measured by RT-PCR,and endotoxin concentrations were detected by the modified chromogenic limulus amebocyte lysate（LAL） assay on days 1,3,5,7,14,21 in SAP patients and days 1,3,5,7 in MAP patients after admission.Results The plasma endotoxin levels were increased in all patients with AP.As compared with those of MAP patients,the plasma endotoxin levels in SAP group were significantly increased at all time points,there was a significant difference between the two groups（P0.05）.As compared with those（0.596± 0.103） in control group,the TLR4 mRNA levels in PBMCs on day 1 after admission in SAP patients were significantly increased by 1.55 times（P0.05）,which lasted for a longer period.The correlation analysis showed that the TLR4 mRNA levels were positively correlated with endotoxin concentrations on days 3,5,7 after admission（P0.05 or P0.01）.Conclusion The abnormality of TLR4 pathway may be involved in the pathogenesis of SAP and inflammatory reaction,and its induction is closely related with endotoxin stimulus.