TLR9基因多态性与重型颅脑损伤术后颅内感染的关联

Association between intracranial infection and TLR9 gene polymorphism after severe head injury

目的探讨重型颅脑损伤术后颅内感染与Toll样受体9(TLR9)基因多态性的关联性。方法选择中山市中医院神经外科2018年1月-2021年1月收治的重型颅脑损伤患者作为研究对象,根据术后是否发生颅内感染按照1∶2比例选择颅内感染患者30例纳入研究组,选择未发生颅内感染患者60例纳入对照组。患者在入院后当天抽取外周静脉血,采用聚合酶链式扩增反应(PCR)扩增TLR9基因rs187084和rs5743836位点目的序列,将PCR反应产物送公司进行测序。研究组患者在感染诊断当天,对照组患者在术后第2天清晨按照无菌操作规则抽取脑脊液标本,检测脑脊液标本中C-反应蛋白(CRP)、降钙素原(PCT)水平,采用酶联免疫吸附法检测TLR9水平。结果哈迪-温伯格平衡检验结果显示,研究组和对照组rs187084和rs5743836位点基因型分布理论值和实际值分布差异无统计学意义;研究组rs187084位点AA基因型频率、A等位基因频率高于对照组(P<0.05);Logistic回归分析结果发现携带在隐形模型和加性模型下颅内感染风险均增加(OR=1.864,P=0.025,OR=1.997,P=0.019);TLR9基因rs187084位点携带AA基因型颅内感染患者脑脊液TLR9、CRP和PCT水平高于携带GA/GG型患者(P<0.05)。结论TLR9基因rs187084位点AA基因型增加重型颅脑损伤术后颅内感染风险,其机制可能与上调TLR9水平有关。

OBJECTIVE To explore the relationship between intracranial infection and Toll like receptor 9(TLR9)gene polymorphism after severe head injury.METHODS Patients with severe craniocerebral injury who were admitted to the department of Neurosurgery of Zhongshan Hospital of Traditional Chinese Medicine from Jan 2018 to Jan 2021 were enrolled as the research subjects.According to whether intracranial infection occurred after surgery,30 patients with intracranial infection were divide into the study group and 60 patients without intracranial infection were included in the control group,at a ratio of 1∶2.In the control group,the patients’peripheral venous blood was drawn on the day after admission,and the target sequences of rs187084 and rs5743836 site at TLR9 gene were amplified by polymerase chain amplification(PCR)assay,and the products were sequenced by a company.On the day of infection diagnosis,the patients in the study group were taken cerebrospinal fluid samples in the morning,and those were taken from patients in the control group on the 2 nd day after the operation according to aseptic operation.The levels of C-reactive protein(CRP)and procalcitonin(PCT)in the cerebrospinal fluid samples were detected.TLR9 level were detected by linked immunosorbent assay.RESULTS Hardy-Weinberg balance test showed that the difference between the theoretical and actual genotype distributions of rs187084 and rs5743836 in the study and control groups were not significantly different.AA genotype frequency and A allele frequency at rs187084 locus in the study group were significantly higher than those in the control group(P<0.05).Multivariate Logistic regression analysis showed that the risk of intracranial infection increased in both the invisible model and the additive mode(OR=1.864,P=0.025,OR=1.997,P=0.019);the levels of TLR9,CRP and PCT in the cerebrospinal fluid of patients with intracranial infection carrying AA genotype at the rs187084 locus of TLR9 gene were significantly higher than those carrying GA/GG genotype(P<0.05).CONCLUSION The AA genotype at rs187084 of the TLR9 gene significantly increases the risk of intracranial infection after severe craniocerebral surgery.The mechanism may be related to the up-regulation of TLR9 level.