成人慢性化脓性中耳炎TLR2和TLR4基因多态性及其临床意义

Polymorphisms of TLR2 and TLR4 genes in adult patients with chronic suppurative otitis media and its clinical significance

目的探讨Toll样家族受体(TLR)2、TLR4基因多态性对成人慢性化脓性中耳炎(CSOM)易感性和病情严重程度的影响。方法选择2017年5月-2019年12月医院耳鼻喉科收治CSOM的患者112例作为研究组。选择同期医院进行体检的健康人80名作为对照组。采集研究组患者鼓室内分泌物标本,对病原菌分布进行调查;提取两组患者外周血DNA后,选择TLR2基因Arg753Gln位点及TLR4 Asp299Gly位点作为研究位点,采用聚合酶链式扩增反应(PCR)对模板中目的序列进行扩增,在凝胶成像仪中观察分型结果;分析TLR2基因Arg753Gln位点及TLR4 Asp299Gly位点基因多态性与CSOM患者听力损伤程度的关系。结果112例CSOM患者共128耳共有110耳培养出病原菌,阳性率85.94%,110株检出的病原中革兰阳性菌69株,占62.73%,革兰阴性菌38株,占34.55%,真菌3株,占2.73%;研究组患者TLR2 Arg753Gln位点AA基因型、A等位基因频率高于对照组(P<0.05),GG基因型频率低于对照组(P<0.05);两组研究对象TLR4 Asp299Gly位点基因型、等位基因频率分布差异无统计学意义;校正Logistic回归分析,结果显示TLR2 Arg753Gln位点AG、AA、AG/AA基因型是CSOM发生的危险因素(P<0.05);CSOM患者不同耳聋程度TLR2 Arg753Gln位点基因型分布频率存在统计学差异(P<0.05),TLR4 Asp299Gly位点基因型分布差异无统计学意义。结论成人CSOM分泌物病原菌以革兰阳性菌为主,携带TLR2基因Arg753Gln位点A基因是CSOM发生的危险因素。

OBJECTIVE To investigate the effect of Toll like receptors 2(TLR2)and Toll like receptors 4(TLR4)gene polymorphisms on the susceptibility and severity of chronic suppurative otitis media(CSOM)in adults.METHODS A total of 112 patients with CSOM admitted to the department of otorhinolaryngology of hospital from May 2017 to Dec 2019 were recruited.Total of 80 healthy volunteers who underwent physical examinations in the hospital during the same period were in the control group.Samples of secretions in the tympanic cavity of the study group were collected to investigate the pathogenic distribution.The peripheral blood DNA of the two groups of patients was extracted,and the Arg753Gln locus and TLR4Asp299Gly locus of the TLR2 gene were selected as the study sites,which were amplified by the polymerase chain amplification reaction(PCR).The amplification products were observed in a gel imager and the relationship between TLR2 gene Arg753Gln locus and TLR4 Asp299Gly locus gene polymorphisms and the degree of hearing damage in CSOM patients was analyzed.RESULTS Pathogens were isolated from 110 ears in 128 ears of 112 CSOM patients,with a positive rate of 85.94%.Among the 110 pathogens detected,69 strains were gram-positive bacteria,accounting for 62.73%,38 strains of gram-negative bacteria,accounting for 34.55%.3 strains of fungi,accounting for 2.73%.The frequencies of AG,AA genotype,and A allele at Arg753Gln locus of TLR2 in the study group were higher than those in the control group(P<0.05),and the frequency of GG genotype was lower than that in the control group(P<0.05).There were no significant differences in the genotype and allele frequency distribution of TLR4Asp299Gly locus between the two groups.Adjusted logistic regression analysis showed that AG,AA,AG/AA genotypes at Arg753Gln locus of TLR2 were risk factors for the occurrence of CSOM(P<0.05).The difference in the distribution frequency of TLR2 Arg753Gln locus genotypes among different degrees of deafness in CSOM patients was significant(P<0.05).There was no significant difference in lgenotype distribution of TLR4 Asp299Gly locus.CONCLUSION Gram-positive bacteria are the main pathogens in adult CSOM secretion,and the Arg753Gln locus A gene of TLR2 gene is a risk factor for the occurrence of CSOM.