鼻病毒感染社区获得性肺炎儿童黑色素瘤分化相关基因5基因多态性及其临床意义

Analysis of gene polymorphism of melanoma differentiation-related gene 5 in children with community-acquired pneumonia caused by rhinovirus and its clinical significance

目的探讨鼻病毒(HRV)感染社区获得性肺炎(CAP)儿童黑色素瘤分化相关基因5(MDA5)基因多态性及其临床意义。方法选择鄂州市妇幼保健院儿科2020年1月-2022年1月明确HRV感染CAP患儿86例为研究组,按照1∶1比例随机选择医院接受体检健康儿童86名为对照组。统计所有儿童性别、年龄、接种肺炎疫苗和被动吸烟情况;统计HRV感染者混合感染、合并呼吸困难和住院天数。所有患儿均在入院当天抽取外周血标本,根据HRV病毒VP4/VP2结合区片段以及MDA基因多态性位点设计特异性引物,采用一步法实时荧光定量聚合酶链式反应(RT-PCR)以相同条件进行扩增,根据CT值区分HRV分型和MDA基因多态性基因型分布情况。结果研究组和对照组MDA5基因GG、GA和AA基因型实际频数和理论频数比较差异无统计学意义;研究组携带GG基因型、G等位基因频率较对照组低,携带AA基因型、A等位基因频率较对照组高(P<0.05),两组携带GA基因型频率对比未见统计学差异;研究组携带AA基因型患儿和携带GG/GA型患儿HRV分型、混合感染、合并呼吸困难和住院天数比较差异无统计学意义。结论MDA5基因的遗传性差异可能是导致不同儿童对HRV感染所致CAP的因素之一,其机制还需进一步深入研究。

OBJECTIVE To explore the gene polymorphism of melanoma differentiation-related gene 5(MDA5)in children with community-acquired pneumonia(CAP)infected by rhinovirus(HRV)and to analyze its clinical significance.METHODS A total of 86 children with HRV-infected CAP in Ezhou Maternal and Child Health Hospital from Jan 2020 to Jan 2022 were enrolled as the research group,and 86 healthy children under physical examination in our hospital were randomly selected by the ratio of 1∶1 into the control group.The gender,age,vaccination against pneumonia and passive smoking in all children were asked,and mixed infection,dyspnea and hospitalization days of HRV-infected patients were counted.Peripheral blood samples were collected from all the children on the day of admission.Specific primers designed according to HRV virus VP4/VP2 binding region fragments and MDA gene polymorphism sites were used to amplify the fragments by one-step real-time quantitative polymerase chain reaction(RT-PCR).Amplification was performed under the same conditions,and HRV typing and MDA gene polymorphism genotype distribution were distinguished according to CT values.RESULTS The differences between the actual and theoretical frequencies of the GG,GA and AA genotypes of the MDA5 gene in the study group and the control group were not significant.The frequency of GG genotype and G allele in the study group was significantly lower than that in the control group,while the frequency of AA genotype and A allele was higher than that in the control group(P<0.05).There was no significant differences in HRV typing,mixed infection,and dyspnea hospitalization days between children carrying GA genotype and carrying GG/GA genotype in the study group.CONCLUSION Genetic differences in MDA5 gene may be one of the factors that lead children′s CAP caused by HRV infection,which mechanism needs to be further studied.