Association Of HLA-A33 Phenotype、TNF-a/TNF-RII Promoter Polymorphisms With The Susceptibility To Enterovirus71 Infection

ObjectiveTo investigate the genetic susceptibility factors of EV71 infection by studying the interactions among HLA-A33 phenotype and TNFa/TNFRII by SNP and the information about the effects of different genes on risk of encephalitis of EV71 infection.MethodsReverse transcription polymerase chain reaction(RT—PCR)was used to detect the specific primers of EV71 in the faeces of patients with EV71 infection. Genomic DNA of white blood cell were extracted, then PCR-SSP were used to determine phenotype of HLA-A33 and genotype for the A/G polymorphism at -308 position of TNFa gene and PCR-RFLP was used to genotype for the T/G polymorphism at +196 position of TNFRII gene.Results1.Compared with that of the normal children, there were obvious statistical significance in EV71 infection patients of the rate of HLA-A33 phenotype x2-6.099,P<0.05)2.In EV71 infection groups, the genotype frequency of TNFa-308GG was significantly lower than that in normal controls (x2=5.393,P<0.05), and the TNFa-308A allele was more common than in normal group(x2=6.367,P<0.05), although there were no obvious statistical significance between mild and critical case groups.3.There were no obvious statistical significance in the frequencies of TNFRII+196T allele between the patients and control group (P>0.05).4.In EV71 group, TG genotype of TNFRII+196 was more common than in control group based on HLA-A33 phenotype(+) x2=3.866,P<0.05).Conclusions1. The Polymorphism of HLA-A33 is associated with susceptibility to EV71 infection.2.The Polymorphism ofTNFa-308 single nucleotide may correlate with EV71 infection, maybe TNFa-308GG was the.protective genotype which protect children keep away from EV71.3.Althougu there were no obvious statistical significance in EV71 infection patients by SNP, the TNFRⅡ +196(TG) may increased the risk of EV71 infection based on HLA-A33 phenotype(+).