Association Of IL-18-607A/C,-137C/G Gene Polymorphism With The Susceptibility To Severity Of Enterovirus-71 Infection

ObjectiveThe goal of this study was to examine the relationship between IL-18-607A/C(rs1946519),-137C/G(rs187238)gene polymorphism and severity of Enterovirus 71(EV71) infection. We can explore the effects of different genotypes on risk of EV71 infection. MethodsThis study was performed in 187 patients with EV71 infection and 232 healthy control subjects. Genomic DNA of white blood cell were extracted and clinical characteristics of the case patients were collected. EV71 infection was diagonosed by a reverse-transcriptase polymerase chain reation(RT-PCR). The polymerase chain reaction with sequence specific primers(PCR-SSP) were used to determine genotype for A/C polymorphism at-607 position and the C/G polymorphism at-137 position of IL-18 gene. Results1. We observed that compared to healthy controls, the genotype frequency of IL-18-607 AA was significantly higher in EV71-infected patients(χ2=7.320,P=0.026), and the A allele in IL-18-607A/C was more frequent than C allele in EV71-infected patients than in normal controls(χ2=6.018,P=0.014). However, no significant differences were found in the distribution of genotype and allele frequency of the IL-18-137C/G polymorphisms between the healthy control group and EV71-infected patients.2. The A allele in the IL-18-607A/C was more frequent in patients with severe EV71 infection. No significant difference was observed between EV71 encephalitis and severe cases. No significant difference was found in the distribution of genotype IL-18-137C/G among the mild cases, severe cases, and EV71 encephalitis cases.3. There were significant differences in fever days, white blood cell count, C-reactive protein level, blood glucose concentration among genotypes of IL-18-607A/C in EV71-infected patients, but no significant differences were found in age or gender. Conclusion1. The polymorphism of IL-18-607A/C is associated with susceptibility to EV71 infection, and the A carrier of IL-18 confer susceptibility to the severity of EV71 infection.2. The polymorphism of IL-18-607A/C is associated with severity of EV71 infection, and the A carrier of IL-18 confer susceptibility to the severity of EV71 infection.3. The polymorphism of IL-18-137C/G is not associated with the susceptibility to EV71 infection.