Relationship Between Gene Polymorphisms Of Oligoadenylate Synthase And Cluster Of Differentiation 14 And EV71 Infection In Children

Objective:Our study aimed to evaluate the association of the oligoadenylate synthase 3(OAS3)rs1859330 G/A ? oligoadenylate synthase 2(OAS2)rs739901 C/A and cluster of differentiation 14(CD14)rs2569190 G/A genetic polymorphisms with susceptibility and severity to enterovirus 71(EV71)infection,and to explore the possible genetic predisposition to EV71 infection,further to find the new mechanism of EV71 infection.Methods:We investigated children who were diagnosed to have hand,foot and mouth disease(HFMD)with EV71 infection in the Pediatric Department of the Affiliated Hospital of Qingdao University and Qingdao Women & Children?s Hospital,China,between May 2015 and October 2016,and healthy children undergoing physical examination in the same period.370 EV71-infected patients with HFMD and 344 healthy children were studied in the OAS3 project.294 EV71-infected patients with HFMD and 252 healthy children were studied in the OAS2 project.186 EV71-infected patients with HFMD and 234 healthy children were studied in the CD14 project.All patients were proven to have EV71 infection through viral nucleic acid testing by reverse transcription – polymerase chain reaction(RT-PCR)of swab samples.Concerning the conditions of patients,we divided the patients with EV71 infection into two groups: mild cases and severe cases.Genomic DNA specimens were extracted from peripheral blood.An improved multiplex ligation detection reaction(iMLDR)technique was carried out to examine the genotype distributions and allele frequencies of OAS3 rs1859330?OAS2 rs739901 and CD14 rs2569190.We collected the clinical data of patients with EV71 infection,such as: age,gender,clinical symptoms,signs,peripheral blood white cell(WBC),C-reactive protein(CRP),aspartate amino-transferase(AST),alanine amino-transferase(ALT),creatine kinase-myocardial isozyme(CK-MB),blood glucose(BG),cerebrospinal fluid(CSF),an electroencephalogram(EEG),and brain computed tomography(CT)/magnetic resonance imaging(MRI)data,to analyze the differences of these markers in different OAS3 rs1859330?OAS2 rs739901 and CD14 rs2569190 genotypes of patients with EV71 infection.Enzyme-linked immunosorbent assay(ELISA)was used to measure IFN-? plasma levels in EV71-infected patients and controls.Statistical analysis was performed with the SPSS 19.0 software.A P-value less than 0.05 was considered statistically significant.Results:1.In the study of OAS3,we examined 370 patients(196 males,174 females)with EV71-infected HFMD,aged from 5 months to 7.8 years old(average 4.1±1.6 years old),within this group there were 214(130 males,84 females aged 4.1±1.7 years old)with mild EV-71 disease and 156(66 males,90 females aged 4.0±1.6 years old)that were classed as having severe disease.In the study of OAS2,we investigated 294 cases(152 males,142 females)HFMD patients with EV71 infection with the age from 4 months to 6 years old(4.1±1.6 years old),of these subjects,165 cases(83 males,82 females,average age 4.0±1.5 years old)were mild and 129 cases(69 males,60 females,average age 4.1±1.7 years old)were diagnosed as having encephalitis.In the study of CD14,we examined a total group of 186 EV71-infected patients(115 males and 71 females)who aged from 1.2 to 6.7 years,within this group there were 103(51 males,52 females)with mild EV-71 disease and 183(64 males,19females)with severe EV-71 disease.2.To compare the EV71-infected patients with the controls,there were no statistical differences in the genotype distributions(P=0.075,P=0.854)and allele frequencies(P=0.776,P=0.842)of OAS3 rs1859330 and CD14 rs2569190,however,the CA genotype distribution(P=0.007),A allele frequency(OR 1.32,95% CI 1.03–1.71,P=0.034)of OAS2 rs739901 were obviously elevated in EV71-infected patients.When compared the severe cases with the mild cases,the AA genotype distribution(P=0.002)and A allele frequency(OR 1.83,95% CI 1.3-2.5,P<0.001)of OAS3 rs1859330 were obviously higher in severe cases;the GG genotype distribution(P=0.015)and G allele frequency(P=0.007)of CD14 rs2569190 were also obviously higher in severe cases than in mild cases,however,there were no statistically significant differences of OAS2 rs739901 between mild cases and encephalitis cases(P>0.05).3.Subjects with the OAS3 rs1859330 AA genotype had raised levels of WBC counts(P=0.032)and BG concentrations(P=0.029),WBC counts(P=0.034)and BG concentrations(P=0.042)were raised in A carriers(CA+AA)of OAS2 rs739901 compared to CC genotype,the AG and GG genotypes of CD14 rs2569190 had raised levels of WBC counts(P<0.001)and BG concentrations(P=0.004)comparied with AA genotype.What?s more,the OAS3 rs1859330 AA and GA genotypes had higher CRP levels(P=0.024),the AG and GG genotypes of CD14 rs2569190 also had raised levels of CRP compared with AA genotype(P=0.016).4.IFN-?concentrations in severe cases were lower in the OAS3 rs1859330 A allele carriers(AA+GA)(118.5±12.6pg/mL)than in the GG homozygotes(152.6±56.3pg/mL,P<0.05),but in the mild cases,there were no obvious differences in IFN-?concentrations between OAS3 rs1859330 A allele carriers(AA+GA)(62.4±11.7pg/mL)and GG homozygotes(67.1±13.2pg/mL,P>0.05).In encephalitis cases,IFN-? levels were reduced in OAS2 rs739901 CA(89.4±15.6 pg/mL)and AA(93.1±16.2 pg/mL)compared to CC genotypes(118.2±34.3pg/mL,P<0.05);in mild cases,there were no significant differences of IFN-? levels among CC(60.4±12.7 pg/mL)?CA(56.3±11.5 pg/mL)and AA(51.6±11.2 pg/mL)genotypes.In mild cases with EV71 infection,IFN-? levels of CD14 rs2569190 GG genotype(54.28±26.79pg/mL,P<0.001)and AG genotype(106.17±14.18pg/mL,P=0.017)were reduced compared to AA genotype(150.09±25.64pg/mL),IFN-?levels of GG genotype were also lower than AG genotype(P=0.002);in severe cases with EV71 infection,IFN-?levels of GG genotype(88.15±23.92pg/mL,P<0.001)and AG genotype(108.61±30.89 pg/mL,P=0.002)were reduced compared to AA genotype(157.59±26.93pg/mL).Conclusions:1.OAS3 rs1859330 G/A and CD14 rs 2569190 G/A genetic polymorphisms were associated with the severity to EV71 infection in children.2.OAS3 rs1859330 A allele and CD14 rs 2569190 G allele might be risk factors for the severity to EV71 infection in children.3.OAS2 rs739901 C/A genetic polymorphisms had relationshp with the susceptibility to EV71 infection in children.4.OAS2 rs739901 A allele might be a risk factor for the susceptibility to EV71 infection in children.5.In the process of EV71 infection,OAS3 rs1859330,OAS2 rs739901 and CD14 rs2569190 gene polymorphisms might all play an important role by regulating the products of IFN-?.