A Study Of The Association Between IL-8Gene Polymorphisms And Late-onset Alzheimer’s Disease

Objective To explore the relationship between single nucleotide polymorphisms ofInterleukin-8gene-251A/T，781C/T and1633C/T and genetic susceptibility oflate-onset Alzheimer’s disease in Xinjiang Han people.This provided reference basisfor genetic research of late-onset Alzheimer’s disease.Methods According to the genome database material, and determine enzyme genelocus, the designation of their primers refer to literatures. Random selecting XinjiangHan population late-onset Alzheimer’s disease patients80cases, compared with80normal control, extracted venous blood, and picked up DNA. For the extracting DNA,proceeded polymerase chain reaction (PCR), and PCR products were used detectiontechnology of restriction fragment length polymorphism (RFLP) to make enzymecutting. Directly using method of counting to calculate of alleles and gene frequenciestype. Type of gene proceeded Hardy-Weinberg balance estimates, other statisticalanalysis completed with SPSS13.0software, comparing of genotype frequencies andallele frequencies made use of the chi-square test(χ2test).Results (1) In IL-8gene-215A/T, frequencies distribution of every genotype andallele both had significant difference (P=0.035for genotype,P=0.010for alleles) inLOAD group and control group. Frequencies of AT and AA type (50.0%,16.3%) inLOAD group were high than those in the control group (40.0%,7.5%), and frequencyof TT type (52.5%) in the control group was high than in LOAD group (33.7%). InLOAD group A allele (41.2%) was dominant, and in control group T allele (72.5%) was dominant. In LOAD patients A alleles more significantly increased than in thecontrol group (P=0.010), so it may was LOAD risk factors (OR=1.851). In LOADpatients and controls AA genotype had significant difference (P=0.023), so it mayincreased the risk of LOAD (OR=3.370). In LOAD patients frequency of ATgenotype was higher than one in the control group, it may have no relation with therisk of LOAD (OR=1.944，95%CI=0.994-3.803), but the difference was notstatistically significant (P>0.05).(2) For IL-8gene781C/T, in LOAD group AA, ATand TT genotype and C, T allele frequencies were26.3%,38.8%,34.9%,45.6%and54.4%respectively, and in control group they respectively were26.3%,43.6%,30.1%,48.1%and51.9%respectively, the difference was not statistically significant（P>0.05）.(3) For IL-8gene1633C/T,in LOAD group CC genotype frequencies(20.0%), CT genotype frequencies (41.2%)and TT genotype frequencies (38.8%),compared with CC, CT and TT genotype frequencies of the control group(11.3%,40.0%,48.7%), the difference between the two groups was not statisticallysignificant (P>0.05).Conclusion (1) IL-8gene-251A/T polymorphisms has some relation with risk oflate-onset Alzheimer’s disease, maybe increased genetic susceptibility of late-onsetAlzheimer’s disease. And A alleles possibly was one risk factor of pathogeny.(2) Polymorphism of781C/T and1633C/T probably has no relationship with risk ofLOAD. In the study population, we had not yet find that there was relationshipbetween single nucleotide polymorphisms of781C/T and1633C/T sites geneticsusceptibility of late-onset Alzheimer’s disease.