Association Of Interleukin-8 Gene Polymorphisms And Its Serum Levels With Chronic HBV Infection

Objective To investigate the relationship between the gene polymorphism of interleukin-8 -251A/T,-738T/A and -845T/C in the gene promoter and its serum levels with chronic HBV infection.Methods A retrospective case-control study design was applied for the present study. The case group included 60 patients with chronic HBV infection (25 cases with mild,17 cases with moderate,and 18 cases with severe degree ) .The control group consisted of 40 cases of acute self-limited infection(HBeAb, HBcAb, HBsAb of at least two positive, but HBsAg and HBV DNA are negative and there were no vaccinated against HBV vaccine),we collected peripheral blood from the two groups and extracted genomic DNA of them.We employed polymerase chain reaction- restriction fragment length polymorphism(PCR-RFLP) to analyze the genotype distribution and allele frequency of IL-8-251A/T,-738T/A and -845T/C.Chi-square test(χ2 test)was used for statistical comparison of genotype distribution and allele frequency between the case group and the control group. Odds ratio(OR) and 95%confidence interval(CI)indicated relative risk. The serum interleukin-8 levels were measured enzyme-linked immunosorben assay(ELISA).Results①IL-8-251A/T single nucleotide polymorphisms include three genotypes :AA,AT and TT, there was significant difference in frequencies of allele and genotype in interleukin-8 -251A/T polymorphism between chronic HBV infection and controls(p<0.05). Relative risk analysis indicated that the risk of chronic HBV infection in A allele was 3.080 times higher than that in T allele(OR=3.080, 95%CI:1.697-5.590).②The frequencies of genotypes and allele of IL-8 -251A/T were found no significant difference between chronic HBV infection mild degree,moderate degree and severe degree(p>0.05).③IL-8-738T/A single-nucleotide polymorphisms only found a TT genotype and no significant difference between chronic HBV infection and controls(p>0.05); IL-8-845T/C single-nucleotide polymorphisms only found a TT genotype and no significant difference between chronic HBV infection and controls(p>0.05).④Serum levels of interleukin-8 were significantly increased in chronic HBV infection compared with controls(p<0.05), the serum levels of interleukin-8were gradually rising and found significant difference between chronic HBV infection mild degree group,moderate degree group and severe degree group (p<0.05).According to the genotype AA,AT,TT of IL-8-251A/T single nucleotide polymorphisms,we devided in case group into three groups, three genotypes have different serum of IL-8 level(p<0.05). People with genotype AA have a higher serum IL-8 level. Conclusions Interleukin-8-251A/T polymorphism was associated with chronic HBV infection,but there were no associations among three group;The chronic HBV infection of TT genotype was not easy to become chronic, instead,the chronic HBV infection of AA genotype easier to become chronic,and A allele might be a risk factor for chronic HBV infection;The polymorphism of interleukin-8-738T/A and interleukin-8-845T/C was not associated with chronic HBV infection. The levels of serum interleukin-8 was increased in chronic HBV infection,which was correlated with liver damage degree and illness severity. The genotype of interleukin-8 was associated with the serum levels of interleukin-8,the genotype AA may elevate the interleukin-8 levels.