| Objective: More than2billion people have been infected with HBVworldwide. The clinical outcome of the infection varies widely and mayinclude spontaneous recovery, chronic hepatitis, HBV related liver cirrhosis orhepatocellular carcinoma. Persistent HBV infection is influenced by acomplex combination of genetic, environmental, viral components. GeneticEpidemiology supports the role of host genetic components in determining theinfection and its outcomes of HBV. We analyzed the impact of candidategenes single nucleotide polymorphisms (SNPs) including interleukin28A(IL28A), interleukin28B (IL28B), p21_activated kinases4(PAK4),iron/zinc purple acid phosphatase-like protein(PAPL), interleukin10receptor,beta(IL10RB), interleukin28receptor, alpha(IL28RA), DEP domaincontaining5(DEPDC5) and environmental components including drinkingand smoking on the infection and infection outcomes of HBV. Meanwhile, weexplored the interaction between genetic polymorphisms and tobacco andalcohol habit in HBV infection.Methods:1Method of Selecting candidate genesSearching candidate genes about autoimmune diseases by CNKI andPubmed. Selecting tagSNPs of candidate genes in Han Chinese by Hapmap.Removing SNPs of linkage disequilibrum (LD) by Haploview.2ParticipantsCases and controls were recruited from Hebei Province of northern Chinaincluding507healthy individuals,350spontaneous recoveries,792persistentchronic HBV carriers (484chronic carriers without HCC,308HCC patients).Meanwhile, we collected the baseline, illness situation, checkup results of allthe subjects. 3GenotypingGenomic DNA was obtained from human leukocyte nuclei isolated fromwhole blood by Genomic DNA Purification Kit. IL28B-rs8099917(TT,CT,CC), IL28A-rs12980602(TT,CT,CC), PAK4-rs9676717(TT,CT,CC),PAPL-rs423058(CC,AC,AA), IL28RA-rs10903034(CC,TC,TT), IL10RB-rs2834167(GG,AG,AA), DEPDC5-rs1012068(AA,CA,CC) were genotypedby Matrix Assisted Laser Desorption/ionization Time of Flight MassSpectrometry (MALDI-TOF MS).4Statistical analysisAll statistical analyses were conducted by SPSS16.0software. Group t-test was used to compare the measurement data of single factor between casesand controls. Chi-square test was used to compare the enumeration date ofsingle factor between cases and controls. Logistic regression models wereused for calculating odds ratios (95%confidential interval) and thecorresponding P values, controlling for covariates. Multifactor DimensionalityReduction (MDR) analysis was performed for studying higher orderinteractions among various SNPs and tobacco and alcohol habit. A two-tailedP<0.05was used as the criterion of statistical significance.Results:1The genotype frequencies for7polymorphisms conformed to HWEexpectations for controls (P>0.05). Participants could represent the generalpopulation.2Risk factors of HBV infectionCase control study performed in healthy individuals and persistentchronic HBV carriers indicated that tobacco habit, alcohol habit and PAPL-rs423058A were associated with the risk of HBV infection. Smokers had anincreased risk of HBV infection compared with non-smokers (OR=1.676,95%CI=1.251-2.243). Drinkers had an increased risk of HBV infectioncompared with non-drinkers (OR=1.472,95%CI=1.110-1.951). Individualswith the rs423058CA, rs423058AA, rs423058CA+AA genotype presented anreduced risk of HBV infection compared with those with the rs423058CC genotype (OR=0.695,95%CI=0.546-0.884),(OR=0.577,95%CI=0.386-0.863),(OR=0.672,95%CI=0.534-0.847).The interaction between rs9676717, rs1012068, rs423058, rs2834167gave the best gene-gene model with statistical significance. The risk of HBVinfection in "high-risk"population which were combinated by41blocks was1.774(1.269,2.812) times as compared with the"low-risk"population. Theinteraction between tobacco and alcohol habit gave the best gene-environmentmodel with statistical significance. The risk of HBV infection in "high-risk"population who posses bacco and alcohol habit was2.225(1.483,3.338)times as compared with the"low-risk"population. The redundancy interactionwith related to PAPL-rs423058with tobacco and alcohol habit may associatedwith the risk of HBV infection.3Risk factors associated with outcomes of HBV infection3.1Risk factors associated with HBV clearanceCase control study performed in spontaneous recoveries and persistentchronic HBV carriers indicated that tobacco and alcohol habit and IL10RB-rs2834167A were associated with HBV clearance. Non-smokers had anincreased ability of HBV clearance compared with Smokers (OR=1.656,95%CI=1.104-2.484). Non-drinkers had an increased ability of HBV clearancecompared with drinkers (OR=1.554,95%CI=1.052-2.294). Individuals withthe rs2834167AA with acute HBV infection have a reduced risk of HBVpersistence compared with those with the rs2834167GA+GG (OR=0.661,95%CI=0.476-0.919).The redundancy interaction between tobacco and alcohol habit gave thebest gene-environment model with statistical significance. The "low-risk"population were combinated by group who don't smoke and drink had anincreased ability of HBV clearance compared with "high-risk"population(OR=2.164,95%CI=1.635-2.540). The synergy interaction with related toIL10RB-rs2834167with tobacco and alcohol habit may affect patients' abiltyof HBV clearance.3.2Risk factors associated with HBV-HCC Case control study performed in chronic carriers without HCC and HBV-HCC patients indicated that gender, age, tobacco and alcohol habit andDEPDC5-rs1012068C were associated with HBV-HCC. Men with chronicHBV infection had an increased risk of developing HCC compared withwomen (OR=2.357,95%CI=1.569-3.540). HBV chronic carriers for eachadditional20-year-old had an increased risk of developing HCC (OR=3.574,95%CI=2.746-4.653). Smokers with chronic HBV infection had an increasedrisk of developing HCC compared with non-smokers (OR=1.681,95%CI=1.146-2.464). Drinkers with chronic HBV infection had an increased risk ofdeveloping HCC compared with non-drinkers (OR=1.939,95%CI=1.350-2.785). Individuals with chronic HBV infection with the rs1012068CA,rs1012068CC, rs1012068CA+CC genotype presented an increased risk ofdeveloping HCC compared with those with the rs1012068AA(OR=1.531,95%CI=1.088-2.154),(OR=2.515,95%CI=1.392-4.544),(OR=1.678,95%CI=1.216-2.315). Individuals with chronic HBV infection with the rs1012068CCgenotype presented an increased risk of developing HCC compared with thosewith the rs1012068CA+AA(OR=2.114,95%CI=1.191-3.751).The synergy interaction between rs9676717, rs1012068gave the bestgene-gene model. The risk of HBV-HCC in "high-risk"population which werecombinated by rs1012068CA,CC&rs9676717and rs9676717CC&rs1012068was2.844(2.335,3.548) times as compared with the "low-risk" populationwhich were combinated by rs1012068AA&rs9676717TT,CT. The synergyinteraction with related to rs9676717and rs1012068with tobacco habit gavethe best gene-environment model. The "high-risk"population with chronicHBV infection have an increased risk of developing HCC compared withthe"low-risk"population (OR=3.904,95%CI=3.178-4.621).Conclusions:1This study indicates that tobacco and alcohol habit are correlated withsusceptibility to HBV infection, PAPL-rs423058A allele plays a protectiveeffect for HBV infection. The combination of rs9676717, rs1012068,rs423058, rs2834167may increase HBV infection risk. The redundancy interaction with related to PAPL-rs423058with smoking and drinking mayassociated with the risk of HBV infection.2The negative effect on the viral clearance is significant among smokers,drinkers and individuals with IL10RB-rs2834167G. The redundancyinteraction between tobacco and alcohol habit together with the synergyinteraction with related to IL10RB-rs2834167with tobacco and alcohol habitmay affect patients' abilty of HBV clearance.3This study showed that an increased risk of HBV chronic infection toHBV-HCC was associated with male, older age, tobacco and alcohol habit andDEPDC5-rs1012068C. The synergy interaction between rs9676717andrs1012068together with the redundancy interaction with related to rs9676717with rs1012068and tobacco habit increase the risk of HBV-HCC. |
