乙型肝炎病毒家族聚集性感染者的基因型和基因变异特征分析

目的:研究HBV家族聚集性感染者的基因型和基因变异特征．方法:选择HBV聚集性感染家族成员内部基因型完全相同的共27个家族84人,其中HBV 携带者(ASC)29例;慢性活动性肝炎(CAH)23 例;肝硬化(LC)21例;肝细胞癌(HCC)11例;用基因芯片法检验前C1896和BCP1762,1764双突变;用测序法检验HBV基因型,并设相应基因型的HBV感染对照组．结果:B型HBV家族聚集感染者ASC率显著大于C型家族(X2=5．0734,P=0．0243,P<0．05); 其BCP1762．1764双突变的发生率也显著低于 C基因型(X2=22．4000,P=0．0000,P<0．001)．两种基因型的家族聚集感染者组与相应的对照组相比在疾病临床类型方面均无显著差异．结论:检验HBV家族聚集感染者的基因型和／或BCP区1762、1764基因的双突变可以协助疾病的预测分析．     

慢性乙型肝炎病毒感染者病毒前C区和基本核心启动子区变异检测及意义

目的 探讨乙型肝炎病毒（HBV）前C区和基本核心启动子（BCP）区变异与基因型及疾病进展间的关系。方法 收集HBV携带者（ASC）、慢性乙型肝炎（CHB）、肝炎肝硬化（LC）、肝细胞肝癌（HCC）患者血清148份，用半巢式聚合酶链反应扩增HBV前C／C基因部分片段，产物纯化后直接测序，检测前C区A1896及BCP区T1762／A1764变异。用S基因聚合酶链反应-限制性片段长度多态性分析（PCR-RFLP）方法确定HBV基因型。结果 有128份血清能够成功分型和测序，其中B基因型60份，C基因型68份。在B基因型感染者中前C区A1896变异检出率（48．33％）明显高于C基因型感染者（29．41％，X^2=4．83，P〈0．05）；而BCP区T1762／A1764变异检出率却明显低于C基因型感染者，差异亦有统计学意义（30．00％：73．54%，X^2=24．25。P〈0．05）。前C区A1896变异在CHB、LC、HCC中的阳性检出率分别为46．88％（15/32）、39．39％（13／33）、51．52％（17／33）。与ASC的13．33％（4／30）相比，P分别〈0．05，差异有统计学意义。BCP区T1762／A1764变异检出率在HCC、LC组分别为87．88％（29／33）和72．73％（24／33）．明显高于CHB组的37．50％（12／32）及ASC组10.00％（3／30）（P〈0．05）。结论 前C区A1896变异常见于B基因型感染者，而BCP区T1762/A1764变异C基因型感染者多见。除ASC外．前C区A1896变异与疾病进展关系不大．而BCP区T1762/A1764变异与乙型肝炎进展及顶后相关。     

Hepatitis B virus subgenotypes and basal core promoter mutations in Indonesia

AIM： To identify the distribution of hepatitis B virus （HBV） subgenotype and basal core promoter （BCP） mutations among patients with HBV-associated liver disease in Indonesia.
METHODS： Patients with chronic hepatitis （CH, n =61）, liver cirrhosis （LC, n = 62）, and hepatocellular carcinoma （HCC, n = 48） were included in this study. HBV subgenotype was identified based on S or preS gene sequence, and mutations in the HBx gene including the overlapping BCP region were examined by direct sequencing.
RESULTS： HBV genotype B （subgenotypes B2, B3, B4, 85 and B7） the major genotype in the samples, accounted for 75.4%, 71.0% and 75.0% of CH, LC and HCC patients, respectively, while the genotype C （subgenotypes C1, C2 and C3） was detected in 24.6%, 29.0%, and 25.0% of CH, LC, and HCC patients, respectively. Subgenotypes B3 （84.9%） and C1 （82.2%） were the main subgenotype in HBV genotype B and C, respectively. Serotype adw2 （84.9%） and adrq＋ （89.4%） were the most prevalent in HBV genotype B and C, respectively. Double mutation （A1762T/G1764A） in the BCP was significantly higher in LC （59.7%） and HCC （54.2%） than in CH （19.7%）, suggesting that this mutation was associated with severity of liver disease. The T1753V was also higher in LC （46.8%）, but lower in HCC （22.9%） and CH （18.0%）, suggesting that this mutation may be an indicator of cirrhosis.
CONCLUSION： HBV genotype B/B3 and C/C1 are the major genotypes in Indonesia. Mutations in BCP, such as A1762T/G1764A and T1753V, might have an association with manifestations of liver disease.     

Basal core promoter T1762/A1764 and precore A1896 gene mutations in hepatitis B surface antigen-positive hepatocellular carcinoma: a comparison with chronic carriers.

BACKGROUND: Chronic hepatitis B virus (HBV) infection is associated with hepatocellular carcinoma (HCC), and specific viral factors have been identified that may increase the risk for HCC development. However, the differences in these viral factors in chronic carriers who seldom develop HCC compared with HCC patients have not been adequately evaluated. METHODS: From 1989 to 2005, 101 hepatitis B surface antigen-positive patients presented to our clinic with HCC. Baseline basal core promoter (BCP) T1762/A1764 mutants, precore (PC) A1896 mutants, HBV genotypes and HBV DNA in HCC patients were compared with 67 chronic carriers who had been followed for a mean of 112.1+/-77.7 standard deviation months. RESULTS: At baseline, HCC patients had lower levels of serum albumin, but higher values of alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, bilirubin and alpha-foetoprotein than those of chronic carriers (P<0.001 for all comparisons). The presence of genotype C, higher frequencies of PC A1896 mutants, BCP T1762/A1764 mutants and higher circulating levels of HBV DNA were more frequently detected in HCC patients than that in chronic carriers (P<0.001 for all observations). Logistic regression analysis revealed that BCP T1762/A1764 mutants [odds ratio (OR) 11.14, 95% confidence interval (CI) 3.05-40.72; P<0.001] and PC A1896 mutants (OR 3.75, 95% CI 1.14-12.34; P<0.05) were significantly associated with HCC development. CONCLUSION: Our results indicate that the presence of BCP and PC mutations significantly increases the risk for HCC in chronic hepatitis B patients. These mutations were less often detected in chronic carriers who seldom develop HCC.     

Role of hepatitis B virus precore/core promoter mutations and serum viral load on noncirrhotic hepatocellular carcinoma: a case-control study

BACKGROUND: Apart from the presence of liver cirrhosis, hepatitis B virus (HBV) factors have also been shown to play a role in the development of hepatocellular carcinoma (HCC). Studying HBV-related noncirrhotic HCC may help clarify the effect of viral factors. METHODS: In a hospital-based, age- and genotype-matched study, we aimed to determine the role played by basal core promoter (BCP) T1762/A1764 mutation, precore A1896 mutation, and serum viral load in noncirrhotic hepatocarcinogenesis by comparing 44 patients with HBV-related noncirrhotic HCC, 45 patients with chronic hepatitis B, and 42 patients with HBV-related cirrhotic HCC. HBV genotype, precore and BCP mutations, and viral load were determined by molecular assays. RESULTS: In univariate analysis, statistically significant odds ratios were obtained for male sex (P=.005) and BCP T1762/A1764 mutation (P=.0003) in patients with noncirrhotic HCC, compared with patients with chronic hepatitis B. By multiple logistic regression analysis, male sex, BCP T1762/A1764 mutation, and viral load >or=10(5) copies/mL were independently associated with the risk of noncirrhotic HCC. The virologic characteristics were similar between patients with cirrhotic HCC and those with noncirrhotic HCC. CONCLUSIONS: Our results suggest that BCP T1762/A1764 mutation and higher viral load may be involved in the carcinogenesis of cirrhotic and noncirrhotic HCC.     

Hepatitis B Virus Genotypes: Clinical Relevance and Therapeutic Implications

At least ten hepatitis B virus (HBV) genotypes (A to J) with distinct geographic distributions have been recognized. HBV genotype is not only predictive of clinical outcome but also implicated in responsiveness to antiviral therapy, especially interferon-based regimens. HBV genotype-specific immunologic and virological pathogenesis may contribute to heterogeneous clinical outcomes in chronic hepatitis B patients. For example, patients with genotypes C and D infection have a lower rate of spontaneous HBeAg seroconversion. In addition, genotype C and D have a higher frequency of basal core promoter A1762T/G1764A mutation than genotype A and B. Genotypes C and D also carry a higher risk of cirrhosis and HCC development than genotype A and B. Therapeutically, genotype A and B patients have a better response to interferon-based therapy than genotypes C and D patients, but the response to nucleos(t)ide analogues is comparable across all HBV genotypes. In conclusion, genotyping of HBV can help practicing physicians identify chronic hepatitis B patients who are at risk of disease progression and optimize anti-viral therapy in clinical practice.     

Basal core promoter mutations of hepatitis B virus increase the risk of hepatocellular carcinoma in hepatitis B carriers

BACKGROUND & AIMS: Hepatitis B viral (HBV) genotype C is associated with the development of hepatocellular carcinoma (HCC) compared with genotype B; however, the virologic factors contributing to the pathogenic differences remain unknown. We investigated the prevalence of T1762/A1764 basal core promoter mutant in a cohort of 250 genotype B- or C-infected HBV carriers with different stages of liver disease to clarify a possible role for this mutant in hepatocarcinogenesis. METHODS: The sequences of basal core promoter of HBV genome were determined in 60 inactive HBV carriers and 190 patients with histologically verified chronic liver disease and HCC. RESULTS: Genotype C has a higher prevalence of T1762/A1764 mutation than genotype B (odds ratio, 5.18; 95% confidence interval [CI], 2.59-10.37; P < 0.001). The likelihood of T1762/A1764 mutation parallels the progression of liver disease, from 3% in inactive carriers to 64% in HCC patients (odds ratio, 20.04; 95% CI, 7.25-55.41; P < 0.001). By multiple logistic regression analysis, patients with T1762/A1764 mutation were significantly associated with the development of HCC than those without (odds ratio, 10.60; 95% CI, 4.92-22.86; P < 0.001), and the risk was observed for both genotypes B and C. In addition, the prevalence of T1762/A1764 mutation in younger HCC patients was comparable with older HCC patients but was significantly higher than that in age-matched inactive carriers, irrespective of genotypes. CONCLUSIONS: Our data suggest that HBV carriers with T1762/A1764 basal core promoter mutant are at increased risk for HCC and that this mutant may contribute to the pathogenesis of HBV infection.     

Clinical relevance and public health significance of hepatitis B virus genomic variations

Ten hepatitis B virus (HBV) genotypes (A-J) and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard to clinical outcome, prognosis, and response to interferon treatment. Infection with subgenotype A2 is frequently associated with high viral load, resulting in acute infection via horizontal transmission. Genotypes A and B are more sensitive to interferon treatment than genotypes D and C, respectively. Genotype B is more frequent in acute hepatitis than genotype C, whereas genotype C (C2) is more frequently associated with an increased risk of hepatocellular carcinoma (HCC), mostly cirrhotic, as compared with genotype B (B2). Genotype mixture is associated with high viral load and worse outcome of HBV infection. HBV mutations in the S genes, especially amino acids substitution at position 145 (G145R), are associated with immune escape, whereas mutations in the PreS or S genes which impair HBsAg secretion could present a risk to blood safety. HBV variants harboring mutations in the viral polymerase gene that confer resistance to nucleoside analogs may be selected during antiviral therapy. Different genotypes have distinct mutation patterns in the PreS and EnhⅡ/BCP/Precore regions.PreS deletions, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. HCCassociated HBV mutants may not transmit via motherto- child transmission, and are likely generated during HBV-induced pathogenesis. Examination of HBV mutations alone or in combination and host genetic suscep susceptibility will be helpful in classifying the HBV-infected subjects who will develop HCC and need active antiviral treatments.     

海南汉族乙型肝炎病毒基因型与BCP区和前C区基因突变的关系

目的探讨海南汉族乙型肝炎病毒（HBV）基因型与前C区G1896A和BCP区A1762T／G1764A基因突变的关系。方法采用RT-PCR方法检测乙型肝炎患者的HBV基因型,PCR方法扩增包含C启动子和前C区基因核苷酸（nt1643-nt2112）,对PCR产物进行DNA测序。结果基因型C的BCP区A1762T／G1764A突变率（58．82％）显著地高于基因型B（10．53％）（P〈0．05）。基因型CG1896A突变率为29．41％,基因型BG1896A突变率为47．37％,两者比较差异无统计学意义（P〉0．05）。结论不同基因型HBV致病能力可能与病毒基因组BCP区A1762T／G1764A突变率的不同有关,而与前C区G1896A突变无关。     

乙型肝炎病毒基本核心启动子突变与基因型的关系

目的研究乙型肝炎病毒（HBV）基本核心启动子（BCP）突变与HBV基因型的关系。方法随机选取我院68例慢性乙型肝炎患者外周血，采用荧光定量PCR结合TaqmanMGB探针技术检测HBV基因型，并用基因扩增和DNA测序方法检测BCPT1762／A1764双突变。结果68例患者HBV分型中，B基因型20例，C基因型46例，B、C混合型1例，未分型（非B非C型）1例。66例B、C两基因型中，B基因型组T1762／A1764双突变5例，突变率25．0％（5／20），C基因型组T1762／A1764双突变24例，突变率52．2％（24／46），C基因型T1762／A1764双突变率明显高于B基因型（P〈0．05）。结论苏州地区慢性乙型肝炎患者基因型以C型和B型为主，C基因型比B基因型更易发生T1762／A1764双突变。     

慢性乙型肝炎病毒基因型与BCP区变异的临床研究

为了研究乙型肝炎病毒 (HBV)基因型与C基因启动子 (BCP)基因变异的关系 ,对 6 9例慢性乙型肝炎患者分别用聚合酶链反应 (PCR)—限制性片段长度多态性 (RFLP)技术和PCR微板核酸分子杂交技术 ,进行基因分型及HBVBCP基因变异检测。在 6 9例慢性乙型肝炎患者中 ,各基因型发生的BCP区A176 2T/G176 4A双突变分别为C型 18例 (4 3 9% )B型 3例 (16 7% )D型 2例 (2 0 % )。C型的BCP双突变率明显高于B型 ,两者相比有显著性差异(P <0 0 5 )。故可以认为乙型肝炎病毒基因型与BCP区双突变存在有一定的相关性。推测A176 2T/G176 4A双突变可能是造成C型患者比B型存在更严重肝损害的原因之一     

Molecular and serological characterization of hepatitis B virus in deferred Ghanaian blood donors with and without elevated alanine aminotransferase

Candidate blood donors in Ghana are frequent carriers of hepatitis B virus (HBV). A comparative study of 117 donor samples including 46 with alanine aminotransferase (ALT) > or = 60 IU/L and 71 with < or =40 IU/L level was undertaken. S and the basic core promoter-precore regions (BCP/PC) sequencing was used to identify genotypes and variants relevant to HBV natural history, respectively. Age, viral load, HBe status were correlated with molecular data. HBV genotype E (87%) was dominant with little genotypes A (10%) and D (3%). Comparing individuals with or without liver disease, an association between liver disease and older age (P = 0.004) and higher viral load (P = 0.002) whether as a whole population or only genotype E was found. Compared with a commercial assay, BCP/PC sequencing had lower sensitivity to detect mixtures of wild-type and variant viruses but detected BCP deletions. BCP 1762/1764 variants were positively correlated with older age (P < 0.0001) and elevated ALT levels (P = 0.01). PC 1896 stop codon was marginally correlated with viral load (P = 0.09). HBV genotype E infection natural history appears different from genotypes B and C prevalent in Asia. Donors with liver disease being older, with higher viral load and higher BCP variant proportion may be at higher risk of cirrhosis and hepatocellular carcinoma.     

Hepatitis B virus genotype and basal core promoter/precore mutations are associated with hepatitis B‐related acute‐on‐chronic liver failure without pre‐existing liver cirrhosis

Summary. The study was undertaken to investigate the features and clinical implications of hepatitis B virus (HBV) genotypes, basal core promoter (BCP) and precore (PC) mutations in hepatitis B‐related acute‐on‐chronic liver failure (HB‐ACLF). Samples from 75 patients with HB‐ACLF and without pre‐existing liver cirrhosis and 328 age‐matched patients with chronic hepatitis B (CHB) were analyzed. HBV genotype and BCP/PC mutations were determined by direct sequencing. Mutations at 8 sites of the BCP/PC region were compared between the two groups of patients. A significantly higher ratio of genotype B to C was found in patients with HB‐ACLF than in patients with CHB (30.7–69.3%vs16.5–82.6%, P < 0.01). Single mutations including T1753V (C/A/G), A1762T, G1764A, G1896A and G1899A and triple mutations T1753V/A1762T/G1764A and A1762T/G1764A/C1766T (or T1768A) were more frequently detected in patients with HB‐ACLF than in patients with CHB. Correspondingly, BCP/PC wild‐type sequences were absent in patients with HB‐ACLF in contrast to 27.1% in patients with CHB. The BCP/PC mutations were found to be associated with increased HBeAg negativity, higher alanine aminotransferase level and lower viral load. Patients with HB‐ACLF infected with the PC mutant virus had a higher mortality. The findings suggest that patients with CHB infected with genotype B with BCP/PC mutations were more likely to develop HB‐ACLF than those with genotype C with wild‐type BCP/PC regions, and patients with HB‐ACLF with the PC mutation had increased risk of a fatal outcome.     

Correlation of hepatitis B virus (HBV) genotypes and mutations in basal core promoter/precore with clinical features of chronic HBV infection.

BACKGROUND/AIMS: To investigate the correlation of hepatitis B virus (HBV) genotypes and basal core promoter (BCP) and precore (PC) mutations in patients with chronic hepatitis B. METHODS: HBV genotyping, nucleotide mutation, serum HBV DNA level and serological markers were analyzed in 121 patients with chronic HBV infection using INNO-LiPA HBV genotyping, polymerase chain reaction (PCR) product-based sequencing, fluorescence quantitative PCR and enzyme-linked immunosorbent assays respectively. RESULTS: Forty (33.0%), 77 (63.6%), two (1.7%) and two (1.7%) patients had genotypes B, C, B/C and D infections respectively. Significant differences were found in serum HBV DNA levels (log10 copies/ml: 6.18 vs. 5.61, P=0.042) and mutations at nucleotide (nt) 1762/1764 (71.4% vs. 42.5%, P=0.002) between genotypes C- and B-infected patients. There were significant differences in the mean age, serum biochemical parameter levels and mutation rates in BCP/PC among hepatitis e antigen (HBeAg)-positive and -negative chronic hepatitis B (CHB) and liver cirrhosis (LC) groups. CONCLUSION: Genotypes C and B are predominant in China, and the frequent nt 1762/1764 mutation, which occurs commonly in HBeAg-negative CHB, especially in genotype C patients, may be associated with the progress of chronic HBV infection.     

青岛地区乙型肝炎病毒基本核心启动子区基因突变与乙型肝炎病毒所致原发性肝癌的相关性

目的通过分析山东省青岛地区HBV核心启动子基因序列的突变特征,探讨其与乙型肝炎相关原发性肝癌的相关性。方法收取慢性乙型肝炎患者和乙型肝炎相关原发性肝癌患者的血清标本各60例,然后从中提取HBV DNA,采用聚合酶链反应(PCR)扩增、纯化、克隆后测序,根据S基因区的编码序列确定患者的基因型和血清型;分别将HBV核心启动子区的各序列结果与GeneBank中的HBV标准株做对比,用DNAMAN软件对基因序列进行突变分析。采用SPSS17.0软件进行统计学分析。结果 120例标本,HBV株均为B或C基因型,以C基因型为主,其中,HBV组的C基因型所占比率为83.33%,HCC组为90.00%(χ2=0.65,P=0.42);血清型均为adw2或adrq+。HBV基因组核心启动子区常见的点突变为C1653T、T1753V、C1754T及A1762T/G1764A,发生率分别为42.73%、86.36%、71.82%、38.18%。与慢性乙型肝炎患者相比,肝癌患者中发生率比较高的突变位点为C1653T(78.85%,χ2=52.58,P<0.001)及A1762T/G1764A(73.08%,χ2=50.88,P<0.001)。结论山东青岛地区HBV基因组常见为B、C基因型,其中以C型为主;核心启动子区突变发生率高,其中,T1753V与HCC发生无关,C1653T、A1762T和G1764A位点无论单独或是联合突变均与HCC发生密切相关。     

Clinical significance and evolution of core promoter and precore mutations in HBeAg-positive patients with HBV genotype B and C: a longitudinal study.

BACKGROUND/AIMS: The aims of this longitudinal study were to investigate whether the clinical outcome and evolution of core promoter and precore mutations were different during hepatitis B e antigen (HBeAg) seroconversion between hepatitis B virus (HBV) genotypes B and C in HBeAg-positive patients with chronic hepatitis B. PATIENTS AND METHODS: The core promoter and precore sequences were determined from serial sera of 156 HBeAg-positive patients with chronic HBV infection. RESULTS: In HBV genotype C, the T1762/A1764 mutant was detected earlier than the A1896 mutant, and the frequency was significantly higher than in HBV genotype Ba over the entire follow-up period. In HBV genotype Ba, A1896 was found earlier than the T1762/A1764 mutant, and the frequency was significantly higher than in genotype C only before HBeAg seroconversion, and the A1896 mutant played an important role in HBeAg seroconversion in HBV genotype Ba. In addition, the T1846 variant was an independent factor associated with HBeAg seroconversion. Furthermore, HBV genotype C was associated with the development of G or C1753 and T1766/A1768 mutations, and the reactivation of hepatitis after HBeAg seroconversion. Based on Cox's regression analysis, the significant risk factors of liver cirrhosis were older age at entry [hazard ratio (HR)=1.085, 95% confidence interval (CI)=1.036-1.136, P=0.001], alanine transaminase (ALT) >80 U/l (HR=3.48, 95% CI=1.37-8.86, P=0.009), and the T1762/A1764 mutant (HR=5.54, 95% CI=2.18-14.08, P<0.001). CONCLUSIONS: Our study showed that different HBV genotypes were associated with various mutations in the core promoter and precore regions during HBeAg seroconversion. T1762/A1764 mutation could be useful in predicting clinical outcomes in HBeAg-positive patients with HBV infection.     

Virological and clinical implication of core promoter C1752/V1753 and T1764/G1766 mutations in hepatitis B virus genotype D infection in Mongolia

Background and Aim: The aim of the present study was to reveal virological and clinical features of hepatitis B virus (HBV) genotype D infection. Methods: One hundred and twenty‐two Mongolian chronic liver disease (CLD) patients infected with HBV were subjected for serological HBV‐markers screening and HBV‐enzyme immunoassay (EIA) genotyping. Nucleotide sequences were analyzed for 48 HBV/D strains (23 isolated from hepatocellular carcinoma (HCC) and 25 from CLD patients). Results: Prevalence of hepatitis B e antigen (HBeAg) positivity was low (25.9%) in young patients (≤30 years old) indicating early HBeAg seroclearance in HBV/D carriers. The T1764/G1766 double mutation was the most common basal core promoter (BCP) mutation (29.2%) and was frequent in HBeAg‐negative patients (39.3%). Patients harboring T1764/G1766 mutants exhibited lower HBV‐DNA and HBV core antigen (HBcAg) levels than those with wild‐type BCP strains (P = 0.024, 0.049, respectively). C1752 and/or V (not T) 1753 mutation was significantly prevalent in HCC patients (HCC vs CLD; 52.2% vs 20%, P = 0.033). T1762/A1764 mutation was detected in 75.0% of HCC patients with high viral load (≥5 log copies/mL). Precore stop codon mutation A1896 was detected in (70.8%) of HBV/D‐infected patients. Conclusions: In Mongolians infected with HBV/D, C1752 and/or V1753 mutation was associated with HCC.     

The Effect of HBV Genotype C on the Development of HCC Differs Between Wild-Type Viruses and Those With BCP Double Mutations (T1762A1764)

Background:

Association of hepatitis B virus (HBV) genotype C with hepatocellular carcinoma (HCC) development remains controversial. HBV basal core promoter (BCP) double mutations (T¹⁷⁶²A¹⁷⁶⁴) are very strong confounding factors of genotypes B and C in HCC development.

Objectives:

To investigate the association of HBV genotype C with HCC development after controlling for BCP double mutations.

Materials and methods:

Four hundred and two serum samples from patients with HCC, liver cirrhosis (LC) and chronic hepatitis (CH) and also from asymptomatic HBsAg carriers were analyzed.

Results:

Genotypes B (31.1%), C (62.8%), and I (6.1%) were detected. With the severity of liver disease the prevalence of genotype B decreased, but genotype C increased. No trend was found for genotype I. The prevalence of BCP double mutations in genotypes C and I viruses was significantly higher than genotype B. BCP double mutations are risk factors for CH, LC and HCC. Genotype C was not identified as a particular risk factor for HCC prior to the stratification analysis but after that genotype C viruses with BCP double mutations were found to be a particular risk factor for HCC (P = 0.008, OR = 17.19 [95% CI: 2.10 - 140.41]), but those with the wild-type BCP were not. In the interaction analysis, genotype C and BCP double mutations were found to have a synergistic effect on HCC development (P < 0.0001, OR = 52.56 [95% CI: 11.49-240.52]).

Conclusions:

The effect of HBV genotype C on the development of HCC differs between wild-type viruses and those with BCP double mutations, suggesting that not all individuals infected with genotype C HBV are at increased risk of HCC.     

Mutations of Basal Core Promoter and Precore Regions in Hepatitis B Virus Genotypes B and C

Background:

Mutations in basal core promoter (BCP) and precore regions of hepatitis B virus (HBV) are associated with course and treatment outcomes of chronic HBV infection. While BCP and precore mutation analysis have been carried out in adult patients between different genotypes, this analysis has rarely been performed for chronically infected children.

Objectives:

The aim of this study was to assess the mutation profiles of BCP and precore regions in different HBV genotypes in chronically infected children.

Patients and Methods:

A cohort of 245 children and 92 adults with chronic HBV infection was included in this study. BCP and precore regions were analyzed by PCR amplification and sequenced.

Results:

Ten nucleotide positions, including nt1679, nt1721, nt1753, nt1757, nt1758, nt1762, nt1764, nt1775, nt1856 and nt1858 in BCP/precore regions of HBV genome, showed obviously higher frequencies of mutation in genotype C subjects than in genotype B subjects among children, while there were only three positions, including nt1679, nt1758 and nt1775 showing higher mutation frequencies in genotype C subjects than in genotype B subjects in adults. Several combined mutations were obviously highly distributed in children with chronic HBV genotype C infection, such as G1721A/A1775G/T1858C triple mutation; a novel combined mutation type, exclusively detected in children with chronic HBV genotype C infection. In addition, G1721A/A1775G/T1858C combined mutation was associated with higher viral load and lower age distribution.

Conclusions:

The mutation ratio difference between genotypes B and C in children was higher than that of adults and several combined mutations were exclusively detected in children with chronic HBV genotype C infection associated with higher viral load.     

The Effect of ICOS Polymorphism Interactions with HBV Mutations on HBV Subtype Infection Outcomes

Introduction and aim. Hepatitis B virus (HBV) infection remains a public health problem worldwide. In addition, HBV infection results are influenced by various virological, immunological, and genetic factors. Inducible T-cell costimulator (ICOS) polymorphisms involving chronic HBV infection have been confirmed in previous studies. This study was to explore the effects of ICOS single nucleotide polymorphisms in HBV subtypes and their interactions with viral mutations on HBV infection outcomes.Material and methods. A total of 1,636 Han Chinese individuals were recruited, including 47 asymptomatic HBV carriers (ASC), 353 chronic hepatitis B (CHB) patients, 327 HBV-related liver cirrhosis (LC) patients, 193 HBV-related hepatocellular carcinoma (HCC) patients, 464 patients with spontaneous recovery from HBV infection (SR), and 252 healthy controls (HC). DNA samples from these subjects were genotyped for four ICOS SNPs (rs11883722, rs10932029, rs1559931, and rs4675379). Direct sequencing was used to determine the HBV mutations in the enhancer II, basal core promoter, and pre-core regions.Results. We found that the genotype “TC” of ICOS rs10932029 SNP was associated with decreased HBV-related LC risk in the genotype C group. Additionally, the A1762T, G1764A and A1762T/G1764A mutations were associated with an increased risk of LC in the genotype C group. Further study indicated that interactions between ICOS rs10932029 genotype “TC” and A1762T or A1762T/G1764A mutations significantly decreased the LC risk in the genotype C group.Conclusion. The rs10932029 genotype “TC” might be an LC-protective factor for HBV genotype C infection. The interactions between the rs10932029 genotype “TC” and A1762T or A1762T/G1764A mutations could decrease the risk of LC.