Precore/core region mutations of hepatitis B virus related to clinical severity

Despite the availability of an effective vaccine, hepatitis B virus (HBV) infection remains a major health problem, with more than 350 million chronically infected people worldwide and over 1 million annual deaths due to cirrhosis and liver cancer. HBV mutations are primarily generated due both to a lack of proofreading capacity by HBV polymerase and to host immune pressure, which is a very important factor for predicting disease progression and therapeutic outcomes. Several types of HBV precore/core (preC/C) mutations have been described to date. The host immune response against T cells drives mutation in the preC/C region. Specifically, preC/C mutations in the MHC class II restricted region are more common than in other regions and are significantly related to hepatocellular carcinoma. Certain mutations, including preC G1896A, are also significantly related to HBeAg-negative chronic infection. This review article mainly focuses on the HBV preC/C mutations that are related to disease severity and on the HBeAg serostatus of chronically infected patients.

Analysis of point mutation in site 1896 of HBV precore and its detection in the tissues and serum of HCC patients

INTRODUCTION Hepatitis B is one of the common infectious diseases,which severely impairs the health of the people in our country and has close relationship

Review on hepatitis B virus precore/core promoter mutations and their correlation with genotypes and liver disease severity

Of 350 million people worldwide are chronically infected with hepatitis B virus(HBV)and are at risk of developing cirrhosis and hepatocellular carcinoma(HCC)later in life.HBV is the most diverse DNA virus,and its genome is composed of four open reading frames:Presurface antigen/surface antigen gene(preS/S),precore/core gene(preC/C),polymerase gene(P),and theχgene(χ).HBV produces quasispecies naturally or in response to antiviral agents because of the absence of proofreading activity amid reverse transcription and a high replication rate.The virus has 10 genotypes(A to J)with different geographical distributions.There are various HBV mutations in the HBV genome,including preC/C mutations,preS/S mutations,P gene mutations,andχgene mutations.The core promoter region plays a vital part in the replication,morphogenesis and pathogenesis of the virus.The precore region also plays a crucial role in viral replication.Both core promoter and precore mutations rescue the virus from host immune surveillance and result in the formation of mutated strains that may have altered pathogenicity.preC/C mutations are associated with liver disease progression.Precore mutations stop hepatitis B e antigen(HBeAg)production and basal core promoter mutations downregulate HBeAg production.Mutations in the basal core promoter are also associated with increased HBV replication and an increased incidence of advanced liver diseases such as cirrhosis and HCC.The emergence of antiviral-resistant mutations is the main reason for treatment failure.This review focuses mainly on preC/C promoter mutations and their correlation with genotypes and liver disease severity.Thorough perception and knowledge of HBV genetic variety and mutants could be vital to discover techniques for the prognosis and control of HBV infection.

ANALYSIS OF POINT MUTATION IN SITE 1896 OF HBV PRECORE AND ITS DETECTION IN THE TISSUES AND SERUM OF HCC PATIENTS

Aim The 3’-base specific polymerase chain reaction (3’- BS- PCR) method was es-tablished to investigate the relationship between the mutation of precore region of Hepatitis B virus(HBV) and the liver damage to the patients caused by HBV and the possibility of HBV precore gene in-tegration in liver cells。 Mdthods According to the DNA sequence of precore region of HBV,themethod of 3’- BS- PCR is applied to analyze the point mutation site 1896 of HBV precore in 126 clini-cal serum specimens and 23 hepatoeellular carcinoma (HCC) patients’ tissues and serum whose trmorshave been surgically excised and pathologically diagnosed.Rdsults The point mutation in site 1896 ofHBV precore has been successfully rates of preore gene of HBV in the 23 patients’ tissues and serum are52.2 % (12/23) and 30.4 % (7/23) respectively.Conclusion The established method for HBV ore-core mutation analysis is simple and results can well repeated.It has provided a new approach to clinicalHBV research and its relationship to liver damage.The results obtained suggested that HBV precoremutation exists in a wide range among serum and tissue of the patients infected by HBV and HCC pa-tients,and the pre-c gene of HBV can not be detected in the serum of 21.8% of the HCC patients(tissue HBV precore gene positive).We may deduce that there may be the integration of HBV precoregenee in the genome of liver cells,which may play an important role in the carcinogenesis of HCC.

Association of core promoter mutations of hepatitis B virus and viral load is different in HBeAg(+) and HBeAg(-) patients

AIM:To identify the prevalence of hepatitis B e antigen (HBeAg) and to assess the association of hepatitis B virus (HBV) core promoter mutations and viral load in Indonesian patients.METHODS:Sixty-four patients with chronic hepatitis,65 with liver cirrhosis and 50 with hepatocellular carcinoma were included in this study.HBeAg and hepatitis B e antibody (HBeAb) tests were performed using enzyme-linked immunosorbent assay and the mutations were analyzed by sequencing.Viral load was measured by real-time polymerase chain reaction.RESULTS:Of 179 patients,108 (60.3%) were HBeAg(-) and 86 (79.6%) of these HBeAg(-) patients had been seroconverted.The A1896 mutation was not found in HBeAg(+) patients,however,this mutation was detected in 70.7% of HBeAg(-) patients.This mutation was frequently found when HBeAg was not expressed (87.7%),compared to that found in HBeAg seroconverted patients (65.1%).The A1899 mutation was also more prevalent in HBeAg(-) than in HBeAg(+) patients (P=0.004).The T1762/A1764 mutation was frequently found in both HBeAg(+) and HBeAg(-) patients,however,the prevalence of this mutation did not significantly differ among the two groups (P=0.054).In HBeAg(+) patients,the T1762/A1764 mutation was correlated with lower HBV DNA (P < 0.001).The A1899 mutation did not correlate with HBV DNA (P=0.609).In HBeAg(-) patients,the T1762/A1764 mutation alone was not correlated with HBV DNA (P=0.095),however,the presence of either the T1762/A1764 or A1896 mutations was associated with increased HBV DNA (P < 0.001).CONCLUSION:The percentage of HBeAg(-) patients is high in Indonesia,and most of the HBeAg(-) patients had been seroconverted.The A1896 mutation was most likely the major cause of HBeAg loss.The T1762/A1764 mutation alone was associated with lower viral loads in HBeAg(+) patients,but not in HBeAg(-) patients.

Precore/basal core promoter mutants quantification throughout phases of hepatitis B virus infection by Simpleprobe

AIM:To investigate precore/basal core promoter(PC/BCP) mutants throughout hepatitis B virus(HBV) infection and to determine their relationship to hepatitis B early antigen(HBeA g) titers.METHODS:We enrolled 191 patients in various stages of HBV infection at the Huashan Hospital and the Taizhou Municipal Hospital from 2010 to 2012.None of the patients received antiviral therapy.HBV DNA from serum,was quantified by real-time PCR.The HBV genotype was determined by direct sequencing of the S gene.We used the Simpleprobe ultrasensitivequantitative method to detect PC/BCP mutants in each patient.We compared the strain number,percentage,and the changes in PC/BCP mutants in different phases,and analyzed the relationship between PC/BCP mutants and HBe Ag by multiple linear regression and logistic regression.RESULTS:Patients with HBV infection(n = 191) were assigned to groups by phase:Immune tolerance(IT) = 55,Immune clearance(IC) = 67,Low-replicative(LR) = 49,and HBeA g-negative hepatitis(ENH) = 20.Of the patients(male,112; female,79) enrolled,122 were HBe Ag-positive and 69 were HBe Ag-negative.The median age was 33 years(range:18-78 years).PC and BCP mutation detection rates were 84.82%(162/191) and 96.86%(185/191),respectively.In five HBe Ag-negative cases,we detected double mutation G1896A/G1899 A.The logarithm value of PC mutant quantities(log10 PC) significantly differed in IT,IC,and LR phases,as well as in the ENH phase(F = 49.350,P < 0.001).The logarithm value of BCP mutant quantities(log10 BCP) also differed during the four phases(F = 25.530,P < 0.001).Log10 PC and log10 BCP values were high in the IT and IC phases,decreased in the LR phase,and increased in the ENH phase,although the absolute value at this point remained lower than that in the IT and IC phases.PC mutant quantity per total viral load(PC%) and BCP mutant quantity per total viral load(BCP%) differed between phases(F = 20.040,P < 0.001; F = 10.830,P < 0.001),with PC% and BCP% gradually increasing in successive phases.HBeA g titers negatively correlated with PC%(Spearman's rho =-0.354,P < 0.001) and BCP%(Spearman's rho =-0.395,P < 0.001).The negative correlation between PC% and HBeA g status was significant(B =-5.281,P = 0.001),but there was no such correlation between BCP% and HBeA g status(B =-0.523,P = 0.552).CONCLUSION:PC/BCP mutants become predominant in a dynamic and continuous process.Log10 PC,log10 BCP,PC% and BCP% might be combined to evaluate disease progression.PC% determines HBeA g status.

Relationship between the different replication status of HBV and mutations in the core promoter in mothers and their children infected via mother-to-infant transmission

OBJECTIVE: To study the relationship between the different replication status of hepatitis B virus (HBV) and mutations in the core promoter (CP) in mother and her child infected by mother-to-infant transmission. METHODS: The core promoter was amplified by PCR and cloned into pGEM-T vector with the T-A choning technique. The recombinant plasmid pGEM-CP was confirmed by digestion with restriction enzyme Apa I and Sac I. Two clones were selected to be sequenced in each patient. RESULTS: Every pair of mother and child had same serotype and genotype and the homology of nucleotides encoding 'a' determinant was 98%-100%. The number of mutations in the core promoter of patients with a high replication status was less than that in those with a low replication status. Mutations were mainly distributed in basia core promoter (BCP) and the inbibitor region of Kunitz-type serine protease. This difference was not associated with mother or child. CONCLUSION: The different replication status of HBV is caused by mutations in the core promoter in mother and child infected hy mother-to-infant transmission and appears to be not associated with the status of development of the infection.

Precore/basal core promoter mutants and hepatitis B viral DNA levels as predictors for liver deaths and hepatocellular carcinoma

AIM： To conduct a retrospective study in 400 chronic hepatitis B patients in order to identify hepatitis B viral factors associated with complications of liver disease or development of hepatocellular carcinoma. METHODS： The mean follow-up time was 83.6 ± 39.6 mo. Alpha-fetoprotein test and abdominal ultrasound were used for cancer surveillance. Hepatitis B basal core promoter mutants, precore mutants, genotypes, hepatitis B viral DNA （HBV DNA） level and hepatitis B e antigen （HBeAg） were measured. Univariate analysis and logistic regression were used to assess odds ratios for viral factors related to liver deaths and hepatocellular carcinoma development. RESULTS： During follow-up, 38 patients had liver deaths not related to hepatocellular carcinoma. On multivariate analysis, older age [odds ratio： 95.74 （12.13-891.31）, P 〈 0.0001], male sex [odds ratio： 7.61 （2.20-47.95）; P = 0.006], and higher Iogzo HBV DNA [odds ratio： 4.69 （1.16-20.43）; P 〈 0.0001] were independently predictive for these liver related deaths. Also, 31 patients developed hepatocellular carcinoma. Multivariate analysis showed that older age [odds ratio： 26.51 （2.36-381.47）; P = 0.007], presence of precore mutants [odds ratio： 4.23 （1.53-19.58）, P = 0.02] and presence of basal core promoter mutants [odds ratio： 2.93 （1.24-7.57）; P = 0.02] were independent predictors for progression to hepatocellular carcinoma. CONCLUSION： Our results show that high levels of baseline serum HBV DNA are associated with non- hepatocellular carcinoma-related deaths of liver failure, while genetic mutations in the basal core promoter and precore regions are predictive for development of hepatocellular carcinoma.

Mutations in pre-core and basic core promoter regions of hepatitis B virus in chronic hepatitis B patients

AIM: To investigate the frequency of mutations in pre-core (pre-C) and basic core promoter (BCP) regions of hepatitis B virus (HBV) from Shanxi Province, and the association between mutations and disease related indexes.METHODS: One hundred chronic hepatitis B patients treated at Shanxi Province Hospital of Traditional Chinese Medicine were included in this study. PCR-reverse dot blot hybridization and mismatch amplification mutation assay (MAMA)-PCR were used to detect the mutations in the HBV pre-C and BCP regions. HBV DNA content and liver function were compared between patients with mutant HBV pre-C and BCP loci and those with wild-type loci. The consistency between PCR-reverse dot blot hybridization and MAMA-PCR for detecting mutations in the HBV pre-C and BCP regions was assessed.RESULTS: Of the 100 serum samples detected, 9.38% had single mutations in the pre-C region, 29.17% had single mutations in the BCP region, 41.67% had mutations in both BCP and pre-C regions, and 19.79% had wild-type loci. The rates of BCP and pre-C mutations were 65.7% and 34.3%, respectively, in hepatitis B e antigen (HBeAg) positive patients, and 84.6% and 96.2%, respectively, in HBeAg negative patients. The rate of pre-C mutations was significantly higher in HBeAg negative patients than in HBeAg positive patients (χ2 = 26.62, P = 0.00), but there was no significant difference in the distribution of mutations in the BCP region between HBeAg positive and negative patients (χ2 = 2.43, P = 0.12). The presence of mutations in the pre-C (Wilcoxon W = 1802.5, P = 0.00) and BCP regions (Wilcoxon W = 2906.5, P = 0.00) was more common in patients with low HBV DNA content. Both AST and GGT were significantly higher in patients with mutant pre-C and BCP loci than in those with wild-type loci (P < 0.05). PCR-reverse dot blot hybridization and MAMA-PCR for detection of mutations in the BCP and pre-C regions had good consistency, and the Kappa values obtained were 0.91 and 0.58, respectively.CONCLUSION: HBeAg negative patients tend to have HBV pre-C mutations. However, these mutations do not cause increased DNA copies, but associate with damage of liver function.

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.

Mutations in hepatitis B virus core regions correlate with hepatocellular injury in Chinese patients with chronic hepatitis B

AIM: To elucidate the relationship between the frequency of core mutations and the clinical activity of hepatitis B virus (HBV)-related liver disease and to characterize the amino acid changes in the core region of HBV.METHODS: We studied 17 Chinese patients with chronic hepatitis B according to their clinical courses and patterns of the entire core region of HBV.RESULTS: Amino acid changes often appeared in the HBV core region of the HBV gene in patients with high values of alanine aminotransferase (ALT) or with the seroconversion from HbeAg to anti-HBe. The HBV core region with amino acid changes had high frequency sites that corresponded to HLA Ⅰ/Ⅱ restricted recognition epitopes reported by some investigators.CONCLUSION: The core amino acid changes of this study occur due to influence of host immune system. The presence of mutations in the HBV core region seems to be important for predicting the clinical activity of hepatitis B in Chinese patients.

Precore mutation enhances viral replication to facilitate persistent infection especially in HBeAg-negative patients

Naturally occurred precore(PC,G1896A)and/or basal core promoter(BCP,A1762T/G1764A)mutations are prevalent in chronic HBV-infected patients,especially those under HBeAg-negative status.However,the replicative capacity of HBV with PC/BCP mutations remains ambiguous.Herein,meta-analysis showed that,only under HBeAg-negative status,the serum HBV DNA load in patients with PC mutation was 7.41-fold higher than those without the mutation.Both PC mutation alone and BCPþPC mutations promoted HBV replication in cell and hydrodynamic injection mouse models.In human hepatocyte chimeric mouse model,BCPþPC mutations led to elevated replicative capacity and intrahepatic core protein accumulation.Mechanistically,preC RNA harboring PC mutation could serve as mRNA to express core and P proteins,and such pgRNA-like function favored the maintenance of cccDNA pool under HBeAg-negative status.Additionally,BCPþPC mutations induced more extensive and severe human hepatocyte damage as well as activated endoplasmic reticulum stress and TNF signaling pathway in livers of chimeric mice.This study indicates that HBeAg-negative patients should be monitored on HBV mutations regularly and are expected to receive early antiviral treatment to prevent disease progression.

Systematic evaluation of HBV BCP/PC mutations on the risk of hepatocarcinogenesis

Objective:To evaluate of the effects of mutations in BCP-A1762T/G1764A and PC-G1896A genes on hepatocarcinogenesis.Methods:Computer searches for PubMed,SCI,CNKI,VIP and WanFang Data databases were conducted to collect literature on the role of mutations in the disease process associated with HBV infection from database creation to July 1,2021.Two researchers independently screened the articles,extracted information and evaluated the quality of the studies.Review Manager software version 5.4 was used for Meta-analysis.Results:A total of 40 articles were included,with a total of 12423 cases and 3710 cases of hepatocellular carcinoma.Meta-analysis showed that mutations in BCP-A1762T/G1764A gene were associated with the disease process of HBV infection and promoted hepatocellular carcinogenesis.mutations in BCP/PC gene were significant in the process of HBV infection in BCP-A1762T/G1764A in HCC vs non-HCC[OR=4.05,95%CI=2.64~6.22],CHBC[OR=3.90,95%CI=2.13~7.17],CHB[OR=2.77,95%CI=1.78~4.32],LC[OR=1.64,95%CI=0.95~2.84],which were statistically significant;in PC-G1896A mutation HCC vs non-HCC[OR=1.49,95%CI=1.02~2.17],CHBC[OR=1.56,95%CI=0.89~2.72],CHB[OR=1.80,95%CI=1.17~2.77]were statistically significant,while the difference was not statistically significant when comparing HCC with LC(P=0.4).The BCP-A1762T/G1764A mutation in the B genotypes/genotyped versus the C genotype[OR=0.36,95%CI=0.20~0.64],with a statistically significant difference,and no statistically significant difference in the PC-G1896A mutation.BCP-A1762T/G1764A mutation in the C gene in HCC versus non-HCC[OR=3.71,95%CI=1.82~7.61]and PC-G1896A mutation in HCC vs non-HCC[OR=2.81,95%CI=1.34~5.91],the differences were statistically significant.Conclusions:Current evidence suggests that mutations in the BCP-A1762T/G1764A and PC-G1896A genes have a significant effect on the increased risk of hepatocellular carcinoma and are genotype dependent.However,due to the limitation of the number and quality of included studies,these findings need to be validated by more high-quality studies.

Quasispecies groups in the core promoter region of hepatitis B virus

Objectives: To investigate the mutation of the basic core promoter (BCP) of hepatitis B virus (HBV) and clarify the significance of HBV quasispecies groups in patients with chronic HBV infection. Methods: A set of specific primers was synthesized according to the HBV DNA sequence of a Chinese strain. The BCP was amplified by PCR method from the serum of 40 patients with chronic HBV infection, and the PCR products of 2 patients were subcloned into pGEM Teasy vectors. Polyacrylamide gel elec- trophoresis (PAGE) was employed to display the de- letion mutations, and clones with differential length were selected to be sequenced. Sequence comparison was made to find the difference. Results: Two or three bands were displayed by PAGE in 60% patients. The results of sequence anal- ysis showed that there are some kinds of mutations in the BCP region. The substitution always occurs in TATA-like boxes, especially from T to C on 140 site. The deletion mutations were detected in TA1, TA2 and TA3. The 8bp, 20bp deletion mutations fre- quently happened. Conclusions: There is a hot deletion region in the BCP. The deletion and the substitution in the TATA- like box may influence the expression of preC/C pro- tein. The sequencing results indicate that there are HBV quasispecies groups in patients with chronic HBV infection.

核心结合因子相关急性髓系白血病的实验室诊断和预后影响因素分析

目的分析核心结合因子(CBF)相关急性髓系白血病(AML)患者的年龄、性别等一般临床特征和相关实验室检测结果与疗效、复发和生存时间等预后因素的相关性,以期为临床优化治疗方案提供参考。方法选取2014年1月—2021年12月上海市第一人民医院使用标准诱导和巩固化疗方案的CBF-AML患者116例,其中77例接受了异基因造血干细胞移植(allo-HSCT)。根据融合基因分为伴RUNX1::RUNX1T1(第1组)AML和伴CBFB::MYH11(第2组)AML,采用Kaplan-Meier生存曲线分析2个组预后的差异。采用Cox回归分析评价预后影响因素。结果第1组和第2组基线特征[发病年龄、外周血白细胞计数和血红蛋白含量、骨髓原始细胞比例、额外染色体异常发生率、性染色体丢失、KRAS突变、NRAS突变]差异有统计学意义(P<0.05)。复发患者总生存期(OS)低于未复发患者(P=0.008)。男性、TET2突变和del(9q)的患者OS较短(P<0.05)。血小板计数<20×10~9·L-1的患者OS和无复发生存时间(RFS)均较短(P<0.05)。移植后复发患者的OS显著短于移植后未复发患者(P=0.001)。多因素Cox回归分析结果显示,复发、TET2突变和染色体del(9q)是CBF-AML患者OS缩短的显著危险因素(P<0.05),达到缓解天数是AML伴RUNX1::RUNX1T1患者OS的独立影响因素(P=0.038),骨髓原始细胞比例是AML伴CBFB::MYH11患者OS的独立影响因素(P=0.044)。结论CBF-AML患者2种融合基因亚组间在基线特征方面具有明显的异质性,TET2突变和del(9q)可显著影响患者生存天数,建议复发患者及时进行挽救性移植。应关注AML伴RUNX1::RUNX1T1患者达到缓解的天数,关注CBFB::MYH11患者原始细胞比例。

KIT突变与核心结合因子急性髓系白血病患儿临床特征和预后的关系

目的 分析核心结合因子急性髓系白血病(CBF-AML)患儿KIT位点表达及其与患儿临床特征和预后的关系。方法 选取2014年2月-2022年8月郑州大学附属儿童医院初诊确诊CBF-AML患儿72例,收集其相关临床资料。根据细胞遗传学分析结果分为RUNX1-RUNX1T1组(60例)和CBFβ-MYH11组(12例);根据KIT基因突变情况分为KIT阳性组(31例)和KIT阴性组(41例)。比较KIT阳性组和KIT阴性组相关临床特征和预后差异。结果 KIT阳性组和KIT阴性组性别、年龄、初诊白细胞计数、初诊外周血和骨髓原始细胞比例、髓外白血病、第一疗程完全缓解(CR)率,以及5年无事件生存率和5年总生存率差异均无统计学意义(P>0.05)。结论 KIT突变对CBF-AML患儿临床表现和预后无明显影响。

STRUCTURE IN THE PRECORE REGION OF HEPATITIS B CORE GENE AFFECTING ITS EXPRESSION IN E.coil

Restriction fragments of HBV-DNA, cleaved by endonuclease HhaI,containing HBcAg gene were trimmed by BAL-31 exonuclease to remove different lengths of the precore sequence.They were inserted into plasmid pUR222 at EcoRI site through synthetic linker ligation. Transformants in E.coli BMH7118 showing different levels of HBcAg gene expression were screened and analyzed for their nucleotide sequences in the junction region both by Maxam and Gilbert's chemical degradation method and by M13 chain termination method. Results of sequence analysis of different transformants revealed a partial palindromic (loop and stem) structure, at -7 to -35 nucleotide with regard to ATG of the HBcAg gene as position +1, which has dramatic effect on the level of expression of the inserted gene using the same promoter,SD sequence and identical N-terminus.The amount of HBcAg synthesized differed from 9% in the high expressing plasmid to less than 0.01% of the total cell proteins in the low expressing transformants.The findings were compared to results obtained by other workers in studies of HBcAg expression in procaryotes and their significance in the expression of eucaryotic genes in procaryotic cells were discussed.

乙型肝炎病毒C基因启动子和前C基因变异与HBeAg含量和肝炎病情的临床研究

研究乙型肝炎病毒(HBV)C基因启动子(CP)和前C基因变异对HBeAg表达和病情的影响。通过DNA扩增、基因序列分析检测48例慢性乙肝和12例慢性重型乙肝患者血清的HBV CP和前C基因序列,及通过微粒子发光法定量检测血清中HBeAg的含量。(1)前C终止变异(nt1896G→A)在重型乙型肝炎病例中的发生率显著升高(66.7％);CP双变异(nt1762A→T和1764G→A)则在慢性乙型肝炎中度和重度的病例中的发生率显著升高(分别为52.6％和54.5％)。(2)双变异组和终止变异组的HBeAg含量均显著下降,P<0.01。但终止变异组HBeAg含量的下降较双变异组更为明显,P<0.05,且eAb阳性率也显著升高,P<O.05。终止变异联合双变异组的HBeAg含量及eAb阳性率同终止变异组相近。前C终止变异对HBeAg表达的影响较CP双变异更大,对肝炎病情的影响也更明显。

抗-HBe阳性乙型肝炎病毒C基因启动子和前C基因变异

研究抗 -HBe阳性乙型肝炎病毒C基因启动子 (CP)和前C基因变异。用基因序列分析检测基因变异。(1)抗 -HBe阳性患者的前C终止变异 (nt1896G→A)的发生率显著高于抗 -HBe阴性组 (P <0 0 0 1) ;而CP双变异(nt176 2A→T和 176 4G→A)则在两组中无明显差异。 (2 )同抗 -HBe阳性慢性乙肝组比较 ,抗 -HBe阳性重型乙肝患者的前C终止变异和CP双变异发生率无明显差异 ,而CPnt175 2A→G变异发生率则显著增高 (P <0 0 5 )。前C终止变异与抗 -HBe阳性乙型肝炎密切相关 ;而CPnt175 2变异则可能与抗

慢性重型乙型肝炎患者的乙型肝炎病毒C基因启动子和前C基因变异及与e抗原系统的关系

目的 研究慢性重型乙型肝炎患者血清的HBVC基因启动子 (CP)和前C基因变异情况。方法 通过DNA扩增、基因序列分析检测 75例慢性乙型肝炎 (CHB)和 14例慢性重型乙肝 (CSH)患者血清的HBVCP和前C基因序列 ,通过微粒子发光法定量检测血清中HBeAg的含量及通过荧光定量PCR技术定量检测血清中的HBVDNA。结果 (1)前C终止变异 (nt1896G→A)在CSH组中的发生率显著高于CHB组 (71 4 %和 2 6 7% ) ;CP双变异 (nt 176 2A→T和 176 4G→A)则在CSH组和CHB组的发生率无显著差异 (4 2 9%和 4 8 0 % )。 (2 )CSH组的HBeAg含量显著低于CHB组 ;CSH组的HBeAb阳性率则显著高于CHB组 (71 4 %和 32 0 % )。 (3)CSH组和CHB组的HBVDNA定量则无明显差异。结论 前C终止变异 ,对e系统有明显影响 ,与CSH的发病有关。