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.     

Low frequency of mutations in the X gene, core promoter and precore region of hepatitis B virus infected Vietnamese

Numerous mutations in the hepatitis B virus (HBV) genome have been described, but in most cases their role in the pathogenesis of HBV infection is still unclear. Therefore, we analysed specific mutations in HBV-infected Vietnamese patients and assessed their potential relationship with their clinical outcome. A total of 153 HBV-infected Vietnamese patients with well-characterised clinical profiles were enrolled. None of the study participants had a history of alcohol or drug use and none received any antiviral or immunosuppressive therapy before or during the course of this study. The HBx- and core promoter regions were analysed by sequencing. The majority of isolates corresponded to genotype A. The presence of hepatitis B e antigen (HBeAg) was associated with significantly higher viral loads in the chronic HBV-infection group (P = 0.026). Double mutations in the core promoter (1762/1764) were more frequent in those with cancer than in noncancer patients (P < 0.01). Mutations at nucleotide (nt) 1766/1773 were found at low prevalence but with no obvious association to clinical presentation. Cytosine at nt 1858 was predominant but the stop codon mutation in the precore region was not detected. In the study, 4/48 hepatocellular carcinoma (HCC) patients revealed truncated HBx, whilst the serine to alanine mutation (codon 31) of HBx was more prevalent in cancer patients than in asymptomatic HBV carriers (P < 0.01). Thus, the low frequency of mutations indicates the relation of the absence of antiviral pressure in this population. The exclusively found prevalence of certain mutations detected in those with HBV-related carcinoma nevertheless indicates a degree of association with disease progression.     

Effects of hepatitis B virus precore and basal core promoter mutations on the expression of viral antigens: genotype B vs C

Hepatitis B virus (HBV) genotypes/mutants are known to affect natural outcomes. The virologic differences among HBV genotype, precore and basal core promoter (BCP) mutations were investigated. HBV strains were isolated from 18 hepatitis B e antigen (HBeAg)-positive patients (nine genotype B and nine genotype C). All had precore and BCP wild-type sequences. After cloning of full-length HBV genome, the effects of viral genotype, precore and BCP mutations singly or additively on the expression of viral DNA and antigens were investigated by mutagenesis and transfection assays in Huh7 cells. Significant findings included the following: (i) expression of intracellular core protein increased when precore or BCP mutation was introduced in genotype C strains; (ii) expression of intracellular surface protein was lower in genotype C precore wild-type strain compared with genotype B; (iii) precore mutation was associated with a lower extracellular expression level of HBV DNA; (iv) secretion of hepatitis B surface antigen in genotype C was lower than that in genotype B; and (v) secretion of HBeAg in genotype B was lower than that in genotype C. No additive effect was observed by combining precore and BCP mutations. Hence, HBV genotype and precore/BCP mutations correlate with intrahepatic expression of viral antigens in vitro.     

Performance of sequence analysis, INNO-LiPA line probe assays and AFFIGENE assays in the detection of hepatitis B virus polymerase and precore/core promoter mutations

In this study, we compare results obtained by sequences analysis and commercial kits in the detection of hepatitis B virus (HBV) polymerase and precore (PC) and core promoter mutations. A total of 23 serum samples from lamivudine treated patients were tested for polymerase mutations by direct sequencing, INNO-LiPA HBV DR and AFFIGENE HBV DE/3TC. Full concordance among the three assays was observed in 63% of the total analysed codons. Concordant results were obtained between sequencing and LiPA in 80%, between sequencing and AFFIGENE in 73% and between LiPA and AFFIGENE in 74% of all tested codons. All discrepancies were observed in mixed population samples in which AFFIGENE and LiPA detected additional viral variants not revealed by sequence. In two patients, with serial samples, LiPA detected earlier than sequence and AFFIGENE an emerging mutate strain. PC and core promoter viral variants were detected in 28 serum samples collected from 14 HBV inactive carriers and from 14 hepatitis B patients with chronic liver disease. Direct sequencing, INNO-LiPA HBV PreCore and AFFIGENE HBV MUTANT VL 19 showed fully coincident results in 88% of tested positions. These findings showed that all assays evaluated were sensitive and accurate tools to analyse HBV genomic variability. Sequence analysis is essential to study new emerging mutations as LiPA and AFFIGENE assays are more easily useful in clinical laboratories to detect the appearance of well-characterized HBV variants.     

Comparative study of genotype B and C hepatitis B virus-induced chronic hepatitis in relation to the basic core promoter and precore mutations

BACKGROUND: The clinicopathological profiles and outcome of chronic hepatitis B can differ by hepatitis B virus (HBV) genotypes. In Japan, genotype B and C are two major HBV genotypes. The basic core promoter and precore mutations are other known viral factors for disease activity, although the relationship between HBV genotypes and these mutations is not fully understood. METHODS: The HBV genotypes in 90 patients with chronic hepatitis B were determined using an ELISA. Obtained data were correlated with clinicopathological parameters, basic core promoter, precore and the nucleotide 1858 mutations of the HBV genome. RESULTS: Among 90 cases, 20 (22.2%) had genotype B and 70 (77.8%) had genotype C HBV. Genotype B patients were older than genotype C patients (44.0 +/- 13.9 vs 34.7 +/- 11.0 P = 0.0022). The HBeAg was more prevalent in genotype C than B patients (P = 0.0008) while anti-HBe was more common in genotype B than C patients (P = 0.0002). Serum aspartate aspartate aminotransferase/alanine aminotransferase levels (B: 220.7 +/- 612.8/257.0 +/- 498.0 IU/L vs C: 111.3 +/- 122.8/201.6 +/- 229.4 IU/L, P = 0.16/0.48) and HBV viral loads in blood (B: 6.1 +/- 3.1 log genome equivalent [LGE]/mL vs C: 6.7 +/- 2.3 LGE/mL, P = 0.42) were equivalent. The seroconversion from HBeAg to anti-HBe occurred significantly earlier in genotype B than C patients (62 +/- 53 months vs 136 +/- 54 months, P = 0.0028) during the mean observation period of 149 +/- 82 months even under various therapeutic modalities. The categories III and IV of the histological activity index in genotype C were higher (III: P < 0.005, IV: P < 0.05, n = 68) than that in B patients whereas category II was higher in genotype B than C patients (P < 0.05). The double mutation (1762T/1764A) in the basic core promoter was more frequently found in genotype C than in B HBV (P = 0.0068), whereas the precore mutation (1896A) was more common in genotype B than C HBV (P = 0.0233). The incidence of 1858C that was complementary to the precore mutation site in the stem-loop structure in, was equally rare in both genotype B and C HBV. CONCLUSIONS: Genotype B patients were older, had earlier HBeAg seroconversion and exhibited more severe lobular necroinflammation, less portal inflammation and fibrosis than genotype C patients. This genotypic difference is related to the basic core promoter and precore mutations irrespective of 1858C. (c) 2004 Blackwell Publishing Asia Pty Ltd.     

Frequent integration of precore/core mutants of hepatitis B virus in human hepatocellular carcinoma tissues

The development of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) frequently follows persistent HBV infection and may arise in individuals who are hepatitis B e antigen (HBeAg) negative, indicating the possible presence of precore/core mutants. It is unclear whether precore/core mutants are associated with tumour development or are selected for after chromosomal integration of the wild-type viral DNA. We studied the status and sequence variation of the precore/core region of HBV in 56 patients with HBV-associated HCC and in various corresponding non-tumour tissues by Southern blot analysis, polymerase chain reaction and direct sequencing. Southern blot showed that integrated HBV DNA existed in 43 of 56 HCC tissues. Sequence analysis revealed mutations in 65% of the HCC (26/40) and 45% (14/31) of the corresponding non-tumour tissues. The mutation at nucleotide (nt) 1896, known to prevent HBeAg synthesis, was detected in 40% (16/40) of the tumours and in 35.4% (11/31) of the non-tumour tissues. Other mutations were found at nt 1899 (eight of 40 in HCC; three of 31 in non-tumour tissues), nt 1898 (seven of 40 in HCC; two of 31 in non-tumour tissues), nt 1912 (seven of 40 in HCC; none of 31 in non-tumour tissues) and nt 1886 (three of 40 in HCC; none of 31 in non-tumour tissues). To determine whether this finding merely reflected the prevalence of such mutants in this geographical region, HBV DNA from the sera of patients (also in this region) with acute and chronic hepatitis were sequenced. The nt 1896 mutant was found in 5.6% (one of 18) of patients with acute hepatitis B and in 22.8% (nine of 35) of patients with chronic hepatitis B. However, the nt 1898 mutation was not found in any of these sera. The precore/core mutant was observed with increasing frequency from acute hepatitis to chronic hepatitis, non-tumour and HCC, and this difference in frequency was significant between HCC and acute hepatitis B groups (P < 0.01), suggesting that the precore/core mutant or hepatocytes harbouring this mutant may be under immune selection and that such mutations may facilitate integration and subsequent tumour development.     

Enrichment in selected genotypes,basal core and precore mutations of hepatitis B virus in patients with hepatocellular carcinoma in Cameroon

Worldwide, the development of hepatocellular carcinoma (HCC) is known to be influenced by several hepatitis B viral factors. However, the effect of hepatitis B virus (HBV) genotypes and a landscape of nucleotide changes affecting the precore (PC) and basal core promoter (BCP) during infection leading to HCC remain largely unknown in the Central Africa region. Thus, we performed a case‐control study on patients with HBV‐related HCC and matched controls without HCC but with chronic HBV infection. Genotypes and mutation spectrums were evaluated using a hemi‐nested amplification and sequencing analysis focused on the BCP and PC regions. We identified the co‐circulation of HBV quasi‐subgenotype A3 (QS‐A3) and genotype E in both groups. Interestingly, HBV‐QS‐A3 was significantly more prevalent in patients with HCC (80.0%) than in controls (31.9%, P = 4.5 E‐7, OR = 11.5, 95% CI: 3.8‐38.5). HBV mutation spectra and nucleotide changes were significantly more polymorphic in patients with HCC. Remarkably, HCC patients infected with HBV‐QS‐A3 were significantly more mutated compared to patients infected with genotype E (P < 0.0001). In addition, G:C>T:A transversions, generally associated with aflatoxin B1 exposure in tropical regions, were significantly more prevalent in HCC patients infected either with HBV‐QS‐A3 or HBV genotype E (P = 2.2 E‐05) when compared to controls. In conclusion, our results indicate that patients infected with HBV‐QS‐A3 are at increased risk to develop HCC. In addition, viral genomes isolated for patients with tumour are more heavily altered than those found in controls. Preferential targeting of these patients for antiviral treatment is of paramount importance to reduce future HCC incidence in Cameroon.     

Hepatitis B virus genotypes and precore mutations in Scottish blood donors

BACKGROUND AND OBJECTIVES: This study was carried out to determine the frequency of hepatitis B virus (HBV) core promoter variants (nucleotide positions 1762, 1764) and precore variants (nucleotide position 1896) in hepatitis B surface antigen (HBsAg)-positive Scottish blood donors. HBV genotypes present in this population were also identified. MATERIALS AND METHODS: A total of 85 HBsAg-positive blood donor samples were included in the study. Of these, 79 were polymerase chain reaction (PCR) positive and had sequence and mutation information. They were divided into two groups: group 1 (23 individuals) were hepatitis B e antigen (HBeAg)-positive and negative for antibody to HBe (anti-HBe); and group 2 (56 individuals) were HBeAg negative and positive for anti-HBe. A line probe assay was used to detect mutations, and a comparison was made by using direct sequence analysis. A different line probe assay was used to identify HBV genotype. RESULTS: The frequencies of mutations in group 1 were 22% each for mutations 1762, 1764 and 1896, increasing to 26%, 35% and 55% in group 2, respectively. By contrast, direct sequence analysis failed to identify 70% of wild-type/mutant mixes. The prevalence of viral genotypes was 41% for genotype A, 12% for genotype B, 5% for genotype C, 30% for genotype D and 12% for mixed-genotype infections. Precore mutations were seen in 10%, 88%, 25% and 74% of genotypes A, B, C and D, respectively. CONCLUSIONS: The results indicate that core promoter and/or precore mutants may be under-reported. The combination of HBV PCR and line probe assays is useful for supplementing HBV serological tests. Non-Caucasian genotypes are present in the UK blood-donating population and will therefore affect the demographics of HBV infection.     

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.     

Hepatitis B virus reactivation in patients receiving chemotherapy for malignancies: role of precore stop-codon and basic core promoter mutations

Hepatitis B virus (HBV) strains carrying the precore stop-codon mutation (A1896) have been considered among the predisposing factors for reactivation during chemotherapy for malignancies. The role of the T1762/A1764 basic core promoter (BCP) mutations has not been fully evaluated. We aimed to record any changes in HBV serological markers after reactivation, detect the presence of A1896 and BCP mutations and evaluate the type of cytotoxic drugs involved. We retrospectively screened eight patients presenting with HBV reactivation following chemotherapy for malignancies. The chemotherapy regimens used included corticosteroids (CSs), fludarabine and cyclophosphamide/adriamycine. The INNO-LiPA HBV PreCore kit was used for the detection of the A1896 and BCP mutations. Six patients who were hepatitis B surface antigen (HBsAg)-(+)/hepatitis B e antigen (HBeAg)-(-) before chemotherapy, had disease reactivation following a mean of four cycles of chemotherapy. Four survived and two died of hepatic failure. At the time of reactivation, all six patients carried the A1896 and five of them the BCP mutations. The remaining two patients were HBsAg-(-)/anti-HBs-(+)/anti-hepatitis B core (HBc)-(+)/HBeAg-(-) before chemotherapy. One of them reverted to HBeAg-(+) status but remained HBsAg-(-), while the other became HBsAg-(+)/HBeAg-(+), following three and eight cycles of fludarabine treatment, respectively. The former carried the A1896 and the latter the wild-type virus. Both died from causes associated with their haematological disease. All but one of our patients with HBV reactivation during chemotherapy carried the precore stop-codon and BCP mutations. Whether this occurs more frequently in such patients than those carrying the wild-type virus needs further investigation. Fludarabine should be added to the list of drugs inducing HBV reactivation. HBV reactivation following fludarabine treatment occurred in HBsAg-(-) patients who had been anti-HBs-(+).     

Hepatitis B virus genotypes, precore and core promoter variants among predominantly Asian patients with chronic HBV infection in a Canadian center.

BACKGROUND AND AIMS: The epidemiology of hepatitis B virus (HBV) infection in North America may be changing as a result of immigration from endemic countries. The purpose of this study was to determine the prevalence of HBV genotypes, precore (PC) and core promoter (CP) variants, and the proportion of patients meeting treatment criteria for HBV. METHODS: A cross-sectional study of consecutive HBV patients attending a Canadian tertiary liver center was conducted. HBV DNA was quantified by polymerase chain reaction assay. HBV genotypes and variants were determined using a line probe assay. RESULTS: Two hundred and seventy-two patients were enrolled; 200 were not receiving treatment at enrollment, of whom 116 were men and 84 women with a mean age 42+/-14 years. Among this group, 177 (88%) patients were Asian and 19 (10%) were Caucasian and 69 (35%) patients were hepatitis B e antigen (HBeAg) positive. Genotypes B and C were found in 42% and 50% untreated patients, respectively; while CP and PC were detected in 52% and 43% patients, respectively. Approximately 20% patients not receiving treatment (29% HBeAg positive, 14% HBeAg negative) met AASLD guidelines for antiviral therapy. If lower cutoff values for alanine aminotransferase and HBV DNA levels were used, 49% patients would qualify for treatment. CONCLUSIONS: The vast majority of patients at a Canadian tertiary referral center were Asian. Virological and clinical characteristics of these patients reflect their country of origin. Our findings highlight the need to monitor the changing patterns of HBV infection in countries with large immigrant populations.     

Association of hepatitis B virus subgenotypes and basal core promoter/precore region variants with the clinical features of patients with acute hepatitis

BACKGROUND: In endemic areas, including Japan, basal core promoter (BCP) and precore (PC) variants of hepatitis B virus (HBV) have been reported to be associated with the clinical outcome of acute hepatitis B patients. However, the associations of BCP/PC variants with clinical outcomes have not been observed in nonendemic areas. HBV subgenotypes, which show geographic variations in prevalence, may underlie this discrepancy in clinical outcomes. Little is known about the differences in the clinical and virological features of HBV subgenotypes and BCP/PC variants. The aim of this study was to investigate the distributions of subgenotypes and BCP/PC variants to identify clinical differences in acute hepatitis B patients. METHODS: One hundred thirty-nine patients with acute hepatitis were enrolled. Nested polymerase chain reaction was used to amplify the pre-S region of HBV for genotyping and the BCP/PC regions for variant screening. RESULTS: HBV subgenotypes A1 (n = 3), A2 (n = 28), B1 (n = 3), B2 (n = 9), C1 (n = 5), C2 (n = 84), C variant (n = 1), D2 (n = 3), and H (n = 3) were detected. BCP/PC variants were not associated with progression to chronic hepatitis. Patients infected with subgenotype C2 who progressed to fulminant hepatic failure frequently carried variants at nucleotides non-T1753 and non-T1754 and T1762, A1764, and A1896. CONCLUSIONS: BCP/PC variants would be associated with progression to fulminant hepatitis in subgenotype C2. Knowledge of HBV subgenotypes and BCP/PC variants is useful for developing strategies to treat acute hepatitis B patients.     

Clinical features of hepatitis B patients at immune‐tolerance phase with basal core promoter and/or precore mutations

Little data exist on basal core promoter/precore (BCP/PC) mutations in chronic hepatitis B (CHB) patients at the immune‐tolerance (IT) phase. We studied consecutive treatment‐naïve, CHBe‐antigen (HBeAg)‐positive patients who had undergone liver biopsy and genotyping. Those in the IT phase or immune‐clearance (IC) phase were enrolled for comparison of the frequency of BCP/PC mutations and their clinical presentations. Subgroup analyses for the IT group were also performed between patients with and without mutations, and IC patients between fibrosis stages ≤2 vs fibrosis >2. Among 301 patients enrolled, 88/301 (29.24%) and 213/301 (70.76%) were at the IT and IC phase, respectively. The frequency of BCP/PC mutations in IT phase was significantly lower than those in IC phase (15.91% vs 64.79%, P < .001). The BCP mutation only was significantly more frequent than the PC mutation in both groups and also in all IC subgroups. IT patients with BCP/PC mutations had significantly higher quantitative anti‐HBc levels compared with those of patients with wild‐type virus (P < .05). They also had significantly lower mean levels of alanine transaminase, aspartate transaminase, total bilirubin and qAnti‐HBc compared with those of IC patients (all P < .05). Additionally, they were significantly younger in mean age, had higher platelet count, higher levels of HBV DNA and surface antigen, as well as higher frequency of genotype B than those of IC patients with fibrosis >2 (all P < .05). BCP/PC mutations were found in IT patients with CHB. They had distinct clinical characteristics when compared with patients with wild‐type or at IC phase. Further studies are needed to understand their natural history and treatment outcomes.     

Association of core promoter/precore mutations and viral load in e antigen-negative chronic hepatitis B patients

Apart from core promoter A1762T/G1764A and precore G1896A mutations, other hepatitis B virus (HBV) mutants are detected in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). The aim of this study was to determine the effects of those mutants on clinical manifestation and viral loads of genotypes B and C HBV. Seventy-nine HBeAg-negative CHB patients with hepatitis flare were enrolled in this study and their HBV precore/core region were sequenced. Serial biochemical profiles and viral loads were assessed and compared. Fifty-three patients (67%) were infected by genotype B HBV and 26 (33%) were infected by genotype C HBV. The clinical manifestation and HBV viral loads were comparable between the two groups. However, genotype B was significantly associated with precore G1896A mutation (92.5%), and more mutations within nucleotide 1809-1817 were detected in patients infected by genotype B as compared with those infected by genotype C (18.9%vs 3.8%). Most of the cases had mutations at the -2, -3 or -5 position from the precore AUG initiation codon. Triple core promoter mutations T1753C/A1762T/G1764A [corrected] appeared to be linked to genotype C rather than genotype B HBV (19.2%vs 1.9%; P = 0.013). In multivariate analysis, the presence of either triple core promoter 1753/1762/1764 mutation or nucleotide 1809-1817 mutation was the only factor associated with lower HBV viral load (<70 Meq/mL) (odds ratio = 9.01; 95% CI 1.11-71.43; P = 0.04). In conclusion, minor HBV variants with mutations in the core promoter and precore region were detectable in genotypes B and C. Such HBV variants are genotype specific and related to viraemia levels.     

Hepatitis B genotypes and precore/basal core promoter mutants in HBeAg-negative chronic hepatitis B

Background. Mutations in the precore stop codon (G1896A) and the basal core promoter (A1762T and G1764A) are frequently found in hepatitis B envelope antigen (HBeAg)-negative chronic hepatitis B. However, the clinical significance of these mutations remains controversial. We therefore investigated the influence of hepatitis B virus (HBV) genotypes, as well as precore/basal core promoter mutants, on the clinical and virological features of patients with HBeAg-negative chronic hepatitis B. Methods. Serum samples from 37 patients with HBeAg-negative chronic hepatitis B were collected for serological and molecular assays. The precore and basal core promoter regions were amplified by polymerase chain reaction and the amplicons were directly sequenced and analyzed. HBV geno-type was determined by polymerase chain reaction-restriction fragment length polymorphism. Results. Most of the patients had detectable serum HBV DNA, and genotypes B and C were the predominant strains. The overall prevalence of the precore stop codon mutant and basal core promoter mutant was 67% and 60%, respectively. The baseline clinical and virological features of patients with genotype B and genotype C infection were comparable. However, in the patients with precore/basal core promoter dual mutations there was a significantly lower proportion of individuals with a high detectable serum HBV DNA level (>100 pg/ml) than in the patients with either the precore stop codon mutation alone or the basal core promoter mutation alone (P = 0.04 by the logistic regression test for the trend). Conclusions. Our data suggest a high prevalence of precore stop codon and basal core promoter mutation in Taiwanese patients with HBeAg-negative chronic hepatitis B, and the influence of the basal core promoter mutation on HBV replication is modulated by the emergence of the precore stop codon mutation. Received: May 14, 2001 / Accepted: September 14, 2001     

Initial load of hepatitis B virus (HBV), its changing profile,and precore/core promoter mutations correlate with the severity and outcome of acute HBV infection

Background The pathogenesis of the fulminant or severe form of acute hepatitis B virus (HBV) infection remains unclear, although both host- and virus-specific factors are considered to have a great impact on the c course. We aimed to define possible viral factors implicated in the severe form of acute HBV infection. Methods We investigated viral factors in 42 patients with acute HBV infection: 11 had fulminant hepatitis (FH); 9 had a severe form of acute hepatitis (SAH), defined as having a prothrombin activity of less than 40% without encephalopathy; and 22 had acute self-limited hepatitis (AH). Results Although there was no significant difference in serum HBV DNA levels on admission among the three groups, the level decreased more rapidly in patients with SAH or FH than in those with AH. In patients with SAH or FH, the HBV load on admission was higher in patients who died than in those who recovered (7.0 ± 1.6 vs 5.6 ± 1.0 log copies/ml; P = 0.0293). In univariate analysis, seronegativity for hepatitis B envelope antigen (HBeAg) and mutations in both the precore (G1896A and/or G1899A) and core promoter (T1753A/C and/or T1754C/G and/or A1762T/G1764A) were associated with FH (odds ratio [OR], 5.60; P = 0.0269 and OR, 52.0; P = 0.0006; respectively). In multivariate logistic regression analysis, only the presence of precore/core promoter mutations was associated with FH (OR, 42.8; P = 0.0020). Conclusions The rapid decrease in viral load in the early phase of acute HBV infection was associated with the severity of the disease. A high viral load on admission and the presence of both precore and core promoter mutations in patients with severe coagulopathy closely correlated with mortality.     

乙型肝炎病毒前C区和BCP区突变及基因型对HBeAg表达的影响

研究乙型肝炎病毒前C区和BCP区突变及基因型对HBeAg表达的影响。分别用基因芯片和基因测序的方法检验HBV DNA阳性的乙型肝炎病毒前C区和BCP区突变及基因型,应用时间分辨免疫荧光法检测HBeAg含量,按照有无HBV前C区1896、BCP区1762、1764双突变、基因型等指标进行分组分析。无前C区1896和BCP区1762/1764双突变组、单纯1762、1764双突变和1896突变组以及1896、1762、1764联合突变组之间相互比较,HBeAg含量相差显著,F=6.47,P〈0.01;B、C基因型间HBeAg含量相比,相差无显著性,t=0.1394,P〉0.05。乙型肝炎病毒前C区和BCP区突变能显著影响HBeAg量的表达,从而导致乙型肝炎病毒致病能力的变化。     

Community-based epidemiology of hepatitis B virus infection in West Bengal, India: prevalence of hepatitis B e antigen-negative infection and associated viral variants

BACKGROUND AND AIMS: There is a paucity of population-based epidemiological information regarding hepatitis B virus (HBV) infection in India. The present study was planned to outline the magnitude and pattern of HBV infection, hepatitis B e antigen (HBeAg)-negative infection and the associated viral mutants in India. METHODS: A community-based epidemiological study of HBV infection was carried out in West Bengal, India. Serological markers of infection and potential risk factors for HBV transmission were determined. Among the infected individuals, HBV-DNA, genotypes and mutations in the precore (PC) stop codon and basal core promoter (BCP) regions were determined by DNA sequencing and polymerase chain reaction (PCR) restriction fragment length polymorphism methods. RESULTS: Of the 7653 people included in the study, 227 (2.97%) tested positive for hepatitis B surface antigen (HBsAg), of whom 204 (90%) were HBeAg-negative and hepatitis B e antibody (anti-HBe)-positive, and 78% had normal alanine aminotransferase (ALT) levels. HBV-DNA could be detected by PCR in only 32% of people. G1896A PC stop codon mutants were present in 12% of people, BCP mutants in 18% and the remainder (70%) of the HBeAg-negative infections were associated with wild type sequences in these regions. CONCLUSIONS: This first general population-based epidemiological study of HBV infection from India suggests that HBV acquisition starts in early childhood and peaks in adulthood. Most infections in the community are e-negative and inactive. The point prevalence of PC stop codon and BCP mutants is low in this primarily inactive and asymptomatic HBV-infected population sample in eastern India.     

乙型肝炎病毒前C/BCP区变异的研究现状

HBV的前C区及基本核心启动子（BCP）变异可降低HBeAg的合成与分泌,也可增加病毒复制能力,导致HBeAg阴性慢性乙型肝炎（CHB）,对临床产生重要的影响。本文就HBV前C/BCP区变异的分子机理、生物学意义、实验室检测以及对临床和抗病毒治疗的影响等方面的研究进展作一综述。     

Clinical significance of precore and core promoter mutations in genotype D hepatitis B-related chronic liver disease

SUMMARY: The impact of mutations in the precore and basal core promoter (BCP) regions of the hepatitis B virus on the course of chronic liver disease is not well established. We sought to examine the relationship of these characteristics to the clinical expression of liver disease in patients infected with genotype D chronic hepatitis B (CHB). BCP and precore mutations in 110 patients with genotype D1 CHB were determined and correlated with clinical phenotype. Of 110 patients, 95 (86.5%) were HBeAg-negative. Compared with HBeAg-positive subjects, HBeAg-negative patients were over a decade older and had lower viral loads (3.70 +/- 0.98 vs 5.77 +/- 0.69 log copies/ml, P < 0.001). The double mutation A1762T-G1764A was more prevalent in patients with advanced liver disease (AdLD) and was associated with higher alanine aminotransferase and viral load. After adjusting for age, there was a more than fourfold increase in the risk of AdLD with this mutation (OR = 4.4; 95% CI: 1.13-16.92, P < 0.03). Conversely, the G1757A substitution was associated with protection, being 90% less frequent among patients with AdLD (P = 0.001). The results indicate that in genotype D CHB, the presence of the A1762T-G1764A mutation was associated with more aggressive liver disease while the G1757A substitution was associated with protection from advanced disease.