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1.
The evolution of precore stop codon mutation (A1896) and dinucleotide mutation (T1762/A1764) in the basic core promoter (BCP) of hepatitis B virus (HBV) genome during transient seroconversion and seroreversion of hepatitis B e antigen (HBeAg) remains unclarified. Five HBeAg-positive HBV carriers who experienced transient seroconversion followed by seroreversion of HBeAg (Group I, 3.3%) and 3 HBeAg-negative HBV carriers with documented reversion of HBeAg (Group II, 2.5%) in a prospective cohort of 272 patients with chronic hepatitis B were thus identified. The sequential changes at the precore nucleotide 1896 and BCP dinucleotide 1762/1764 were determined by polymerase chain reaction and direct sequencing. At enrollement, precore A1896 and BCP T1762/A1764 were noted in 4 (50%) and 1 (13%) of the eight patients. During a median follow-up period of 58 months (range: 31-76 months), 12 episodes of transient HBeAg seroconversion followed by seroreversion were encountered in Group I patients and 3 episodes of HBeAg seroreversion in Group II patients. Accompanying acute exacerbations were found in two-thirds of patients with either HBeAg seroconversion or seroreversion. Overall, precore nucleotide A1896 remained identical in 73% and 83% of the seroconversion and seroreversion events, respectively. BCP dinucleotide T1762/A1764 remained unchanged in 94% and 92% of the seroconversion and seroreversion events, respectively. At the end of follow-up, only one had both precore and BCP mutations. In conclusion, these data suggested that HBeAg seroreversion might be due to the lack of sustained precore and BCP mutations after HBeAg seroconversion. Although uncommon, HBeAg seroreversion can be associated with hepatitis exacerbation.  相似文献   

2.
To investigate further the possible role of mutant hepatitis B viruses in the pathogenesis of fulminant hepatitis B, the genomic sequence of hepatitis B virus isolates from 9 South African blacks with this disease, including 5 entire genomes, was analysed. Seven of the isolates were genotype A. The mutation most often reported in patients with fulminant hepatitis B, the G1896A precore stop-codon substitution, was, as expected, not present in the genotype A isolates with the exception of one in which it was accompanied by a compensatory C1858T substitution. G1896A was, however, present in the one genotype D isolate. No other precore-defective mutants were detected. The other mutation commonly found in patients with fulminant hepatitis B, the paired A1762T, G1764A substitution in the basic core promoter, was present in only one patient and G1764A in one other. The pre-surface initiation-codon mutation documented in a number of patients with fulminant hepatitis B was not found in our isolates. An 18-amino acid deletion present in the pre-surface region of one isolate has not previously been described in fulminant hepatitis B. Variations within the surface region were mainly genotype specific and not previously described. A relatively large number of mutations were present in the middle region of the core gene in those isolates without G1896A or A1762T, G1764A mutations, although the pattern was not consistent with those in published studies. Thus, as in other published series in which the entire genome of hepatitis B virus responsible for fulminant hepatitis was sequenced, we detected many mutations in different genes, but none was common to all the reported isolates.  相似文献   

3.
It is well known that fulminant hepatitis B can occur in infants born to hepatitis B e antigen (HBeAg)-negative hepatitis B virus (HBV) carrier mothers, whereas fulminant hepatitis and severe hepatitis are uncommon in infants born to HBeAg-positive mothers. We have encountered an infant with severe acute hepatitis B born to a HBeAg-positive mother. The aim of this study was to determine whether HBV variants contribute to the pathogenesis of fulminant hepatitis and severe hepatitis in an infant born to an HBeAg-positive mother. The nucleotide sequence of HBV genomes from the infant and his HBeAg-positive carrier mother was analyzed. All HBV isolated from the infant and his mother were subtype adr. The sequences of the cloned HBV genomes, each including a part of the X and precore/core regions, isolated from the infant were almost identical (homology of 99.1-99.9%) to those from his mother. There was no mutation in any of the 17 clones examined at nucleotides 1762 and 1764 in the core promoter, which is reported to be associated with fulminant hepatitis. A point mutation at nucleotide 1758 in the second AT-rich region of the basic core promoter was present in all clones. None of the clones had a point mutation at nucleotide 1896 of the precore region. In this study, no specific HBV variants contributing to the development of neonatal severe hepatitis were found. There is a possibility that host factors rather than viral factors play an important role in some cases of severe neonatal hepatitis B.  相似文献   

4.
目的探讨重型肝炎(重肝)乙型肝炎病毒(HBV)基因型与基本核心启动子(BCP)及前C区突变的关系。方法采用聚合酶链反应(PCR)-限制性片段长度多态性分析技术(PCR-RFLP)对52例重肝和52例慢性乙肝(CHB)进行HBV基因分型。采用PCR产物直接测序技术,随机对15例B型和15例C型重肝患者的BCP区和前C区进行序列测定,分析HBV基因型与BCPT1762/A1764及前C区A1896突变的关系。结果泉州地区重肝的基因型以B型为主(48.08%),其次为C型(30.77%)和B/C混合型(17.31%),无A、E、F型存在。与CHB组比较,重肝组B型检出率明显降低,而C型和BIC混合型检出率明显升高。C型重肝患者BCPT1762/A1764双突变率显著高于B型(P〈0.05),而前C区A1896突变率在B、C型感染者中差异无统计学意义(P〉0.05)。结论C型感染易引起较重肝损伤,而B/C型混合感染可能是导致重肝发生的重要原因之一。C型重肝患者BCP T1762/A1764双突变率显著高于B型。  相似文献   

5.
6.
To assess the prevalence and clinical significance of hepatitis B virus (HBV) genotypes and precore and core promoter mutations in Taiwan, a cohort of 200 Taiwanese chronic hepatitis B patients was analyzed. The HBV genotypes and sequences of the precore and the core promoter regions were determined in 66 asymptomatic carriers and 134 patients who had liver biopsy-verified chronic hepatitis and liver cirrhosis. The HBV e-antigen (HBeAg)-negative patients had a higher frequency of mutations at core promoter nucleotides 1753 and 1773 and precore nucleotides 1846, 1896, and 1899 than HBeAg-positive patients. Among the 200 patients, the frequencies of genotype C, T1762 and A1764, C1753, T1766 and A1768, and A1896 mutations increased and the frequencies of T or G1752, T1773, G1799, and C1858 mutations decreased with advancing liver diseases. These factors were different between those with HBeAg-positive status and those with HBeAg-negative status. Based on multiple logistic regression analysis, the risk factors of liver cirrhosis for 200 patients were the presence of T1762 and A1764 mutations (odds ratio [OR] = 11.11; 95% confidence interval [CI] = 3.91 to 31.25; P < 0.001), age > or =35 years (OR = 3.42; 95% CI = 1.33 to 8.77; P = 0.011), and genotype C (OR = 2.87; 95% CI = 1.21 to 6.81; P = 0.017). Further categorical analysis found that 62.1% of patients with genotype C, T1762 and A1764 mutations and age > or =35 years had liver cirrhosis. None of the 55 patients infected with the genotype B, A1762 and G1764 wild type and age <35 years showed liver cirrhosis. In conclusion, our data suggest that pathogenic differences between HBeAg-positive and -negative patients may exist. In Taiwan, HBV genotype C and the T1762 and A1764 mutations may play a role in HBV-related liver cirrhosis, and these could serve as molecular markers for prediction of the clinical outcomes of chronic HBV patients.  相似文献   

7.
8.
In spite of hepatitis B virus (HBV) vaccination, HBV infection remains an important public health problem worldwide. Although the HBV genotype distribution has been determined in some parts of South Central Asia, no survey has been conducted to determine the HBV genotype in Afghanistan. Twelve Afghan patients infected with HBV living in Afghanistan were enrolled in this study. Partial HBsAg and basic core promoter, precore, and core (BCP/preC/C) regions were amplified and subjected for direct sequencing. In parallel, precore G1896A mutation was also determined by an amplification-created restriction site method. Results revealed HBV genotype D (95% bootstrap value), sub-genotype D1 (98% bootstrap value), and subtype ayw2 in all Afghan isolates. Afghan isolates clustered in a separate branch in the D1 sub-genotype called D1', while supported by 82% bootstrap value. The percentage of intra-genotypic distance among Afghan isolates was 1.05% and inter-genotypic distance with the other genotype D was 2.87% and with other genotypes was 7.50%-11.1%. The wild-type, mixed infection, and precore mutant were found in six, two, and four HBV isolates, respectively. The A1762T/G1764A BCP dual mutation was found in one isolate. Three isolates presented single mutation in the BCP dual mutation region, whereas two showed a novel G1764T mutation. In conclusion, this preliminary study revealed HBV genotype D, sub-genotype D1, and subtype ayw2 of HBV among hepatitis B infected patients from Afghanistan. Further investigation should be carried out.  相似文献   

9.
10.
Recently, hepatitis B virus (HBV) genotypes and mutations have been reported to be related to hepatocellular carcinoma (HCC). This cross‐sectional case–control study examined the relationship between HCC and mutations in the enhancer II/core promoter and precore regions of HBV by comparing 135 Korean HCC patients infected with HBV genotype C2 (HBV/C2; HCC group) with 135 age‐, sex‐, and hepatitis B e antigen (HBeAg) status‐matched patients without HCC (non‐ HCC group). Age and sex were also matched between HBeAg‐positive and ‐negative patients. The prevalence of T1653, A1689, V1753, T1762/A1764, T1846, A1850, C1858, and A1896 mutations was evaluated in this population. The prevalence of the T1653 mutation in the box α region, the A1689 mutation in between the box α and β regions, and the T1762/A1764 mutations in the basal core promoter region was significantly higher in the HCC group compared to the non‐HCC group (8.9% vs. 2.2%, P = 0.017; 19.3% vs. 4.4%, P < 0.001; and 60.7% vs. 22.2%; P < 0.001). Among HBeAg‐negative patients, the frequency of the T1653 mutation was higher in the HCC group. Regardless of HBeAg status, the prevalence of the A1689, and T1762/A1764 mutations was higher in the HCC group than in the non‐HCC group. However, no association was observed between mutations in the precore region and HCC. Upon multivariate analysis, the presence of the T1653, A1689, and T1762/A1764 mutations was an independent predictive factor for HCC. The addition of the T1653 or A1689 mutation to T1762/A1764 increased the risk of HCC. In conclusion, the T1653, A1689, and/or T1762/A1764 mutations were associated with the development of HCC in Korean patients infected with HBV/C2. J. Med. Virol. 81:1002–1008, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

11.
Factors influencing and predictive of seroconversion from hepatitis B e antigen (HBeAg) to antibody (anti-HBe) were sought in a case-control study of 61 patients with chronic hepatitis B who had been observed from 5 years before to 1 year after seroconversion, and 32 patients who did not seroconvert during the entire 6-year period. Almost all of the patients (96%) were infected with HBV genotype C. HBV DNA levels began to decrease 3 years before seroconversion in the seroconverters, while they remained high in the non-converters. The frequency of precore mutation and the loss of HBeAg (A1896) started to increase 1 year before in the converters, and became significantly higher at seroconversion (23 vs. 3%, P = 0.030) than that in the non-converters. Double mutation in the core promoter (T1762/A1764) was more common in the seroconverters than in the non-converters 5 years before seroconversion (48 vs. 28%), and became significantly more frequent at seroconversion (65 vs. 41%, P = 0.046). Seroconversion occurred in 75% of the patients with at least HBV DNA levels <5.5 logarithmic equivalents/mL; precore mutation in 20% or more of HBV DNA; or core promoter mutation. Seroconversion occurred in 50% of those patients within 1 year, 88% within 2 years, and 93% within 5 years. These results indicate that a decrease in HBV DNA levels and mutations in the precore region and the core promoter were associated significantly and complementarily with seroconversion, and each of them or a combination thereof was predictive of seroconversion years ahead.  相似文献   

12.
The existence of statistical associations between hepatitis B‐related acute‐on‐chronic liver failure and both hepatitis B virus (HBV) genotype and mutations in the basal core promoter (BCP) and precore (PC) regions needs to be confirmed. A total of 322 patients with a chronic HBV infection, including 77 with hepatitis B‐related acute‐on‐chronic liver failure, 109 with hepatocellular carcinoma (HCC) and 136 with chronic hepatitis B (CHB) were enrolled. The HBV genotype and the presence of mutations in the BCP/PC regions were determined by direct sequencing, and the frequencies were compared in the three patient groups. Overall, 198/322 (61.5%) were infected with genotype B and 124/322 (38.5%) with genotype C. Genotype B was significantly more frequent in patients with acute‐on‐chronic liver failure than CHB (92.2% vs. 60.3%, P < 0.001). As a contrast, genotype C was more common in patients with HCC than CHB (58.7% vs. 39.7%, P = 0.003). In genotype B patients, the A1762T/G1764A, A1846T, and G1896A mutations were significantly more prevalent in patients with acute‐on‐chronic liver failure than CHB (50.7% vs. 28.0%, P = 0.004; 59.2% vs. 34.1%, P = 0.002; 69.0% vs. 41.5%, P = 0.001, respectively). In multivariate analysis, the risk factors for acute‐on‐chronic liver failure were genotype B, A1762T/G1764A, and G1896A. In conclusion, CHB patients with genotype B, G1896A, and A1762T/G1764A had a higher tendency to develop liver failure than patients with genotype C. Therefore, HBV genotyping and detecting G1896A and A1762T/G1764A mutations might have important clinical implications as predictive risk factors for hepatitis B‐related acute‐on‐chronic liver failure. J. Med. Virol. 83:1544–1550, 2011. © 2011 Wiley‐Liss, Inc.  相似文献   

13.
Among the many mutations found in the hepatitis B virus (HBV) genome, some have been associated with fulminant hepatitis, as exemplified by precore-defective mutations. The aim of this study was to determine whether such mutations also are found in Vietnamese cases of fulminant hepatitis B. The full-genome nucleotide sequence of HBV in three patients with fulminant hepatitis (F-2, F-3, and F-6) and one with acute hepatitis (A-3), who were admitted to Cho Ray Hospital, Ho Chi Minh City, Vietnam was ascertained. Additionally, two patients with fulminant hepatitis (F-1 and F-7) and three with acute hepatitis (A-1, A-2, and A-5) were examined only for the precore/core region of HBV. Remarkably, the nonsense mutation at precore codon 28 (Trp82Stop) was found in four of the five patients with fulminant hepatitis, while all the acute hepatitis patients harbored wild type (one had a mixture of wild and mutant types). The missense mutations within the core region, Ile97Leu and Pro130Ile/Thr/Ser, were also remarkable in fulminant hepatitis. Only F-2 was free from these precore/core mutations, but F-2 was unique in that it possessed a chimeric genotype: it could be classified into genotype C as a whole, but its X region was of genotype B, like the other four fulminant hepatitis isolates (F-1, F-3, F-6, and F-7). The codon 41 of the X protein was Pro in all three fulminant hepatitis cases examined for this region, while it was Ser in the wild-type isolates of genotype B. Of note as negative data, the mutations C1653T and T1753M of the enhancer II (Enh II) and A1762T and G1764A of the precore/core promoter regions, once reported to be relevant to severe or fulminant hepatitis, were not found in the present cases. The results with the Vietnamese cases of fulminant hepatitis corroborated results of previous studies with respect to the mutations Trp28Stop of precore and Ile97Leu and Pro130Ile/Thr/Ser of core, but not for the mutations within Enh II and precore/core promoter region. Whether the Ser41Pro mutation in the X region of genotype B HBV is Vietnam-specific or disease-specific deserves further investigation.  相似文献   

14.
One hundred forty-two precore/core sequences were obtained from Gambian chronic hepatitis B virus (HBV) carriers and the predominant variants defined. The two point mutations, from A to T and G to A at nt positions 1762 and 1764 in the basic core promoter region, were found in only 7/99 (7%) of the samples where this region was sequenced. These mutations were found in both HBeAg-positive and -negative patients. The precore stop-codon mutation at nt position 1896 was found in 14/51 (27%) of HBeAg-negative samples, which is a lower prevalence rate in comparison with other parts of the world with high carrier rates. In HBeAg-positive patients the core amino acid sequences were conserved, but after seroconversion to anti-HBe significantly more changes were apparent. Several of the amino acid substitutions found have been described previously been in wild-type viruses of other genotypes.  相似文献   

15.
The nucleotide sequences of the core upstream and precore regions (371 nucleotide length, nt. 1604-1974) of hepatitis B virus (HBV) were analysed sequentially in three subjects who were positive serorogically for anti-HBe and had acute clinical exacerbation after immunosuppressive treatment. These patients were asymptomatic HBV carriers before therapy. The results revealed that the mutant with an 8-bp deletion (nt. 1768–1775) located in the basic core promoter region was dominant in the asymptomatic HBV carrier phase in two of three subjects. After exacerbation, however, such mutant clones possessing 8-bp deletion disappeared or decreased in number and were replaced by the clones possessing a precore stop codon mutation G to A (nt. 1896) or by the clones possessing additional contiguous point mutations A to T (nt. 1762) and G to A (nt. 1764) and a new point mutation C to T (nt. 1653). Possible relationships between acute exacerbation of liver function accompanied by mutation and the transition of the dominant clones were discussed. J. Med. Virol. 53:266–272, 1997. © 1997 Wiley-Liss, Inc.  相似文献   

16.
The precore (G1896A) and core promoter (A1762T, G1764A) mutations of the hepatitis B virus gene are known to be associated with changes in immunologic phase or the progression to complicated liver disease in adults. We analyzed these mutations in chronically HBV-infected children. Serum was collected from 37 children with chronic HBV infection from March 2005 to September 2008. HBV DNA extraction and nested PCR were followed by sequencing of the PCR products. The children were 6.7 ± 4.6 yr old. All of 37 children had HBV genotype C. Of the cohort, 31 (83.8%) were HBeAg-positive and 6 (16.2%) were HBeAg-negative; the former group comprised 18 (48.6%) who were in the immune-tolerance phase (ITP) and 13 (35.2%) in the immune-clearance phase (ICP). Most of the patients had HBV DNA levels of > 1.0 × 10(8) copies/mL. In the ITP group, only 1 (5.5%) had core promoter mutations, and none had the precore mutation. In the ICP group, only 2 (15.4%) had core promoter mutations; the remaining 6 patients had HBV DNA levels of < 2.0 × 10(3) copies/mL and no core promoter/precore mutations. The very low incidence of the precore/core promoter gene mutation, in children, suggests that these mutations may be the result of life-long chronic HBV infection.  相似文献   

17.
Hepatitis B virus (HBV) is characterized by genetic heterogeneity, including genotypes and mutations. Eight genotypes (A-H) have been identified throughout the world with a characteristic geographical distribution. Previous studies also suggest that the viral genotypes may correlate with differences in clinical features of the infection. Two types of mutations were particularly described, precore and basal promoter mutations; they may play an important role in the clinical outcome of HBV infection. The aim of this study was to investigate the prevalence of HBV genotypes and HBV variants in Tunisia, and their eventual association with severity of liver disease. Using a molecular method, HBV genotypes, precore and basal core promoter mutations were determined in 56 asymptomatic carriers and in 82 patients with histologically verified chronic liver disease and hepatocellular carcinoma (HCC). Three genotypes (D, A, and E) were detected; the prevalence was 80%, 8%, and 9%, respectively. No significant difference was observed for genotype D with clinical status. HBV mutants were detected in 93% of cases, precore mutants were the most prevalent. Basal core promoter mutants were observed in 61% of cases, they were frequently characterized by a double mutation in 1762 and 1764. Co-infection by these two types of mutants was detected in 50% of cases. Genotype D was the most prevalent HBV genotype in Tunisia. High circulation of precore and basal core promoter mutants are common in chronic hepatitis B infection in Tunisia.  相似文献   

18.
Relatively few genomic sequences of Korean hepatitis B virus (HBV) isolates are available. Moreover, no comparative study has been made between the full-length genomes of Korean HBV isolates and clinical status. To evaluate mutations in HBV isolates obtained from chronically infected HBV patients in terms of clinical significance, we determined the genomic sequences of HBV isolates obtained from three hepatocellular carcinoma (HCC) patients (He52, He53, and He82) and from three asymptomatic carriers (He74, He100, and He127). A comparison of sequence variations showed that the HBV isolates from the three HCC patients showed higher frequencies of mutation than the isolates from the three asymptomatic carriers. Three characteristic mutation patterns were identified in the HBV isolates from the HCC patients, which distinguished the HBV isolates from the asymptomatic carriers. First, HBV isolates from the three HCC patients both had double mutations in a core promoter (T1762/A1764) and a precore mutation (A1896). Second, although these isolates belonged to genotype C, 11 amino acids deletions in the preS1 region, specific for HBV genotype D, were detected in the isolates of two HCC patients (He52 and He82). Third, mutations (I127T/N, K130M, and V131I) at three codons in the carboxy functional region of X protein were observed in isolates from all three HCC patients. Additionally, phylogenetic analysis based on the entire HBV sequences showed that all six isolates belonged to genotype C2, as do other Korean strains.  相似文献   

19.
Hepatitis B virus (HBV) subgenotypes Ba, C1 (Cs), and C2 (Ce) are the most prevalent HBV variants in China. To investigate the virological characteristics of these subgenotypes and their clinical implications, we enrolled a cohort of 211 patients in the Guangdong Province of China, including 132 with chronic hepatitis B virus infection (CH), 32 with liver cirrhosis (LC), and 47 with hepatocellular carcinoma (HCC) according to clinical examination, liver function test, and ultrasonograph results. Overall, HBV Ba was found in 51.2% (108/211), HBV C1 in 33.6% (71/211), and HBV C2 in 15.2% (32/211) of the cases. The distribution of HBV genotype C was greater among patients in the LC and HCC groups than among patients in the CH group, while the distribution of HBV genotype B was greater among the CH patients than among the LC and HCC patients. No significant differences in clinical features were found among patients with HBV Ba, C1, and C2. Virologically, HBV C1 had the strongest association with the A1762T G1764A double mutation, while the mutation at position 1896 resulting in A (1896A) was uncommon. In contrast, HBV Ba had the highest frequency of 1896A but the lowest of A1762T G1764A, and HBV C2 had intermediate frequencies of these mutations. Mutations of 1653T and 1753V were specifically associated with HBV C2 and C1, respectively. Multivariate analyses showed that the 1653T, 1753V, and A1762T G1764A mutations and patient age significantly increased the risk of HCC development. In conclusion, HBV Ba, C1, and C2 have different mutation patterns in the enhancer II/core promoter/precore region. Therefore, genotyping and detecting the 1653T and 1753V mutations, in addition to the A1762T G1764A double mutation, might have important clinical implications as predictive risk factors for hepatocarcinogenesis.  相似文献   

20.
The genotype-related differences between genotype C and genotype D of the hepatitis B virus (HBV) remain unknown. The relationship was studied between the HBV genotypes and their clinical features, paying special attention to genotypes C and D. Serum samples from 413 HBV carriers were genotyped using an enzyme immunoassay (EIA) and by restriction fragment length polymorphism. The nucleotide sequences at the basic core promoter (BCP) and precore (PreC) regions were analysed by direct sequencing. The full genome sequences of three HBV genotype D cases were also examined. Almost all carriers with HBV genotype D were asymptomatic carriers (84.2%). Genotype D was not found in patients with liver cirrhosis and hepatocellular carcinoma. In contrast, carriers with genotype C had mainly chronic liver disease (63.2%; P<0.001). The ratio of hepatitis B e antigen (HBeAg)/anti-HBe was significantly higher in genotype C than in genotype D in the young age-matched group (P<0.01). The mutation at BCP (T1762, A1764) was significantly lower in genotype D than in genotype C among HBeAg-negative patients (P<0.05). The HBV full-genome sequences are very similar to certain HBV genotype D sequences from Europe. In conclusion, genotype C was associated with chronic liver disease, whereas genotype D was related to asymptomatic carriers with earlier HBeAg seroconversion. Thus, the outcome of chronic HBV infection may be different in persons infected with HBV genotypes C and D.  相似文献   

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