Serological detection of hepatitis B virus genotypes by ELISA with monoclonal antibodies to type-specific epitopes in the preS2-region product

Characteristics of lamivudine-resistant hepatitis B virus (HBV) strains with and without breakthrough hepatitis in patients with chronic hepatitis B evaluated by serial HBV full-genome sequences

Lamivudine therapy often causes breakthrough of hepatitis B virus (HBV) DNA and breakthrough hepatitis. The aim of this study was to determine the viral factors that relate to HBV-DNA breakthrough with and without breakthrough hepatitis. Among 82 patients with chronic hepatitis B (CHB) who received lamivudine at a dose of 100 mg daily for more than 24 months, 23 patients had HBV-DNA breakthrough induced by a lamivudine-resistant mutant. Of these 23 patients, 16 had breakthrough hepatitis and 7 had only HBV-DNA breakthrough. Serial HBV-DNA full-genome sequences during therapy were examined in 10 (7 had breakthrough hepatitis and 3 did not) of these 23 patients by direct sequencing. Mutations in the S region were examined by cloning in representative patients. There were no significant differences in the baseline clinical backgrounds and virus marker between patients with and without breakthrough hepatitis. The HBV amino acid substitutions at breakthrough hepatitis were identical to those at HBV-DNA breakthrough. Cloning analysis revealed that monoclonal mutational strain appeared at breakthrough and no such mutations existed at baseline. Regarding HBV amino acid substitutions in the polymerase region, S region, X region, and precore-core region with breakthrough compared to baseline, there was no significant differences of the numbers of amino acid substitution between breakthrough hepatitis and non-breakthrough hepatitis. There were no common amino acid changes in patients with breakthrough hepatitis. Although monoclonal lamivudine-resistant strain emerged at HBV-DNA breakthrough in patients with CHB, there were no common amino acid changes, suggesting viral factor may have insignificant role in breakthrough hepatitis.

Analysis of hepatitis B virus quasispecies distribution in a Korean chronic patient based on the full genome sequences

Although Korea is a hepatitis B virus (HBV) endemic area, relatively few full-length genome sequences are available. In particular, no comparative analysis has been performed on the full-genome sequences of different HBV quasispecies from a single Korean patient. This report describes the full-length sequences of five HBV clones (two clones with shorter PCR amplicons and three clones with longer amplicons). Large deletions, that is, 685-bp, 487-bp, and 144-bp, that might interfere with the production of normal proteins were observed in four of five clones. Double mutations in the basal core promoter (BCP) region (T1762/A1764) were detected in two clones but no precore mutations (A1896) were detected in any of the five clones. These data support previous results that genotype C, in particular Korean clones of this genotype, is prone to mutations. Two independent mechanisms, namely, the deletions of long lengths and amino acid substitutions followed by BCP double mutations might contribute to the diversity of HBV quasispecies. Considering the importance of HBV quasispecies as HBV variant sources, the distribution of HBV quasispecies in mutation prone genotype C prevalent areas like Korea, should be monitored to improve the management of chronic HBV infections and to control HBV variants that arise due to the administration of vaccine or antiviral therapy.

Hepatitis B virus (HBV) genotypes in Egyptian pediatric cancer patients with acute and chronic active HBV infection

Background

There are eight genotypes of hepatitis B virus (A-H) and subgenotypes are recognized. Genotyping can be accomplished based on a partial sequence of HBV genome such as the pre-S or S gene. Several methods have been developed and used for HBV genotyping. This study was undertaken to determine the HBV genotypes in Egyptian pediatric cancer patients with acute and chronic liver disease.

Methods

HBV genotypes were determined in 22 patients who had acute forms of liver disease (AH) and in 48 patients with chronic active hepatitis (CAH). A type-specific primer based the nested-PCR method was employed in the HBV genotyping.

Results

This study showed that HBV infections in pediatric cancer patients are attributed predominantly to viral genotypes D and B that constituted 37.1% and 25.7%, respectively of the total infections. In addition, there was a relatively high prevalence of mixed infections of 15.7% among the studied group especially mixed A/D genotype infections. Genotype D was found significantly more often in patients with CAH than in patients with AH [23/48(47.9%) v 3/22 (13.6%)].

Conclusion

These findings show the distribution of HBV A-D genotypes in pediatric cancer Egyptian patients. Furthermore, our results indicate a markedly high prevalence of mixed A/D genotype infections in subjects with CAH and a possible association of mixed infections with the severity of liver diseases.

Pre- and post-treatment predictors of the early achievement of HBeAg loss in lamivudine-resistant patients receiving adefovir therapy

BACKGROUND AND AIM

This study investigated the clinical variables that predict hepatitis B e antigen (HBeAg) loss in lamivudine-resistant patients receiving adefovir therapy.

METHODS

Fifty-six consecutive HBeAg-positive patients treated with adefovir for at least 12 months were enrolled in this study. All had serum alanine aminotransferase (ALT) levels over twice the upper limit of normal (ULN) as a result of lamivudine resistance. Predictors of HBeAg loss after switching from lamivudine to adefovir were examined.

RESULTS

During the follow-up period, 18 (32.1%) of 56 patients showed a loss of HBeAg. The estimated rates of HBeAg loss at 6, 12, and 18 months were 11.5%, 26.8%, and 42.9%, respectively. Univariate analysis revealed that pretreatment ALT levels >10 x ULN (P = 0.029), a viral load at 3 months of therapy (P = 0.017), and viral decline by >3 log(10) from baseline at 3 months (P < 0.001) were significantly associated with the loss of HBeAg within 12 months of therapy. With multivariate analysis using the stepwise logistic regression model, pretreatment ALT > 10 x ULN (odds ratio [OR], 4.22; 95% confidence interval [CI], 1.09-19.44; P = 0.044) and viral suppression >3 log(10) at 3 months (OR, 10.39; 95% CI, 1.86-58.07; P = 0.008) were identified as the two independent predictors of HBeAg loss.

CONCLUSIONS

Pretreatment ALT levels and the initial pattern of post-treatment viral decline are the strongest predictors of the early achievement of HBeAg loss following treatment with adefovir in lamivudine-resistant patients. These results may provide useful information for the optimal timing of adefovir rescue as well as for better monitoring after treatment.

Characterization of two hepatitis B virus populations in a single Korean hepatocellular carcinoma patient with an HBeAg-negative serostatus: a novel X-Gene-deleted strain with inverted duplication sequences of upstream enhancer site II

OBJECTIVES

The aim of the study was to elucidate mutation patterns related to hepatocarcinogenesis in a Korean hepatocellular carcinoma (HCC) patient.

METHODS

We analyzed full genome sequences of 6 hepatitis B virus (HBV) clones from an HCC patient.

RESULTS

This patient harbored 2 HBV populations with genomes of different lengths (3,221 and 2,212 bp). In addition, we found 2 characteristic features not described so far in the full-genome sequence of deleted strains. First, 3 large deletion events (847, 144 and 48 bp) and a premature termination of the 182th codon of the surface antigen could lead to truncated or possibly nonfunctional forms of all HBV proteins. Second, these showed a novel mutation type not reported to date, which is a complex of an inverted duplication of 36-bp sequences containing an upstream enhancer site II (UEII), a remote insertion, and a large deletion event of the X region by homologous recombination.

CONCLUSION

The fact that UEII is a binding site of liver-specific nuclear factor, which is expressed only in highly differentiated liver cells such as cancerous HepG2, strongly suggests a relationship between this novel mutation and hepatocarcinogenesis in this patient.

Factors associated with the virological response of lamivudine-resistant hepatitis B virus during combination therapy with adefovir dipivoxil plus lamivudine

BACKGROUND

The aim of this study was to investigate the factors associated with the response of lamivudine-resistant hepatitis B virus (HBV) during combination therapy with adefovir dipivoxil plus lamivudine.

METHODS

Sixty-three patients with breakthrough hepatitis received a 10-mg once-daily dose of oral adefovir dipivoxil.

RESULTS

The rates of undetectable serum HBV-DNA were 49.2% after 24 weeks, 61.9% after 48 weeks, and 67.2% after 72 weeks. The cumulative hepatitis B e antigen (HBeAg) loss rates in patients with alanine aminotransferase (ALT) levels of more than twice the upper limit of normal (ULN) were significantly higher than in patients with ALT less than twice the ULN (P = 0.0145). Multivariate analysis revealed that baseline ALT level (P = 0.003) and HBeAg status (P = 0.049) were associated with early virological response.

CONCLUSIONS

Baseline ALT level was associated with HBeAg loss and seroconversion, and baseline ALT level and HBeAg status were associated with the virological response of lamivudine-resistant HBV during combination therapy with adefovir dipivoxil plus lamivudine.

Lamivudine and IFN-beta sequential therapy in HBe antigen-positive patients with chronic hepatitis B virus genotype C infection

Sequential treatment with lamivudine and interferon (IFN) has induced sustained biochemical and virologic responses in the majority of patients with chronic hepatitis B in France. However, the efficacy of sequential treatment in patients with chronic hepatitis B virus (HBV) genotype C infection has not been evaluated. Twenty-four HBe antigen-positive patients were treated with 100 mg lamivudine alone for 16-32 weeks, then with both 6 MU IFN-beta and lamivudine for 4 weeks, and lastly with IFN-beta alone for 20 weeks. Sustained response was achieved in 7 (29%) patients 24 weeks after the end of therapy. No lamivudine-resistant variants emerged in any patient. Hepatitis flare occurred in 3 patients after the withdrawal of lamivudine, but none had decompensation. The patients with sustained response were significantly younger at baseline (p = 0.033) and had a significantly lower HBV DNA level at the start of IFN (p = 0.020) than those without sustained response. In conclusion, the rate of response to sequential therapy with lamivudine and IFN in HBe antigen-positive patients with HBV genotype C infection was lower than the rate reported previously. Patients who were young or who had a favorable virologic response to lamivudine were more likely to have a sustained response.

Preliminary study on hepatitis B virus genotypes in Xiamen city

AIM: To investigate the genotypes of hepatitis B virus (HBV) in Xiamen city by nested polymerase chain reaction (PCR) with multiplex pairs of genotype-specific primers.

METHODS: A total of 250 HBV-infected patients were included in this study. The serum samples were collected and the serum HBV DNA was used as templates. Ten outer and inner primers were designed on the basis of nucleotide sequences in the regions of Pre-S1 and S genes, of which 8 genotype-specific inner primers were divided into 2 groups: A and B. Genotype A, B, C or D, E, F of HBV were amplified, respectively. The genotypes of the second-round PCR products were identified using agarose gel electrophoresis (30 g/L).

RESULTS: Of the 250 selected patients, 120 received the above genotyping successfully. There were 90 (75.0%) diagnosed with chronic hepatitis B, 7 (5.8%) with acute hepatitis B, 8 (6.7%) with liver cirrhosis, and 15 (12.5%) with hepatocellular carcinoma. Of the 120 cases, 58 (48.3%) were found with genotype B, 30 (25.0%) with genotype C and 32 (26.7%) with genotype B/C. In the patients with positive HBeAg, genotype B and B/C were confirmed in 63.8% and 21.9% of them, respectively. However, the patients with genotype B/C and B accounted for 68.8% and 25.9% of the anti-HBe-positive patients. There were significant differences between the 2 sub-groups in the genotype distribution (P < 0.05).

CONCLUSION: Genotype B prevails among HBV-infected patients in Xiamen city, and type B/C HBV infection a considerable problem.

Determination of hepatitis B virus genotype by flow-through reverse dot blot

BACKGROUND

The clinical outcome and response to therapy of hepatitis B virus infection differ depending upon viral genotype. Most methods of determining the viral genotype are relatively time-consuming and costly. Moreover, the results of some methods are influenced by single nucleotide mutations.

OBJECTIVES

To develop a novel HBV genotyping process insensitive to single nucleotide mutations using an improved reverse dot blot method employing the principle of "flow-through hybridization".

STUDY DESIGN

The flow through reverse dot blot (FT-RDB) method was developed using DNA from different HBV genotypes. HBV sequences from Genebank were used to design primers and probes. Specificity and sensitivity of the method were evaluated with clinical samples in which the HBV viral load was quantified by real-time PCR. Results were compared to those of multiplex PCR and sequencing. Another 59 clinical samples were used to test the clinical applicability of the method.

RESULTS

We showed that FT-RDB could be made insensitive to single nucleotide mismatch by adjusting the hybridization temperature. All HBV-negative samples showed no signals in the assay. The detection sensitivity of the method was found to be between 10(3) and 10(4) DNA copies/ml. The results of FT-RDB were 84% concordant with those of multiplex PCR, and 96% concordant with sequencing results in 101 cases. The genotype all 59 clinical samples was accurately identified.

CONCLUSIONS

We demonstrated that the FT-RDB method was rapid, reliable, accurate and inexpensive. It appears to be useful for routine clinical HBV genotyping even in non-specialized hospital laboratories.

Hepatitis B virus (HBV) genotypes/subgenotypes in China: mutations in core promoter and precore/core and their clinical implications

BACKGROUND

The association of hepatitis B virus (HBV) genotypes with clinical course of infection is increasingly recognized.

OBJECTIVES

In order to investigate the genetic diversity of HBV and its clinical implications, 241 HBV-infected patients including 34 with hepatocellular carcinoma (HCC) were enrolled in this study.

METHODS

HBV genotyping was performed with an ELISA assay. HBV subgenotypes were determined by PCR-RFLP. HBV core promoter/precore/core mutations were analyzed by direct sequencing.

RESULTS

The overall prevalence of HBV/B and C was 65% and 33%, respectively. Among HBV/C, 42% were Cs/C1 and 58% were Ce/C2. The HBV/C1 was only found in the patients originating from Southern China (p=0.0001). Among HCC patients, HBV/C2 was only found in the elder age group (> or =51 years; p<0.05) and HBV/Ba was associated with young HCC patients (<35 years). Mutations associated with HCC were V1753 and T1762/A1764 (p<0.01). The prevalence of the V1753 was higher in HBV/C1 strains (p<0.04), A1898 was only found among HBV/C1 (p=0.056). T1762/A1764 was frequently demonstrated in both subgenotypes. The T1858 (90%) and A1896 (40%) mutations were most frequent in HBV/C2 (p<0.008).

CONCLUSIONS

HBV/C1 and HBV/C2 have distinct geographic distributions in China. V1753 in addition to T1762/A1764 double mutation in the basal core promoter region seems to be associated with HCC development, especially in the patients with HBV/C1.

Characteristics of geographic distributions and route of infection for hepatitis B virus genotype D in Ehime area in western Japan

AIMS

Hepatitis B virus genotype D (HBV/D) is rare in Japan, and has been shown to circulate in Ehime prefecture in western Japan. HBV/D is suspected to have been transferred into Ehime from Russia as a result of the Japanese-Russian War. This study examined the current geographic spread and infectious route for HBV/D in Ehime.

METHODS

HBV genotype was determined for 508 patients with chronic HBV infection and 46 patients with acute HBV infection hepatitis (acute hepatitis, AH), all of whom were living in Ehime. Ehime was divided into three areas and genotypic distributions were studied.

RESULTS

The ratio of genotypes A,B,C and D in chronically infected patients were 1.8%, 4.5%, 87.8% and 5.9%, respectively. Most patients chronically infected with HBV/D lived in the central area. Only two patients lived in the east and south-west areas, and both had lived in the central area in childhood. Patients with AH due to HBV/D were found only in the central area.

CONCLUSION

HBV/D has not yet spread widely to areas other than central Ehime, although small numbers of infected people have moved to other areas. The major infectious route for patients with AH is sexual transmission, regardless of HBV genotype.

A male patient with severe acute hepatitis who was domestically infected with a genotype H hepatitis B virus in Iwate, Japan

Although all eight genotypes of hepatitis B virus (HBV) strains are circulating in Japan, no cases of acute hepatitis with foreign HBV strains of genotype H have thus far been reported in Japan. Here, we report a 35-year-old Japanese patient with severe acute hepatitis who was domestically infected with genotype H HBV. On admission, he had a high HBV load of 1.0 x 10(9) copies/ml, elevated levels of total bilirubin (7.0 mg/dl) and alanine aminotransferase (3606 IU/l), and reduced prothrombin activity of 39.0%. The HB-JAIW05 isolate obtained in the present study was composed of 3215 nucleotides and had the highest similarity of 99.7% with the reported genotype H HBV isolate recovered from a Japanese blood donor. The HB-JAIW05 isolate had neither precore (A1896) nor core promoter (T1762/A1764) mutations. However, upon comparison with the consensus sequence of ten reported HBV isolates of the same genotype, the HB-JAIW05 isolate had 17 nucleotide substitutions including five missense mutations in the P gene, which may be related to vigorous replication of HBV in this case. He had no history of traveling abroad, but had had extramarital sexual contact with two Japanese women living in Iwate, Japan, 2 weeks and 2 months before the disease onset, respectively. Our results suggest that rare HBV genotypes such as H may be spreading in Japan via sexual contact. Further molecular epidemiological studies on HBV to clarify the exact changing profiles of de novo HBV infection in Japan in relation to genotype and genomic variability are warranted.

Long-term presence of HBV in the sera of chronic hepatitis B patients with HBsAg seroclearance

OBJECTS

The aim of this study was to elucidate the presence of serum hepatitis B virus (HBV) DNA at a prolonged time after seroclearance of hepatitis B surface antigen (HBsAg).

METHODS

Seventy Japanese patients who had been observed for >5 years after HBsAg seroclearance were included in this study. Anti-HBs, anti-HBe and anti-HBc antibodies were measured 0, 5 and 10 years after HBsAg seroclearance. Serum HBV DNA was measured using nested polymerase chain reaction (PCR) at 0, 5 and 10 years after HBsAg seroclearance. The PCR detection of serum HBV DNA using the X gene and core gene primers was done. The HBV DNA was regarded as positive when PCR detection of HBV DNA using either or both the X gene and core gene primers was positive. A multivariate regression analysis was used to assess the factors contributing to the positivity of serum HBV DNA 5 years after HBsAg seroclearance: the factors examined included age, gender, histological findings, HBV genotype, aminotransferase, total protein and interferon administration.

RESULTS

The titers of 200-fold diluted serum anti-HBc were 6.5 +/- 4.0 at 0 year after HBsAg seroclearance, 1.8 +/- 1.4 at 5 years and 0.9 +/- 0.7 at 10 years. The titers of 200-fold diluted serum anti-HBc decreased 5 and 10 years after HBsAg seroclearance with statistical significance. The positive rate of HBV DNA by the nested PCR was 71.4% (50/70) at 0 year after HBsAg seroclearance, 21.4% (15/70) at 5 years and 14.3% (3/21) at 10 years. However, there were no significant factors contributing to the positivity of serum HBV DNA 5 years after HBsAg seroclearance.

CONCLUSION

Our results suggest that serum HBV DNA disappears with an incidence of 10-20% 5 and 10 years after HBsAg seroclearance.

Genotype B and younger patient age associated with better response to low-dose therapy: a trial with pegylated/nonpegylated interferon-alpha-2b for hepatitis B e antigen-positive patients with chronic hepatitis B in China

BACKGROUND

Cost and clinically significant adverse effects are the major limiting factors of interferon (IFN) use in therapy for chronic hepatitis B virus (HBV) infection. A clinical trial was conducted in China to study the efficiency and clinical relevance of low-dose regimen of IFN treatment for chronic HBV infection and to reveal factors predicting sustained combined response.

METHODS

During a randomized, open-label control study, hepatitis B e antigen (HBeAg)-positive patients with chronic HBV infection (n=230) were assigned to receive pegylated IFN- alpha -2b (1.0 micro g/kg) (n=115) or IFN- alpha -2b (3 MIU; n=115) for a 24-week period. Sustained combined response was assessed 24 weeks after the completion of treatment.

RESULTS

The greater rate of HBeAg loss in the pegylated IFN-group (23%) was the only statistically significant difference between the 2 treatment arms observed at the end of follow-up. The results of the multivariate statistical analysis revealed that HBV genotype B and patient age (< or =25 years) were 2 independent factors associated with sustained combined response. A total of 40% of patients with HBV genotype B aged < or =25-years achieved sustained combined response. Only 4 (1.7%) of 230 patients discontinued therapy because of clinically significant adverse effects.

CONCLUSIONS

The choice of low-dose IFN regimen might be a relevant clinical option to reduce the cost and adverse effects of therapy for younger patients with chronic HBV infection and genotype B infection in countries where it is prevalent.

Adefovir Dipivoxil Monotherapy and Combination Therapy with Lamivudine for the Treatment of Chronic Hepatitis B in an Asian Population

Aim

To determine differences in Chinese patients treated with adefovir (ADV) monotherapy or ADV in combination with lamivudine (3TC) after development of resistance to 3TC, with respect to biochemical improvement, HBV DNA suppression and development of subsequent ADV resistance.

Methods

All hepatitis B patients with 3TC resistance treated with ADV for 3 months or more at our centre were included, and monitored 3–6 monthly for biochemical and virological response, and development of ADV resistance.

Results

A total of 56 patients were included, 50% switched to ADV monotherapy and 50% received combination 3TC/ADV therapy. Median follow-up was 15.5 months. Normalization of alanine aminotransferase (ALT) occurred in 25 (89%) patients in the ADV group compared with 24 (86%) in the 3TC/ADV group (P=0.686). Virological response (VR) was achieved in seven (35%) patients in the ADV group at 12 months compared with five (28%) in the 3TC/ADV group (P=0.637). By 24 months, seven (64%) patients in the ADV group achieved VR compared with two (40%) in the 3TC/ADV group (P=0.377). Cumulative probability of developing genotypic ADV resistance in the ADV group at 24 months was 18% compared with 7% in the 3TC/ADV group (P=0.94).

Conclusions

There was no obvious improvement in ALT normalization and virological suppression or reduction in the development of ADV-resistant mutations with 3TC/ADV therapy compared with ADV monotherapy. Further studies with longer follow-ups are required to determine whether combination 3TC/ADV therapy will reduce the emergence of ADV resistance compared with ADV monotherapy.

Mutational patterns of hepatitis B virus genome and clinical outcomes after emergence of drug-resistant variants during lamivudine therapy: Analyses of the polymerase gene and full-length sequences

It remains unclear whether mutational patterns of the hepatitis B virus (HBV) genome are associated with the development of severe hepatitis after the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) variants during lamivudine treatment. Thirty patients with chronic hepatitis B who had YMDD variants during lamivudine therapy and were followed up subsequently while receiving lamivudine alone for at least 6 months were examined retrospectively. The lamivudine resistant mutations in the HBV polymerase gene were detected by a line probe assay, and the full-length sequences of HBV DNA were determined in some patients. Between months 5 and 33 of therapy, mutations from methionine to isoleucine at rt204 (rtM204I) were detected in 18 patients, and mutations from methionine to valine at rt204 (rtM204V) were detected in 12. The rtM204V mutations were always accompanied by mutations from leucine to methionine at rt180 (rtL180M), while rtM204I mutations were not. Baseline characteristics, alanine aminotransferase (ALT) levels, and HBV DNA levels within 6 months after the emergence of YMDD variants did not differ significantly between patients with rtM204I alone and those with rtL180M/rtM204V. No specific mutation was identified on full-length sequence analysis in three patients with a hepatitis flare. During long term follow-up, the addition of rtL180M to rtM204I was found in four patients 7-31 months after detecting the change at rt204 and was linked to increased ALT levels. In conclusion, mutational patterns of HBV DNA at the time of emergence of YMDD variants were apparently unrelated to the clinical outcomes in Japanese patients with chronic hepatitis B during lamivudine therapy.

Comparison of interferon and lamivudine treatment in Japanese patients with HBeAg positive chronic hepatitis B

The aim of this study was to elucidate the long-term outcome after interferon (IFN) or lamivudine (LMV) treatment in Japanese patients with hepatitis B e antigen (HBeAg) positive chronic hepatitis B. Inclusion criteria were biopsy proven chronic hepatitis or liver cirrhosis, no history of IFN or LMV treatment. Three hundred twenty-seven patients satisfied above criteria were treated with IFN or LMV. The primary end point of our study was serum clearance of HBeAg and decrease of serum HBV-DNA to < or =5 LEG/ml after the initiation of treatment. This study was a retrospective cohort study. Attainment of serum clearance of HBeAg and decrease of serum HBV-DNA to < or =5 LEG/ml was regarded as response. Two hundred eighty-six patients had got response after the initiation of treatment. The cumulative rate of response was 28.0% in the first year, 56.2% at the 5th year and 82.5% at the 10th year. Response occurred when HBV-DNA load was high level of more than 7 LEG/ml, and serum ALT level was more than 100 IU/L, HBV genotype was B. IFN and LMV were the similar effect on response (P = 0.410). On IFN therapy, cumulative rate of response in patients of <35 years was higher than that in patients > or =35 years (P = 0.002). Our results suggest that (1) IFN and LMV are the similar effect on response, (2) IFN therapy is more effective for younger patients.

Analysis of the complete hepatitis B virus genome in patients with genotype C chronic hepatitis in relation to HBeAg and anti-HBe

To investigate the relationship between viral factors and the development of chronic hepatitis B, the entire hepatitis B virus (HBV) genome of chronic carriers at different disease stages were analyzed. Eighty genotype C HBV carriers including 12 hepatitis B e antigen (HBeAg) positive asymptomatic carriers (Group A), 49 HBeAg positive patients with chronic liver diseases (Group B) and 19 anti-HBe positive patients with chronic liver diseases (Group C) were studied. HBV nucleic acid from serum samples was sequenced directly and compared with GenBank reference sequences HBV X01587 and M12906. On phylogenetic analysis, 76 cases were genotype C2. Of the 76 genotype C2 cases, the nucleotide and amino acid substitution rates in the precore/core region were significantly higher in Groups B and C than in Group A, also in Group C than in Group B. The nucleotide substitution rates in the full genome and the core promoter region were significantly higher in Group C than in Group A, also in group C than in Group B. The nucleotide and amino acid substitution rates in the X region were significantly higher in Group C than in Group A. The amino acid substitution rate in the pre-S2 region was significantly higher in Group C than in Group B. Deletion mutations were found mainly in Groups B and C. This whole genome analysis of HBV chronic carriers suggested that the nucleotide substitutions and deletions in HBV were closely associated with the pathogenesis of chronic HBV infection.

Heterogeneity of Hepatitis B Virus Genotype D in Japan

OBJECTIVE

Hepatitis B virus (HBV) genotypes B and C are predominant in Japan. Previously, we reported that approximately 9% of HBV carriers in the Ehime area of western Japan were infected with genotype D (HBV/D) and their sequences closely related. Recently, serum samples from 3 patients with chronic HBV/D infections living in Tokyo and the surrounding area became available for testing. The purpose of this study was to determine whether the HBV/D isolates from these different areas of Japan are closely related.

METHODS

Of the 3 Tokyo area patients infected with HBV/D, 2 had chronic hepatitis, and 1 had hemophilia with a history of frequent coagulation factor injections. The complete HBV/D genome sequences of each were determined, and compared with those of subjects from the Ehime area.

RESULTS

All 3 HBV/D sequences had a genomic length of 3,182 bases, and the hepatitis B surface antigen subtype was ayw3. Phylogenetic analysis revealed that the 1 of the HBV/D isolates was closely related to the isolates from Ehime Prefecture, while 1 was similar and 1 was clearly distinct.

CONCLUSION

Our results indicate that HBV/D infections in Japan are heterogeneous.

Molecular epidemiology of hepatitis B virus (HBV) genotypes and serotypes in patients with chronic HBV infection in Korea

OBJECTIVES

Although hepatitis B virus (HBV) is endemic to Korea, no large-scale survey of HBV genotypes and serotypes based on sequence analysis has been performed.

METHODS

In the present study, we genotyped and serotyped HBV strains from 209 patients in two Korean regions, Seoul (107 patients) and Jeju (102 patients), an island off the southeastern Korean coast. Analyses were conducted using the direct sequencing method targeting the partial surface (S) gene (541 bp).

RESULTS

Phylogenetic analysis showed that all HBV strains from the 209 patients belonged to genotype C2 (100%). Of the 209 patients, 193 (92.3%), 12 (5.7%) and 1 (0.5%) were found to have the adr, adw and ayr serotypes, respectively. The other three strains (1.5%) showed unique serotype and were not typeable by sequence analysis. No HBV strains characteristic of Jeju island were observed.

CONCLUSIONS

The extraordinary predominance of genotype C2 in chronic Korean patients, which is known to be associated with more severe liver disease than genotype B, suggests that the clinical manifestations of Korean HBV chronic patients are likely to differ from those found in other Asian countries, especially in Japan and Taiwan, where genotypes B and C coexist.

Specific mutations in enhancer II/core promoter of hepatitis B virus subgenotypes C1/C2 increase the risk of hepatocellular carcinoma

BACKGROUND/AIMS

Hepatitis B virus genotype C (HBV/C) has been classified into two geographically distinct subgenotypes; HBV/C1/Cs (Southeast Asia) and HBV/C2/Ce (East Asia).

METHODS

Viral differences in enhancer II/core promoter and precore regions between the subgenotypes and their association with hepatocellular carcinoma (HCC) were assessed in a matched cross-sectional control study of 118 carriers (from Hong Kong) with HBV/C1/Cs (48.0 years, 81% male, 40% HBeAg+, 44% HCC) and 210 HBV/C2/Ce (172 from Japan, 38 from Hong Kong) (50.2 years, 78% male, 30% HBeAg+, 46% HCC).

RESULTS

Univariate analyses showed that mutation V1753 was predictive for HCC among HBeAg-positive-C1/Cs-carriers (P=0.0055), and T1653 among HBeAg-positive-C2/Ce-carriers (P=0.018), and T1653 or V1753 or T1762/A1764 among HBeAg-negative-C2/Ce-carriers (P<0.05). In the multivariate analysis on all HBV/C subjects, independent predictive factors for HCC were subgenotype C2/Ce (odds ratio, 4.21; 95% confidence interval, 1.07-16.23), T1653 (3.64; 1.93-6.86), V1753 (3.07; 1.66-5.65) and T1762/A1764 (2.58; 1.21-5.49) mutations, age (50 years), gender (male) and HBeAg (positive).

CONCLUSIONS

Our data indicate that T1653 and/or V1753 mutations in addition to T1762/A1764 are differently associated with HCC in context of HBeAg status among HBV/C1/Cs and C2/Ce-carriers. HBV/C subgenotypes have specific mutation patterns, which is probably responsible for increased carcinogenesis of HBV/C2/Ce.

Response to long-term lamivudine treatment in patients infected with hepatitis B virus genotypes A, B, and C

Response to lamivudine treatment longer than 1 year was compared in 15 patients persistently infected with hepatitis B virus (HBV) genotype A, 38 with genotype B, and 449 with genotype C. Patients with genotype A were younger (median age 37 [range 24-49] vs. 47 [24-67] or 44 [18-73], P = 0.015), possessed hepatitis B e antigen (HBeAg) more frequently (73% vs. 21% or 56%, P < 0.001) and HBV DNA in higher levels (8.6 [6.1-8.7] vs. 6.5 [<3.7-8.7] or 6.5 [<3.7-8.7] log genome equivalents (LGE)/ml, P = 0.024) than those with genotype B or C. During lamivudine, YMDD mutants (89% vs. 53% or 42%, P = 0.0001) and breakthrough hepatitis developed more often (47% vs. 21% or 29%, P = 0.023) in patients with genotype A than B or C. YMDD mutants elicited more frequently in patients with genotype A than B or C who were positive (82% [9/11] vs. 25% [2/8] or 48% [117/245], P = 0.037) or negative for HBeAg (75% [3/4] vs. 30% [9/30] or 33% [68/204], P = 0.003). HBeAg (hazard ratio 2.1 [95% confidence interval 1.53-2.92], P < 0.001) and genotype A (2.78 [1.08-7.12], P = 0.034) enhanced the emergence of YMDD mutants by the Cox proportional hazard model. The risk for breakthrough hepatitis was increased by the baseline alanine aminotransferase level <500 IU/L (2.56 [1.82-5.50], P = 0.018), HBeAg (2.11 [1.40-3.16], P < 0.001), cirrhosis (1.92 [1.24-2.97], P = 0.004) and HBV DNA > or =8.0 LGE/ml (1.57 [1.04-2.36], P = 0.03); it was influenced by genotypes only in patients with HBeAg. In conclusion, HBV genotypes help in predicting response to long-term lamivudine treatment and development of YMDD mutants in patients with chronic hepatitis B.

Long-term follow-up of HBeAg-positive young adult Japanese patients treated with corticosteroid withdrawal therapy for chronic hepatitis B

OBJECTIVES

To evaluate the long-term effects of corticosteroid withdrawal therapy (CSWT) in young adult Japanese patients with chronic hepatitis B (CH-B) virus infection.

METHODS

The subjects were 106 patients with CH-B who received CSWT, were less than 35 years of age and had been followed for more 10 years after CSWT.

RESULTS

Retreatment was not required in 41 patients (38.7%; retreatment(-) group) while 65 (61.3%) received treatment after the initial CSWT (retreatment(+) group). Larger proportions of patients of the retreatment(-) group were females, had liver histology stage F2/F3, high ICG R15, and genotypes A/B/D/E, compared with the retreatment(+) group. At the last follow-up examination, the HBeAg seronegative rate was 90.2% in the retreatment(-) group and 98.5% in retreatment(+) group. In the retreatment(-) group, the rate of liver cirrhosis (LC; 7.3%, 3 patients) was lower, but the rate of hepatocellular carcinoma (HCC; 12.2%, 5 patients) was higher than in the retreatment(+) group (20%, 13 patients, and 4.6%, 3 patients, respectively). At the 10-year period, the overall HBsAg loss, LC and HCC rates were 2.8, 13.2 and 1.9%, respectively.

CONCLUSIONS

Our results suggest that CSWT is good short-term therapy and has possible long-term effects in young adult Japanese patients with CH-B.

Classification of hepatitis B virus genotypes by the PCR-Invader method with genotype-specific probes

Hepatitis B virus is a worldwide public health problem. A simple and effective test to identify viral genotypes would greatly aid efforts to understand and control the spread of this disease. A serial invasive signal amplification reaction assay (PCR-Invader assay) was developed for distinguishing the known eight genotypes (A-H) and four subgenotypes (Aa, Ae, Ba, Bj) of hepatitis B virus (HBV). The preS/S and core regions were amplified by multiplex PCR and delivered to 12 wells containing genotype-specific Invader probes. By observing the fluorescence patterns in the wells, HBV sub/genotypes can be assigned. A total of 505 serum samples containing HBV/HBsAg in Japan was examined by PCR-Invader and compared the results with those from ELISA assays with monoclonal antibodies against epitopes on gene products of the preS2 region and with a genotype-specific probe assay (GSPA) based on the preS1 region. Genotypes determined by the PCR-Invader agreed with those of the ELISA method in 98.2% of cases and with the GSPA method in 97.1% of cases. Co-infection with two distinct genotypes was correctly identified by the PCR-Invader in four serum samples, as determined by GSPA. Thus, the PCR-Invader assay is a useful tool for detecting the 10 known HBV sub/genotypes.

Molecular epidemiology of hepatitis B virus in the United Republic of Tanzania

In the United Republic of Tanzania, 457 voluntary blood donors were enrolled in hepatitis B virus (HBV) serological screening; 4.8% (22/457) carried HBsAg, 13.6% (3/22) of whom were HBeAg-positive. The mean age among HBeAg-negative carriers was 31 years. HBV DNA was detectable in 81.8% (18/22), the mean level was 3.67 (+/-1.77) log copies/ml. Genotype A was determined in 90.9% (20/22) and 18/20 were classified into subgenotype Aa (Asia/Africa). The basal core promoter, precore and partial core nucleotide sequences were analyzed in the 18 strains; T1809/T1812 ("Kozak" sequence) and A/T1888 (encapsidation signal) variants were identified in 100% and 78%, respectively. The complete genome sequencing for one of the Tanzanian strains revealed no recombination. In conclusion, HBV seroprevalence is high among general population in Tanzania, and the HBV/Aa-infection is predominant. The indicated tendency to early HBeAg seroconversion and declining of the viral load should be confirmed further in case-control studies.

Long-term lamivudine treatment for chronic hepatitis B in Japanese patients: A project of Kyushu University Liver Disease Study

AIM: To determine the efficacy of long-term lamivudine treatment of a large number of Japanese patients with chronic hepatitis B.

METHODS: In this retrospective, multi-center trial, 318 Japanese patients with chronic hepatitis B received 100 mg of lamivudine daily for up to 36 (median 21) mo. Virological response was a decline to a serum HBV DNA level less than 3.7  log copies/mL. Virological breakthrough was defined as the reappearance of a serum HBV DNA level to more than 10-fold the minimum during treatment.

RESULTS: Lamivudine produced virological response in 86.8% of the 318 patients at 6 mo, in 80.2% of 252 patients at 12 mo, in 69.2% of 133 patients at 24 mo, and in 53.6% of 28 patients at 36 mo. Forward stepwise logistic regression analysis showed an HBV DNA level less than 6.8  log copies/mL (P < 0.0001), HBeAg negativity (P < 0.0001), a platelet count of 100 × 10⁹/L or more (P = 0.0162) at baseline, and a decline of the HBV DNA level of more than 3.2  log copies/mL as compared with the baseline level at 3 mo after the start of treatment (P = 0.0003) to be significantly associated with virological response. Among patients with a virological response, virological breakthrough was seen in 5.3% of 19 patients who responded virologically at 1 mo, in 20.7% of 203 patients at 3 mo, in 27.5% of 51 patients at 6 mo, in 33.3% of 12 patients at 9 mo, and in 100% of 3 patients at ≥15 mo. A virological breakthrough was found significantly more often in patients with delayed virological response.

CONCLUSION: Lamivudine treatment could suppress serum HBV DNA in most of the tested Japanese patients. Long-term efficacy might be seen in patients without HBeAg at baseline, in the absence of cirrhosis, and in patients with a decline in HBV DNA level soon after the start of treatment.

Genotyping of hepatitis B virus (HBV) by oligonucleotides microarray

Oligonuleotides (oligo) microarray is a promising method for virus genotyping. In this study, we developed an oligo microarray used for genotyping hepatitis B virus (HBV). It consists of 15 probes targeting HBV genotypes A-G and two genotypes of apes, and one conserved probe selected from the HBV pre-S region. To test a clinical sample, the gene targets of clinical samples were amplified and labelled with Cy5-dCTP in a PCR reaction using primers covering the flanking region of the HBV pre-S gene. Following purification, the labelled PCR products were hybridized to the microarray. In an analysis of 96 HBV patients' serum samples using our developed microarray, we identified 34 genotype B, 60 genotype C and 2 genotypes B/C coinfection samples. Sequencing results of 24 randomly selected samples agreed 100% with microarray data. Geographic distribution of genotypes C and B was also divergent, 95.7% (44/46) of genotype C and 64.0% (32/50) of genotype B samples were collected from Northern and Southern China, respectively. The accuracy of genotyping was confirmed by analyzing DNA sequences of 24 samples. It is demonstrated that low-density oligo microarray can serve as a reliable and time-saving method to HBV genotyping from patient's sera.

Nonresponse to 18-month Lamivudine Monotherapy in Chronic Hepatitis B Patients with Dual Genotype B and C Infection and Acute Exacerbation

Molecular epidemiologic studies have indicated the possible existence of mixed infection of different hepatitis B virus (HBV) genotypes in chronic hepatitis B (CH-B) carriers, but the effect of dual HBV genotype B and C infection on the efficacy of lamivudine therapy remains unclear. We report four CH-B patients with dual HBV genotype B and C infection and acute exacerbation who received lamivudine monotherapy for about 18 months. None of them had achieved a sustained response at the end of the 18-month trial of treatment.

Natural history of compensated cirrhosis in the Child-Pugh class a compared between 490 patients with hepatitis C and 167 with B virus infections

Natural histories of compensated cirrhosis in the Child-Pugh class A were compared between the 490 patients infected with hepatitis C virus (HCV) and 167 patients with hepatitis B virus (HBV) who were followed for more than 1 year up to 20 years without antiviral treatment. Patients with HCV were older (median age: 59 vs. 45 years), less predominantly male (59.0% vs. 76.0%), transfused more frequently (49.2% vs. 9.0%), and had higher aminotransferase as well as lower albumin levels and fewer platelets (P < 0.001 for all). Death was commoner (55.1% vs. 35.9%, P < 0.001) and hepatocellular carcinoma developed more often (53.9% vs. 28.7%, P < 0.001) in patients with HCV than HBV. In multivariate analysis, low albumin levels (hazard ratio: 1.65), alpha-fetoprotein (1.55), alcohol consumption (1.49), age >55 years (1.47), and retention of indocyanine green (1.39) were independent risk factors for the survival in patients with HCV, while male gender (4.43), age >45 years (2.24), retention of indocyanine green (2.14), hepatitis B e antigen (2.11), and low platelet counts (1.91) were in those with HBV. Chances for survival was significantly different (P < 0.001) among patients with HCV having low (number of factors: 0-1), medium (2-3), and high risks (4-5), as well as in those with HBV having low (0-1), medium (2-4), and high risks (5-6). In conclusion, survival and development of hepatocellular carcinoma, and factors for survival, are considerably different between patients with compensated cirrhosis infected with HCV and HBV, which would need to be taken into consideration in their management and planning treatment strategies.

Long-term outcome after hepatitis B surface antigen seroclearance in patients with chronic hepatitis B

PURPOSE

The aim of this study was to elucidate the long-term outcome after hepatitis B surface antigen (HBsAg) seroclearance in a large number of Japanese patients.

METHODS

We studied the biochemical, virologic, histologic, and prolonged prognoses of 231 Japanese patients with HBsAg seroclearance (median follow-up, 6.5 years). Serum alanine aminotransferase, serum hepatitis B virus (HBV) markers, liver histology, and clinical aspects were monitored. HBV-DNA levels were measured with the qualitative polymerase chain reaction assay. The mean age of patients with HBsAg seroclearance was 52 years.

RESULTS

After HBsAg seroclearance, 203 patients (87.9%) had normal alanine aminotransferase levels 1 year after HBsAg seroclearance. HBV-DNA showed positive results in 4 patients (1.7%) 1 year after HBsAg seroclearance. Thirteen patients were examined for histologic changes of the liver after HBsAg seroclearance. All patients showed marked improvement of necroinflammation of the liver, but only 2 of the 13 patients showed no liver fibrosis. Liver cirrhosis and hepatocellular carcinoma did not develop in any of the 164 patients without evidence of liver cirrhosis at the time of HBsAg seroclearance. Hepatocellular carcinoma developed in 2 of the 67 patients with liver cirrhosis at the time of HBsAg seroclearance. During the observation period, 15 patients died. However, the cause of death of these 15 patients was not related to liver disease, such as hepatocellular carcinoma, decompensated liver cirrhosis, and rupture of esophageal varices.

CONCLUSION

Our results suggest that HBsAg seroclearance confers favorable long-term outcomes in patients without hepatocellular carcinoma or decompensated liver cirrhosis at the time of HBsAg seroclearance.

Stopping lamivudine therapy after biochemical breakthrough may be a feasible option in selected HBeAg-positive patients

Drug resistance remains a major problem during lamivudine treatment for patients with hepatitis B virus infection. Continuing or stopping lamivudine in patients with biochemical breakthrough is an issue that has not been investigated extensively. Particularly, HBeAg seroconversion and its durability achieved in these settings have never been studied so far. In this study, we compared the clinical outcomes including HBeAg seroconversion in hepatitis B e antigen (HBeAg)-positive patients who either continued or stopped lamivudine treatment after biochemical breakthrough. This was a retrospective cohort study of 73 consecutive patients with biochemical breakthrough followed up for at least 12 months. Of these, 35 (Group I) stopped and the remaining 38 (Group II) continued lamivudine therapy after breakthrough. During 12 months, there was a tendency towards higher rates of HBeAg seroconversion in Group I compared with Group II (P = 0.078). By multivariate analysis, age >or=45 years and acute exacerbation within 6 months of stopping lamivudine were the two independent predictors of HBeAg seroconversion for Group I (P = 0.034 and P = 0.012, respectively). There was no difference in the overall incidence of acute exacerbation and hepatic decompensation between the two groups (P = 0.333 and P = 0.555, respectively). Six patients (17.1%) in Group I developed hepatic decompensation, for which bilirubin >or=1.2 mg/dl was an independent predictor (P = 0.002). The therapeutic gain in continuing lamivudine for biochemical breakthrough is questionable. This study suggests that discontinuation of lamivudine may be an option in older patients with normal bilirubin level.

Distribution of HBV genotypes among HBV carriers in Benin:phylogenetic analysis and virological characteristics of HBV genotype E

AIM: To determine the distribution of Hepatitis B virus (HBV) genotypes in Benin, and to clarify the virological characteristics of the dominant genotype.

METHODS: Among 500 blood donors in Benin, 21 HBsAg-positive donors were enrolled in the study. HBV genotypes were determined by enzyme immunoassay and restriction fragment length polymorphism. Complete genome sequences were determined by PCR and direct sequencing.

RESULTS: HBV genotype E (HBV/E) was detected in 20/21 (95.2%), and HBV/A in 1/21 (4.8%). From the age-specific prevalence of HBeAg to anti-HBe seroconversion (SC) in 19 HBV/E subjects, SC was estimated to occur frequently in late teens in HBV/E. The comparison of four complete HBV/E genomes from HBeAg-positive subjects in this study and five HBV/E sequences recruited from the database revealed that HBV/E was distributed throughout West Africa with very low genetic diversity (nucleotide homology 96.7-99.2%). Based on the sequences in the basic core promoter (BCP) to precore region of the nine HBV/E isolates compared to those of the other genotypes, a nucleotide substitution in the BCP, G1757A, was observed in HBV/E.

CONCLUSION: HBV/E is predominant in the Republic of Benin, and SC is estimated to occur in late teens in HBV/E. The specific nucleotide substitution G1757A in BCP, which might influence the virological characteristics, is observed in HBV/E.

Classifying genotype F of hepatitis B virus into F1 and F2 subtypes

AIM: To explore the propriety of providing hepatitis B virus (HBV) genotypes F and H with two distinct genotypes.

METHODS: Eleven HBV isolates of genotype F (HBV/F) were recovered from patients living in San Francisco, Japan, Panama, and Venezuela, and their full-length sequences were determined. Phylogenetic analysis was carried out among them along with HBV isolates previously reported.

RESULTS: Seven of them clustered with reported HBV/F isolates in the phylogenetic tree constructed on the entire genomic sequence. The remaining four flocked on another branch along with three HBV isolates formerly reported as genotype H. These seven HBV isolates, including the four in this study and the three reported, had a sequence divergence of 7.3-9.5% from the other HBV/F isolates, and differed by >13.7% from HBV isolates of the other six genotypes (A-E and G). Based on a marked genomic divergence, falling just short of >8% separating the seven genotypes, these seven HBV/F isolates were classified into F2 subtype and the former seven into F1 subtype provisionally. In a pairwise comparison of the S-gene sequences among the 7 HBV/F2 isolates and against 47 HBV/F1 isolates as well as 136 representing the other six genotypes (A-E and G), two clusters separated by distinct genetic distances emerged.

CONCLUSION: Based on these analyses, classifying HBV/F isolates into two subtypes (F1 and F2) would be more appropriate than providing them with two distinct genotypes (F and H).

Hepatitis B virus genotype C prevails among chronic carriers of the virus in Korea

Hepatitis B virus (HBV) is one of the major causative agents of chronic liver diseases in Korea. HBV has been classified into 8 genotypes by a divergence of >8% in the entire genomic sequence, and have distinct geographic distributions. There are limited data on the relevance between HBV genotypes and clinical outcomes in Korea. To investigate the clinical feature relating to HBV genotype in Korea, a total 120 serum samples with HBsAg (65 from Seoul and 55 from the other city in Korea) were obtained from each 30 chronic HBV carriers with asymptomatic carrier (ASC), chronic hepatitis (CH), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). HBV genotype was determined by either enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies against genotype-specific epitopes in the preS2-region or the direct sequencing of small S gene. HBV genotypes were determined in 105 (87.5%) of 120 samples. HBV genotype C was identified in all HBV carriers with ASC, CH, LC, and HCC. Genotypes A, B, D, E, F and G were not detected in any of them. Genotype C HBV prevails predominantly among chronic carriers of the virus in Korea, irrespective of their clinical stages of liver disease and geographic origin.

Prevalence of naturally occurring surface antigen variants of hepatitis B virus in Korean patients infected chronically

Although Korea is one of the endemic areas of hepatitis B virus (HBV) infection, the prevalence of naturally occurring variants in the major hydrophilic region (MHR) of the surface (S) gene of HBV has not been determined. In the present study, the prevalence of these variants was examined in terms of the clinical state, and HBeAg serostatus in a large series of Korean patients with chronic HBV infection by direct sequencing analysis of part of the S gene containing the MHR of HBV isolated from 101 chronic HBV patients (51 HBeAg-positive and 50 HBeAg-negative): 37 were asymptomatic carriers, 21 had chronic hepatitis, 20 had liver cirrhosis, and 23 had hepatocellular carcinoma (HCC). Forty-seven MHR variants (46.5%) of the 101 patients were detected, involving a total of 59 amino acid substitutions at 12 positions inside and 14 position outside the 'a' determinant, and 33 'a' determinant variants (32.7%). A total of 17 novel variants and 14 novel mutation patterns were detected. The prevalence of MHR variants in HBeAg-negative patients tended to be higher than in HBeAg-positive patients (54.0% vs.39.2%) and the prevalence of MHR variants in HCC and liver cirrhosis tended to be higher than in asymptomatic carriers (65.2% vs. 40.5% and 50.0% vs. 40.5%, respectively). In conclusion, three important findings were found in the present study. First, an unexpectedly high prevalence of naturally occurring MHR variants was found in Korean chronic patients. Second, several novel variants associated with mutations outside the 'a' determinant were detected. Finally, a higher prevalence of MHR variants was associated with HBeAg-negative serostatus and severe liver disease, particularly HCC.

Genotyping of hepatitis B virus isolated from chronic hepatitis B patients in the south of Turkey by DNA cycle-sequencing method

The 8 genotypes of hepatitis B virus (HBV A-H) show a distinct geographic distribution and influence the course of disease and the prognosis of treatment. In this study, we have genotyped 50 HBV isolates circulating in the south of Turkey by DNA cycle sequencing, based on their compatibility with reference sequences of a part of S gene. In our cases, all 50 (100%) HBV sequences from the patients demonstrated full compatibility with the sequences of ayw subtype viruses in genotype D. However, we have found some nucleotide sequence variations within genotype D, 47 (94%) of which were related to HBVGEN1 (Z35716 genotype D) and 3 (6%) were related to HBVDNA (X68292, genotype D).

Hepatic necroinflammation and fibrosis in patients with genotypes Ba and C, core-promoter and precore mutations

The role of infection with hepatitis B virus (HBV) genotypes on liver histology is largely unknown. The aim of study was to investigate the relationships between HBV genotypes (B, C), core-promoter (CP) and precore mutants and liver histology in 66 patients. Liver biopsies were scored by histologic activity index (HAI). HBV genotypes were determined by enzyme-linked immunosorbent assay (ELISA). Eighteen (27.3%) and 48 patients (72.7%) had genotype B (all were subtype Ba) and C, respectively. Forty-seven (71.2%) and 27 (40.9%) had CP and precore mutations, respectively. Patients with genotype C compared with subtype Ba had higher median scores of HAI-necroinflammation (HAI-NI) (7 vs 3), HAI-fibrosis (HAI-F) (1 vs 0) and total HAI (8.5 vs 3) (all P < 0.03). Patients with CP mutations compared with wild-type had higher median scores of HAI-NI (7 vs 3), HAI-F (3 vs 0) and total HAI (9 vs 3) (all P < 0.03). Forty patients (83.5%) with genotype C had CP mutations. Age and alanine aminotransferase levels were positively correlated with HAI scores while albumin levels were negatively correlated (P < 0.01 for all, except albumin levels and HAI-F, P = 0.08). There was no association between precore mutations and HAI scores. Multivariate analysis indicated that higher alanine aminotransferase (ALT) levels were associated with higher HAI scores (P < 0.04) and CP mutations were associated with higher HAI-NI (P = 0.034), but not with HAI-F score (P = 0.3). CP mutations were associated with more severe necroinflammation. The association between genotype C and poor histology was probably because of the association between genotype C and CP mutations.

Distinct geographic distributions of hepatitis B virus genotypes in patients with acute infection in Japan

Genotypes of hepatitis B virus (HBV) were determined in 145 patients with acute hepatitis B from various districts in Japan to establish their geographic distribution and evaluating the influence on the clinical illness and outcome. Genotypes were A in 27 (19%) patients, B in 8 (5%), C in 109 (75%) and mixed with B and C in the remaining one (1%). Genotype A was more frequent in metropolitan than the other areas (21/69 (30%) vs. 6/76 (8%), P < 0.001). On phylogenetic analysis, seven of the nine (78%) HBV/A isolates selected at random clustered with those from Europe and the United States, while the remaining two with those of subgroup A' prevalent in Asia and Africa. Maximum ALT levels were lower (2069 +/- 1075 vs. 2889 +/- 1867 IU/L, P = 0.03) and baseline HBV DNA titers were higher (5.90 +/- 1.45 vs. 5.13 +/- 1.36 log genome equivalents (LGE)/ml, P = 0.002) in patients infected with genotype A than C. Hepatitis B surface antigen persisted longer in patients infected with genotype A than C (1.95 +/- 1.09 vs. 1.28 +/- 1.42 months, P = 0.02). HBV infection became chronic in one (4%) patient with genotype A and one (1%) with genotype C infection. Fulminant hepatic failure developed in none of the patients with genotype A, one (13%) with genotype B and five (5%) with genotype C. The point mutation in the precore region (A1896) or the double mutations in the basic core promoter (BCP) region (T1762/A1764) were detected in none of the patients with genotype A, two (25%) with genotype B and 27 (26%) with genotype C. In conclusion, genotype A is frequent in patients with acute hepatitis B in metropolitan areas of Japan, probably reflecting particular transmission routes, and associated with longer and milder clinical course than genotype C.

Persistence of acute infection with hepatitis B virus genotype A and treatment in Japan

Among the 97 adult patients with acute hepatitis B who were admitted to the Toranomon Hospital in Metropolitan Tokyo during 28 years from 1976 to 2003, 31 (32%) were infected with hepatitis B virus (HBV) genotype A, nine (9%) with genotype B, 44 (45%) with genotype C, one (1%) each with genotypes E and F. HBV in the remaining 11 (11%) patients were untypeable. All the 31 patients with acute hepatitis B caused by HBV genotype A infection were male with a median age of 31 years, and 16 (52%) contracted infection through extramarital sexual contacts. The baseline HBV DNA level was higher in the seven (23%) patients in whom infection with HBV genotype A persisted than the remaining 24 (77%) with spontaneous resolution (median: >8.7 vs. 6.0 log genome equivalents/ml, P = 0.004). Persistent infection was more frequent in patients with maximum alanine aminotransferase <500 IU/L than > or =500 IU/L (83% [5/6] vs. 4% [1/25], P = 0.0001). Of the six patients with persistent HBV genotype A infection who received interferon and/or lamivuidine for treatment of chronic active hepatitis, three (50%) responded with the loss of hepatitis B e antigen (HBeAg); hepatitis B surface antigen (HBsAg) was cleared from serum in one patient who received interferon and lamivudine in sequence. HBV genotype A persisted along with HBeAg in the remaining three patients given antiviral therapy as well as another who was not treated. In conclusion, infection with HBV genotype A prevails in patients with acute hepatitis B in Japan where genotypes B and C are common, is often contracted sexually (16/31 [52%]) and tends to persist (7/31 [23%]). Infection was cleared in only one of the six (17%) patients who received antiviral therapy.

Characterization of seven genotypes (A to E, G and H) of hepatitis B virus recovered from Japanese patients infected with human immunodeficiency virus type 1

To investigate the prevalence of hepatitis B virus (HBV) genotypes and characteristics of HBV isolates among Japanese patients infected with human immunodeficiency virus type 1 (HIV), serum samples collected between September 1990 and March 2002 from 471 HIV-infected patients (age, 38.8 +/- 11.4 [mean +/- standard deviation] years; male, 90%) were tested for hepatitis B surface antigen (HBsAg) and HBV DNA. Positivity for HBsAg and HBV DNA was seen in 42 patients (8.9%), 41 of whom had contracted HIV infection through sexual activity and 1 had hemophilia. Genotypes of HBV were determined by comparative and phylogenetic analyses of the S gene sequence (396 nucleotides [nt]). The distribution of HBV genotypes among the 42 HBV-viremic patients was: A (50%), B (5%), C (24%), D (5%), E (2%), H (10%), A plus D (2%), A plus G (2%). The hemophilia patient had HBV genotype D. Genotypes E, G, and H which had not been reported in Japan, were found in one patient each who had traveled to Zambia, the US, and South America, respectively. Genotypes A and D, which are rare in Japan, were found in patients who had no history of traveling abroad. The entire genome of the HB-JI411 (genotype E [3,212 nt]), HB-JI444G (genotype G [3,248 nt]), and HB-JI260 (genotype H [3,218 nt]) isolates had the highest identity of 98.3%, 99.9%, and 98.5%, respectively, with reported HBV isolates of the same genotype. Most Japanese patients coinfected with HIV and HBV had HBV genotypes that are found rarely or had not been reported in Japan.

Virological and biochemical relapse after discontinuation of lamivudine monotherapy for chronic hepatitis B in Japan: comparison with breakthrough hepatitis during long-term treatment

OBJECTIVE

Comparison of virological and biochemical relapse in patients with chronic hepatitis B, based on continuation or discontinuation of lamivudine monotherapy.

METHODS

In Japanese genotype C-dominant hepatitis B patients, 25 patients who stopped treatment at normal levels of alanine transferase (ALT) were retrospectively compared with 75 patients who continued treatment. Both groups were matched for age, sex, and observation period after start of treatment. We investigated the relapse rates, and evaluated predictive factors for relapse and efficacy of retreatment of the discontinuous group.

RESULTS

Virological and biochemical relapse occurred significantly earlier in the discontinuous than continuous group, and the peak levels and ratios of peak to pretreatment levels of serum bilirubin and ALT after relapse were not significantly different between the two groups. Multivariate analysis identified three independent factors at discontinuation of treatment associated with early biochemical relapse: HBeAg positivity, presence of liver cirrhosis, detection of basic core promoter mutant. Normalization of ALT levels with retreatment occurred in 62.5% of patients, but 2 HBeAg-positive patients retreated after the emergence of YMDD motif mutant developed severe relapse with hyperbilirubinemia.

CONCLUSION

Our results in Japanese patients with genotype C-dominant hepatitis B suggest that discontinuation of lamivudine monotherapy, and retreatment after the emergence of YMDD mutant should be given attention.

A new subtype (subgenotype) Ac (A3) of hepatitis B virus and recombination between genotypes A and E in Cameroon

Blood samples (n=544) from two different populations (Pygmies and Bantus) in Cameroon, West Africa, were analysed. Serological tests indicated that the anti-hepatitis C virus (HCV) prevalence in Bantus (20.3 %) was higher than that in Pygmies (2.3 %, P<0.0001), whereas the distribution of hepatitis B virus (HBV) serological markers was equally high in both populations: in total, 9.4, 17.3 and 86.8 % for HBsAg, anti-HBs and anti-HBc, respectively. HBV genotype A (HBV/A) and HBV/E were predominant (43.5 % each) in both populations, and HBV/D was found in a minority (13 %). The preS/S region was sequenced in nine cases (five HBV/A and four HBV/E) and the complete genome in six cases (four HBV/A and two HBV/E). Subsequent phylogenetic analysis revealed that the HBV/A strains were distinct from the subtypes (subgenotypes) described previously, Ae (A2) and Aa (A1), and in the preS/S region they clustered with previously reported sequences from Cameroon. Based on the nucleotide difference from Aa (A1) and Ae (A2), more than 4 % in the complete genome, the Cameroonian strains were suggested to represent a new subtype (subgenotype), designated HBV/Ac (A3). A high (3.9 %) nucleotide divergence in HBV/Ac (A3) strains suggested that the subtype (subgenotype) has a long natural history in the population of Cameroon. One of the HBV/Ac (A3) strains was found to be a recombinant with an HBV/E-specific sequence in the polymerase reverse transcriptase domain. Further cohort studies will be required to assess detailed epidemiological, virological and clinical characteristics of HBV/Ac (A3), as well as its recombinant form.

Epitope mapping of recombinant hepatitis B surface antigen by murine monoclonal antibodies

Hepatitis B surface antigen (HBsAg) induces a potent protective antibody response in immunized healthy individuals. The antibody response in humans is largely directed to a restricted conformational immunodominant region of HBsAg, identified as "a" determinant. Our aim was generation and characterization of murine monoclonal antibodies (MAbs) against recombinant HBsAg and their use for epitope mapping of the antigen. Hybridoma cells were established from Balb/c mice immunized with recombinant HBsAg of the "adw" subtype and cloned by limiting dilution. Specificity of MAbs was studied by indirect ELISA and immunoblotting. Topology of the epitopes was analyzed by competitive and inhibition ELISA. Eight hybridoma clones producing MAbs specific for the immunogen were established. Five of the MAbs recognized overlapping conformational epitopes, whereas the remaining three MAbs were found to identify linear epitopes. Cross-inhibition studies suggest recognition of mutually exclusive epitopes by these MAbs. Our data suggest that, similar to the human system, the mouse antibody response is largely directed to restricted conformational overlapping epitopes of HBsAg.

Effect of lamivudine in HBeAg-positive chronic hepatitis B: Discordant effect on HBeAg and HBV DNA according to pretreatment ALT level

AIM: To clarify differences in antiviral effect of the drug in patients with different ALT levels, we examined the changes in HBV markers in patients with high or low ALT levels with or without lamivudine treatment.

METHODS: Thirty-seven HBeAg-positive patients were studied. Ten patients with ALT levels higher than 200 IU/L (group 1) and 8 patients with ALT below 200 IU/L (group 2) were treated orally with 100 mg/d of lamivudine. As untreated control, 9 patients with ALT above 200 IU/L (group 3) and 10 patients with ALT below 200 IU/L (group 4) were examined. ALT level, HBeAg/HBeAb status, and HBV DNA level were examined monthly for 11.9±0.4 mo.

RESULTS: The ALT level normalized in all 10 patients of group 1, 7/8 of group 2, 4/9 of group 3, and 1/10 of group 4 within 6 mo (groups 1 vs 2, P = NS; groups 1 vs 3, P = 0.002; groups 1 vs 4, P<0.0001). HBV DNA fell below the detection limit in all 10 patients of group 1, 7/8 of group 2, 0/9 of group 3, and 0/10 of group 4 within 6 mo (groups 1 vs 2, P = NS). HBeAg became seronegative in 7/10 patients of group 1, 1/8 of group 2, 3/9 of group 3, and 0/10 of group 4 within 12 mo (groups 1 vs 2, P = 0.02; groups 1 vs 3, P = NS).

CONCLUSION: Our data suggest that HBeAg-positive patients with higher ALT levels can be considered good candidates for lamivudine therapy, probably because lamivudine accelerates the natural seroconversion of HBeAg, accompanied by HBV DNA loss, in these patients.

Co-Infection with Hepatitis B Virus Genotype D and Other Genotypes in Western Japan

OBJECTIVE

Genotypes B and C are the prevalent hepatitis B virus (HBV) genotypes in eastern Asia. Although very rare in this region of the world, genotype D was found to be prevalent in a small area of western Japan. In this study, we confirm the frequency and clinical significance of co-infection with different genotypes among patients from that area infected with genotype D.

METHODS

Twenty-three patients from the same area of western Japan infected with HBV genotype D, determined using a genotyping enzyme immunoassay, were studied. Cloning was done using DNA extracted from serum samples, and polymerase chain reaction assays with the restriction fragment length polymorphism for HBV genotyping were performed with 10 clones from each patient.

RESULTS

Four (17.4%) of the 23 patients were found to be co-infected with HBV genotype C, and the HB surface antigen subtype was ayw in both mono- and co-infected patients. No clinical differences were found between mono-infected and co-infected patients carrying genotype D.

CONCLUSION

A significant number of patients from the study area found to be infected with HBV genotype D were co-infected with genotype C. Additional study with a larger number of patients is needed to elucidate the possible clinical significance.

Virological differences between patients infected with subtypes Ba and Bj of hepatitis B virus genotype B

BACKGROUND

Hepatitis B virus (HBV) genotype B is classified into subtype Ba with the recombination with genotype C in the precore region plus core gene and subtype Bj without recombination. Virological and clinical differences between infections with subtypes Ba and Bj, however, are yet to be determined.

METHODS

During 1976 through 2001, 224 patients visited Toranomon Hospital in Tokyo, Japan who were infected with HBV genotype B. Subtypes of genotype B were determined by sequencing HBV-DNA recovered from sera for detecting recombination with genotype C.

RESULTS

Subtype Ba was detected in 53 patients (24%) and Bj in 167 (75%); subtypes were not able to be determined in the remaining four (1%). The only virological difference was that detection of hepatitis B e antigen at the presentation was more frequent in the patients infected with subtype Ba than those with Bj (63% vs 33%, P = 0.016). There were no differences in the distribution of liver disease of various forms between the patients infected with subtypes Ba and Bj at presentation. No differences were noted, either, in the development of liver cirrhosis or hepatocellular carcinoma, or the loss of hepatitis B surface antigen from serum, between the patients infected with subtypes Ba and Bj during follow up of up to 26 years.

CONCLUSIONS

Although there were some virological differences between the patients infected with subtypes Ba and Bj of HBV genotype B, they do not seem to influence the long-term clinical outcome.

Comparison of full length sequences of hepatitis B virus isolates in hepatocellular carcinoma patients and asymptomatic carriers of Korea

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.

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.

Hepatitis B virus: significance of genotypes

Hepatitis B Virus (HBV) genotypes have come of age. The concept that HBV genotypes may influence the course of disease and relevant biological differences has now been recognised. However, there are still major gaps in our knowledge. Most clinical data come from Asia and describe findings in patients infected with genotypes B and C. Large scale studies with genotypes A and D as found in Europe or A, D and E from Africa are urgently needed to broaden our understanding. Experimental data which explain in vivo findings in terms of differences in molecular biology in vitro are still in the beginning. The succeeding years will see many interesting studies which will aid our understanding of how variants and genotypes of HBV influence the spectrum of disease in people infected with HBV.