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Background: We determined the antiviral potency and viral breakthrough rate after 10 years of continuous entecavir treatment in patients with chronic hepatitis B (CHB) infection., Methods: The cumulative rates of undetectable hepatitis B virus DNA (HBV-DNA, < 2.1 log copies/mL), alanine aminotransferase (ALT) normalization, hepatitis B e antigen (HBeAg) seroclearance, hepatitis B surface antigen (HBsAg) seroclearance, and viral breakthrough of 1094 nucleos(t)ide analogue-naïve CHB patients (HBeAg-positive: 47%) who were on continuous entecavir treatment for 10 years were calculated., Results: The median age was 50 years and follow-up period was 5.5 years, with 999, 804, 591, 390, 182 and 87 patients followed up for at least 1, 3, 5, 7, 9 and 10 years, respectively. Incremental increases were noted in the rates of undetectable HBV-DNA, ALT normalization, HBeAg seroclearance, and HBsAg seroclearance, reaching 96, 79, 38 and 3.7%, respectively, by the tenth year. The mean decline in HBsAg level from baseline was - 0.08 log IU/mL/year. Multivariate analysis identified HBsAg level and genotype (A) as independent predictors of HBsAg seroclearance. Sixteen patients experienced viral breakthrough. The cumulative percentages of patients with viral breakthrough analyzed by the Kaplan-Meier test were 1.5 and 2.5% at years 5 and 10, respectively. There were no serious adverse events during treatment., Conclusions: Long-term entecavir treatment of nucleos(t)ide analogue-naïve CHB patients was associated with an excellent viral response and a low rate of entecavir-resistant mutations at 10 years. Baseline HBsAg levels and genotype were predictors of HBsAg seroclearance during entecavir treatment.

It is currently unclear what impact serum microRNA-122 (miR-122) levels have on clearance of hepatitis B virus (HBV) surface antigen (HBsAg) in HBV-infected patients who had not received antiviral therapy. The current study evaluated the impact of serum miR-122 levels on HBsAg seroclearance in 367 consecutive HBV-infected patients who had not received antiviral therapy between their initial and last visit, and investigated the predictive factors of HBsAg seroclearance. Cumulative HBsAg seroclearance rates were 13.5%, 32.0%, and 37.4% after 10, 20, and 30 years, respectively. The yearly incidence of HBsAg seroclearance over the investigated 30-year period was 1.25%. A significant and strong correlation was observed between serum miR-122 and HBsAg levels. Moreover, there was a significant correlation between serum miR-122 levels and the levels of HBV DNA, hepatitis B e-antigen, and HBV core-related antigen. The HBsAg seroclearance rate in patients with a <1.0-fold change of serum miR-122 levels was significantly higher than in those with a ≥1.0-fold change. Multivariate analysis identified age (≥30 years), HBV DNA levels (<2.2 log U/mL), HBV genotype (non-C), and serum miR-122 levels (<1.0-fold change) as significant predictors of HBsAg seroclearance. Our results indicated that serum miR-122 level is an important predictor of HBsAg seroclearance in Japanese patients who do not receive antiviral therapy. Understanding the complexity of the interactions among various virus-related and host-related factors could potentially help in the design of new therapies that enhance HBsAg seroclearance., (© 2018 Wiley Periodicals, Inc.)

Background & Aims: Genome-wide association studies (GWAS) recently indicated that polymorphisms in the human leucocyte antigen (HLA)-DP genes were associated with risk of persistent hepatitis B virus (HBV) infection and clearance of HBV, but the effect of HLA-DP gene polymorphisms on the effect of antiviral therapy was unknown. We here investigated whether such polymorphisms were associated with decreases in HBsAg levels and seroclearance in patients who received long-term lamivudine (LAM) treatment., Methods: Japanese patients (202) who were hepatitis B e antigen positive at baseline, received LAM as first-line treatment, and consented to HLA-DP genotyping (HLA-DPA1 rs3077 and HLA-DPB1 rs9277535) were categorized into two cohorts, viz., a cohort who achieved virological response without rescue therapy (cohort 1) and those who did so with rescue therapy (cohort 2)., Results: Serum HBsAg levels declined significantly between year 3 and 9 from baseline among cohort 1 patients possessing ≥2 A-alleles at rs3077 and rs9277535. The percentages of such patients in cohort 1 patients with decreases in HBsAg ≥0.5 log IU/ml were higher than those with <2 A-alleles (71.8% [28/39] vs. 38.9% [23/59]; P = 0.004). However, there was no significant difference in cumulative HBsAg seroclearance rates between patients with ≥2 and those with <2 A-alleles in cohort 1. In cohort 2, HBsAg seroclearance rates were higher in patients with ≥2 A-alleles than in those with <2 A-alleles (P = 0.003)., Conclusion: We found an association between HLA-DP polymorphisms and decreases in HBsAg levels and seroclearance among HBeAg-positive patients treated with LAM., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Few studies have investigated the emergence of multidrug resistance to adefovir dipivoxil (ADV) plus lamivudine (LAM) combination therapy for patients with LAM-refractory chronic hepatitis B (CHB). In this retrospective study, we investigated the long-term clinical course of these patients with or without multidrug resistance mutations., Methods: We analyzed 406 Japanese patients with LAM-refractory CHB treated with combination therapy with follow-up for a median of 5.4 (0.5-9.5) years. Multidrug resistance of hepatitis B virus (HBV) DNA was analyzed using direct sequencing or cloning methods at baseline and viral breakthrough or insufficient decline during combination therapy., Results: Ratio of patients with undetectable serum HBV DNA levels (<2.6 log copies/mL) during combination therapy was 63, 72, 75, 79, 82, 80 and 85 % at years 1 through 7, respectively. Substitutions associated with multidrug resistance were identified in 11 patients (2.7 %) at baseline, and in 12 patients (3 %) during therapy. HBV DNA levels of patients with rtA181S mutation at baseline and emergence of rtA181T + rtN236T double mutation or a wide variety of mutations during combination therapy could not be suppressed. Moreover, using ultra-deep sequencing, rtA181T/V mutations were detected at baseline in 7 of 10 patients with emergent multidrug resistance during combination therapy, although 6 of these 7 patients had very low frequency (<1 %) variants., Conclusion: Long-term ADV plus LAM combination therapy is effective in LAM-refractory patients. However, HBV DNA levels of the patients with multidrug resistance at baseline or during combination therapy sometimes could not achieve complete suppression or were re-elevated after a decrease.

Background: Rate of hepatitis B surface antigen (HBsAg) seroclearance was determined in 2,112 Japanese patients with chronic hepatitis B who were followed up for at least 15 years., Methods: Patients had a median age of 37 years and included 1,431 (67.8 %) men. Median values were AST/ALT, 43/62 IU/L; platelet counts, 182 × 10(3)/mm(3); HBsAg, 3,400 IU/mL; and hepatitis B virus (HBV) DNA, 6.2 log copies/mL. Factors influencing HBsAg seroclearance were evaluated by the Cox proportional model and annual rate of HBsAg seroclearance by the Kaplan-Meier life table method., Results: The overall annual rate of HBsAg seroclearance was 1.75 % in 2,112 patients; it was 1.65 % in 1,130 untreated and 2.05 % in 982 treated patients (p = 0.289). In untreated patients, seroclearance was influenced by age, no HBV infections in third-degree or closer relatives, and HBsAg levels in univariate analysis. Seroclearance was influenced by a median age ≥50 years [relative risk (RR) 1.61 (p = 0.018)] and HBsAg ≤2,000 IU/mL [RR 1.77 (p = 0.014)] in multivariate analysis. In treated patients, age, male gender, no HBV infections in third-degree or closer relatives, interferon therapy, chronic hepatitis, high AST and γ-GTP levels, low platelet counts, hepatitis B e antigen (HBeAg)-negative status, low HBsAg levels and the wild-type precore sequence significantly influenced HBsAg seroclearance. In multivariate analysis, no family history [RR 2.22 (p = 0.006)], interferon treatment [RR 3.15 (p < 0.001)], and HBeAg-negative status [RR 3.75 (p < 0.001)] significantly influenced HBsAg seroclearance., Conclusions: In this retrospective cohort study, the annual rate of HBsAg seroclearance was 1.65 % in untreated patients and 2.05 % in treated patients.

Background: Clearance of hepatitis B surface antigen (HBsAg) is considered the ultimate goal in chronic hepatitis B treatment. One treatment option is long-term nucleot(s)ide analog (NA) therapy. We followed a group of long-term NA therapy patients to evaluate the efficacy of this treatment in promoting clearance and longitudinal declines of HBsAg., Method: The study included 791 NA therapy patients who received lamivudine as their first drug. At the baseline, 442 patients were hepatitis B e antigen (HBeAg)+ and 349 were HBeAg-. All analyses were performed after separating the HBeAg+ and HBeAg- cohorts. Cox proportional hazards models were used to determine which factors were associated with HBsAg clearance., Results: HBsAg clearance was observed in 18 (4.1 %) of the HBeAg+ patients and 20 (5.7 %) of the HBeAg- patients at baseline, giving seroclearance rates of 6.4 and 6.9 %, respectively, over the nine-year study period. HBsAg clearance was influenced by several independent factors that varied according to HBeAg cohort. For HBeAg+ patients, these included previous interferon therapy, infection with hepatitis B virus (HBV) genotype A, a ≥0.5 log IU/mL decline in HBsAg level within six months, and clearance of HBeAg at six months. For HBeAg- patients, these included infection with HBV genotype A, decline in HBsAg at six months, and a baseline HBsAg level of <730 IU/mL., Conclusion: This study suggests that both direct antiviral potential and host immune response are needed to achieve HBsAg clearance by NA therapy. Viral genotype strongly influenced HBsAg clearance during NA therapy.

Background: Severe acute exacerbation of chronic hepatitis B can sometimes occur and lead to hepatic failure and death. The objective of this study was to elucidate the predictors of progression to hepatic decompensation during severe acute exacerbation., Methods: We prospectively analyzed 37 consecutive patients with acute exacerbation of chronic hepatitis B (accompanied by jaundice and coagulopathy) for clinical outcome and factors that influenced the development of severe acute exacerbation, including viral kinetics., Results: Fourteen (37.8%) patients progressed to severe acute exacerbation (accompanied by encephalopathy). Multivariate analysis identified serum bilirubin (>5 mg/dl, P = 0.002) as a significant determinant of progression to hepatic failure and prothrombin activity (<45%, P = 0.028) and as a determinant of liver-related death. The hepatitis B virus (HBV) DNA level before therapy was measured in 25 patients. HBV DNA levels increased or did not change from before commencement of treatment in all 11 patients who progressed to severe acute exacerbation. On the other hand, HBV DNA levels did not change or increased in 8 of 14 patients (57%) with acute exacerbation (P = 0.02)., Conclusions: Serum bilirubin and prothrombin activities were significant predictors of clinical outcome in patients with severe acute exacerbation of chronic hepatitis B. Viral kinetics until commencement of therapy can predict the severity of acute exacerbation of chronic hepatitis B.

Background & Aims: We determined the antiviral potency and viral resistance rate after 4 years of continuous entecavir treatment in patients with chronic hepatitis B (CHB) infection., Methods: The cumulative rates of undetectable hepatitis B virus DNA (HBV DNA;<2.6 log(10) copies/ml), hepatitis B e antigen (HBeAg) seronegativity, seroconversion, alanine aminotransferase (ALT) normalization, and entecavir signature mutations were calculated in 474 nucleos(t)ide-naïve CHB patients (HBeAg-positive: 47%) on continuous entecavir treatment for 4 years., Results: Median age was 47 years and follow-up period was 2.4 years, with 403, 281, 165, and 73 patients followed-up for at least 1, 2, 3, and 4 years, respectively. Incremental increases were observed in the rates of undetectable HBV DNA, HBeAg seroclearance and seroconversion, and ALT normalization, reaching 96%, 42%, 38% and 93%, respectively, by the fourth year. In all, 100% and 93% of patients negative and positive for HBeAg, respectively, had undetectable HBV DNA at year 4. Of 165 patients, HBV DNA was detectable in nine patients after 3 years. Multivariate analysis identified HBV DNA level (≤7.6 log(10) copies/ml, OR=15.8; 95% CI=43.1-79.9, P=0.001) as an independent predictor of undetectable HBV DNA at year 3. Five patients experienced virological breakthrough including two (0.4%) who developed entecavir-resistance mutations., Conclusions: Continuous treatment of nucleos(t)ide-naïve CHB patients with entecavir over 4 years was associated with 96% chance of undetectable HBV DNA and only 0.4% chance of emerging entecavir-resistant mutations., (Copyright © 2012 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Early detection of resistant mutations of hepatitis B virus (HBV) is important for patients on nucleos(t)ide analog therapy. An assay based on the PCR-Invader technology was developed to detect resistant mutations with high sensitivity. The assay specifically detects mutations at codons 180, 181, 184, 202, 204, and 250 of the HBV polymerase reverse transcriptase domain. These mutations result in resistance to lamivudine and entecavir. In mixtures of plasmids containing wild-type and resistant mutants, fold-over-zero values for resistant mutations were detected in 2% of the total. Seventy-five serum samples from patients, whose treatment had been switched from lamivudine to entecavir, were examined by the PCR-Invader assay and direct sequencing. The PCR-Invader assay detected all resistant mutations that were detected by direct sequencing and even detected the presence of mutants that direct sequencing could not. Cloning sequencing confirmed those mutations found by the PCR-Invader assay and not by direct sequencing. The PCR-Invader assay is a useful tool for the early detection of drug-resistant mutations., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Background/aims: The recurrence rate of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is high even in patients receiving curative therapy. In this study, we analysed the risk factors for tumour recurrence after curative therapy for HBV-related HCC while under treatment with nucleot(s)ide analogues (NAs) by measuring serum HBcrAg and intrahepatic covalently closed circular DNA (cccDNA) levels to elucidate the viral status associated with HCC recurrence., Methods: We enrolled 55 patients who developed HCC during NA therapy and underwent either curative resection or percutaneous ablation for HCC., Results: Hepatocellular carcinoma recurred in 21 (38%) of the patients over a period of 2.2 (range, 0.2-7.4) years. In multivariate analysis, serum HBcrAg levels ≥4.8 log U/ml at the time of HCC diagnosis (hazard ratio, 8.96; 95% confidential interval, 1.94-41.4) and portal vein invasion (3.94, 1.25-12.4) were independent factors for HCC recurrence. The recurrence-free survival rates of the high cccDNA group were significantly lower than those of the low cccDNA group only in patients who underwent resection (P=0.0438). A positive correlation (P=0.028; r=0.479) was observed between the intrahepatic cccDNA and the serum HBcrAg levels at the incidence of HCC., Conclusion: HBcrAg is a predictor of the post-treatment recurrence of HCC during antiviral therapy. Serum HBcrAg and intrahepatic cccDNA suppression by NAs may be important to prevent HCC recurrence., (© 2010 John Wiley & Sons A/S.)

Ideally, long-term lamivudine therapy should not induce tyrosine-methionine-aspartate-aspartate (YMDD) mutants (reverse transcription [rt]; rt M204I/V) in patients with chronic hepatitis B. There is little or no information on the clinical features of patients who do not develop such mutants. We analyzed 368 patients who received lamivudine therapy for more than 6 months between 1995 and 2003. Among them, 98 patients were negative for YMDD mutants during 5-year lamivudine therapy. Multivariate analysis identified hepatitis B e antigen (HBeAg) negativity, lack of cirrhosis, and high gamma glutamyltranspeptidase (GGTP) level as independent factors associated with lack of emergence of YMDD mutants during 5-year treatment. In these 98 patients, 21 patients developed YMDD mutants in the 5-year posttreatment follow-up. Old age was identified as the only factor associated with the emergence of YMDD mutants during that period. For all patients, 53 showed no elevation of alanine aminotransferase (ALT) or viral load after emergence of YMDD mutants during 5 years. Short latency to emergence of YMDD mutants, mixed (tyrosine-isoleucine-aspartate-aspartate (YIDD) [rtM204I] + tyrosine-valine-aspartate-aspartate (YVDD) [rtM204V]) type, and low ALT level were identified as independent factors associated with elevation ALT or viral load. HBeAg negativity, lack of cirrhosis, and high GGTP level were associated with lack of emergence of YMDD mutants during 5-year period. Young age protected against emergence of YMDD mutants over the 5-year period. Moreover, after the emergence of YMDD mutants, short latency to the emergence of YMDD mutant, mixed type mutants, and low baseline ALT level were associated with elevation of ALT or viral load., (2010 Wiley-Liss, Inc.)

Background and Aims: Long-term lamivudine therapy is required for patients with chronic hepatitis B, because hepatitis reappears frequently after it has withdrawn. However, hepatitis B virus (HBV) mutants resistant to lamivudine emerge frequently accompanied by breakthrough hepatitis., Methods: Effects of entecavir were evaluated in 19 patients who had developed breakthrough hepatitis during lamivudine therapy for longer than 5 years. This study is a subgroup analysis of a previously reported study. Entecavir, in either 0.5 or 1.0 mg/day doses, was given to 10 and nine patients for 52 weeks, respectively, and then all received 1.0 mg/day entecavir for an additional 68-92 weeks., Results: There were no differences in biochemical and virological responses in the two groups of patients with respect to the two different initial doses of entecavir. Serum levels of alanine aminotransferase were normalized in 17 (90%) patients, and hepatitis B e antigen (HBeAg) disappeared from the serum in two (14%) of the 14 patients who were HBeAg-positive before. Furthermore, a decrease in histological activity index score greater than 2 points was achieved in nine of the 11 (82%) patients in whom annual liver biopsies were performed during 3 years while they received entecavir. HBV mutants resistant to entecavir emerged in five of the 19 (26%) patients, and hepatitis flare occurred in two of them (40%)., Conclusion: Entecavir in the long term would be useful for histological improvement of breakthrough hepatitis induced by lamivudine-resistant HBV mutants in patients with chronic hepatitis B. However, the relatively high rate of entecavir resistance is a concern, and other strategies need to be considered when available.

During 35 years from 1971 to 2005, 153 patients with acute and 4,277 with chronic HBV infection visited the Toranomon Hospital in Tokyo, Japan. They were grouped into seven 5-year periods, and HBV genotypes/subgenotypes were determined. Patients with acute HBV infection were younger (P = 0.046), predominantly male (P = 0.004), possessed higher alanine aminotransferase levels (P < 0.001), positive more frequently for HBeAg (P < 0.001), and had lower HBV DNA loads (P = 0.014) than those with chronic infection. Sexual transmission was more frequent in patients with acute than chronic HBV infection (67% vs. 3%, P < 0.001). The number of patients with acute infection increased throughout 1971-2005. Patients with chronic infection increased since 1971, peaked in 1986-1990 and then decreased. The number of patients increased since 1990-2000 again, however, reflecting recent boost of acute HBV infection. The distribution of HBV genotypes was considerably different between patients with acute and chronic infections (A, B, and C: 28.6%, 10.3%, and 59.5% vs. 3.0%, 12.3%, and 84.5%, respectively, P < 0.001). Since 1991, genotype A foreign to Japan started to increase sharply in patients with acute infection, and gradually in those with chronic infection. There was a trend for the foreign subgenotype B2/Ba to increase recently (P < 0.05). Despite immunoprophylaxis of high-risk babies born to carrier mothers with hepatitis B e antigen, implemented nationally since 1986, acute and chronic infections with HBV have been increasing in Japan. Based on genotypes/subgenotypes changing with time, the resurgence of hepatitis B could be attributed to infections, with foreign HBV genotypes/subgenotypes, spreading swiftly by sexual contact., (2008 Wiley-Liss, Inc.)

Aims: The long-term efficacy of adefovir dipivoxil in combination with lamivudine to chronic hepatitis B virus (HBV) infection is still unclear., Methods: Virological response and hepatocarcinogenesis during lamivudine + adefovir were investigated in 183 lamivudine-resistant Japanese patients with chronic genotype C-dominant HBV infection. As the predictors of virological response, an assessment of clinical parameters and a nucleotide (nt) sequence analysis of the negative regulatory element to core gene (nt 1611-2450) were performed at the start of adefovir., Results: The cumulative HBV-DNA non-detectable and ALT normalization rates were 93.6 and 97.6% at the end of 3 years, respectively. Multivariate analysis identified total bilirubin, AST, and nt substitutions (nt 1762, 1768, 1846, 1896, 2134, 2288, 2441) as determinants of early non-detectable HBV-DNA. The yearly incidence of hepatocellular carcinoma (HCC) during the first 3 years was 2.7%. At the diagnosis of HCC, ALT normalization, HBV-DNA non-detectable, and HBeAg-seronegative conversion rates were 75.0, 83.3, and 57.1%, respectively. Furthermore, the cumulative HBV-DNA non-detectable and ALT normalization rates were not significantly different according to the development of HCC or not., Conclusions: Lamivudine-resistant patients treated with lamivudine + adefovir could achieve the excellent virological response and biochemical response, but the low hepatitis activity was not enough to suppress hepatocarcinogenesis., (Copyright 2009 S. Karger AG, Basel.)

Emergence of a lamivudine (LAM)-resistant hepatitis B virus (HBV) with amino acid substitutions in the YMDD motif is a well-documented problem during long-term LAM therapy. Entecavir (ETV) is a new drug approved for treatment of HBV infection with or without LAM-resistant mutants. This report describes an ETV-resistant strain of HBV, which emerged after prolonged ETV therapy in a patient who did not respond to LAM therapy. Direct sequence analysis of the ETV-resistant strain showed appearance of amino acid substitution rtS202G in the reverse transcriptase (RT) domain, together with rtL180M + M204V substitution that had developed at the emergence of LAM-resistant mutant. In vitro analysis demonstrated that the rtL180M + M204V + S202G mutant strain displayed a 200-fold and a 5-fold reduction in susceptibility to ETV compared with the wild- type and the rtL180M + M204V mutant strain, respectively. Adefovir was effective against the ETV-resistant strain both in vitro and during the clinical course. In conclusion, this study showed that virological and biochemical breakthrough due to ETV could occur in patients infected with LAM-resistant HBV and confirmed that the addition of rtS202G substitution to the rtL180M + M204V mutant strain is responsible for ETV resistance and we could treat the resistant mutant successfully., ((c) 2007 Wiley-Liss, Inc.)

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., ((c) 2007 S. Karger AG, Basel.)

We present a case report of a Japanese patient who showed prolonged infection after acute hepatitis B with genotype H. The patient was a 60-year-old man who underwent an annual health care check every year for several years and was never pointed out to have any liver damage, and markers for hepatitis B and C were negative. He was found to be positive for hepatitis B surface antigen (HBsAg) at his health care check in December 2005. After one month, he had an elevated aminotransferase level with hepatitis B e antigen and a high level of serum HBV DNA. He was diagnosed as having acute hepatitis B. On HBV genotype, he had genotype H by the direct sequence method, and he was given a 100 mg of lamivudine daily. However, his acute hepatitis tended to go toward prolonged infection. After two months, he was treated with interferon daily for 28 days. He had negative HBsAg in August 2006. Genotype H, the newest type of hepatitis B, could be the type which shows a poor response to lamivudine. The present paper is the first report, describing the clinical course of acute hepatitis B with genotype H from onset to remission.

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.

Amino acid substitutions in the S gene of hepatitis B virus (HBV), especially in the 'a' determinant region, have been suggested to affect the antigenicity of the virus and the clinical outcome of the infected patient. However, no convincing evidence has been presented for this hypothesis, partly because the 3D structure of the S protein has not been determined. Comparative analysis of viral genes offers an approach to testing this hypothesis, as it may reveal signals of natural selection and provide insights into the functional significance of the observed amino acid substitutions. In this study, we analyze HBV S gene sequences obtained from 24 patients infected with HBV genotypes B or C, together with 16 representative viral strains of HBV genotypes A-F retrieved from GenBank. We use phylogenetic methods to infer evolutionary changes among HBV genotypes and to identify amino acid residues potentially under positive selective pressure. Furthermore, we employ the fragment assembly method to predict structural changes in the S protein. The results showed that an amino acid substitution within the 'a' determinant, T126I, was unique to genotype C, may affect the antigenicity of the HBsAg, and may result in poorer clinical outcomes of patients infected with genotype C viral strains. We suggest that an integrated approach of evolutionary comparison and structural prediction is useful in generating hypotheses for further laboratory validation.

Purposes: To elucidate the incidence of hepatitis activation and hepatocellular carcinogenesis in patients with negative HBe antigen and normal aminotransferase, long-term observation was performed in a retrospective cohort., Methods: Among 116 consecutive patients with normal aminotransferase and negative HBe antigen at the time of liver biopsy, sequential frozen sera for initial 5 years were available for 95 patients. Hepatitis B virus (HBV) DNA assay (sensitivity >400 copy/mL) and aminotransferase were annually examined in the initial 5 years after biopsy., Results: Liver biopsy showed minimal hepatitis (F0) in 9, F1 in 53, F2 in 21, F3 in 6, and F4 or cirrhosis in 6. Initial HBV DNA concentration was low (less than 10(4) copies/mL) in 33, intermediate (10(4)-10(6)) in 53, and high (10(6) or more) in 9. Hepatitis activation rates with twice as high as normal aminotransferase at the end of the third year were 12.1% in the low DNA group, 43.4% in the intermediate group, and 66.7% in the high DNA group. Initial HBV DNA values were significantly associated with future increase in aminotransferase (P <.0001). Initial DNA, history of aminotransferase elevation, and histological staging independently affected future hepatitis activation. Carcinogenesis rate in patients with and without high DNA of 10(6) copies/mL during the initial 3 years were 6.9% and 0%, respectively, at the end of the 5th year, and 11.5% and 1.8%, respectively, at the 10th year, (P=.021)., Conclusion: Advanced stages of hepatitis were sometimes found in HBe antigen-negative, aminotransferase-normal HBV carriers. Serial HBV DNA assessment in early 3 years predicted future hepatitis activation and carcinogenesis.

Lamivudine is a major drug approved for treatment of chronic hepatitis B virus (HBV) infection. Emergence of drug-resistant mutants with amino acid substitutions in the YMDD motif is a well-documented problem during long-term lamivudine therapy. Here we report a novel lamivudine-resistant strain of HBV with an intact YMDD motif, which included an amino acid substitution, rtA181T, in the reverse transcriptase (RT) domain of HBV polymerase. The substitution also induced a unique amino acid substitution (W172L) in the overlapping hepatitis B surface (HBs) protein. The YMDD mutant strains were not detected even by using the sensitive peptide nucleic acid-mediated PCR clamping method. The detected nucleotide substitution was accompanied by the emergence of an additional nucleotide substitution that induced amino acid change (S331C) in the spacer domain. The rtA181T mutant strain displayed a threefold decrease in susceptibility to lamivudine in in vitro experiments in comparison with the wild type. In vivo analysis using human hepatocyte-chimeric mice confirmed the resistance of this mutant strain to lamivudine. We developed a method to detect this novel rtA181T mutation and a previously reported rtA181T mutation with the HBs stop codon using restriction fragment length polymorphism PCR and identified one patient with the latter pattern among 40 patients with lamivudine resistance. In conclusion, although the incidence is not high, we have to be careful regarding the emergence of lamivudine-resistant mutant strains with intact YMDD motif.

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.

The addition of adefovir dipivoxil (ADV) to ongoing lamivudine therapy is effective against lamivudine-resistant virus in patients with hepatitis B virus (HBV) infection. We studied 39 patients who received ADV added to lamivudine for breakthrough hepatitis. We determined early viral changes (12 weeks) in YMDD mutants (rtM204I [YIDD sequence], rtM204V [YVDD]) and rtL180M in all 39 patients as well as amino acid changes in the polymerase reverse transcriptase (rt) region and precore/core promoter mutations in 15 patients who received long-term treatment (more than 1 year). Changes in rtM204I and rtL180M viral loads were greater than that of the rtM204V, albeit statistically insignificant. Moreover, the greatest change in viral load was seen for rtM204I without hepatitis B e antigen (HBeAg). The precore mutant was replaced with wild-type virus in three of eight patients after 1 year of added ADV therapy. Compared to baseline with lamivudine therapy only, new amino acid mutations were seen in the rt region at baseline with ADV in seven patients. At 1 year after ADV coadministration, the YMDD motif was replaced with wild-type (rt204M) in two patients, in whom mutations were fewer and of a different type. We conclude that the rtM204I may be more sensitive to ADV in vivo. ADV tended to select wild-type virus from precore mutants. Moreover, viruses that were wild-type in the rt region reappeared after 1 year of ADV coadministration in some patients., (2006 Wiley-Liss, Inc.)

Patients who develop YMDD mutant during lamivudine therapy for hepatitis B virus (HBV) infection exhibit various clinical courses. Some patients show normal ALT levels, whereas others develop severe hepatitis exacerbations (SHEs) due to YMDD mutants. We studied 136 patients with YMDD mutant among 362 Japanese adult patients on lamivudine therapy. Clinical and virological features of patients without elevated HBV DNA after emergence of YMDD mutant (non-elevated group) were investigated. Moreover, virological analysis was also performed in patients with SHE due to YMDD mutants. Patients in the non-elevated group were characterized by HBeAg-negative pretreatment, HBeAg loss during therapy, a longer duration from commencement of therapy until emergence of YMDD mutant, and no mixed-type YMDD mutants. Patients with SHE had more substitutions in the reverse transcriptase (rt) region within the polymerase gene at the time of exacerbation than those without SHE, although no specific substitutions were noted. Sequence analysis of full-length HBV genome showed more substitutions in X, rt, and surface proteins in patients with SHE than in those without elevated HBV DNA level. In conclusion, negativity for HBeAg at commencement of therapy or before emergence of YMDD mutant was an important factor among non-elevated group. More substitutions in the rt region and the other proteins may be related to the emergence of severe hepatitis caused by lamivudine-resistant virus.

In a single hospital in Tokyo, the 87 patients infected persistently with hepatitis B virus (HBV) genotype A, the 413 with B, and the 3,389 with C were compared for virological outcome. Hepatitis B surface antigen (HBsAg) was cleared from the serum in 12% (3/26), 2% (2/112), and 3% (23/826) of patients with genotypes A, B, and C, respectively, at 5 years of follow-up (P = 0.0395). Hepatitis B e antigen (HBeAg) was cleared from serum more frequently in patients with genotype B than those with A or C (78% [32/41] vs. 58% [11/19] or 45% [251/562], P = 0.00001) at 5 years. Of the 45 individuals infected with genotype A and followed for 3 years or longer, HBeAg was more frequent (16% [3/19] vs. 73% [19/26], P = 0.0002) and levels of HBV DNA higher (median <2.6 [range: <2.6-5.6] vs. >7.6 [<2.6->7.6] log copies/ml, P = 0.001) in the 26 patients with biopsy-proven chronic hepatitis than the 19 asymptomatic carriers. Among the 26 hepatitis patients infected with HBV genotype A, decreases in HBV DNA were less frequent (20% [1/5] vs. 93% [13/14] or 86% [6/7], P = 0.0095) and increases in serum levels of hyaluronic acid > or =10 ng/ml commoner (80% [4/5] vs. 14% [2/14] or 14% [1/7], P = 0.017) in the patients who kept HBeAg than in those who seroconverted or who remained HBeAg-negative. In conclusion, patients persistently infected with HBV genotype A fare better than those with genotype B or C. However, high levels of HBV DNA continue in those in whom HBeAg persists along with fibrosis in the liver.

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., (Copyright 2005 Wiley-Liss, Inc.)

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.

The long-term efficacy of lamivudine therapy in patients with hepatitis B virus (HBV) infection is still not clear. In this study, 20 non-cirrhotic Japanese patients infected with HBV received lamivudine therapy for more than 1 year and were followed for a median period of 8.5 years (range, 6.7-8.7 years). The rates of HBe antigen (HbeAg) negative, HBV-DNA undetectable, and alanine aminotransferase (ALT) normal level at the start of lamivudine were 55%, 25%, and 20% and 85%, 80%, and were 80%, respectively, at the last visit, including patients who received additional treatment. The values at the last visit tended to and were significantly higher than those at the start. The values improved at the last visit regardless of the emergence of YMDD motif mutant and continuation of lamivudine. YMDD mutant and biochemical relapse with mutant virus (breakthrough hepatitis) appeared in 65% and 45% during follow-up, respectively, but severe breakthrough hepatitis occurred in only 5%. Furthermore, 80% of patients who received additional treatment for breakthrough hepatitis, regardless of continuation of lamivudine, were ALT normal level at the last visit, in contrast to 25% untreated. HBsAg clearance occurred in two patients of the discontinuous lamivudine group with non-vertical transmission, who were relatively young. One was infected with HBV genotype C with breakthrough hepatitis and the other had no YMDD mutant and was infected with genotype D, a rare type in Japan. None developed cirrhosis or hepatocellular carcinoma (HCC) during follow-up. Our results suggest that long-term lamivudine therapy improves long-term prognosis, especially when additional treatment for breakthrough hepatitis is used., ((c) 2005 Wiley-Liss, Inc.)

Hepatitis B virus (HBV) has been classified into eight genotypes (A-H) based on genome sequence divergence. Genotypes of HBV have distinct geographical distributions, and two genotypes account for most HBV worldwide. Hepatitis B e antigen expression lasts longer and liver disease is more severe with graver outcomes in carriers of genotype C than B in Asia. Accumulating lines of evidence indicate a better response to interferon and lamivudine in patients with chronic hepatitis B who are infected with genotype B rather than C. The therapeutic response may differ, however, in patients infected with HBV of the same genotype. For example, the response to lamivudine is poorer in patients infected with subtype Ba, which contains a recombination with genotype C, than in those with subtype Bj without such a recombination. Influence of genotypes on therapeutic response needs to be examined in patients infected with the other genotypes, particularly in those with genotype A or D infection.

To elucidate the influence of serum hepatitis B virus (HBV) load on hepatocellular carcinogenesis in cirrhotic patients, HBV-DNA was sequentially measured. In a nested, case-control study using 96 patients without antiviral therapy, high HBV-DNA (> or =10(3.7) copies/ml) in the last 3 years was significantly associated with carcinogenesis (a patient group without hepatocellular carcinoma (HCC) development; 0/48 vs. a patient group with eventual HCC development; 22/48, p < 0.0001). No patient with a continuously low HBV-DNA for the last 3 years developed HCC. Persistence of high HBV-DNA concentration suggested an increased risk of carcinogenesis. In a retrospective cohort study using 57 patients with interferon therapy, HCC developed in 2 (8.0%) of the 25 patients with HBV-DNA loss, while carcinogenesis was found in 11 (34.4%) of 32 patients without HBV-DNA loss (Fisher's exact test, p = 0.026). A significant decrease or loss of serum HBV-DNA stops HCC development, and its sequential analysis could be very useful both in the prediction and early detection of small HCC.

Hepatitis B virus (HBV) genotypes B (HBV/B) and C (HBV/C) are prevalent in Asia. Recently HBV/B has been classified into two subtypes, HBV/Ba which is ubiquitously found in Asia, and HBV/Bj which is specific in Japan. In addition, the frequency of positive HBeAg has been reported to be higher in patients with HBV/Ba than those with HBV/Bj. However, little is known about the differences between patients with various genotypes who developed hepatocellular carcinoma (HCC). In 296 serum samples of HCC patients collected from all over Japan, HBV genotypes were determined with the restriction fragment length polymorphism. HBV/A was detected in 1.0%, HBV/Ba in 4.4%, HBV/Bj in 7.4%, and HBV/C in 86.5%. In the Tohoku district and Okinawa, HBV/Ba, HBV/Bj and HBV/C were found in 6.7, 40.0 and 48.9%, compared to 4.0, 1.6 and 93.2% in the other districts in Japan. HBV/Bj patients were more frequently found in the group older than 65 years while HBV/Ba patients were found in all age groups. The frequency of positive HBeAg in HBV/Bj patients was significantly low compared to that in the other patients. More than 60% of the patients with HCC had cirrhosis as the underlying liver diseases. However, in HBV/Ba patients aged 50 years or younger, 80% of them had chronic hepatitis, while 87.5% of those aged older than 50 years had cirrhosis. These data suggest that great differences exist among patients with HCC infected with different genotypes., (Copyright (c) 2005 S. Karger AG, Basel.)

Background and Aim: Because the anti-carcinogenic effect and mechanism of interferon (IFN) in patients with hepatitis B virus (HBV)-related cirrhosis have not been elucidated, quantitative analysis of HBV-DNA concentration was carried out sequentially., Method: Of 60 consecutive patients with cirrhosis who began IFN therapy between 1986 and 1990, 57 patients were completely observed for the appearance of hepatocellular carcinoma (HCC). All patients underwent intermittent administration of IFN for a median period of 18 months. HBV-DNA was quantified using transcription mediated amplification and hybridization protection assay. A HBV-DNA count <3.7 log-genome equivalent (LGE)/mL (equivalent to 10(3.7) or 5000 copies/mL) was considered to be a negative value., Results: Of 25 patients who had HBV-DNA loss after IFN therapy, nine lost HBV-DNA during the therapy and 16 lost HBV-DNA after cessation of the therapy. The other nine patients showed a transient loss of HBV-DNA, and the remaining 23 retained persistently positive HBV-DNA during and after therapy. Although HCC developed in two (8.0%) of the 25 patients with HBV-DNA loss, carcinogenesis was found in 11 (34.4%) of 32 patients without HBV-DNA loss (Fisher's exact test, P = 0.026). In the two exceptional patients, HCC was detected at 1.2 and 3.6 years after loss of HBV-DNA, respectively. When the HBV-DNA concentration decreased by 2 LGE/mL (decrease to 1/100) at 6 months after initiation of interferon, HBV-DNA became negative eventually in 15 (60.0%) of 25 patients., Conclusion: A significant decrease or loss of serum HBV-DNA prevents development of HCC, and sequential analysis of HBV-DNA could be very useful in both the prediction and the early detection of small HCC.

Hepatitis B virus (HBV) mutants with mutations in the YMDD motif of viral DNA polymerase/reverse transcriptase are described in patients infected with HBV who have not received lamivudine therapy, but their pathogenetic potential is not clear. These mutants were detected by the polymerase chain reaction with peptide nucleic acid clamping in pretreatment sera from two patients who later received lamivudine. One patient developed acute exacerbation with hepatic encephalopathy and received lamivudine along with plasma exchange, which were effective on his illness. YIDD mutants were detected in all three pretreatment sera and both posttreatment sera from him. HBV DNA clones from pretreatment and posttreatment sera, however, did not have the same amino acid sequence. In the other patient who developed severe breakthrough hepatitis after receiving lamivudine, YIDD mutants were detected in two pretreatment and two posttreatment sera. When amino acid sequences of HBV DNA clones with the YIDD mutation were compared before and after he received lamivudine, however, they were not in accord. Hence, YIDD mutants in both patients with chronic hepatitis B before treatment were not selected by lamivudine after they had been placed on it. Numerous amino acid conversions were detected in HBV DNA clones with YIDD mutations, and some of them created stop codons in the overlapping S gene sequence. In Conclusion, HBV mutants with mutations in the YMDD motif in patients before treatment would not be selected by lamivudine or induce breakthrough hepatitis, and some of these would not be replication-competent due to stop codons in the S gene.

Background: Because genotype A of hepatitis B virus (HBV) is not indigenous, there have been only few data on infection with it in Japan., Methods: We examined clinical and virological features of the 66 Japanese patients who admitted Toranomon Hospital in Tokyo, Japan, between 1976 and 2001, who were found to have HBV/A infection. HBV genotype A was classified into subtype A (European type) and A' (South African type) by phylogenetic analysis of the preS1 and preS2 regions, and the S gene sequences., Results: Of the 66 patients infected with HBV/A, 14 (21%) were asymptomatic carriers, 26 (39%) presented with acute hepatitis, 22 (33%) with chronic hepatitis, and 4 (6%) with liver cirrhosis. HBV/A infection persisted for more than 6 months in 5 of the 26 (19%) patients with acute hepatitis. The frequency of acute hepatitis in patients infected with HBV/A was higher after than before 1991 (2/22 [9%] vs 24/44 [55%]; P < 0.0001). The frequency of nucleotide 1858 of T was higher in asymptomatic carriers than in patients with acute hepatitis in whom infection was resolved (5/14 [36%] vs 0/21 [0%]; P = 0.008). Of the 57 patients for whom subtypes of genotype A were determined, subtype A was identified in 53 (93%) and subtype A' in only 4 (7%). All patients infected with subtype A' were persistently infected with HBV., Conclusions: HBV/A infection has become more frequent during recent years, predominantly presenting as acute hepatitis, and subtype A' is uncommon in the Tokyo metropolitan area.

We have previously reported 2 subtypes of hepatitis B virus (HBV) genotype B, one of which has the recombination with genotype C over the precore region plus core gene (Ba) and the other of which does not (Bj). A restriction fragment-length polymorphism method with 2 endonucleases was newly developed for distinguishing between subtypes Ba and Bj and was applied to 313 carriers of HBV genotype B in Japan. Subtype Ba was detected in 38 (12%) and subtype Bj in 275 (88%) of the carriers of HBV genotype B. Hepatitis B e antigen in serum was found more frequently in patients with chronic infection with subtype Ba than in those with chronic infection with subtype Bj (8 [32%] of 25 vs. 25 [9%] of 273; P<.01). The new method for distinguishing between Ba and Bj by restriction fragment-length polymorphism would be useful in examining the distribution of these 2 subtypes in situations in which HBV genotype B is prevalent.

Complete nucleotide sequences of 19 hepatitis B virus (HBV) isolates of genotype A (HBV/A) were determined and analysed along with those of 20 previously reported HBV/A isolates. Of the 19 HBV/A isolates, six including three from Japan and three from the USA clustered with the 14 HBV/A isolates from Western countries. The remaining 13 isolates including four from The Philippines, two from India, three from Nepal and four from Bangladesh clustered with the six HBV/A isolates reported from The Philippines, South Africa and Malawi. Due to distinct epidemiological distributions, genotype A in the 20 HBV isolates was classified into subtype Ae (e for Europe), and that in the other 19 into subtype Aa (a for Asia and Africa) provisionally. The 19 HBV/Aa isolates had a sequence variation significantly greater than that of the 20 HBV/Ae isolates (2.5+/-0.3 % vs 1.1+/-0.6 %, P<0.0001); they differed by 5.0+/-0.4 % (4.1-6.4 %). The double mutation (T1762/A1764) in the core promoter was significantly more frequent in HBV/Aa isolates than in HBV/Ae isolates (11/19 or 58 % vs 5/20 or 25 %, P<0.01). In the pregenome encapsidation (epsilon) signal, a point mutation from G to A or T at nt 1862 was detected in 16 of the 19 (84 %) HBV/Aa isolates but not in any of the 20 HBV/Ae isolates, which may affect virus replication and translation of hepatitis B e antigen. Subtypes Aa and Ae of genotype A deserve evaluation for any clinical differences between them, with a special reference to hepatocellular carcinoma prevalent in Africa.

Objective: Adefovir dipivoxil (ADV) is a nucleoside analogue that inhibits wild-type hepatitis B virus (HBV) and lamivudine-resistant HBV mutants in vitro and in vivo. The aim of this study was to evaluate the efficacy of ADV against lamivudine-resistant mutants and of adefovir and interferon (IFN) add-on to lamivudine for patients with severe acute exacerbation of hepatitis caused by lamivudine-resistant mutants., Methods: Fourteen patients with breakthrough hepatitis were treated with ADV. Four of the 14 patients also received IFN as combined treatment for severe acute exacerbation of hepatitis., Results: At week 24, serum HBV DNA levels had significantly decreased by a median of over 4.8 log copies/ml in the ADV group and over 5.9 log copies/ml in the ADV + IFN group compared to baseline. The median decrease in alanine aminotransferase (ALT) levels from baseline to week 24 was -1.05 times the upper limit of normal (ULN) in the ADV group [significant at week 24 compared with baseline (p = 0.012)] and -22.3 times the ULN in the ADV + IFN group., Conclusions: Administration of ADV add-on to lamivudine for patients with breakthrough hepatitis reduced HBV DNA and ALT levels. ADV and IFN add-on to lamivudine could prevent a fatal course in patients with severe acute exacerbation of hepatitis., (2004 S. Karger AG, Basel.)

Background: Lamivudine is used for the treatment of chronic hepatitis B (CH-B), and exhibits excellent antiviral activity. However, longterm administration increases the likelihood of the emergence of resistant viruses, with an accompanying relapse of hepatitis. However, recent studies have reported lamivudine-resistant viruses in patients with CH-B before such treatment. The aim of this study was to investigate whether YMDD mutants occur in nature., Methods: The existence of lamivudine-resistant viruses was examined in 20 asymptomatic carriers of hepatitis B virus (ASC), 10 patients who lost hepatitis B surface antigen (HBsAg) during follow-up and in 20 lamivudine-treated patients with and without breakthrough hepatitis. Both polymerase chain reaction (PCR) restriction fragment length polymorphism and SMITEST hepatitis B virus (HBV)-YMDD mutation detection methods were used to detect resistant viruses., Results: No YMDD mutants were detected in the sera of the 20 ASC at the initial and final medical examinations, nor were YMDD mutants detected in sera collected at the initial medical examination, about 6 months before, or immediately after the loss of HBsAg in the 10 patients. In the 20 patients treated with lamivudine, YMDD mutants were not detected in any of them before treatment, whereas mutants were detected in the sera of 10 patients during treatment., Conclusions: Our results suggest that lamivudine-resistant YMDD mutant viruses were present in a few patients with HBV infection before they have been treated with lamivudine.

Whether the type of lamivudine-resistant virus in hepatitis B virus (HBV) influences the clinical outcome, it is not completely understood. We evaluated the serial changes in YMDD motif mutant in 60 Japanese genotype C-HBV patients who received long-term lamivudine monotherapy. YIDD or YVDD alone tended to stop shifting to the mixed type (YVDD and YIDD) within 12 months after the detection of mutant virus. Hence, the characteristics, virological relapse (DNA breakthrough) and biochemical relapse (breakthrough hepatitis) of 49 patients, who could be classified into three types (continuous YVDD, continuous YIDD, and the mixed type), were investigated. YVDD and YIDD type tended to have the opposite background with regard to age, histology, and viral load. The mixed and YIDD types tended to have similar backgrounds, except for viral load. In the mixed type, both the HBeAg-positive rate and viral load as risk factors for emergence of the mutant tended to be high. Mutant virus, DNA breakthrough and breakthrough hepatitis emerged significantly earlier in the mixed type than the two other types. The incidence of severe breakthrough hepatitis accompanied by icteric flare-up tended to be higher in the mixed type than the other types. Our results suggest that the YMDD motif mutant type might emerge from different backgrounds and modulate the virological and biochemical relapse after the emergence. Large-scale studies of each mutant type should be conducted in the future to confirm these findings., (Copyright 2003 Wiley-Liss, Inc.)

HBe antigen (HBeAg) loss or seroconversion can occur during lamivudine therapy. The purpose of this study was to analyze nucleotide sequences in precore and core promoter regions, and examine the influence of mutations in these regions on the disappearance of HBeAg during lamivudine therapy. Serial serum samples were obtained from 51 patients (HBeAg loss in 26 patients) at commencement of therapy (baseline) and after 1 year of lamivudine therapy. Serum samples were amplified with PCR and nucleotide sequences of HBV were analyzed. At baseline, a precore stop codon mutation (A1896) was identified in 8 of 26 HBeAg loss patients and in 8 of 25 HBeAg non-loss patients. At 1 year, precore mutation was observed in 4 of 14 patients analyzed who showed HBeAg loss. At 1 year, however, a precore mutation was observed also in 3 of 9 analyzed patients who showed no HBeAg loss. Core promoter mutations were noted in 21 of 26 HBeAg loss patients and in 20 of 25 HBeAg non-loss patients. At 1 year, core promoter mutations were noted in 11 of 14 HBeAg loss patients and in 8 of 9 HBeAg non-loss patients. Our data suggested that during lamivudine therapy, core promoter and precore mutations do not influence HBeAg loss or seroconversion but may reduce the viral level upon HBeAg loss or seroconversion., (Copyright 2003 Wiley-Liss, Inc.)

Background/aims: Genotype-dependent development of lamivudine resistance in hepatitis B virus (HBV) has not been reported., Methods: We determined the cumulative rate of emergence of YMDD motif mutant in 213 Japanese patients with chronic hepatitis B infected with genotype A, B, or C and treated with lamivudine for more than 1 year., Results: The emergence rate of lamivudine resistance was independent of the genotype (A, B, and C). In contrast, the emergence rate was significantly higher in the Ba ("a" stands for Asia) subgroup of HBV than in Bj ("j" for Japan) subgroup (P<0.05). For genotype C (HBV/C), the emergence rate in hepatitis B e antigen (HBeAg)-positive was significantly higher than in HBV/C-HBeAg-negative (P<0.05), but the rate in HBV/B-HBeAg-positive was similar to HBV/B-HBeAg-negative. Only four patients with HBV/C developed severe acute exacerbation of hepatitis accompanied by emergence of YMDD mutant, but none of the patients with other genotypes developed such complication., Conclusions: Our results suggest that lamivudine resistance in HBV does not seem to depend on the genotype but rather on the subgroup of HBV/B. The results also suggest that lamivudine resistance according to HBeAg state might be different between HBV/B and HBV/C. Large-scale prospective studies of each genotype should be conducted in the future to confirm these findings.

Background: To elucidate the influence of serum hepatitis B virus (HBV) load on hepatocellular carcinogenesis in cirrhotic patients, HBV-DNA was sequentially measured., Patients and Methods: Among 160 consecutive patients with HBV-related cirrhosis who received no anti-viral therapy, serial assay of HBV-DNA concentration was available in 146 (91.3%): 48 developed hepatocellular carcinoma (HCC) and 98 did not during a median of 11.7 years. HBV-DNA of 10(3.7) copies/ml or less was considered as low., Results: Of the 48 cases with eventual HCC development (group A), 9 showed intermittently high HBV-DNA, and the other 39 persistently high values. Among 48 age- and sex-matched control patients (group B) selected from the 98 HCC-free patients, 9 had continuously low HBV-DNA, 13 showed a settled down course of HBV-DNA, 9 intermittently high, and the remaining 17 patients demonstrated continuously high HBV-DNA. High HBV-DNA in the last 3 years was significantly associated with carcinogenesis (group A; 0/48 vs. group B; 22/48, p < 0.0001). No patient with a continuously low HBV-DNA for the last 3 years developed HCC., Conclusion: Persistence of high HBV-DNA concentration suggested an increased risk of carcinogenesis. Sequential analysis of HBV-DNA is important in the assessment of the carcinogenesis risk., (Copyright 2003 S. Karger AG, Basel)

Background: Hepatitis B virus (HBV) genotype A is predominant in northern Europe and central Africa. In the present study, we examined the clinical features associated with HBV genotype A disease in the Tokyo metropolitan area., Methods: We investigated 53 cases of HBV surface antigen (HBsAg)-positive Japanese patients with HBV genotype A. The 53 cases were further classified as to their serum alanine aminotransferase (ALT) status being within the normal range (asymptomatic carriers, n = 17), chronic hepatitis (n = 15), liver cirrhosis (n = 4), and acute hepatitis (n = 17)., Results: Chronic hepatitis patients had significantly higher HBV DNA levels (P = 0.003) and hepatitis B e antigen (HBeAg) positivity rates at the initial visit than did asymptomatic carriers or patients with liver cirrhosis (P = 0.003 and P = 0.054, respectively). The efficacy of treatment (HBeAg seroconversion rate) was 75% in 12 chronic hepatitis patients, which was excellent. A family history of HBsAg positivity was identified in eight (15%) families (five asymptomatic carriers, three with chronic hepatitis). However, none of the mothers in the study was positive for HBV genotype A., Conclusions: Maternal transmission of HBV has often been reported in Japan, but our present findings suggest that horizontal infection of HBV genotype A is more prevalent in the Tokyo metropolitan area. Our data indicate that HBV genotype A exhibits a mode of infection different from that of conventional HBV previously seen in Japan.

Objective: Factors influencing the resolution of persistent hepatitis B virus (HBV) infection were sought for., Methods: The loss of hepatitis B surface antigen (HBsAg) from serum was correlated with mutations in HBV DNA for a hepatitis B e antigen (HBeAg)-minus phenotype in patients infected with HBV genotype C and positive for HBeAg at presentation., Results: HBeAg turned negative in all the 22 patients in whom HBV infection resolved, but only in 11 of the 25 patients with severe liver diseases (100 vs. 44%, p = 0.0001). The precore wild type (G1896) persisted significantly more frequently in the 22 patients in whom HBV infection resolved than in the 11 patients who developed decompensated liver cirrhosis or hepatocellular carcinoma (15/22 or 68% vs. 1/11 or 9%, p = 0.005). The double mutation in the core promoter (T1762/A1764) was comparably frequent in the two groups of patients at presentation (14/22 or 64% vs. 7/11 or 64%) and >15 years thereafter (18/22 or 82% vs. 10/11 or 91%)., Conclusion: The precore wild type (G1896) would seem to facilitate the resolution of HBV infection, while the precore mutant (A1896) may induce severe liver diseases in patients with HBeAg-positive chronic hepatitis who have lost HBeAg from serum., (Copyright 2003 S. Karger AG, Basel)

From September 1995 through April 2002, 286 patients with chronic hepatitis B were started on lamivudine at the Toranomon Hospital in Tokyo, Japan, and most of them continued with it. At present, 16 patients received lamivudine for 5 years, 7 of whom for 7 years or longer. YMDD mutants increased gradually and developed in 69% of them during the 7 years on lamivudine. Biochemical and virological responses were achieved in 9 of the 16 patients (56%) at 5 years, and in 4 of the 7 patients (57%) at 7 years. Histological assessments were performed at 3 years in the 16 patients and further at 4 and 7 years in the 7 patients. Necroinflammatory changes improved remarkably with a decrease in the total histological activity score from 11.3 +/- 3.0 to 4.1 +/- 1.7 (p < 0.0001) at 3 years in the 16 patients. Histological improvements continued in 4 of the 7 patients (57%) at 7 years on lamivudine, while the pathology was unchanged in 2 patients (29%) and aggravated in the remaining 1 patient (14%). Severe acute exacerbation of hepatitis developed in 1 patient, who received additional interferon-alpha therapy to cope with it. Based on my experience, the continuation of lamivudine in patients with chronic hepatitis B benefits approximately two thirds of them with persistent virological and biochemical responses accompanied by histological improvements. Breakthrough hepatitis induced by YMDD mutants along the way in a small number of patients needs to be diagnosed promptly by regular monitoring for transaminases and, if it develops, it can be treated with interferon or other antiviral agents., (Copyright 2003 S. Karger AG, Basel)

Objective: Several reports have examined the efficacy of long-term lamivudine therapy and the risk factors involved in emergence of viral resistance in Japanese patients with hepatitis B virus (HBV) infection. However, the patient cohorts in such studies are relatively small., Methods: We analyzed 234 chronically HBV-infected Japanese patients who were treated with lamivudine for more than 12 months. They comprised patients with HBV genotype A (n = 8), genotype B (n = 21), genotype C (n = 203) and other HBV genotypes (n = 2)., Results: In most patients, lamivudine resulted in normalization of alanine transaminase (ALT) levels at 6 and 12 months, and suppression of serum HBV DNA to undetectable levels by the branched chain DNA probe assay (bDNA). Rates of ALT normalization and non-detection of HBV DNA were higher among patients with genotype B than genotype C disease. The proportions of patients who achieved HBeAg loss were 27, 42 and 45% after 6 months, 1 year and 2 years, respectively. The emergence of mutations was not different among genotypes A, B and C by the Kaplan-Meier method. Multivariate analyses identified high HBV DNA level (bDNA >or=100 MEq/ml) as an independent factor associated with emergence of the YMDD motif mutation in all patients. Among patients with genotype C disease, which is the predominant HBV genotype in Japan, multivariate analysis also identified high HBV DNA level and HBeAg positivity as factors associated with emergence of resistance., Conclusion: Patients exhibiting these factors at the commencement of lamivudine treatment must be monitored carefully at regular intervals for emergence of viral resistance., (Copyright 2003 S. Karger AG, Basel)

Objective: The long-term effects of lamivudine and the influence of YMDD mutants on the histology of chronic hepatitis B are not known., Methods: 3-year lamivudine therapy was given to 16 patients with chronic hepatitis B. YMDD mutants did not develop in 9 patients (group A), while they appeared in the remaining 7 patients (group B)., Results: Biochemical and virological responses were invariably achieved in the 9 patients without YMDD mutants, while virological breakthroughs with or without biochemical relapses occurred in all 7 patients with such mutants. All 16 patients accomplished histological improvement, with the total histology activity index (HAI) score decreasing from 11.3 +/- 3.0 to 4.1 +/- 1.7 (p < 0.001). The total HAI score decreased from 11.6 +/- 3.8 to 3.4 +/- 1.3 in the 9 patients in group A (p < 0.001). Although to a significantly lesser extent (p < 0.02), the total HAI score also decreased in the 7 patients in group B from 10.9 +/- 1.0 to 5.0 +/- 1.7 (p < 0.001)., Conclusion: The results obtained indicate that 3-year lamivudine therapy can induce histological improvements, regardless of the appearance of YMDD mutants accompanied by virological breakthroughs and biochemical relapses., (Copyright 2003 S. Karger AG, Basel)

Background/aims: Comparison of long-term prognosis in patients with chronic hepatitis B treated with lamivudine, with or without severe acute exacerbation (SAE)., Methods: In chronic hepatitis B HBeAg-positive patients on lamivudine monotherapy, 21 patients with SAE were retrospectively compared with 63 patients without SAE. Both groups were matched for age and sex. We investigated the efficacy and problems associated with monotherapy with respect to SAE., Results: In SAE and non-SAE, HBeAg seroconversion rates were 21.1 vs. 27.6%, 20.0 vs. 50.0%, and 14.3 vs. 66.7% at 1, 2, and 3 years, respectively. YMDD mutant emerged later in SAE than in non-SAE, but the emergence rates in SAE almost exceeded those of non-SAE from 2 years (rates of about 35%). DNA breakthrough (hepatitis B virus DNA becoming detectable after a period of negativity, accompanied by emergence of YMDD mutant) and breakthrough hepatitis (alanine aminotransferase becoming abnormal after a period of normalization, accompanied by DNA breakthrough) also appeared later in SAE than in non-SAE, but the rates in SAE exceeded those of non-SAE at 3 years., Conclusions: Our results suggest that Japanese genotype C-dominant hepatitis B patients with SAE seem to be at greater risk of re-exacerbation after temporary relief of the initial SAE by long-term lamivudine monotherapy, compared with those without SAE.

Acute hepatitis B virus (HBV) infection was diagnosed in 57 adults admitted to Toranomon Hospital in Tokyo, Japan. Genotypes of HBV were determined by a serological method and compared to those in 1,077 patients with chronic hepatitis B. The distribution of genotypes were: genotype A (acute, 22.8% vs. chronic, 1.9%; P < 0.00001); B (14.0% vs. 9.4%); C (43.9% vs. 87.7%, P = 0.004); D (1.8% vs. 0.2%); F (1.8% vs. 0.2%); and unable to be typed (15.8% vs. 0.6%, P = 0.001). The infection persisted in seven (12%) of them. They included six (86%) of the seven patients who received prednisolone or glycyrrhizin during an acute phase of illness and one of the 41 (2%) who did not (P = 0.01). Interferon was given to the seven patients with acute prolonged HBV infection, and four of them responded by clearing hepatitis B e antigen (HBeAg) and surface antigen (HBsAg) from serum. Of the four responders, one was infected with HBV genotype B and three with genotype C. HBsAg persisted in the remaining three patients all of whom were infected with HBV genotype A, and HBeAg stayed positive in one of them. These results indicate that HBV genotype A prevails in Japanese patients with acute hepatitis B, and suggest a high efficacy of interferon in the adult patients with acute prolonged HBV infection, except in those infected with HBV genotype A., (Copyright 2002 Wiley-Liss, Inc.)