Clinical and virological features of non-breakthrough and severe exacerbation due to lamivudine-resistant hepatitis B virus mutants.

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.

Association of amino acid substitution pattern in core protein of hepatitis C virus genotype 1b high viral load and non-virological response to interferon-ribavirin combination therapy.

Objective: Patients with high titer (>/=100 kIU/ml) of hepatitis C virus (HCV) genotype 1b do not achieve highly sustained virological response rates to combination therapy with interferon plus ribavirin. Non-virological responders (NVRs, namely ultimate resistant cases) who do not achieve HCV-RNA negativity during treatment are also encountered. We investigated the pretreatment virological features of NVRs.

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.

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.

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.

Clinical and virological characteristics of untreated patients with chronic hepatitis C who develop serum alanine aminotransferase flare-up.

Among patients with chronic hepatitis C virus (HCV) infection, serum alanine aminotransferase (ALT) rarely increases above 500 IU/L. We examined the clinical and virological features of untreated patients with serum ALT > or = 500 IU/L. One thousand seven hundred and sixty adult patients with chronic HCV infection were followed-up.

Efficacy of lamivudine treatment in Japanese patients with hepatitis B virus-related cirrhosis.

Background: Several clinical trials have suggested that lamivudine therapy is effective in patients with hepatitis B virus (HBV)-related cirrhosis. However, there are few studies of lamivudine therapy in Japanese patients with HBV cirrhosis. The aim of this study was to evaluate the efficacy of lamivudine therapy in Japanese patients with cirrhosis, and to evaluate the clinical course after the emergence of YMDD mutants.

Infection with hepatitis B virus genotype A in Tokyo, Japan during 1976 through 2001.

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.

Efficacy of 6-month interferon therapy in chronic hepatitis B virus infection in Japan.

Background: In Japan, there are few studies of long-term (more than 1 month) interferon (IFN) therapy for chronic hepatitis B (CHB). In this retrospective study, we investigated the efficacy and predictors of response to 6-month IFN therapy.

Methods: We analyzed 66 Japanese patients with CHB who were treated with IFN for 6 months.

YMDD mutants in patients with chronic hepatitis B before treatment are not selected by lamivudine.

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.

Peripheral CD8+/CD25+ lymphocytes may be implicated in hepatocellular injuries in patients with acute-onset autoimmune hepatitis.

Background: The mechanism of liver injuries in autoimmune hepatitis (AIH) is not fully understood, especially because the onset is insidious and the clinical courses fluctuate with spontaneous exacerbation and improvement even without immunosuppressive therapies.

Methods: Eleven patients with acute-onset AIH, some of whom were without hypergammaglobulinemia or anti-nuclear antibodies, and 41 patients with chronic AIH were compared serologically, biochemically, and histologically to determine differences in liver injuries between patients with acute-onset and chronic AIH. All patients fulfilled the diagnostic criteria according to a scoring system proposed in 1999.

Hepatocellular carcinoma in noncirrhotic young adult patients with chronic hepatitis B viral infection.

Background: The aims of this study were to define the clinical characteristics of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in young adult patients without cirrhosis and to evaluate the efficacy of interferon (IFN) therapy on HCC recurrence.

Methods: Of 187 patients with HBV-related HCC treated at our hospital, 4 had no liver cirrhosis and were less than 30 years of age (10, 22, 23, and 26 years).

Results: At the time of diagnosis of HCC, all cases had antibody to hepatitis B e antigen (anti-HBe) and histological staging of nontumorous liver was F0 or F1, i.

Severe acute exacerbation of liver disease may reduce or delay emergence of YMDD motif mutants in long-term lamivudine therapy for hepatitis B e antigen-positive chronic hepatitis B.

The pretherapy factors that could influence the emergence of resistant hepatitis B virus (HBV) tyrosine-methionine-aspartate-aspartate (YMDD) motif mutants against lamivudine are not fully known in prolonged lamivudine therapy for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B. We analyzed prospectively 116 consecutive lamivudine-naïve patients who received long-term lamivudine therapy (>1 year) by using multivariate regression analyses. The cumulative HBeAg loss rates were 29, 44, and 47% at 1, 2, and 3 years of treatment, respectively.

Low rate of YMDD motif mutations in polymerase gene of hepatitis B virus in chronically infected patients not treated with lamivudine.

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.

Virological and biochemical relapse according to YMDD motif mutant type during long-term lamivudine monotherapy.

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.

Clinical features of hepatitis B virus genotype A in Japanese patients.

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.

Efficacy of lamivudine therapy and factors associated with emergence of resistance in chronic hepatitis B virus infection in Japan.

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.

Precore wild-type hepatitis B virus with G1896 in the resolution of persistent hepatitis B virus infection.

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.

HBe antigen loss during lamivudine therapy is not caused by mutations in precore and core promoter genes in patients with chronic hepatitis B.

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.

Viral genotypes and response to interferon in patients with acute prolonged hepatitis B virus infection of adulthood in Japan.

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.

Clinical characteristics of patients infected with hepatitis B virus genotypes A, B, and C.

Background: The aim of the present study was to evaluate the clinical characteristics at first hospital consultation, according to the genotype of hepatitis B virus (HBV), in patients with chronic liver diseases and positivity for hepatitis B surface antigen (HBsAg) in metropolitan Tokyo.

Methods: The subjects consisted of 1077 patients with chronic liver diseases who were HBsAg-positive. HBV genotype was determined by an enzyme-linked immunosorbent assay (ELISA), using PreS2 monoclonal antibody, which is specific for HBV genotypes in the PreS2 region.