Clearance of serum HBsAg and anti-HBs seroconversion following antiviral therapy for chronic hepatitis B.

In this study, we have analyzed the evolution of serum HBsAg levels in 16 patients with chronic hepatitis B who showed an HBsAg seroconversion following antiviral therapy. The data showed that the clearance of serum HBsAg is slower than that of serum HBV DNA, which may reflect a slow kinetics of clearance of infected hepatocytes. Interestingly, HBsAg was detectable for a longer time using the Architect assay than with the Bio-Rad assay. As viremia suppression is achieved in most patients under therapy with the new generation of nucleoside analogs, these data suggest that the quantitative monitoring of serum HBsAg may represent a novel tool for the assessment of antiviral therapy efficacy.

Adefovir dipivoxil is effective for the treatment of cirrhotic patients with lamivudine failure.

BACKGROUND/AIMS: Data on the efficacy of adefovir dipivoxil (ADV) in elderly and cirrhotic patients with lamivudine-resistant (LAM-R) chronic hepatitis B are scarce. This retrospective cohort study evaluated the safety and efficacy of ADV in this specific patient population. METHODS: Sixty-eight cirrhotic LAM-R patients, of whom 19 (27.9%) were elderly (>or=65 years of age) and nine had severe disease (two post-orthotopic liver transplantation, four pre-orthotopic liver transplantation and three decompensated), with hepatitis B virus (HBV) infection received ADV. Virological and biochemical responses to the addition of ADV were analysed. RESULTS: At inclusion, all patients were receiving LAM; ADV was added. 75.4% of patients received a combination of LAM and ADV throughout this study for a median treatment duration of 12.6 months; the remainder received ADV with an overlap with LAM treatment for a median duration of 7.9 months. At the end of follow-up, 41.2% of patients had undetectable HBV DNA (

[Study of the antiviral mechanism of action of ribavirin in the bovine viral diarrhea virus model]. / Etude du mécanisme d'action antivirale de la ribavirine dans le modèle du virus de la diarrhée bovine.

AIM: Due to the absence of a cell culture model for HCV, this study evaluated the hypothesis of lethal mutagenic activity of the guanosin analogue ribavirin in HCV, using the BVDV model. METHODS: First the capacity of ribavirin to inhibit BVDV replication in cell culture was studied. We then amplified by RT-PCR the 5'NTR and NS5B regions of BVDV in the supernatants of BVDV-infected cell cultures treated with increasing concentrations of ribavirin. The PCR products were then sequenced to detect potential mutations. RESULTS: At a phenotypic level, the inhibition of BVDV replication by ribavirin was most potent when ribavirin was administered soon after BVDV inoculation. These results show a direct antiviral effect of ribavirin on BVDV at an early stage of the viral cycle. At a genotypic level, ribavirin decreased viral RNA levels. CONCLUSION: This study shows that ribavirin directly inhibits BVDV replication. These results could explain the synergistic effect of ribavirin and IFN in combined therapy in chronic carriers of HCV. This effect must be confirmed with subgenomic replicons of HCV.

Intrafamilial prevalence of hepatitis B virus in Western Brazilian Amazon region: epidemiologic and biomolecular study.

BACKGROUND: Hepatitis B is endemic in the Amazon region. METHODS: Serological markers for hepatitis B virus (HBV) were determined in 266 household members for hepatitis B surface antigen (HBsAg)-positive women (G1) and 395 household members for HBsAg-negative women (G2), randomly selected in Acre State Women's Medical Care Program, in order to evaluate the prevalence of HBV in this population. Before blood sample collection an epidemiological questionnaire was applied. RESULTS: The overall prevalence of HBV carriers (HBsAg) and exposed individuals (anti-HBc, IgG) was, respectively, 21.1% and 60.5% in G1 and 2.8% and 27.4% in G2 (P < 0.0000001). The frequency of HBsAg was higher among siblings from group G1 (75%) compared to the absence of any HBsAg-positive sibling in G2 (P < 0.00006). The HBV markers in other family members was as follows: G1 parents, 27.3% vs 4.5% (P < 0.03), sexual partners, 21.1% vs 2.5% (P < 0.04), and offspring, 10.4% vs 1.5% (P < 0.04). A low prevalence of HBsAg and anti-HBc (IgG) was observed for the last offspring of G2 mothers compared to the high prevalence among children of G1 mothers (0% vs 18.2%, P < 0.01 and 2.3% vs 59.1%, P < 0.0000005, respectively), with children younger than 1 year being the most affected. The frequency of the habit of sharing toothbrushes and the presence of at least one HBsAg carrier were higher in G1 than in G2 (P < 0.0001 and P < 0.000002), respectively. Genotypes A, D and G were found to be predominant by Innolipa test. There were cases that reacted to more than one genotype. CONCLUSION: Intrafamilial transmission of HBV is evident in the present study and is possibly associated with the presence of more than one HBV carrier in the family and the shared use of toothbrushes among household contacts. Genotype analysis confirms intrafamilial transmission.

Sustained HBs seroconversion during lamivudine and adefovir dipivoxil combination therapy for lamivudine failure.

We describe the case of a patient with chronic hepatitis B who became resistant to lamivudine and was treated successfully with adefovir dipivoxil in addition to lamivudine. Lamivudine resistance was associated with the selection of a L180M+M204V polymerase mutant. After the addition of adefovir dipivoxil, serum HBV DNA levels dropped by more than 4log(10), which was followed by HBsAg clearance after 22 months of combination therapy. Moreover, anti-HBs antibody titers rose above 1000 mIU/mL after 32 months of the new treatment regimen. In parallel, HBV DNA declined below 100 copies/mL by a quantitative real time PCR assay. Analysis of intrahepatic viral DNA showed a significant decline of total HBV DNA and cccDNA which was accompanied by a decrease of the number of infected cells expressing viral antigens below the detection limit of immunostaining. In parallel, liver histology analysis showed an improvement in both the activity index and fibrosis score. This report suggests that in patients who previously failed lamivudine therapy, proactive antiviral treatment may lead to a beneficial virological and clinical effect.

Longitudinal assessment of histology surrogate markers (FibroTest-ActiTest) during lamivudine therapy in patients with chronic hepatitis B infection.

OBJECTIVES: The noninvasive serum markers, FibroTest-ActiTest (FT-AT), are an alternative to liver biopsy in patients with chronic hepatitis C and B. The aim was to use these markers in a prospective study of patients treated with lamivudine in order to assess the impact of treatment, as well as the factors associated with fibrosis progression. METHODS: Two hundred and ninety-eight patients were included in a prospective longitudinal study in 50 hospitals across France. FT-AT were measured at baseline, and then after 6, 12, and 24 months of lamivudine 100-mg treatment. Epidemiological, clinical, and virologic characteristics were analyzed by univariate and multivariate analysis. RESULTS: Two hundred and eighty-three patients were included for analysis. The accuracy of FT-AT versus biopsy was validated with the area under the ROC curve, 0.77 (SE = 0.03) for bridging fibrosis and 0.75 (SE = 0.06) for severe activity (A3). At baseline, bridging fibrosis (METAVIR stages F2-F3-F4) was highly associated (p < 0.001) in multivariate analysis with male gender and age and marginally associated with anti-HBe presence (p= 0.05) and non-Asian ethnic origin (p= 0.046). Lamivudine treatment had a very significant impact overall. FT decreased significantly from 0.51 at baseline to 0.37 at 24 months (p < 0.001), and 85% of patients had improvement at 24 months. AT also decreased significantly from 0.56 to 0.13 (p < 0.0001), and 91% of patients had improvement at 24 months. A three-phase kinetics was observed for both fibrosis and activity; there was a marked improvement during the first 6 months, followed by a plateau between 6 and 12 months, and another improvement between 12 and 24 months. The occurrence of a YMDD variant does not entirely explain these three-phase variations. The first phase impact on fibrosis rates was higher in Asian patients (p= 0.01) and in patients younger than 40 yr (p < 0.001). CONCLUSIONS: In patients with chronic hepatitis B, a 24-month course of lamivudine treatment leads to a significant decrease in necroinflammatory grades and fibrosis stages as assessed by noninvasive markers, with the occurrence of a three-phase kinetics. FT-AT should be useful in the noninvasive follow-up of lamivudine treatment.

Selection of a hepatitis B virus strain resistant to adefovir in a liver transplantation patient.

BACKGROUND/AIMS: In contrast to lamivudine, adefovir dipivoxil (ADV) therapy is associated with delayed and infrequent selection of drug resistant hepatitis B virus (HBV). METHODS: A 52 year-old man was treated with lamivudine for an HBV recurrence on his liver graft. A viral breakthrough was observed and the patient received ADV. Serum HBV DNA decreased rapidly and lamivudine was discontinued while ADV monotherapy was maintained. Serum HBV DNA levels remained suppressed until a second breakthrough was observed. Lamivudine was then reintroduced together with ADV, and serum HBV DNA became undetectable by polymerase chain reaction. RESULTS: Sequence analyses of the HBV polymerase gene revealed a sequential selection of lamivudine resistance mutations L180M+M204V, followed by a reversion to wild-type, and subsequently the selection of a novel adefovir resistance mutation N236T. Phenotypic analyses in cell culture assays demonstrated that the HBV isolates at the time of ADV breakthrough had reduced susceptibility to ADV. This mutant remained sensitive to lamivudine, entecavir and emtricitabine in vitro. CONCLUSIONS: We describe the first case of sequential selection of lamivudine and adefovir resistant strains of HBV in a liver transplantation patient. The selection of the N236T polymerase mutant was associated with resistance to ADV but remained sensitive to lamivudine in vitro and in vivo.