Analysis of HBsAg Immunocomplexes and cccDNA Activity During and Persisting After NAP-Based Therapy.

Therapy with nucleic acid polymers (NAPs), tenofovir disoproxil fumarate (TDF), and pegylated interferon (pegIFN) achieve high rates of HBsAg loss/seroconversion and functional cure in chronic hepatitis B virus (HBV) infection. The role of hepatitis B surface antigen (HBsAg) seroconversion and inactivation of covalently closed circular DNA (cccDNA) in establishing functional cure were examined. Archived serum from the REP 401 study was analyzed using the Abbott ARCHITECT HBsAg NEXT assay (Chicago, IL), Abbott research use-only assays for HBsAg immune complexes (HBsAg ICs), circulating HBV RNA, and the Fujirebio assay for hepatitis B core-related antigen (HBcrAg; Malvern, PA). HBsAg became < 0.005 IU/mL in 23 participants during NAP exposure, which persisted in all participants with functional cure. HBsAg IC declined during lead-in TDF monotherapy and correlated with minor declines in HBsAg. Following the addition of NAPs and pegIFN, minor HBsAg IC increases (n = 13) or flares (n = 2) during therapy were not correlated with HBsAg decline, hepatitis B surface antibody (anti-HBs) titers, or alanine aminotransferase. HBsAg IC universally declined during follow-up in participants with virologic control or functional cure. Universal declines in HBV RNA and HBcrAg during TDF monotherapy continued with NAP + pegIFN regardless of therapeutic outcome. At the end of therapy, HBV RNA was undetectable in only 5 of 14 participants with functional cure but became undetectable after removal of therapy in all participants with functional cure. Undetectable HBV RNA at the end of therapy in 5 participants was followed by relapse to virologic control or viral rebound. Conclusion: Anti-HBs-independent mechanisms contribute to HBsAg clearance during NAP therapy. Inactivation of cccDNA does not predict functional cure following NAP-based therapy; however, functional cure is accompanied by persistent inactivation of cccDNA. Persistent HBsAg loss with functional cure may also reflect reduction/clearance of integrated HBV DNA. Clinicaltrials.org number NCT02565719.

Kinetics of Hepatitis B Core-Related Antigen and Anti-Hepatitis B Core Antibody and Their Association With Serological Response in Human Immunodeficiency Virus-Hepatitis B Coinfection.

BACKGROUND: The aim of the current study was to describe the kinetics of quantified hepatitis B core-related antigen (qHBcrAg) and quantified anti-hepatitis B core antibody (qAnti-HBc) during tenofovir (TDF) treatment and assess their ability to predict hepatitis B e antigen (HBeAg) seroclearance in patients coinfected with human immunodeficiency virus (HIV) and hepatitis B virus. METHODS: Serum qHBcrAg, qAnti-HBc, and hepatitis B virus DNA were obtained at TDF initiation and every 6-12 months. The on-treatment kinetics of qHBcrAg (ΔqHBcrAg) and qAnti-HBc (ΔqAnti-HBc) were estimated using mixed-effect linear regression. Hazard ratios (HRs) assessing the association between markers and HBeAg seroclearance were calculated using proportional hazards regression, and the sensitivity (Se) and specificity (Sp) of marker levels in predicting HBeAg seroclearance were assessed using time-dependent receiving operating characteristic curves. RESULTS: During a median of 4.6 years, the cumulative incidences of hepatitis B surface antigen and HBeAg seroclearance were 3.2% (n = 5 of 158) and 27.4% (n = 26 of 95), respectively. ΔqHBcrAg was biphasic in HBeAg-positive patients (-0.051 and -0.011 log10 U/mL/mo during ≤18 and >18 months, respectively) and monophasic in HBeAg-negative patients. ΔqAnti-HBc was monophasic regardless of HBeAg status. In HBeAg-positive patients, baseline qHBcrAg and qAnti-HBc levels were associated with HBeAg seroclearance (adjusted HR, 0.48/log10 U/mL [95% confidence interval, .33-.70] and unadjusted HR, 1.49/log10 Paul Ehrlich Institute units/mL [1.08-2.07], respectively). Cutoffs with the highest accuracy in predicting HBeAg seroclearance at 36 months were qHBcrAg <6.5 log10 U/mL at month 24 (Se, 1; Sp, 0.58) and baseline qAnti-HBc ≥4.1 log10 Paul Ehrlich Institute units/mL (Se, 0.42; Sp, 0.81). CONCLUSIONS: In coinfected patients undergoing TDF, qHBcrAg/qAnti-HBc could be of use in monitoring HBeAg seroclearance.

MxA inhibits hepatitis B virus replication by interaction with hepatitis B core antigen.

UNLABELLED: Human MxA, an interferon-inducible cytoplasmic dynamin-like GTPase, possesses antiviral activity against multiple RNA viruses. Recently, MxA has also been demonstrated to have activity against the hepatitis B virus (HBV), a well-known DNA virus responsible for acute and chronic liver disease in humans. We investigated the molecular mechanism for the anti-HBV activity of MxA. Our results demonstrated that in HepG2.2.15 cells, MxA GTPase independently suppressed the production of hepatitis B surface antigen and HBV DNA without changing the level of hepatitis B core antigen (HBcAg) and the distribution of HBV mRNA. MxA significantly reduced the level of the encapsidated pregenomic RNA. Through its central interactive domain, MxA interacted with HBcAg, causing accumulation of the proteins in perinuclear compartments. MxA-HBcAg interaction significantly affected the dynamics of HBcAg by immobilizing HBcAg in the perinuclear structures. CONCLUSION: MxA displays antiviral activity against HBV involving a mechanism of MxA-HBcAg interaction that may interfere with core particle formation.

Evolution of hepatitis B virus precore/basal core promoter gene in HBeAg-positive chronic hepatitis B patients receiving lamivudine therapy.

AIM: Lamivudine is effective in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, but the relapse rate after cessation of treatment is high. The evolution of viral genome may contribute to the viral replication under antiviral pressure of lamivudine. We therefore determined the evolution of hepatitis B virus (HBV) precore/basal core promoter and polymerase genes in HBeAg-positive chronic hepatitis B patient during lamivudine therapy. METHOD: Thirteen patients with HBeAg-positive chronic hepatitis who had received short-term lamivudine therapy (mean, 30 weeks) during 1999-2001 were enrolled. The precore/basal core promoter region and polymerase gene were amplified and directly sequenced before, during and post lamivudine treatment. RESULT: HBeAg loss or seroconversion occurred in 11, but eight relapsed after stopping therapy and five had reversion of HBeAg. Before treatment, basal core promoter mutation was found in 1. In the first 3 months of therapy, a rapid decline of serum HBV DNA level accompanied with basal core promoter mutation appeared in 11 of 13 patients (vs. before therapy; P=0.003). However, this mutant was replaced by wild-type virus in four of eight patients who relapsed after treatment. There was no significant change of precore sequences before and during therapy. CONCLUSIONS: Lamivudine therapy may result in the rapid development of basal core promoter mutation of HBV, but this mutation may revert to wild type gradually after cessation of therapy.

Clinical evaluation of a new enzyme immunoassay for hepatitis B virus core-related antigen; a marker distinct from viral DNA for monitoring lamivudine treatment.

We aimed to assess the clinical performance of a newly developed chemiluminescence enzyme immunoassay (CLEIA) for the detection of hepatitis B virus (HBV) core-related antigen (HBcrAg) in patients with chronic HBV infection. A total of 82 patients with chronic HBV infection and 167 HBV-negative controls were studied. HBcrAg was measured by CLEIA with monoclonal antibodies to hepatitis B e antigen (HBeAg) and hepatitis B core antigen (HBcAg), and HBV DNA was measured by transcription-mediated amplification assay (TMA) and in-house real-time detection polymerase chain reaction (RTD-PCR). The HBcrAg assay detected viremia in 189 of 216 samples (88%) collected from 72 patients whilst the TMA assay detected viremia in 178 of the 216 samples (82%) (P = 0.019). The HBcrAg concentration correlated linearly with the HBV DNA concentration (P < 0.001) over a range which varied 100 000-fold. The accuracy in the measurement of the patients' HBV load obtained using the HBcrAg assay was not affected by the absence of hepatitis B e antigen from the serum or the presence of precore mutations in the HBV genome. In patients without anti-viral drugs, changes in their serum HBcrAg concentration over time corresponded to their HBV DNA concentration. In six additional patients who were later treated with lamivudine, HBV DNA concentration declined more rapidly than their HBcrAg concentration. Three months after treatment commenced, the ratio of HBcrAg: HBV DNA had increased in all six patients (P = 0.031). The HBcrAg assay is a sensitive and useful test for the assessment of a patient's HBV load. When monitoring the anti-viral effect of lamivudine, HBcrAg provides a viral marker which is independent of HBV DNA.

Effects of interferon alpha therapy on the catalytic domains of the polymerase gene and basal core promoter, precore and core regions of hepatitis B virus.

AIMS: The aim of the present study was to examine the catalytic domains of the polymerase gene, the basal core promoter and the precore and core regions of the hepatitis B virus (HBV) genome for specific mutations. These may account for the response to interferon alpha (IFN-alpha) treatment, which may have prognostic value. METHODS: Multiple serum samples were collected prospectively from 30 patients with chronic active hepatitis B who were treated with IFN-alpha. Patients were assigned to one of three groups: group A (n = 11) and group B (n = 10) individuals were hepatitis B e antigen (HBeAg)-positive prior to treatment. Group A patients underwent HBeAg seroconversion after treatment while group B patients did not. Group C (n = 9) patients were HBeAg-negative prior to treatment. The HBV DNA was extracted from the sera collected before, during and after treatment and the various genomic regions were amplified, sequenced and examined for mutations. RESULTS: During IFN-alpha therapy, multiple changes were found in the catalytic domains of the HBV polymerase gene in all groups. The frequency of mutations and associated amino acid changes were highest in virus from group C patients and lowest in group A patients. The interdomain regions of the viral polymerase were the most affected. Multiple mutations were also found in the precore, core and core promoter regions. However, no specific mutations were associated with clinical response or outcome. CONCLUSIONS: During IFN-alpha treatment, multiple mutations occurred in the HBV genome, including the catalytic domains of the polymerase gene. Changes that did occur could not be correlated to the clinical response or treatment outcome. However, no mutations were found that have been linked to lamivudine escape, indicating that lamivudine therapy would be effective in IFN-alpha non-responder patients.

Inhibition of hepatitis B virus in mice by RNA interference.

Hepatitis B virus (HBV) infection substantially increases the risk of chronic liver disease and hepatocellular carcinoma in humans. RNA interference (RNAi) of virus-specific genes has emerged as a potential antiviral mechanism. Here we show that RNAi can be applied to inhibit production of HBV replicative intermediates in cell culture and in immunocompetent and immunodeficient mice transfected with an HBV plasmid. Cotransfection with plasmids expressing short hairpin RNAs (shRNAs) homologous to HBV mRNAs induced an RNAi response. Northern and Southern analyses of mouse liver RNA and DNA showed substantially reduced levels of HBV RNAs and replicated HBV genomes upon RNAi treatment. Secreted HBV surface antigen (HBsAg) was reduced by 94.2% in cell culture and 84.5% in mouse serum, whereas immunohistochemical detection of HBV core antigen (HBcAg) revealed >99% reduction in stained hepatocytes upon RNAi treatment. Thus, RNAi effectively inhibited replication initiation in cultured cells and mammalian liver, showing that such an approach could be useful in the treatment of viral diseases.

Anti-viral activity of hairpin ribozyme directed against HBV core region in vitro.

To study the preparation and cleavage of hairpin ribozyme (HpRz) directed against the transcript of HBV core region in vitro, HRz gene designed by computer targeting the transcript of HBV core gene was cloned into the vector p1.5 between 5'-cis-Rz and 3'-cis-Rz. 32P-labeled HpRz transcript proved whether the vector fit for the preparation of hairpin ribozyme. 32P-labeled pKC transcript containing HBV core region as targets-RNA was transcribed by using T7 RNA polymerase and purified by PAGE. Cold HpRz transcript was incubated with 32P-labeled target-RNAs under different conditions and radioautographed after denaturing polyacrylamide gel electrophoresis. The results showed that HpRz had the ability of cleavage at 37 degrees C and 12 mmol/L MgCl2 and the design of ribozyme was correct. It is concluded that HpRz prepared in vitro possesses specific catalytic activity, indicating that it is possible for HpRz to intracellularly inhibit the replication of HBV. It may be developed into a nucleic acid drug in the treatment of hepatitis B in the future.

Sequence variation of hepatitis B virus precore-core open reading frame isolated from serum and liver of children with chronic hepatitis B before and after interferon treatment.

DNA and amino acid sequences of the hepatitis B virus (HBV) genome were studied in serum and liver samples taken from 12 children with chronic hepatitis B before and after interferon (IFN) therapy. The purpose was to discover whether the persistence of low levels of viral replication with normal alanine aminotransferases after the response to IFN treatment is due to the appearance of mutations in the sequence of HB core antigen T and B cell epitopes. The existence of mutants was studied by amplification of precore-core region of the HBV genome by polymerase chain reaction (PCR) and direct sequencing of the PCR products. In addition to the wild type sequence, mutation 1896 in the precore region was detected in the baseline serum and liver samples of five children. No changes in the distribution were found in the final samples, except one case. In the core region, both the wild type sequence and amino acid substitutions were observed in the basal serum and/or liver samples of six patients and most of these remained detectable in the samples after treatment. Sixteen (67%) of 24 changes in the core amino acid sequences were found in the T- or B-cell epitopes. The results suggest that viral persistence after response to IFN therapy in children is not due to the appearance of mutants in the HBV core T- and B-cell epitopes and that the host immune response can control the viral replication.

Acute exacerbation of hepatitis due to reactivation of hepatitis B virus with mutations in the core region after chemotherapy for malignant lymphoma.

A 43-year-old Japanese man who was positive for hepatitis B surface (HBs) antigen and HB e antibody, underwent chemotherapy for non-Hodgkin's lymphoma. After the chemotherapy he suffered from acute exacerbation of hepatitis because of reactivation of HBV. Recovery was achieved with interferon-alpha, glucagon-insulin therapy, and plasma exchange. Mutations were detected in codons 97, 100, 129, and 131 of the core region of HBV. The peptide encoded from the core region including such mutations possibly had greater antigenicity to induce cytotoxic T cell activity in the host. Core region mutations may be a crucial cause of the acute exacerbation of hepatitis B seen after chemotherapy.

Comparative study of the immunogenicity and safety of two doses of recombinant hepatitis B vaccine in healthy adolescents.

PURPOSE: A prospective, two-armed, open-label, randomized trial was performed to compare the geometric mean titers (GMT), seroprotection (SP) and seroconversion (SC) rates found after administration of two doses of recombinant hepatitis B vaccine. METHODS: Recombinant hepatitis B vaccine 10 or 20 micrograms was administered IM at 0, 1, and 6 months in healthy adolescents. RESULTS: Volunteers who received either dose of the vaccine had similarly high seroconversion and seroprotection rates at all visits. At Month 8, both doses of the vaccine were highly immunogenic with GMTs of 1989 mIU/mL (10 micrograms dose) and 7672 mIU/mL (20 micrograms dose) and nearly equivalent SP rates (97% and 99% in the 10 and 20 micrograms dose groups, respectively). The geometric mean titers of seroconverters at Months 3, 6 and 8 were significantly greater in the 20 micrograms group as compared to the 10 micrograms group (p < or = 0.003). Both doses were well-tolerated, with injection site pain the most common reported adverse event. Injection site pain was reported significantly (p = 0.004) more by volunteers who received the 20 micrograms dose (10.7%) compared with volunteers who received the 10 micrograms dose (3.8%). CONCLUSION: Vaccination with 10 micrograms of recombinant hepatitis B vaccine may provide a clinically effective and economical alternative to the use of the 20 micrograms dose in healthy adolescents.