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Biomedical subjects

F Zoulim

Publications and source records attributed to F Zoulim.

At least 19 recordsLinked to original sources
PubMed2003

Long term histological improvement and clearance of intrahepatic hepatitis C virus RNA following sustained response to interferon-ribavirin combination therapy in liver transplanted patients with hepatitis C virus recurrence.

BACKGROUND AND AIMS: A proportion of liver transplanted patients with recurrent chronic hepatitis have a sustained virological response to combination therapy with interferon plus ribavirin. However, the long term benefit of antiviral therapy with regard to hepatitis C virus (HCV) RNA clearance remains unknown in patients with HCV recurrence. This study examined the long term biochemical, virological, and histological outcome in transplanted patients with recurrent chronic hepatitis who had a sustained virological response to antiviral therapy. PATIENTS AND METHODS: Fifty four patients with recurrent hepatitis C were treated with antiviral therapy involving induction by combination therapy (interferon (IFN) plus ribavirin) for six months and maintenance ribavirin therapy for 12 months. Fourteen patients who had recurrent chronic hepatitis and sustained virological response to antiviral therapy were followed for three years after the end of antiviral therapy. Serum alanine aminotransferases were assessed every three months during the observation period. Serum hepatitis C RNA detected by polymerase chain reaction was evaluated every six months during follow up, and protocol biopsy procedures were performed routinely every year. Semiquantitative histopathological assessment of allograft hepatitis was performed using the Knodell score and HCV was also detected by polymerase chain reaction on frozen graft tissue samples. RESULTS: At the end of antiviral therapy, the sustained response rate was 26%. A complete response (normal serum alanine aminotransferase level and undetectable serum HCV RNA) was achieved in 13/14 (93%) patients three years after the end of treatment. A comparison of liver histology findings before and after a mean of three years after antiviral therapy showed a clear improvement in 12/14 (86%) patients. In 5/14 (36%) patients, the last biopsy showed normal or near normal histological findings. After three years of follow up, the total Knodell score was 3.2 (range 1-8) versus 8.3 (range 5-12) before treatment (p=0.001). Graft HCV RNA was detectable before treatment in all 14 patients and was undetectable at the end of follow up in 13/14 (93%) patients tested. CONCLUSION: In patients with biochemical and virological responses induced by ribavirin and interferon, a complete response was sustained in 93% for at least three years after cessation of therapy. This long term response was associated with absence of detectable intrahepatic hepatitis C RNA and marked histological improvement.

Adult↗
PubMed2002

Animal models for the study of HBV infection and the evaluation of new anti-HBV strategies.

BACKGROUND: Our aim was to evaluate the anti-HBV activity of a novel L-nucleoside analog, 2',3'-dideoxy-2',3'-didehydro-beta-L-5-fluorocytidine (beta-L-Fd4C), in study models of HBV infection. METHOD: Its mechanism of action was evaluated on the in vitro expressed duck HBV (DHBV) reverse transcriptase and in primary hepatocyte cultures of duck and human origin. The capacity of antiviral therapy to clear viral infection was analyzed in vivo in the duck and woodchuck models. RESULTS: beta-L-Fd4C-TP exhibited a more potent inhibitory effect on the RT activity of the DHBV polymerase than other cytidine analogs (lamivudine-TP, ddC-TP, beta-L-FddC-TP). In primary duck hepatocyte cultures, beta-L-Fd4C exhibited a long-lasting inhibitory effect on viral DNA synthesis but could not clear viral cccDNA. In vivo treatment with beta-L-Fd4C in infected ducklings and woodchucks, induced a greater suppression of viremia and intrahepatic viral DNA synthesis than with lamivudine. However, covalently closed circular DNA persistence explained the relapse of viral replication after treatment withdrawal. Viral spread was strongly reduced in the case of early therapeutical intervention, but the number of infected cells did not decline when therapy was started during chronic infection. Liver histology analysis showed a decrease in the inflammatory activity of chronic hepatitis while no ultrastructural modification of liver cells was observed in electron microscopy studies. Furthermore, in human primary hepatocyte cultures, beta-L-Fd4C induced a significant inhibition of HBV DNA synthesis. CONCLUSION: beta-L-Fd4C is a potent inhibitor of hepadnavirus RT and inhibits viral DNA synthesis in hepatocytes both in vitro and in vivo. These experimental studies allowed as to show that beta-L-Fd4C is a promising anti-HBV agent. Combination therapy should be evaluated to eradicate viral infection.

Animals↗
PubMed2001

Duck hepatitis B virus polymerase gene mutants associated with resistance to lamivudine have a decreased replication capacity in vitro and in vivo.

BACKGROUND/AIMS: Hepatitis B virus mutants of the polymerase gene are frequently selected during lamivudine therapy for chronic hepatitis B. To study the biology of these mutants, we analyzed their replication capacity in the duck hepatitis B virus (DHBV) infection. METHODS: The B and C domain polymerase mutants corresponding to the clinical isolates were engineered by site directed mutagenesis in the DHBV genome in different expression vectors. RESULTS: The study of the enzymatic activity of the mutated viral polymerase polypeptides analyzed in a cell free system demonstrated a lower priming activity and a decreased capacity of elongation of viral minus strand DNA that was consistent with the lower replication capacity of these mutants in transfected leghorn male hepatoma cells compared to wild type genome. These mutants had a lower replication capacity in primary hepatocytes and in in vivo transfected ducklings. Although resistant to lamivudine, these mutants remained sensitive to PMEA. CONCLUSION: YMDD mutants of the DHBV reverse transcriptase have a decreased replication capacity both in vitro and in vivo, and are not cross-resistant to PMEA. These results may be important to design new antiviral strategies to combat the replication of the lamivudine resistant viral strains.

Adenine↗
PubMed2001

Successful combination therapy of polyarteritis nodosa associated with a pre-core promoter mutant hepatitis B virus infection.

BACKGROUND/AIMS: To describe the clinical and virological evolution of a polyarteritis nodosa (PAN) case associated with a hepatitis B virus (HBV) pre-core promoter mutant infection that was successfully treated with plasma exchanges, corticosteroids, and interferon alpha (IFN-alpha). METHODS: Viral markers were used, including HBV DNA quantified by the branched DNA assay and detected by PCR, the HBV genome sequence, pre-S1Ag and anti-HBC IgM which were studied throughout the treatment period and the entire follow-up in the serum, while the presence of virus in extrahepatic sites was detected by immuno-staining. RESULTS: The patient was infected with a typical pre-core promoter mutant harboring four point mutations. Pre-S1Ag was cleared rapidly from serum, most likely via the formation of immune complexes since HBV DNA declined more progressively. Viral infection was then cleared after a second episode of hepatocyte lysis. This was accompanied by a recovery from all clinical manifestations. CONCLUSIONS: The favorable treatment outcome observed in this first case of pre-core promoter HBV mutant associated PAN underlines that combination therapy based on IFN-alpha can clear pre-core promoter HBV infection and cure PAN. It also provides new insight in the pathogenesis of HBV associated PAN.

Adrenal Cortex Hormones↗
PubMed2001

High incidence of hepatitis B infections among chronic hepatitis cases of unknown aetiology.

BACKGROUND/AIMS: In approximately 5% of chronic liver disease cases, no aetiology can be identified. We selected sera from 50 patients with chronic hepatitis of unknown aetiology who were enrolled in this follow-up study whose aim is to gain insight into the possible role of viruses and to define potential clinical outcomes. METHODS: Patients' sera were screened with highly sensitive polymerase chain reaction assays for hepatitis B (HBV), C, D, and G viruses and TT virus. Sera were also retested for antibodies against the core antigen of HBV. RESULTS: Surprisingly, HBV DNA was detected in both serum and liver in 15/50 (30%) patients. Immunostaining for HBV antigens on biopsies from patients positive for HBV DNA showed HBcAg and/or HBsAg expression at low levels in 9/15 samples. Eleven of the fifteen patients were anti-HBc positive. With one exception, all patients carried HBV genomes at low levels (10(4) copies/ml or less). Histological signs of chronic liver disease were observed in all patients. CONCLUSION: Unrecognised HBV infections may account for a high proportion of chronic hepatitis cases of unknown aetiology. Improved HBV detection tests, which appear mandatory for the diagnosis and management of non-A non-E hepatitis as well as for improved safety of transfusions and transplantations are needed.

Adult↗
PubMed2001

Detection of hepatitis B virus resistance to antivirals.

The development of new nucleoside analogs, that inhibit the HBV reverse transcriptase activity, such as lamivudine, famciclovir and others, has provided recently an alternative to interferon therapy for chronic hepatitis B. However, due to the kinetics of viral replication with a high rate of virus production, a relatively long half-life of virus (CCC) DNA in the nucleus of infected hepatocytes, long-term antiviral therapy with a reverse transcriptase inhibitor is required to eradicate viral infection. Recently, it has been reported that lamivudine therapy for chronic hepatitis B in immune competent patients may be associated with the selection of resistant strains in aproximately 20% of the patients after 12 months of therapy. Sequence analysis of the reverse transcriptase domain of resistant viral strains, at the time of viral breakthrough, revealed the occurrence of mutations located in the YMDD motif within the C domain of the viral enzyme with a methionine to valine (M552V) or to isoleucine (M5521) change. Recent reports on larger series of patients pointed that other mutations residing outside of the C domain but mainly in the B domain of the viral polymerase (L528M) could be associated with these mutations in the YMDD motif. The lamivudine resistant mutants, selected in vivo, can be classified in 2 main groups: group I with a double mutation L528M and M552V, and group II with a single mutation M5521. In vitro studies performed in cell culture showed that these mutants have a decreased replication capacity and are indeed resistant to lamivudine. With the development of new antiviral options, genotyping assays and quantitative determination of viremia with highly sensitive assay are clearly warranted for an optimal monitoring of antiviral therapy of chronic hepatitis B. In view of the experimental and clinical data, the capacity of new antiviral strategies based on combination of new inhibitors, including adefavir and entecavir, with immune modulators needs to be further evaluated in animal models and clinical trials to prevent the emergence of resistant viral strains.

Animals↗
PubMed2001

Evolution of hepatitis C virus genome in chronically infected patients receiving ribavirin monotherapy.

Recent results of clinical trials suggest that combination of interferon and ribavirin exhibits an enhanced antiviral effect in the treatment of chronic hepatitis C. To investigate the effect of ribavirin on hepatitis C virus (HCV) infection, we analysed the evolution of the genetic heterogeneity of HCV in relation to the anti-HCV humoral response in patients treated by ribavirin alone. The study population included 35 patients with liver biopsy proven chronic hepatitis C infected with HCV genotype 1. Among them, 26 were treated with ribavirin for at least 12 months and nine untreated patients served as a control group. Serum samples were analysed before and at 6 and 12 months of therapy. Three regions of the HCV genome, i.e. HVR1, a domain of NS5A including part of the interferon sensitivity determining region (ISDR), and a segment of NS5B, were amplified by RT-PCR using specific primers. The PCR products were then studied using single-strand conformation polymorphism (SSCP) analysis followed by either direct sequencing, or cloning and sequencing. In parallel, the humoral anti-E1 response was studied using an ELISA (Innotest HCV E1Ab, Innogenetics). The results of HCV genome analysis showed no significant effect on the amino acid sequence evolution of the HVR1, NS5A and NS5B regions of HCV. Analysis of a phylogenetic tree from the major quasispecies variants showed the absence of correlation with ribavirin response, and the absence of selection of viral strains during ribavirin treatment. A trend towards a decrease in the anti-E1 Ab response was also observed. Altogether these results suggest that ribavirin may not exhibit a direct antiviral effect, but may trigger a favourable response to interferon by modulating the immune response against HCV.

Amino Acid Sequence↗
PubMed2001

Impaired allostimulatory function of dendritic cells in chronic hepatitis C infection.

BACKGROUND & AIMS: Dendritic cells (DC), which play an essential role in the triggering of primary antiviral immune reactions, may also contribute, in some viral models, to the propagation of viral infection and the pathogenesis of viral disease. During natural infection with hepatitis C virus (HCV), the interactions between the virus and DC may contribute to viral persistence, a general feature of HCV infection. METHODS: We compared the phenotypical and biological functions of monocyte-derived DC from patients with chronic hepatitis C (HCV-DC; n = 6), seronegative individuals (naive-DC; n = 8), long-term responders to antiviral therapy (LTR-DC; n = 8), and a group of patients with non-HCV-hepatic disorders (n = 11). The presence and the nature of HCV sequences during the DC cultures was assessed by reverse transcription-polymerase chain reaction and the analysis of the viral quasispecies distribution. RESULTS: Although HCV-DC displayed a normal morphology, phenotype, and capacity to capture antigen, their ability to stimulate the proliferation of allogeneic T cells was dramatically impaired in comparison with naive-DC (P = 0.0013). Mixing experiments revealed that HCV-DC did not affect the proliferation of T cells induced by naive-DC. Remarkably, the allostimulatory function of LTR-DC or DC from patients with non-HCV-hepatic disorders did not show any impairment. The presence of HCV genomic sequences could be documented for 5 of 6 HCV carriers either in the cells and/or the supernatants of the DC cultures. The presence of HCV sequences was found in the DC cultures from one patient showing a dramatic allostimulation defect. For that patient, extensive analysis of the viral quasispecies distribution revealed the presence, in the DC cultures, of genomic sequences of a unique nature, distinct from those identified in the patient's mononuclear cells, serum, or liver. CONCLUSIONS: Overall, these results indicate that chronic infection by HCV is associated with an allostimulatory defect of monocyte-derived DC, possibly because these cells constitute an extrahepatic reservoir for the virus. Although the exact mechanism responsible for such an alteration remains to be unraveled, our observations argue against an active immunosuppression-based mechanism.

Adenovirus E2 Proteins↗
PubMed2001

Initial amplification of duck hepatitis B virus covalently closed circular DNA after in vitro infection of embryonic duck hepatocytes is increased by cell cycle progression.

The relationship between the cell cycle and early amplification of duck hepatitis B virus covalently closed circular (CCC) DNA was studied after in vitro infection of fetal hepatocytes. We first showed that embryonic hepatocytes proliferated for at least 6 days after plating and that complete viral replication including CCC DNA amplification occurred in these proliferating cells. Addition of sodium butyrate or aphidicolin reversibly blocked cells in the G1 phase and diminished CCC DNA synthesis, which was restored after drug withdrawal, concomitantly with the entry of cells into S phase. Cell cycle progression of fetal hepatocytes can be triggered by stimulation with epidermal growth factor (EGF), hepatocyte growth factor (HGF), and tumor growth factor alpha (TGF-alpha). CCC DNA synthesis increased with progression to the S phase induced by EGF, HGF, and TGF-alpha alone or in combination. By contrast, tumor growth factor beta (TGF-beta) alone or in combination with EGF inhibited cell proliferation and viral DNA synthesis. By double labeling, viral nucleocapsids were found predominantly in bromodeoxyuridine-positive hepatocytes, indicating that high viral replication occurs preferentially in proliferating hepatocytes. CCC DNA was also detected mainly in cells in the S and G2/M phases separated from cells in the G1 phase by cell sorting. Taken together, these results show that hepatocyte proliferation may positively regulate the initial amplification of CCC DNA of avian hepadnaviruses, and may explain why mitosis is not necessarily associated with loss of CCC DNA.

Animals↗
PubMed2001

Sequential treatment with lamivudine and interferon monotherapies in patients with chronic hepatitis B not responding to interferon alone: results of a pilot study.

Sustained viral suppression using monotherapy with interferon alfa (IFN-alpha) or lamivudine can only be achieved in a small percentage of patients with chronic hepatitis B. The concomitant administration of lamivudine and IFN-alpha does not enhance efficacy. We postulated that the optimal timing of therapy might be sequential treatment with lamivudine and IFN-alpha. The aim of this study was therefore to assess the efficacy of sequential treatment in patients resistant to IFN-alpha alone. Fourteen male patients, with a median age of 40 years, nonresponders to IFN-alpha with hepatitis B virus (HBV) DNA > 100 pg/mL (branched DNA [bDNA] Chiron) and positive hepatitis B e antigen (HBeAg) in 11 of 14 patients, were treated with lamivudine 100 mg/d alone for 20 weeks, then with both IFN-alpha2b 5 MU 3 times per week and lamivudine for 4 weeks, and lastly with IFN-alpha alone for 24 weeks. At the end of lamivudine therapy, all patients had undetectable serum HBV DNA, and none exhibited an emergence of HBV polymerase mutant or breakthrough. Sustained serum HBV-DNA clearance 6 months after the end of sequential treatment was achieved in 8 of 14 patients, HBeAg-to-anti-HBe seroconversion in 5 of 11 patients, and HBeAg and hepatitis B surface antigen (HBsAg) seroconversions in 3 of 14 patients (anti-HBs > 100 IU/mL). All sustained responders had normalized their alanine transaminase (ALT) values and exhibited histologic improvements. In conclusion, the results of this pilot study suggest that sequential treatment with lamivudine and IFN-alpha can induce a sustained virologic response, including HBs seroconversion, in patients with chronic hepatitis B not responding to IFN-alpha alone, without the selection of drug-resistant mutants. This therapeutic schedule warrants further evaluation in clinical trials.

Adult↗
PubMed2001

Antiviral activity of beta-L-2',3'-dideoxy-2',3'-didehydro-5-fluorocytidine in woodchucks chronically infected with woodchuck hepatitis virus.

The L-nucleoside analog beta-L-2',3'-dideoxy-2',3'-didehydro-5-fluorocytidine (beta-L-Fd4C) was first shown to exhibit potent activity against hepatitis B virus (HBV) in tissue culture and then to significantly inhibit viral spread during acute infection in the duck HBV model (F. Le Guerhier et al., Antimicrob. Agents Chemother. 44:111-122, 2000). We have therefore examined its antiviral activity in a mammalian model of chronic HBV infection, the woodchuck chronically infected with woodchuck hepatitis virus (WHV). Side-by-side comparison of beta-L-Fd4C and lamivudine administered intraperitoneally during short-term and long-term protocols demonstrated a more profound inhibition of viremia in beta-L-Fd4C-treated groups. Moreover, beta-L-Fd4C induced a marked inhibition of intrahepatic viral DNA synthesis compared with that induced by lamivudine. Nevertheless, covalently closed circular (CCC) DNA persistence explained the lack of clearance of infected hepatocytes expressing viral antigens and the relapse of WHV replication after drug withdrawal. Liver histology showed a decrease in the inflammatory activity of chronic hepatitis in woodchucks receiving beta-L-Fd4C. An electron microscopy study showed the absence of ultrastructural changes of hepatic mitochondria, biliary canaliculi, and bile ducts. However, a loss of weight was observed in all animals, whatever the treatment, as was a transient skin pigmentation in all woodchucks during beta-L-Fd4C treatment. There was no evidence that lamivudine or beta-L-Fd4C could prevent the development of hepatocellular carcinoma with the protocols used. These results indicate that beta-L-Fd4C exhibits a more potent antiviral effect than lamivudine in the WHV model but was not able to eradicate CCC DNA and infected cells from the liver at the dosage and with the protocol used.

Animals↗
PubMed2001

Current management strategies for hepatitis B in the elderly.

Despite the availability of an efficient vaccine, chronic hepatitis B virus (HBV) infection remains a major public health problem worldwide. The World Health Organization estimates that there are still 350 million chronic carriers of the virus who are at risk of developing chronic hepatitis, liver cirrhosis and hepatocellular carcinoma (HCC). Antiviral therapy consists of the administration of either interferon-alpha (IFN alpha) or lamivudine. In the elderly, specific issues should be addressed. Because of the long duration of viral infection, screening for HCC is warranted in these patients, as new therapeutic options are being developed. Antiviral treatment for chronic hepatitis B is indicated in patients with elevated transaminases, the presence of HBV replication, and inflammatory activity on liver histology analysis, providing the patient has no other serious health problem impacting on life expectancy. Since IFN alpha therapy may cause many general adverse effects, lamivudine may be the best current treatment option in this patient population. The pharmacokinetics of lamivudine in the elderly are slightly different from those in younger adults but this does not require dose adjustment, except in the presence of renal function impairment. However, the beneficial effects of lamivudine therapy must be weighed against the selection of drug-resistant mutants. New therapeutic strategies are now under evaluation and may be available in the future for the elderly population. Besides mass HBV vaccination programmes, people sharing a house with patients infected with HBV should be vaccinated to prevent viral transmission.

Aged↗
PubMed2001

Evaluation of novel strategies to combat hepatitis B virus targetting wild-type and drug-resistant mutants in experimental models.

Recent studies have shown that the kinetics of hepatitis B virus (HBV) clearance during antiviral therapy are slow, requiring long-term therapy to control viral replication. It has also been shown that emergence of resistant mutants is accelerated by high HBV replication and hepatocyte turnover, which are common features in patients with chronic HBV infection. It is therefore important to continue research on novel antiviral agents to design optimal combination strategies. The duck and woodchuck models of hepadnavirus infection are currently the best models for the investigation of the inhibitory effect of nucleoside analogues on wild-type and lamivudine-resistant mutants. Our studies revealed that these mutants have a decreased priming and elongation activity, and remain sensitive to novel nucleoside analogues. Tissue culture experiments with transient transfection of wild-type and mutant viruses also confirmed these data. Infection studies in primary hepatocytes and in animal models gave insight into the pathobiology of lamivudine-resistant mutants, as well as into the kinetics of wild-type virus clearance during antiviral therapy. Furthermore, it appears that novel strategies inducing a specific anti-HBV immune response by a DNA vaccine approach may induce viral clearance. Altogether, these results suggest that: (i) lamivudine-resistant mutants are likely to be cross-resistant to other L-cytidine analogues; (ii) antiviral therapy using a single reverse transcriptase (RT) inhibitor is likely to fail to eradicate viral covalently closed circular DNA; and (iii) new nucleoside analogues with unique mode of action (inhibition of priming or elongation of RT, or DNA polymerase activity) and activity against lamivudine-resistant strains are emerging. Combination of these new anti-HBV agents with DNA based immunization may prove useful to eradicate viral infection.

Animals↗
PubMed2000

[Hepatitis C virus].

Hepatitis C virus (HCV) is a small enveloped virus whose genome is a RNA molecule encoding a polyprotein that is processed by cellular and viral proteases to produce the 3 structural proteins (the core protein C and the 2 envelope proteins E1 and E2) and the 6 nonstructural proteins (NS2, NS3, NS4A, NS4B, NS5A and NS5B). The HCV genome exhibits a significant genetic heterogeneity. HCV isolates can be divided into genetically distinct groups referred to as genotypes, whereas the population of HCV genomes, within an infected individual, is present as a group of heterogeneous but closely related sequences referred to as quasi-species. Studies of the molecular biology of HCV and of new vaccinal or therapeutic strategies are hampered by the lack of easy to use cellular culture systems and of animal models.

Animals↗
PubMed2000

Evolution of hepatitis B virus polymerase gene sequence during famciclovir therapy for chronic hepatitis B.

Prolonged administration of nucleoside analogues for chronic hepatitis B may result in the emergence of hepatitis B viral polymerase mutants. To gain insight into the mechanism involved in the virus's resistance to famciclovir, the amino acid sequences of the terminal protein and reverse-transcriptase (RT) domains of the viral polymerase were determined during therapy among 28 patients. The antiviral response was independent of viral genotypes, and nonresponse to famciclovir was associated with a complex variability of the RT domain. No mutation in the YMDD motif was observed, whereas an L528M mutation was clearly selected by famciclovir treatment in 2 patients, as well as 14 novel mutations in 7 patients. Clone sequence analysis of the RT domains of patients undergoing retreatment with famciclovir and/or lamivudine showed the selection of a preexisting drug-resistant mutant in one case and indicated that sequential antiviral therapy may allow the rapid selection of resistant strains.

2-Aminopurine↗
PubMed2000

Persistence of viral replication after anti-HBe seroconversion during antiviral therapy for chronic hepatitis B.

BACKGROUND/AIMS: Hepatitis B virus genome mutants may be selected during the immune-mediated clearance of infection or during long-term nucleoside analog administration and may escape both antiviral pressures. The pattern of anti-HBe seroconversion was analyzed in patients receiving new nucleoside analogs, lamivudine or famciclovir, in comparison with patients treated with interferon alpha. METHODS: Eighteen consecutive patients who seroconverted to anti-HBe were included in the study. Serial serum samples were studied with the quantitative determination of HBV DNA by the branched DNA assay (Chiron) and by a quantitative PCR assay (Roche diagnostics), determination of pre-S1 Ag, the genetic analysis of the viral genome with the determination of pre-core promoter or pre-core region mutations with a line probe assay (Innogenetics) and, in selected samples of polymerase gene mutations. RESULTS: The quantitative PCR assay was found to be more sensitive than the bDNA assay, allowing a 25-log decrease in viral DNA levels to be demonstrated after anti-HBe seroconversion. Viral persistence after anti-HBe seroconversion induced by interferon, lamivudine or famciclovir, was often associated with circulating HBV genomes harboring mutations in the precore promoter. The clinical significance of these findings was demonstrated by the observation of reversion to HBeAg in two patients treated with interferon and one with lamivudine. CONCLUSION: Persistence of significant levels of viremia that are not detected by the branched DNA assay may be observed after anti-HBe seroconversion. A precise monitoring of viremia levels with more sensitive assays and HBV mutant strains is warranted in patients undergoing antiviral therapy.

2-Aminopurine↗
PubMed2000

Rapid detection of genotypes and mutations in the pre-core promoter and the pre-core region of hepatitis B virus genome: correlation with viral persistence and disease severity.

BACKGROUND/AIMS: We aimed to clarify the clinical relevance of hepatitis B virus pre-core mutant detection in patients with chronic hepatitis B using a newly developed assay. METHODS: Viral genotypes and pre-core mutations were studied in relation to viral persistence and liver disease severity using INNO-LiPA methodology. The study group included 151 patients with chronic hepatitis B, 85 positive for HBeAg (group I) and 66 positive for anti-HBe (group II). RESULTS: The prevalence of viral genotypes in group I was: 64% A, 1% B, 15% C, 19% D, 0% E, 0% F and in group II: 39% A, 0% B, 2% C, 56% D, 2% E, 2% F (p<0.001). The prevalence of mutations at pre-core codon 28 (M2) was lower in group I (5%) than in group II (64%) (p<0.001). The prevalence of pre-core promoter mutations was also lower in group I (21%) than in group II (61%) (p<0.001). M2 mutations were more frequently detected in genotype D than in genotype A (p<0.001), while the other mutations were not influenced by viral genotype. Serum HBV DNA levels were significantly lower in group II versus group I (p<0.001), and in patients with any of the pre-core mutations versus wild-type sequence (p<0.01). Although cirrhosis was more frequent in group II (37%) versus group I (22%) and in patients with either one of the pre-core mutation (31%) versus wild-type sequence (25%), there was no statistical difference in liver severity assessed by ALT levels and Knodell score. CONCLUSION: Pre-core mutants, whose molecular pattern is strongly dependent on viral genotypes, are associated with viral persistence in anti-HBe positive patients with ongoing chronic hepatitis B. The availability of this rapid assay should allow a precise monitoring of viral pre-core mutants during the course of chronic hepatitis B.

Adolescent↗