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Norder H, Twagirumugabe T, Said J, Tian Y, Tang KW, Lindh M. High Frequency of Either Altered Pre-Core StartCodon or Weakened Kozak Sequence in the CorePromoter Region in Hepatitis B Virus A1 Strainsfrom Rwanda. Genes (Basel) 2019; 10:genes10030182. [PMID: 30813638 PMCID: PMC6471190 DOI: 10.3390/genes10030182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/19/2019] [Accepted: 02/20/2019] [Indexed: 12/11/2022] Open
Abstract
Hepatitis B virus (HBV) is endemic in Rwanda and is a major etiologic agent for chronic liver disease in the country. In a previous analysis of HBV strains from Rwanda, the S genes of most strains segregated into one single clade of subgenotype, A1. More than half (55%) of the anti-HBe positive individuals were viremic. In this study, 23 complete HBV genomes and the core promoter region (CP) from 18 additional strains were sequenced. Phylogenetic analysis of complete genomes confirmed that most Rwandan strain formed a single unique clade, within subgenotype A1. Strains from 17 of 22 (77%) anti-HBe positive HBV carriers had either mutated the precore start codon (9 strains with either CUG, ACG, UUG, or AAG) or mutations in the Kozak sequence preceding the pre-core start codon (8 strains). These mutually exclusive mutations were also identified in subgenotypes A1 (70/266; 26%), A2 (12/255; 5%), and A3 (26/49; 53%) sequences from the GenBank. The results showed that previous, rarely described HBV variants, expressing little or no HBeAg, are selected in anti-HBe positive subgenotype Al carriers from Rwanda and that mutations reducing HBeAg synthesis might be unique for a particular HBV clade, not just for a specific genotype or subgenotype.
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Affiliation(s)
- Heléne Norder
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Theogene Twagirumugabe
- School of Medicine and Pharmacy, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda.
| | - Joanna Said
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Yarong Tian
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Ka-Wei Tang
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
| | - Magnus Lindh
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Gothenburg University, 405 30 Gothenburg, Sweden.
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Impact of HBV genotypes A and D genetic variability on infection evolution. INFECTION GENETICS AND EVOLUTION 2015; 33:281-7. [PMID: 25989376 DOI: 10.1016/j.meegid.2015.05.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 05/04/2015] [Accepted: 05/16/2015] [Indexed: 02/07/2023]
Abstract
HBV is characterized by a high genetic variability, which is the basis of its classification into eight genotypes (A-H). HBV infection is associated with different outcomes, from self-limiting acute hepatitis to active chronic hepatitis, asymptomatic carriage, and occult infection. The aim of this study was to analyze the genetic variability of HBV genotypes A and D isolates from 79 cases of self-limiting acute hepatitis and chronic hepatitis, in order to identify HBV variants associated with resolution or chronicity of acute HBV infection. The entire preS-S sequence and a fragment of 346 bp of the preC-C region, containing Enhancer II and Basal Core Promoter sequences, were analyzed. A phylogenetic analysis of preS/S region showed that the 45.45% (15/33) of isolates from acute hepatitis cases were genotype A compared to 8.69% (4/46) of chronic hepatitis cases. (p = 0.0002). Mutations associated with immune-escape (T131N, D144A/E, G145K), amino acid polymorphisms in "a determinant" domain of S protein and mutations/deletions in preC/C region were found in isolates from acute and chronic hepatitis B cases. In this study mutations/deletions in preS-S and preC-C regions, usually associated with fulminant acute hepatitis, advanced forms of liver disease and increased risk for HCC, were identified in HBV strains of genotype A and D obtained both from patients with self-limiting acute HBV infection and from persistent infected patients. This founding probably is due to the natural viral evolution under host immune response and to the circulation of a wide variety of HBV strains in our geographic area because of the ancient introduction of genotype D and the migrant fluxes from North Africa. Moreover, the analysis of circulation of new HBV antigenic variants is fundamental for the epidemiological surveys and for the evaluation of the impact of viral evolution on vaccine prophylaxis strategies.
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Sede M, Lopez-Ledesma M, Frider B, Pozzati M, Campos RH, Flichman D, Quarleri J. Hepatitis B virus depicts a high degree of conservation during the immune-tolerant phase in familiarly transmitted chronic hepatitis B infection: deep-sequencing and phylogenetic analysis. J Viral Hepat 2013; 21:650-61. [PMID: 25244642 DOI: 10.1111/jvh.12196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/08/2013] [Indexed: 12/13/2022]
Abstract
When intrafamilial transmission of hepatitis B virus (HBV) occurs, a virus with the same characteristics interacts with diverse hosts' immune systems and may thus result in different mutations to escape immune pressure. In this study, the HBV genomic characterization was assessed longitudinally after intrafamilial transmission using nucleotide sequence data of phylogenetic and mutational analyses, including those obtained by deep-sequencing for the first time. Furthermore, HBeAg-anti-HBe profile and variability of HBV core-derived epitopes were also evaluated. Strong evidence was obtained from intrafamilial transmission of HBV genotype D1 by phylogenetic inferences. HBV isolates exhibited high degree (~99%) of genomic conservation for almost 20 years, when patients were persistently HBeAg positive with normal amino transferase levels. This identity remained high among immune-tolerant siblings. In contrast, it diminished significantly (P = 0.02) when the mother cleared HBeAg (immune clearance phase). By deep-sequencing, the quantitative analysis of the dynamics of basal core promoter (BCP) (A1762T, G1764A; A1766C; T1773C; 8-bp deletion; and other) and precore (G1896A) variants among HBV isolates from family members exhibited differences during the follow-up. However, only those from the mother showed amino acid variations at core protein that would impair their MHC-II binding. Hence, when intrafamilial transmission occurs, HBV was highly conserved under the immune-tolerant phase, but it exhibited mutations more frequently during the immune clearance phase. The analysis of the HBV BCP and precore mutants after intrafamilial HBV transmission contributes to a better understanding of how they evolve over time.
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Affiliation(s)
- M Sede
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina; Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Universidad de Buenos Aires, Buenos Aires, Argentina
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Brichler S, Lagathu G, Chekaraou MA, Le Gal F, Edouard A, Dény P, Césaire R, Gordien E. African, Amerindian and European hepatitis B virus strains circulate on the Caribbean Island of Martinique. J Gen Virol 2013; 94:2318-2329. [PMID: 23884366 DOI: 10.1099/vir.0.055459-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Ten Hepatitis B virus (HBV) genotypes, as well as numerous subgenotypes, have been described in well-characterized ethnogeographical populations. Martinique has been at a crossroads between Africa, Europe, India and the Americas because of the slave trade (17th-19th centuries), followed by an important immigration of Indian and West African workers. In this work, we aimed to study the molecular epidemiology of HBV infection in Martinique according to this unique settlement pattern. To that end, blood samples from 86 consecutive HBV-infected patients from the main hospitals of the island, were retrospectively analysed. Direct sequencing of the pre-S1 or pre-C-C region or complete genome sequencing, followed by phylogenetic analyses were performed. HBV genotypes were: HBV/A1 (68.6 %), HBV/A2 (10.5 %), HBV/D, mainly HBV/D3 and HBV/D4 (8.1 %), HBV/F (3.5 %), and also HBV/E (2.3 %), two strains isolated from two West-African patients. Moreover, 74 % of the HBeAg-negative strains harboured classical pre-C-C mutations, and most HBV/A1 strains also containing specific mutations. Finally, various patterns of deletion mutants in pre-S and pre-C-C regions were found. In conclusion, our findings point to historical and migration-related issues in HBV-genotype distribution suggesting that HBV/A1, but not HBV/E, was imported from Africa during the slave trade, and further supporting the hypothesis that HBV/E has emerged recently in West Africa (<150 years). Potential origins of 'European' HBV/A2 and HBV/D3, 'Amerindian' HBV/F, and HBV/D4 strains are also discussed. Such HBV genetic diversity, beyond its epidemiological interest, may have a clinical impact on the natural history of HBV infection in Martinique.
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Affiliation(s)
- Ségolène Brichler
- Service de Bactériologie, Virologie-Hygiène, Assistance Publique-Hôpitaux de Paris; Hôpitaux Universitaires de Paris Seine Saint-Denis, Site Avicenne, Bobigny; Laboratoire Associé au Centre National de Référence des Hépatites B, C et Delta, Université Paris Nord, Sorbonne Paris Cité, France
| | - Gisèle Lagathu
- Service de Bactériologie, Virologie du Centre Hospitalier Régional et Universitaire de Rennes, Pontchaillou, France
| | - Mariama Abdou Chekaraou
- Service de Bactériologie, Virologie-Hygiène, Assistance Publique-Hôpitaux de Paris; Hôpitaux Universitaires de Paris Seine Saint-Denis, Site Avicenne, Bobigny; Laboratoire Associé au Centre National de Référence des Hépatites B, C et Delta, Université Paris Nord, Sorbonne Paris Cité, France
| | - Frédéric Le Gal
- Service de Bactériologie, Virologie-Hygiène, Assistance Publique-Hôpitaux de Paris; Hôpitaux Universitaires de Paris Seine Saint-Denis, Site Avicenne, Bobigny; Laboratoire Associé au Centre National de Référence des Hépatites B, C et Delta, Université Paris Nord, Sorbonne Paris Cité, France
| | - André Edouard
- Service d'Hépato-Gastro-Entérologie, Centre Hospitalier Universitaire de Fort-de-France, Martinique, France
| | - Paul Dény
- Centre de Recherche sur le Cancer, Équipe 16, INSERM U1052, CNRS UMR 5286, Lyon, France.,Service de Bactériologie, Virologie-Hygiène, Assistance Publique-Hôpitaux de Paris; Hôpitaux Universitaires de Paris Seine Saint-Denis, Site Avicenne, Bobigny; Laboratoire Associé au Centre National de Référence des Hépatites B, C et Delta, Université Paris Nord, Sorbonne Paris Cité, France
| | - Raymond Césaire
- Laboratoire de Virologie, Centre Hospitalier Universitaire de Fort-de-France, Martinique; EA 4537, Université Antilles-Guyane, France
| | - Emmanuel Gordien
- Service de Bactériologie, Virologie-Hygiène, Assistance Publique-Hôpitaux de Paris; Hôpitaux Universitaires de Paris Seine Saint-Denis, Site Avicenne, Bobigny; Laboratoire Associé au Centre National de Référence des Hépatites B, C et Delta, Université Paris Nord, Sorbonne Paris Cité, France
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Cassino L, Laufer N, Giuliano SF, Bouzas M, Quarleri J. Short Communication: Hepatitis B Virus Harboring Nucleotide Deletions in the Basal Core Promoter in HBe-Positive HIV-Coinfected Patients Under Lamivudine Therapy. AIDS Res Hum Retroviruses 2011; 27:543-5. [PMID: 20919924 DOI: 10.1089/aid.2010.0096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The presence of HBV genomes with deletions at the basal core promoter (BCP) is associated with more aggressive liver disease. This 3-year longitudinal analysis of two HIV-HBV-coinfected patients allowed identification of three deletions with dissimilar abundance and permanence into the HBV quasispecies composition. These deletions may contribute to HBV pathogenesis in HIV-coinfected individuals.
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Affiliation(s)
- L. Cassino
- Centro Nacional de Referencia para el SIDA, Dto. Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - N. Laufer
- Centro Nacional de Referencia para el SIDA, Dto. Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Unidad de Enfermedades Infecciosas, Hospital Fernández, Buenos Aires, Argentina
| | - S. Fernández Giuliano
- Unidad de Virología, Hospital de Enfermedades Infecciosas “F.J. Muñiz,” Buenos Aires, Argentina
| | - M.B. Bouzas
- Unidad de Virología, Hospital de Enfermedades Infecciosas “F.J. Muñiz,” Buenos Aires, Argentina
| | - J. Quarleri
- Centro Nacional de Referencia para el SIDA, Dto. Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
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Chauhan R, Kazim SN, Bhattacharjee J, Sakhuja P, Sarin SK. Basal core promoter, precore region mutations of HBV and their association with e antigen, genotype, and severity of liver disease in patients with chronic hepatitis B in India. J Med Virol 2006; 78:1047-54. [PMID: 16789012 DOI: 10.1002/jmv.20661] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Spontaneous mutations of hepatitis B virus (HBV) could influence the severity of liver disease. Since the basal core promoter (BCP) and the precore (Pc) regions are important for viral replication, these regions were examined for naturally occurring mutations and were correlated with the genotype, e antigen status, and severity of liver disease. In 82 patients with histologically confirmed chronic hepatitis B, the BCP and Pc regions were sequenced and aligned with known wild-type sequences. Sequence based HBV genotyping was done and HBV DNA was quantified. Thirty-three (40%) patients had decompensated chronic liver disease and the remaining patients had chronic hepatitis B. Forty-six (56%) patients were HBeAg positive. HBV genotype A was found in 28%, D in 65%, and B/C in 7.3%. The Pc G1896A mutation was more common in HBeAg-negative (33% vs. 2%, P < 0.01) patients and was genotype D specific. The Pc G1862T mutation was detected more often in HBeAg-positive than HBeAg-negative (37% vs. 11%, P < 0.01) patients and was genotype A specific (P < 0.01). BCP mutations at the 1,762/64 nucleotide positions were common in HBeAg negative than positive (36% vs. 13%, P < 0.05) and were equally common in different genotypes. TA 1-3 region mutations of the BCP were significantly higher in HBeAg-negative as compared to HBeAg-positive patients (78% vs. 26%, P < 0.01). BCP mutations had significantly higher HBV DNA levels. It is concluded that Pc G1862T mutant is Genotype A-specific but is not always associated with e antigen. The TA 1-3 rich mutations of BCP region are also associated with the absence of e antigen in Indian patients.
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Affiliation(s)
- Ranjit Chauhan
- Department of Gastroenterology, and Advanced Center for Liver Diseases, G.B. Pant Hospital, New Delhi, India
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7
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Drosten C, Nippraschk T, Manegold C, Meisel H, Brixner V, Roth WK, Apedjinou A, Günther S. Prevalence of hepatitis B virus DNA in anti-HBc-positive/HBsAg-negative sera correlates with HCV but not HIV serostatus. J Clin Virol 2004; 29:59-68. [PMID: 14675872 DOI: 10.1016/s1386-6532(03)00090-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Hepatitis B virus (HBV) DNA often remains detectable in serum despite clinical recovery and loss of HBsAg. OBJECTIVE To study whether coinfection with HIV and HCV influence the chance of detecting HBV DNA in sera with markers of past hepatitis B. STUDY DESIGN AND RESULTS The test panel included 160 anti-HBc-positive/HBsAg-negative sera collected in the diagnostic setting. The following parameters were determined in the sera: anti-HIV (32% positive), anti-HCV (34% positive), HCV RNA (18% positive), and anti-HBs (37% positive). A highly sensitive PCR (90%-detection limit 100 copies/ml) amplifying the terminal protein (TP) region of HBV was established and HBV DNA was detected in 12.5% of the samples. In 70% of these samples, the HBV DNA concentration was below 500 copies/ml as measured by real-time PCR in the S gene. Logistic regression analysis revealed that the chance of detecting HBV DNA was increased by a positive HCV serostatus (odds ratio 5.0, 95%-CI 1.6-15.7), whereas HIV coinfection (odds ratio 2.0, 95%-CI 0.7-5.8), anti-HBs (odds ratio 0.9, 95%-CI 0.3-2.6), and HCV RNA status (odds ratio 0.4, 95%-CI 0.1-1.7) had no statistically significant influence. In contrast, the chance of detecting HCV RNA in the subgroup of anti-HCV-positive sera was increased by HIV coinfection (odds ratio 4.5, 95%-CI 1.2-17.4). Sequencing of the TP PCR products revealed neither a specific phylogenetic origin of the circulating HBV DNA nor clustering of uncommon mutations in the TP region. CONCLUSIONS The prevalence of HBV DNA in serum of anti-HBc-positive/HBsAg-negative subjects correlates with HCV rather than HIV serostatus.
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Affiliation(s)
- Christian Drosten
- Department of Virology, Bernhard-Nocht-Institute of Tropical Medicine, Bernhard-Nocht-Strasse 74, D-20359 Hamburg, Germany
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Affiliation(s)
- Scott Bowden
- Victorian Infectious Diseases Reference Laboratory, 10 Wreckyn Street, North Melbourne, Vic. 3051, Australia
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Sallam TA, Tong CYW. Two distinct types of hepatitis B virus core promoter variants in Yemeni blood donors. J Med Virol 2002; 68:328-34. [PMID: 12226818 DOI: 10.1002/jmv.10207] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Genetic variations in the basic core promoter (BCP) region of hepatitis B virus (HBV) occur during the natural history of chronic HBV infection. This study investigates the presence of basic core promoter variations in 28 asymptomatic Yemeni blood donors, correlating variations with HBeAg phenotype and viral load. The core promoter/precore and surface gene region of HBV DNA were amplified using nested PCRs and the PCR products were sequenced either directly or after cloning. HBeAg and viral load were measured when HBV DNA was detectable. Sequencing of 18 surface PCR products indicated that all were of genotype D. Two distinct types of variants were identified in the basic core promoter: substitution only (N = 14) and major deletion (N = 9). The commonest substitutions were located at nucleotide positions 1753, 1762, and 1764; 10/14 (71.4%) were associated with the precore 1896A substitution resulting in the premature stop of the precore reading frame and 6/14 (42.9%) had viral loads above 400 copies/ml. Two forms of deletion variants were found: 8 bp deletion (1763-1770) (N = 2) and a novel 12 (1746-1757) + 8 bp (1763-1770) deletion (N = 7). The deletion sequences were never associated with the precore 1896A substitution and all had viral load below 400 copies/ml with negative HBeAg phenotype. The polymorphism 1773C was found in 9/14 (64.3%) substitution sequences whereas all deletion sequences had 1773T. Two donors had mixed sequences of basic core promoter substitution and major deletions (both 8 bp and 12 + 8 bp). While the deletion variants in these two donors were similar to others found in isolation, the substitutions were of a different pattern. Further studies are required to understand the selection process behind these variants.
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Affiliation(s)
- Talal A Sallam
- Department of Microbiology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Republic of Yemen
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Zampino R, Marrone A, Karayiannis P, Cirillo G, del Giudice EM, Rania G, Utili R, Ruggiero G. Core promoter mutations 3 years after anti-hepatitis B e seroconversion in patients with chronic hepatitis B or hepatitis B and C infection and cancer remission. Am J Gastroenterol 2002; 97:2426-31. [PMID: 12358268 DOI: 10.1111/j.1572-0241.2002.05998.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES In this study, we aimed to evaluate the persistence of hepatitis B virus (HBV) DNA and the role of HBV core promoter and precore region mutations in 28 young cancer survivor patients with HBV or HBV and hepatitis C virus (HCV) infections, and persistently normal ALT levels, after spontaneous or interferon (IFN)-induced anti-hepatitis B e (HBe) seroconversion. METHODS Sera from 15 patients with HBV and 13 with dual HBV-HCV infection were analyzed for the presence of HBV-DNA and HCV-RNA by polymerase chain reaction 3 yr after anti-HBe seroconversion. A total of 21 patients had seroconverted spontaneously and seven did so after IFN treatment. The core promoter and the precore regions were amplified sequenced directly. RESULTS Among patients with HBV infection, HBV-DNA was detected in five of nine (55%) with spontaneous anti-HBe and in all six treated patients (p = 0.092). In the coinfected patients, four had cleared both HBV-DNA and HCV-RNA, five were HBV-DNA negative/HCV-RNA positive and four had the reverse viral pattern. Among the 15 patients with persistence of HBV-DNA, a 7-base pair nucleotide deletion in the core promoter (1757-1763) was present in seven of 10 patients with spontaneous and in one of five patients with IFN-induced seroconversion (p = 0.033). The G1896A precore stop codon mutation was never observed. HBV-DNA levels were significantly lower in patients with the core promoter deletion (p = 0.011). The 7-base pair deletion generated a truncated X protein at amino-acid position 132. CONCLUSIONS A core promoter deletion after anti-HBe seroconversion was associated with low HBV-DNA levels, probably because of downregulation of pregenomic RNA production and truncation of the X protein. HBV-DNA persistence was a frequent event, even in the absence of active liver disease.
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Affiliation(s)
- Rosa Zampino
- Department of Pediatrics,Second University of Naples, Italy
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Li KS, Yamashiro T, Sumie A, Terao H, Mifune K, Nishizono A. Hepatitis B virus harboring nucleotide deletions in the core promoter region and genotype B correlate with low viral replication activity in anti-HBe positive carriers. J Clin Virol 2001; 23:97-106. [PMID: 11595588 DOI: 10.1016/s1386-6532(01)00212-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Emergence of anti-HBe following seroconversion of HBe antigen indicates reduced hepatitis B virus (HBV) replication in the liver and low infectivity in the natural course of infection. However, some patients show continued replication or reactivation even in the presence of anti-HBe. OBJECTIVE To clarify the cause of HBV replication, we investigated genotype differences and mutations in the core promoter and precore region in relation to virus titer. STUDY DESIGN Using quantification of HBV DNA, nucleotide sequencing of the core promoter and precore region, and genotyping with the S gene by restriction fragment length polymorphism (RFLP), we analyzed sera of 26 anti-HBe positive carriers (28 serum samples). RESULTS Various mutations were detected including C to T point mutation at nt 1653, A to T and G to A contiguous point mutations at nt 1762 and 1764 in the core promoter region, and G to A point mutation at nt 1896 in the precore region, but no common mutations were detected that were directly related to the virus titer from earlier reported mutations. In contrast, the mean titer of genotype B virus was 1.5 x 10(5) copies per ml and that of mutant HBV of genotype C having 8 base pairs (8-bp) deletion (nt 1768-1775) in the core promoter region was 7.9 x 10(4) copies per ml (mean titer). These titers showed commonly lower than that of genotype C virus without 8-bp deletion (median titer 5.0 x 10(6) copies per ml). Transition of genotype from C to B after viral reactivation and reduction of proportion of 8-bp deletion mutant at reactivation period was observed in a patient who demonstrated exacerbation of liver dysfunction due to immunosuppressive therapy and increased viral replication. CONCLUSIONS These results confirm those of our earlier study describing low replication ability of 8-bp deletion mutant HBV in vitro, and also indicate that the presence of genotype B correlates with reduced titer of HBV.
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Affiliation(s)
- K S Li
- Department of Microbiology, Oita Medical University, Idaigaoka 1-1, Hasama-machi, Oita, 879-5593, Japan
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Fukuda R, Mohammad R, Hamamoto S, Ishimura N, Ishihara S, Akagi S, Watanabe M, Kinoshita Y. Clinical relevance of precore and basal core promoter variants of hepatitis B virus during natural hepatitis B e antigen seroconversion may be overstated. J Pediatr Gastroenterol Nutr 2001; 33:301-6. [PMID: 11593126 DOI: 10.1097/00005176-200109000-00014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Clinical relevance of nucleotide changes in precore and basal core promoters in the hepatitis B virus genome during hepatitis B e antigen seroconversion may be overstated. The authors investigated the existence and changes in the relative proportion of variants to wild virus that occur with seroconversion. METHODS Sera from 30 school-aged long-term hepatitis B virus carriers, including 11 tested before and after seroconversion during 1 to 8 years of follow-up, were evaluated for variations in nucleotide sequences of the basal core promoter (T1762 and A1764), precore region (A1869), and carboxyl-terminus of the X region of the hepatitis B virus genome using an amplification refractory mutation detection system with mutant-specific primers. RESULTS All variants were found to already exist before seroconversion at various wild-type/mutant ratios. The positive rates of these variants were not changed with loss of hepatitis B e antigen. Although there was a relative increase in the concentration of these mutants in wild-type/mutant mixed populations, most patients with only a wild-type population maintained the same pattern after loss of hepatitis B e antigen. CONCLUSIONS Our results indicate that hepatitis B virus exists as a quasi species, and correlations of nucleotide sequences with clinical and serologic findings must be done with caution.
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Affiliation(s)
- R Fukuda
- Second Department of Internal Medicine, Shimane Medical University, Izumo-city, Shimane, Japan.
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Abstract
The emergence of hepatitis B virus genetic variants occurs under the influence of host immunity, immunization, the use of immune globulin or antiviral chemotherapy. Most of these are probably the result of the 'immune escape' phenomenon. Some variants, in particular those in the precore and core promoter regions, have been associated with disease severity and progression. Surface antigen variants have implications for the accuracy of laboratory diagnosis and may reduce the effectiveness of vaccination. Polymerase variants are selected as a result of the use of antiviral chemotherapeutic agents. It is important to monitor the occurrence of these variants.
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Affiliation(s)
- C.Y. William Tong
- Virology Section, Department of Infection, St Thomas Hospital, London, UK
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