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Michailidis E, Kirby KA, Hachiya A, Yoo W, Hong SP, Kim SO, Folk WR, Sarafianos SG. Antiviral therapies: focus on hepatitis B reverse transcriptase. Int J Biochem Cell Biol 2012; 44:1060-71. [PMID: 22531713 DOI: 10.1016/j.biocel.2012.04.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 12/20/2022]
Abstract
Hepatitis B virus (HBV) is the etiologic agent of mankind's most serious liver disease. While the availability of a vaccine has reduced the number of new HBV infections, the vaccine does not benefit the approximately 350 million people already chronically infected by the virus. Most of the drugs approved by the FDA for the treatment of hepatitis B target the reverse transcriptase (RT or P gene product) and are nucleoside RT inhibitors (NRTIs) that suppress viral replication. However, prolonged monotherapies directed against a single target result in the emergence of viral resistance. HBV genotypic differences affect NRTI resistance, and because the reading frames of the S (surface antigen) and P genes partially overlap, genomic differences that affect the surface of the virus may also alter the viral polymerase sequence, function and drug susceptibility. The scope of this review is to assess the effects of HBV genotypic variation on the development of drug resistance to NRTIs. Some RT residues that vary among different genotypes are in the vicinity of residues that mutate and give rise to NRTI resistance. Interactions between these amino acids can help explain the effect of HBV genotype on the development of NRTI resistance during antiviral therapies, and might help in the design of improved therapeutic strategies.
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Affiliation(s)
- Eleftherios Michailidis
- Christopher S. Bond Life Sciences Center, Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO 65211, USA
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Hosaka T, Suzuki F, Kobayashi M, Hirakawa M, Kawamura Y, Yastuji H, Sezaki H, Akuta N, Suzuki Y, Saitoh S, Arase Y, Ikeda K, Miyakawa Y, Kumada H. Development of HCC in patients receiving adefovir dipivoxil for lamivudine-resistant hepatitis B virus mutants. Hepatol Res 2010; 40:145-52. [PMID: 19788684 DOI: 10.1111/j.1872-034x.2009.00582.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
AIM To identify factors for the development of hepatocellular carcinoma (HCC) in the patients who receive adefovir add-on lamivudine for treatment of lamivudine-resistant hepatitis B virus (HBV) mutants. METHODS A total of 247 patients who developed lamivudine-resistant HBV mutants, with an increase of HBV DNA >/= 1 log copies/mL, received adefovir dipivoxil 10 mg add-on lamivudine 100 mg daily during a median of 115 weeks (range: 25-282 weeks). They were followed for the development of HCC by imaging modalities every 3-6 months. RESULTS HCC developed in 18 of the 247 (7.3%) patients. Eight factors were in significant association with the development of HCC by the univariate analysis. They included age, cirrhosis, platelet counts, levels of bilirubin, aspartate aminotransferase (AST), alanine aminotransferase and alpha-fetoprotein, as well as YMDD mutants at the start of adefovir dipivoxil. By the multivariate analysis, AST levels, YIDD mutants, cirrhosis and age were independent factors for the development of HCC. By the Kaplan-Meier analysis, AST levels >/= 70 IU/L, YIDD mutants, cirrhosis and age >/= 50 years increased the risk of HCC (P = 0.018, P = 0.035, P = 0.002 and P = 0.014, respectively). HCC developed more frequently in the patients with than without cirrhosis at the start of adefovir (10/59 [16.9%] vs. 8/188 [4.3%], P = 0.002). CONCLUSION HCC can develop in cirrhotic patients receiving adefovir add-on lamivudine. Hence, the patients with baseline AST >/= 70 IU/L and YIDD mutants would need to be monitored closely for HCC.
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Affiliation(s)
- Tetsuya Hosaka
- Department of Hepatology, Toranomon Hospital, Tokyo, Japan
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Kobayashi M, Suzuki F, Akuta N, Yatsuji H, Hosaka T, Sezaki H, Kobayashi M, Kawamura Y, Suzuki Y, Arase Y, Ikeda K, Mineta R, Iwasaki S, Watahiki S, Kumada H. Correlation of YMDD mutation and breakthrough hepatitis with hepatitis B virus DNA and serum ALT during lamivudine treatment. Hepatol Res 2010; 40:125-34. [PMID: 19788696 DOI: 10.1111/j.1872-034x.2009.00565.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AIM Continuous lamivudine treatment is associated with high frequency of drug resistance. We analyzed the incidence of tyrosine-methionine-aspartate-aspartate (YMDD) motif mutant and breakthrough hepatitis (BTH) in hepatitis B virus (HBV) DNA positive patients receiving lamivudine for > 1 year and correlated it with HBV DNA and alanine aminotransferase (ALT) levels to evaluate if these measurements can provide a practical option for monitoring patients in clinical practice and define early switch from lamivudine therapy. METHODS Of the 929 patients receiving lamivudine for > 1 year, 359 patients who maintained an ALT level of </= 40 IU/L during the course of lamivudine treatment were stratified into two groups based on the duration of lamivudine treatment - one receiving lamivudine for < 3 years and the other for >/= 3 years. RESULTS The incidence of YMDD motif in patients receiving lamivudine for < 3 years was 27% in patients with ALT </= 20 IU/L, 58% with ALT </= 30 IU/L, and 63% with ALT </= 40 IU/L, (P = 0.002). The corresponding incidence of BTH was 2%, 7%, and 48% (P < 0.001). The incidence of YMDD motif and BTH in these patients was 7% and 2% with HBV DNA < 2.6 (log copies/mL) and ALT </= 20 IU/L, while with ALT at 21-30, the YMDD motif mutant was 16% and BTH was 0%. CONCLUSION Correlation of ALT and HBV DNA levels with YMDD motif mutant and BTH indicates that these measurements can be used in clinical practice for deciding early switch from lamivudine to other suitable antiviral therapies.
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Affiliation(s)
- Mariko Kobayashi
- Research Institute for Hepatology, Toranomon Hospital, Tokyo, Japan
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Kobayashi M, Suzuki F, Akuta N, Hosaka T, Sezaki H, Yatsuji H, Yatsuji H, Kobayashi M, Suzuki Y, Arase Y, Ikeda K, Watahiki S, Iwasaki S, Miyakawa Y, Kumada H. Loss of hepatitis B surface antigen from the serum of patients with chronic hepatitis treated with lamivudine. J Med Virol 2007; 79:1472-7. [PMID: 17705186 DOI: 10.1002/jmv.20994] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Although loss of hepatitis B e antigen (HBeAg) from the serum is sought by treatment with lamivudine, clearance of hepatitis B surface antigen (HBsAg) is the eventual goal of any antiviral therapy. In a single hepatology center in the Metropolitan Tokyo, 486 patients with chronic hepatitis B were followed up for longer than 3 years after they started treatment with lamivudine. HBsAg disappeared from the serum in 17 (3.5%). Age >or=50 years and low HBsAg levels (hemagglutination titer <or=2(7)) at the start of lamivudine were significantly more frequent in the patients who did than did not lose HBsAg from the serum. Except for these two factors, there were no differences between the two groups of patients in the prevalence of HBeAg and HBV DNA levels at the baseline, as well as the development of YMDD mutants and breakthrough hepatitis during lamivudine treatment. Using multivariate analysis, age >or=50 years at the start of lamivudine was the only factor predicting the loss of HBsAg (hazard ratio: 2.96 [95% confidence interval: 1.14-7.68], P = 0.028). By the method of Kaplan-Meier performed on the 486 patients, the loss of HBsAg was estimated to occur in 3% and 13% of patients, respectively, who had received lamivudine therapy for 5 and 10 years. These results indicate that loss of HBsAg occurs in a minority (3.5%) of patients with chronic hepatitis B who receive lamivudine therapy and more frequently in those with lower HBsAg titers and older ages at the start of treatment.
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Affiliation(s)
- Mariko Kobayashi
- Research Institute for Hepatology, Toranomon Hospital, Tokyo, Japan.
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Horiike N, Duong TN, Michitaka K, Joko K, Hiasa Y, Konishi I, Yano M, Onji M. Characteristics of lamivudine-resistant hepatitis B virus (HBV) strains with and without breakthrough hepatitis in patients with chronic hepatitis B evaluated by serial HBV full-genome sequences. J Med Virol 2007; 79:911-8. [PMID: 17516520 DOI: 10.1002/jmv.20915] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Lamivudine therapy often causes breakthrough of hepatitis B virus (HBV) DNA and breakthrough hepatitis. The aim of this study was to determine the viral factors that relate to HBV-DNA breakthrough with and without breakthrough hepatitis. Among 82 patients with chronic hepatitis B (CHB) who received lamivudine at a dose of 100 mg daily for more than 24 months, 23 patients had HBV-DNA breakthrough induced by a lamivudine-resistant mutant. Of these 23 patients, 16 had breakthrough hepatitis and 7 had only HBV-DNA breakthrough. Serial HBV-DNA full-genome sequences during therapy were examined in 10 (7 had breakthrough hepatitis and 3 did not) of these 23 patients by direct sequencing. Mutations in the S region were examined by cloning in representative patients. There were no significant differences in the baseline clinical backgrounds and virus marker between patients with and without breakthrough hepatitis. The HBV amino acid substitutions at breakthrough hepatitis were identical to those at HBV-DNA breakthrough. Cloning analysis revealed that monoclonal mutational strain appeared at breakthrough and no such mutations existed at baseline. Regarding HBV amino acid substitutions in the polymerase region, S region, X region, and precore-core region with breakthrough compared to baseline, there was no significant differences of the numbers of amino acid substitution between breakthrough hepatitis and non-breakthrough hepatitis. There were no common amino acid changes in patients with breakthrough hepatitis. Although monoclonal lamivudine-resistant strain emerged at HBV-DNA breakthrough in patients with CHB, there were no common amino acid changes, suggesting viral factor may have insignificant role in breakthrough hepatitis.
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Affiliation(s)
- Norio Horiike
- Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Ehime, Japan
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Kobayashi M, Suzuki F, Akuta N, Suzuki Y, Arase Y, Ikeda K, Hosaka T, Sezaki H, Kobayashi M, Iwasaki S, Sato J, Watahiki S, Miyakawa Y, Kumada H. Response to long-term lamivudine treatment in patients infected with hepatitis B virus genotypes A, B, and C. J Med Virol 2006; 78:1276-83. [PMID: 16927289 DOI: 10.1002/jmv.20701] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Response to lamivudine treatment longer than 1 year was compared in 15 patients persistently infected with hepatitis B virus (HBV) genotype A, 38 with genotype B, and 449 with genotype C. Patients with genotype A were younger (median age 37 [range 24-49] vs. 47 [24-67] or 44 [18-73], P = 0.015), possessed hepatitis B e antigen (HBeAg) more frequently (73% vs. 21% or 56%, P < 0.001) and HBV DNA in higher levels (8.6 [6.1-8.7] vs. 6.5 [<3.7-8.7] or 6.5 [<3.7-8.7] log genome equivalents (LGE)/ml, P = 0.024) than those with genotype B or C. During lamivudine, YMDD mutants (89% vs. 53% or 42%, P = 0.0001) and breakthrough hepatitis developed more often (47% vs. 21% or 29%, P = 0.023) in patients with genotype A than B or C. YMDD mutants elicited more frequently in patients with genotype A than B or C who were positive (82% [9/11] vs. 25% [2/8] or 48% [117/245], P = 0.037) or negative for HBeAg (75% [3/4] vs. 30% [9/30] or 33% [68/204], P = 0.003). HBeAg (hazard ratio 2.1 [95% confidence interval 1.53-2.92], P < 0.001) and genotype A (2.78 [1.08-7.12], P = 0.034) enhanced the emergence of YMDD mutants by the Cox proportional hazard model. The risk for breakthrough hepatitis was increased by the baseline alanine aminotransferase level <500 IU/L (2.56 [1.82-5.50], P = 0.018), HBeAg (2.11 [1.40-3.16], P < 0.001), cirrhosis (1.92 [1.24-2.97], P = 0.004) and HBV DNA > or =8.0 LGE/ml (1.57 [1.04-2.36], P = 0.03); it was influenced by genotypes only in patients with HBeAg. In conclusion, HBV genotypes help in predicting response to long-term lamivudine treatment and development of YMDD mutants in patients with chronic hepatitis B.
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Affiliation(s)
- Mariko Kobayashi
- Research Institute for Hepatology, Toranomon Hospital, Tokyo, Japan.
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Kobayashi M, Akuta N, Suzuki F, Suzuki Y, Arase Y, Ikeda K, Hosaka T, Saitoh S, Kobayashi M, Someya T, Sato J, Watabiki S, Miyakawa Y, Kumada H. Virological outcomes in patients infected chronically with hepatitis B virus genotype A in comparison with genotypes B and C. J Med Virol 2005; 78:60-7. [PMID: 16299721 DOI: 10.1002/jmv.20504] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In a single hospital in Tokyo, the 87 patients infected persistently with hepatitis B virus (HBV) genotype A, the 413 with B, and the 3,389 with C were compared for virological outcome. Hepatitis B surface antigen (HBsAg) was cleared from the serum in 12% (3/26), 2% (2/112), and 3% (23/826) of patients with genotypes A, B, and C, respectively, at 5 years of follow-up (P = 0.0395). Hepatitis B e antigen (HBeAg) was cleared from serum more frequently in patients with genotype B than those with A or C (78% [32/41] vs. 58% [11/19] or 45% [251/562], P = 0.00001) at 5 years. Of the 45 individuals infected with genotype A and followed for 3 years or longer, HBeAg was more frequent (16% [3/19] vs. 73% [19/26], P = 0.0002) and levels of HBV DNA higher (median <2.6 [range: <2.6-5.6] vs. >7.6 [<2.6->7.6] log copies/ml, P = 0.001) in the 26 patients with biopsy-proven chronic hepatitis than the 19 asymptomatic carriers. Among the 26 hepatitis patients infected with HBV genotype A, decreases in HBV DNA were less frequent (20% [1/5] vs. 93% [13/14] or 86% [6/7], P = 0.0095) and increases in serum levels of hyaluronic acid > or =10 ng/ml commoner (80% [4/5] vs. 14% [2/14] or 14% [1/7], P = 0.017) in the patients who kept HBeAg than in those who seroconverted or who remained HBeAg-negative. In conclusion, patients persistently infected with HBV genotype A fare better than those with genotype B or C. However, high levels of HBV DNA continue in those in whom HBeAg persists along with fibrosis in the liver.
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Affiliation(s)
- Mariko Kobayashi
- Research Institute for Hepatology, Toranomon Hospital, Tokyo, Japan
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Akuta N, Kumada H. Influence of hepatitis B virus genotypes on the response to antiviral therapies. J Antimicrob Chemother 2004; 55:139-42. [PMID: 15618285 DOI: 10.1093/jac/dkh533] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatitis B virus (HBV) has been classified into eight genotypes (A-H) based on genome sequence divergence. Genotypes of HBV have distinct geographical distributions, and two genotypes account for most HBV worldwide. Hepatitis B e antigen expression lasts longer and liver disease is more severe with graver outcomes in carriers of genotype C than B in Asia. Accumulating lines of evidence indicate a better response to interferon and lamivudine in patients with chronic hepatitis B who are infected with genotype B rather than C. The therapeutic response may differ, however, in patients infected with HBV of the same genotype. For example, the response to lamivudine is poorer in patients infected with subtype Ba, which contains a recombination with genotype C, than in those with subtype Bj without such a recombination. Influence of genotypes on therapeutic response needs to be examined in patients infected with the other genotypes, particularly in those with genotype A or D infection.
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Affiliation(s)
- Norio Akuta
- Department of Gastroenterology, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-0001, Japan.
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