• Title/Summary/Keyword: HBV DNA polymerase

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Detection of Lamivudine-Resistant Mutations of HBV DNA Polymerase Gene Using PCR-Direct Sequencing

  • Lee, Kyung-Ok;Lee, Hye-Jung;Byun, Ji-Young;Lee, Sung-Yeun;Kim, Jeong-Sook;Jung, Na-Young;Chung, Soo-Jin;Seong, Hye-Soon;Kim, Kyung-Tae
    • Korean Journal of Clinical Laboratory Science
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    • v.38 no.3
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    • pp.196-202
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    • 2006
  • Treatment of hepatitis B virus (HBV) with lamivudine is effective in suppressing virus replication and results in reduced inflammatory activity. However the most troublesome problem of lamivudine treatment is the emergence of lamivudine-resistant strains with amino acid substitution in the YMDD motif of DNA polymerase gene during the treatment. The aim of this study was to determine the mutation of YMDD motif (codon 552) and codon 528 in chronic HBV patients with lamivudine therapy using PCR-direct sequencing and to investigate the relationship between lamivudine mediated HBV mutation and HBeAg. HBV DNA was extracted from serum samples of HBV patients and amplified by nested PCR with two sets of primer pairs selected in HBV DNA polymerase gene. Amplified PCR product was analyzed by 2% agarose gel electrophoresis and direct sequencing. HBV mutation was detected in 124 out of 207 samples (60%). Single mutation was 50.8% for M552I, 43.5% for M552V, 5.7% for M552I/V and the L528M mutation was 67.0%. Double mutation was 43.6% for M552V/L528M, 33.1% for M552I/L528(wild type), 17.7% for M552I/L528M and 5.6% for M552I/V/L528M. Serine mutation at YMDD motif (M552S) was not found and the L528M mutation frequently accompanied M552V type. In this study, the typical difference of frequencies for HBV mutation depending on HBeAg was not found. Moreover, the PCR-direct sequencing method used in this study might be a powerful tool for the mutation study in clinical reference laboratories with high volume.

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Prevalence of HBV DNA in Packed Red Blood Cells (적혈구 농축제재에서 HBV DNA의 노출정도)

  • Lee, Chae-Hoon;Kim, Chung-Sook;Song, Dal-Hyo
    • Journal of Yeungnam Medical Science
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    • v.12 no.2
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    • pp.339-346
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    • 1995
  • Assays for HBsAg, HBV DNA, anti-HBc and anti-HBs of 285 units of packed red blood cells supplied by Taegu Red Cross Blood Center were performed to evaluate the correlation between the prevalence of HBV DNA and the serologic markers for hepatitis B virus. None of 285 plasma samples was positive for HBsAg, however, HBV DNA were detected by polymerase chain reaction in 2 samples which both presented only with anti-HBc positivity. Of 204 samples tested for anti-HBs, 96 samples(47.1%) were positive and among 216 samples tested for anti-HBc, 80 samples(37.0%) were positive. Of 193 samples tested for both anti-HBs and anti-HBc, 80(41.1%) were all negative and 48(24.9%) were positive on both tests. Those samples which showed positivity only to anti-HBc were 25(13.0%). Considering the above results, transfusion-transmitted hepatitis B virus infection could be prevented by discarding anti-HBc positive blood, however, that may bring insufficient supply of donor bloods in the country like Korea where the prevalence of anti-HBc is high. Anti-HBc positive blood unequivocally positive for anti-HBs should be considered noninfectious for HBV and should be allowed to be transfused. It would reduce the amount of discarding donor blood as the routine blood donor screening tests presently used at Korea Red Cross Blood Center supplemented by anti-HBs and anti-HBc testing.

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Phylogenetic Analysis of Hepatitis B Virus Genome Isolated from Korean Patient Serum

  • Kim, Seon-Young;Kang, Hyen-Sam;Kim, Yeon-Soo
    • Journal of Microbiology and Biotechnology
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    • v.10 no.6
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    • pp.823-828
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    • 2000
  • The complete nucleotide sequence of hepatitis B virus DNA isolated from Korean patient serum was determined and characterized, and its phylogenetic relation was then investigated. The viral genome was 3,215 base pairs long and included four well known open reading frames (i.e. surface antigens, core antigens, X protein and DNA polymerase). The sequence of the surface antigen showed that the HBV genome under investigation, designated HBV 315, was characteristic of subtype adr. A phylogenetic analysis using the total genome sequence revealed that HBV315 was grouped into genomic group C together with isolates from Japan, China, Thailand, Polynesia, and New Caledonia. The mean percent similarity between HBV315 and other HBV isolates in genomic group C was 97.25%, and that with other genomic groups ranged from 86.16% to 91.25%. The predicted amino acid sequences of HBV315 were compared with two closely related subtype adr isolates, M38636 and D12980. The results showed that the X gene product was identical in the three strains, while there were significant amino acid sequence differences between HBV315 and M38636 in the Pre-S1 and Pre-S2 regions.

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Detection of Serum Hepatitis B Virus DNA According to HBV Markers in Chronic Hepatitis B Liver Disease (만성 B형 간질환에서 간염 B virus 표식자 발현에 따른 DNA의 검출)

  • Lee, Dong-Jun;Choi, Jin-Su;Kim, Joon-Hwan;Lee, Heon-Ju
    • Journal of Yeungnam Medical Science
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    • v.14 no.1
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    • pp.155-167
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    • 1997
  • The identification of serum HBV DNA is very important for the assessment of the disease activity in persistent infection, for the evaluation of the infectivity of an individuals blood. The dot blot, however, has limited sensitivity and sometimes inconsistent with other serological markers and clinical settings. Using the most important recent advance in molecular biology, the polymerase chain reaction(PCR), specific DNA sequences can be amplified more than a million-fold in a few hours and with this technique the detection of the extreme low level of DNA is possible. This study was to determine sensitivity of the PCR for the detection of serum HBV DNA in comparison with dot blot analysis and to investigate the serum HBV DNA status and clinical significance of PCR in patients with chronic HBsAg positive liver disease. The subjects of this study were 17 patients with asymptomatic HBsAg carriers(9 HBeAg positive patients, 8 anti-HBe positive patients), 91 chronic hepatitis B(50 HBeAg positive patients, 41 anti-HBe positive patients), 57 liver cirrhosis(21 HBeAg positive patients, 36 anti-HBe positive patients), 27 hepatocellular carcinoma(10 HBeAg positive patients, 17 anti-HBe positive patients). The results were summerized as following; The detection rates of HBV DNA by dot blot, PCR were 58.9%, 72.2% in HBeAg positive patients, 34.3%, 53.9% in anti-HBe positive patients. The detection rates of HBV DNA by PCR in HBeAg negative patients were 25.0% in asymptomatic HBsAg carriers, 61.0% in chronic hepatitis B, 52.8% in liver cirrhosis, 52.9% in hepatocellular carcinoma. The positive rate for HBV DNA is a significant difference between HBeAg positive and negative asymptomatic HBsAg carriers, but not significantly difference in other groups. In conclusions, this study confirmed that the PCR is much more sensitive than the dot blot analysis in detecting the HBV DNA in the sera of patients with chronic liver disease. The presence of HBV DNA in the serum was detected by PCR with higher sensitivity and it suggested that active viral replication is still going on in most patients with chronic HBsAg positive liver disease irrespective of HBeAg/anti-HBe status, and PCR may be used as a prognostic factor in asymptomatic HBsAg carriers.

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A Study of Immune Response to Hepatitis B Vaccine & HBV DNA in Isolated Anti-HBc Positive Subjects (Anti-HBc 단독 양성자에서 B형 간염 백신 접종의 면역 반응과 B형 간염 DNA의 조사)

  • Kim, Soon-Duck;Choi, Ji-Ho;Kim, Sung-Ryul;Lee, Jin-Soo;Koh, Hee-Jeong
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.2
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    • pp.170-174
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    • 2005
  • Objectives: The aim of this study was to evaluate the response to a hepatitis B vaccination, and investigate the HBV DNA in subjects with isolated anti-HBc. Methods: 34 subjects with persistent isolated anti-HBc were included in the study. 32 subjects negative for HBsAg, anti-HBs and anti-HBc were included as a control group. They were all vaccinated with Hepaccine at 0, 1 and 2 months, and anti-HBs titers were measured 1 month after the 1st and 3rd vaccinations (1 and 3 months). The HBV-DNA was tested by polymerase chain reaction in subjects with isolated anti-HBc. Results: After the 1st & 3rd vaccinations, the anti-HBs titers$\geq$10mIU/ml were 70.6 & 70.6% in isolated anti-HBc group, and 34.4 & 81.2% in the control group, respectively. There were statistically significant differences after the 1st vaccination, but none after the 3rd, between the two groups. In the isolated anti-HBc and control groups, the primary, amnestic and no responses were 0 vs. 46.9%, 55.9 vs. 6.3% and 29.4 vs. 18.8%, respectively. The HBV DNA was not detected in all subjects with isolated anti-HBc. Conclusion: None of the subjects with isolated anti-HBc had a false positive result (primary response); therefore, they should be excluded from vaccination programs in Korea. To differentiate between immunity and occult infections, a single dose of vaccine, with a follow-up anti-HBs test, is preferable for subjects with isolated anti-HBc. An amnestic response indicates late immunity, and no response a suspect occult infection.

Interleukin-6-174 Promoter Polymorphism and Susceptibility to Hepatitis B Virus Infection as a Risk Factor for Hepatocellular Carcinoma in Iran

  • Attar, Marzieh;Azar, Saleh Shahbazi;Shahbazi, Majid
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.5
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    • pp.2395-2399
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    • 2016
  • Background: Hepatitis B virus (HBV) is a major risk factor for hepatocellular carcinoma (HCC). Cytokines play an important role in the regulation of immune responses and defense against viral infections. Human interleukin 6 (IL6) is a multifunctional cytokine that participates in these processes. Objective: The aim of this study was to assess the IL6-174 gene polymorphism in patients with chronic hepatitis B virus (HBV) infection as compared with healthy controls in an Iranian population. Materials and Methods: Totals of 297 HBV patients and 368 control individuals were evaluated. Genomic DNA was extracted from peripheral blood and the SSP-PCR (sequence specific primer-polymerase chain reaction) method was applied for genotyping. Results: The frequencies of genotypes C/C, G/G and C/G in HBV cases were 4.7%, 34.3%, 60.9% and in controls were 12.8%, 39.7% and 47.6%, respectively. The frequencies of G and C allele in patients and controls were 78.1%, 21.9% and 67.4%, 32.6 % respectively. There was a significant difference in the frequencies of G/G genotype (CI=1.8-7.1, OR=3.47, P=0.00001) and G allele (CI=1.34-2.23, OR=1.72, P=0.0001) between HBV patients and the control group. Conclusions: These findings suggest that the IL6-174 C/G genotype and the G allele are strongly associated with susceptibility to HBV infection. Demographic information showed that most of the subjects were male (74.4%). According to high frequency of G/G genotype in male participants (63.1%) men probably are more susceptible to hepatitis than women.

Use of ALLGIO Probe Assays for Detection of HBV Resistance to Adefovir in Patients with Chronic Hepatitis B, Kerman, Iran

  • Afshar, Reza Malekpour;Mollaie, Hamid Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5463-5467
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    • 2012
  • Hepatitis B virus (HBV) infection is contagious with transmissiobn vertically or horizontally by blood products and body secretions. Over 50% of Iranian carriers contracted the infection prenatally, making this the most likely route of transmission of HBV in Iran. To evaluate the resistance to adefovir (ADV) therapy in patients with chronic hepatitis B infection, a study was conducted on 70 patients (63 males and 7 females), who had received in first line lamivudine and second line adefovir. All were tested for the presence of hepatitis B surface antigen (HBsAg), hepatitis B envelope antigen (HBeAg), serum alanine amino transferase (ALT) level and HBV DNA load before and after treatment with ADV. In all samples, resistance to lamivudine and ADV was tested with real time PCR. Among seventy patients with chronic hepatitis B infection, 18 (25.7%) were resistant to LAM and 8 (11.4%) were resistant to ADV. Only one patient was negative for the presence of HBS-Ag (5.6%) and two were negative for HBe-Ag (11.1%). In this study we used a new method (ALLGIO probe assay) that has high sensitivity in detection of adefovir resistance mutants, which we recommend to other researchers. Mutant strains of the YMDD motif of HBV polymerase can be found in some patients under treatment with lamivudine and ADV. ADV has been demonstrated to be efficient in patients with lamivudine resistant HBV.

The Production of HBsAg in the Recombinant Yeast Cells (재조합 효모 세포내에서의 간염백신 생산)

  • Park, Cha-Yong;Lee, Hei-Chan
    • Microbiology and Biotechnology Letters
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    • v.14 no.6
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    • pp.455-460
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    • 1986
  • Dane particle was prepared from the plasma of chronic HBsAg carrier with high levels of HBsAg activity. DNA extracted front Dane particle core after a DNA polymerase reaction with $\alpha$-($^{32}$P) dNTP, was identified as HBV DNA by liquid scintillation counter and agarose gel electrophoresis-G.M. counting. To produce Hepatitis B surface antigen for use as a vaccine against Hepatitis B virus infection, yeast strains harboring recombinant plasmid with Apase promoter was used. Recombinant plasmid was construced from pHBV 130 and pAN 82, transformed into E coli, and then transferred into yeast strains. HBsAg was produced by derepression in Burkholder minimal medium with controlled inorganic phosphate concentration. The kinetics of HBsAg production was also investigated. Total HBsAg activity increased rapidly between 3 and 6 hours after transfer to phosphate-free medium and reached a maximum at around 9th hour. The transfer into phosphate-free medium after 6 hours in high phosphate cell growth medium gave maximum activity.

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The Short Term Efficacy of Entecavir Therapy in Chronic Hepatitis B (만성 B형 간염 환자에서 엔테카비어의 단기 치료 효과)

  • Kim, Hyun;Chae, Hee-Bok;Jeon, Won-Joong;Park, Seon-Mee;Youn, Sei-Jin;Eun, Jong-Ryul;Lee, Heon-Ju
    • Journal of Yeungnam Medical Science
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    • v.25 no.1
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    • pp.31-40
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    • 2008
  • Background/Aims : Entecavir is a synthetic nucleoside analogue, cyclopentyl guanine nucleoside, which has a potent antiviral effect and the least viral breakthrough in hepatitis B virus (HBV) replication. Entecavir has been available in Korea since 2007 but there are few reports on its effects. The aim of this study was to evaluate the virological response (VR) and biochemical response (BR) to entecavir in HBV patients at 3, 6 and 9 months after treatment with entecavir. Materials and Methods : Thirty-three chronic hepatitis B patients who took entecavir for at least 9 months were enrolled. We investigated VR and BR by retrospectively reviewing medical records. Patients who satisfied the following criteria were chosen: 1) initial alanine aminotransferase (ALT) levels = 1.5upper limit of normal (ULN) and 2) initial HBV DNA levels = $5\;log_{10}\;copies/ml$. We measured ALT levels every 3 months until month 9. HBV DNA was measured every 2 or 3 months by polymerase chain reaction (PCR) method. Results : Most patients taking entecavir showed good BR (ALT < 40 IU/L). The BR rates were 61%, 73% and 67% at months 3, 6 and 9, respectively. VR (HBV DNA < $5\;log_{10}\;copies/ml$ or 2 log lower than initial HBV DNA) rates were 82%, 91% and 91% at months 3, 6 and 9, respectively. Undetectable HBV DNA (HBV DNA < 4 log10 copies/ml) rates were 49%, 73% and 85% at months 3, 6 and 9, respectively. Two patients presented with virological breakthrough without adverse effects until month 9. Conclusions : Entecavir showed good BR and VR from month 3 and these effects continued through the 9-month observation period. This suggests that entecavir is also a good choice for the first line treatment of chronic hepatitis B (CHB). Further studies are needed to determine the long-term efficacy and drug resistance of entecavir in Korean CHB patients.

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Association of Viral Infections with Risk of Human Lymphomas, Egypt

  • Kadry, Dalia Y;Khorshed, Amira M;Rashed, Reham A;Mokhtar, Nadia M
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1705-1712
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    • 2016
  • Background: The aim of this study was to determine and evaluate the association of different viral infections, with hepatitis B and C viruses, Epstein-Barr virus, cytomegalovirus and human herpes virus-8 (HBV, HCV, EBV, CMV, HHV-8) with the risk of lymphomas (Hodgkin and non-Hodgkin) among Egyptian patients, and correlate with the histopathological staging and typing as well as the prevalence of combined infections. Materials and Methods: A total of 100 newly diagnosed lymphoma patients with 100 healthy age and sex matched normal controls were assayed for viral infection using enzyme linked immunosorbant assay (ELISA) followed by real time polymerase chain reaction (RT-PCR). Results: Our results showed a high statistical significant difference between cases and controls as regards clinical and laboratory findings (P<0.001 and=0.003). A high statistical difference was seen for the association of most viruses and lymphoma cases (p<0.001) except for positive HBs Ag, positive CMV IgG and HHV-8 (p=0.37, 0.70 and 1.0 respectively). No statistical significant difference was found between Hodgkin (HL) and non-Hodgkin (NHL) as regards viral prevalence except HCV antigen, 57.1% for HL and 26.5% for NHL (p = 0.03). Only, HBV DNA showed a high significant value among infiltrated bone marrow cases (p=0.003) and finally, a high significant association of 2 combined viral infections with infiltrated bone marrow lymphoma cases (p=0.04). Conclusions: Our results showed that infection with HBV, HCV, CMV and EBV were associated with increased risk of lymphoma among the Egyptian population. Detection of new associations between infectious agents and risk of cancer development will facilitate progress in elaboration of prophylactic measures, early diagnostic methods and, hopefully, novel therapy of malignant tumours.