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1.
Front Pharmacol ; 12: 648170, 2021.
Article in English | MEDLINE | ID: mdl-33935748

ABSTRACT

Background/Aims: Emergence of tyrosine-methionine-aspartate-aspartate (YMDD) motif in reverse transcriptase is a serious problem in chronic hepatitis B(CHB) patients after Lamivudine (LAM) therapy. However, the relationship between inflammation pharmacological reaction and YMDD mutational patterns of CHB has not been well-characterized. The aim of this study was to investigate the inflammation pharmacological reaction and different YMDD mutants patterns of CHB patients. Methods: We investigated the inflammation pharmacological reaction and YMDD mutational patterns through biochemical, serological and virological detection among 83 CHB patients, including 25 YMDD mutants, 25 under detection, and 33 control patients without YMDD mutants. Results: Prevalence of YMDD mutation patterns is different. Among 25 YMDD mutants patients, YIDD was the dominant mutation (72%), followed YVDD (16%) and the hybrid YIDD + YVDD (12%). The time course during the YMDD mutations was also different. 52.4% patients developed the mutation less than 12 months after the LAM therapy. Serum hepatitis B virus (HBV) DNA level in patients with YMDD mutants were significantly higher than that in control and negative groups. Serum HbsAg and HbeAg in patients with YMDD mutants were also higher than those in control and negative groups, despite no significant difference was found forserum HbeAb. ALT and AST levels were also significantly higher in mutants group. Conclusions: Illuminating inflammation pharmacological reaction and YMDD mutational patterns of CHB during pathological process may have implications for future therapy in YMDD mutation patients. This may have impact on the choice of treatment strategies for lamivudine-resistant HBV.

2.
Clin Microbiol Infect ; 27(3): 443-450, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32360447

ABSTRACT

OBJECTIVES: Undetectable or low-level hepatitis B virus (HBV) DNA and drug resistance mutations in patients may increase the risk of HBV transmission or cause active viral replication and other clinical problems. Here, we established a highly sensitive and practical method for HBV and drug resistance detection using a polymerase chain reaction (PCR) -based CRISPR-Cas13a detection system (referred to as PCR-CRISPR) and evaluated its detection capability using clinical samples. METHODS: Specific CRISPR RNAs (crRNAs) are designed for HBV DNA detection and YMDD (tyrosine-methionine-aspartate-aspartate) variant identification. The HBV DNA was detected in 312 serum samples for HBV diagnosis using quantification PCR (qPCR) and PCR-CRISPR. Additionally, 424 serum samples for YMDD testing were detected by qPCR, direct sequencing, and our assay. RESULTS: Using PCR-CRISPR, one copy per test of HBV DNA was detected with HBV-1 crRNA in 15 min after PCR amplification. Consistent results with qPCR were observed for 302 samples, while the remaining 10 samples with low-level HBV DNA were detectable by PCR-CRISPR and droplet digital PCR but not by qPCR. PCR-CRISPR diagnosed all 412 drug-resistant samples detected by the YMDD detection qPCR kit and direct sequencing, as well as the other 12 drug-resistant samples with low-level HBV DNA undetectable by qPCR and direct sequencing. CONCLUSIONS: We developed a novel PCR-CRISPR method for highly sensitive and specific detection of HBV DNA and drug resistance mutations. One copy per test for HBV DNA and YMDD drug resistance mutations could be detected. This method has wide application prospects for the early detection of HBV infection, drug resistance monitoring and treatment guidance.


Subject(s)
Antiviral Agents/pharmacology , CRISPR-Cas Systems , DNA, Viral/genetics , Drug Resistance, Viral/genetics , Hepatitis B virus/drug effects , Polymerase Chain Reaction/methods , Genotype , Hepatitis B virus/genetics , Mutation , Sensitivity and Specificity
3.
Liver Int ; 40(1): 83-91, 2020 01.
Article in English | MEDLINE | ID: mdl-31498528

ABSTRACT

BACKGROUND: Tenofovir disoproxil fumarate (TDF) imposes a high genetic barrier to drug resistance and potently inhibits replication of multidrug-resistant hepatitis B virus. Few clinical cases with confirmed TDF-resistance have been reported to date. METHODS AND RESULTS: Here, we report viral rebound in a patient with chronic hepatitis B who underwent TDF monotherapy and harboured a quadruple mutant consisting of classic entecavir (ETV)-resistance mutations (rtL180M/T184L/M204V) together with an rtA200V mutation in the reverse transcriptase gene. Sequencing analysis revealed that this quadruple mutant emerged as a major viral population. In vitro phenotyping demonstrated that the rtL180M/T184L/A200V/M204V mutant had moderate resistance to TDF treatment, with a 4.52-fold higher half maximal effective concentration than that of wild-type virus. Importantly, this patient with TDF resistance achieved virological suppression after TDF/ETV combination rescue therapy. CONCLUSION: An rtL180M/T184L/A200V/M204V mutant with moderate resistance to TDF monotherapy was selected during sequential nucleoside analogue (NA) treatment in a stepwise manner. ETV/TDF combination therapy effectively suppressed replication of this TDF-resistant mutant. Our studies provide novel insights into the treatment of NA-naïve patients as well as patients with TDF resistance.


Subject(s)
Drug Resistance, Viral , Guanine/analogs & derivatives , Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , RNA-Directed DNA Polymerase/genetics , Tenofovir/therapeutic use , Antiviral Agents/therapeutic use , Drug Therapy, Combination , Female , Genotype , Guanine/therapeutic use , Humans , Middle Aged , Mutation , Viral Proteins/genetics
4.
Afr Health Sci ; 17(3): 762-772, 2017 Sep.
Article in English | MEDLINE | ID: mdl-29085404

ABSTRACT

BACKGROUND: Hepatitis B Virus (HBV) infection is one of the major causes of liver cirrhosis, hepatocellular carcinoma and deaths due to the acute or chronic consequences worldwide. HBV is distributed into various genotypes based on nucleic acid sequence variation. OBJECTIVES: To develop a method of HBV genotyping and drug resistance interpretation using partial sequencing of polymerase gene. METHODS: This study was performed on 98 HBV infected patients' serum samples from Western India. A nested PCR protocol was designed for amplification of pol gene from HBV genome and Sanger's sequencing of the gene fragment. Sequences were aligned with HBV reference sequences for phylogenetic analysis and for characterization of genetic diversity. Drug resistance mutations were screened using HBVSeq program from Stanford University. RESULTS: Distribution of HBV genotypes showed predominance of genotype D, circulating in 76 (77.55%) patients (p < 0.05). Genotypes A and C were less prevalent and were identified in 4 (4.08%) and 18 (18.37%) patients, respectively. Anti-retroviral drug resistance mutations were not detected in any patient. CONCLUSION: A method for determination of HBV genotypes using pol gene sequencing which simultaneously detects major drug resistance mutations has been established. HBV genetic diversity may play an important role in treatment decision.


Subject(s)
DNA, Viral/genetics , Hepatitis B virus/classification , Hepatitis B virus/genetics , Hepatitis B, Chronic/virology , Mutation , Polymerase Chain Reaction/methods , Polymorphism, Genetic/genetics , Adult , DNA, Viral/blood , DNA-Directed DNA Polymerase , Genetic Variation , Genotype , Hepatitis B virus/isolation & purification , Hepatitis B, Chronic/blood , Hepatitis B, Chronic/epidemiology , Humans , India/epidemiology , Male , Molecular Epidemiology , Phylogeny
5.
Springerplus ; 5(1): 1340, 2016.
Article in English | MEDLINE | ID: mdl-27588233

ABSTRACT

Although the drug-induced mutations of HBV have been ever documented, the evolutionary mechanism is still obscure. To deeply reveal molecular characters of HBV evolution under the special condition, here we made a comprehensive investigation of the molecular variation of the 3432 wild-type sequences and 439 YMDD variants from HBV genotype A, B, C and D, and evaluated the co-variant patterns and the frequency distribution in the different YMDD mutation types and genotypes, by using the naïve Bayes classification algorithm and the complete induction method based on the comparative sequence analysis. The data showed different compensatory changes followed by the rtM204I/V. Although occurrence of the YMDD mutation itself was not related to the HBV genotypes, the subsequence co-variant patterns were related to the YMDD variant types and HBV genotypes. From the hierarchy view, we clarified that historical mutations, drug-induced mutation and compensatory variances, and displayed an inter-conditioned relationship of amino acid variances during multiple evolutionary processes. This study extends the understanding of the polymorphism and fitness of viral protein.

6.
Exp Ther Med ; 12(2): 847-853, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27446286

ABSTRACT

The aim of the present study was to investigate the correlation between feature and genotype with regard to the tyrosine-methionine-aspartate-aspartate (YMDD) mutation in chronic hepatitis B patients after lamivudine (LAM) therapy. A total of 30 patients with chronic hepatitis B were recruited, who underwent one year of LAM therapy. The patients' alanine aminotransferase (ALT) level and hepatitis B envelope antigen (HBeAg) seroconversion were evaluated, hepatitis B virus (HBV) DNA was genotyped using a new genotyping method and YMDD mutations were analyzed prior to treatment and at 6 and 12 months after LAM treatment. Furthermore, the secondary protein structure of the HBV DNA polymerase gene (P gene) was analyzed. Following treatment, the results suggested that LAM therapy improved ALT normalization. There was no correlation between clinical effects and ALT level before treatment. After 12 months treatment, the rate of HBeAg loss increased and the rate of HBeAg seroconversion decreased linearly with the rise of baseline ALT level. While ALT normalization and HBeAg seroconversion were highest in patients with HBV genotype B, HBeAg loss and HBVDNA loss were highest in those with genotype C. The effect was predominant in genotype D. No YMDD mutations were identified prior to 6 months of LAM therapy. The rate of YMDD mutations after 12 months LAM therapy was 12.12%. Two patients with rtM204V + rtL180M belonged to genotype C and another patient with rtL180M alone belonged to genotype D. The turn of secondary protein structure of P gene changed to ß sheet when a rtM204V mutation occurred, and no change of secondary protein structure was associated with the rtL180M mutation. Thus, the present results indicate that one year of LAM therapy is able to improve ALT normalization. Long-term LAM therapy may induce YMDD mutation and drug resistance.

7.
World J Hepatol ; 7(6): 896-902, 2015 Apr 28.
Article in English | MEDLINE | ID: mdl-25937866

ABSTRACT

Currently, although lamivudine (LAM) has a low genetic barrier, only interferon-alpha and LAM are available as a first-line treatment in children with chronic hepatitis B (CHB). LAM is a potent inhibitor of hepatitis B virus-deoxyribonucleic acid (HBV-DNA) polymerase replication by termination of the proviral HBV-DNA chain. LAM has a good safety and tolerability profile in CHB patients with hepatic decompensation. However, the main disadvantages of this HBV reverse transcriptase inhibitor are: (1) pre-existing covalently closed circular DNA cannot be eradicated by LAM, thus relapse after therapy withdrawal is frequent; and (2) although the longer LAM treatment induced the higher seroconversion rate, the risk of viral resistance increased through the selection of YMDD (tyrosine, methionine, aspartate, aspartate) motif. Insufficient suppression of viral replication leads to the emergence of resistant strains that could result in virological breakthrough which is usually followed by biochemical breakthrough. Mutant strains affects additional resistance and cross resistance, leading to drug resistance in a significant number of CHB patients. In this case, efficacy of more powerful anti-viral agents with higher genetic barrier against development of resistance is diminished. Furthermore, strains that are resistant to LAM could bring about vaccine escape mutants, decreasing the efficacy of HBV vaccine. A more potent drug with a high genetic barrier to resistance needs to be approved as the first-line treatment option for CHB in children.

8.
Ann Surg Treat Res ; 86(5): 256-63, 2014 May.
Article in English | MEDLINE | ID: mdl-24851227

ABSTRACT

PURPOSE: HBsAg-positive kidney recipients are at increased risk for mortality and graft failure. The aims of this study were to identify the outcomes of HBsAg-positive recipients who received preemptive antiviral agents after successful kidney transplantation and to analyze risk factors for HBV reactivation. METHODS: We retrospectively reviewed the medical records of 944 patients performed kidney transplantation between 1999 and 2010. RESULTS: HBsAg-negative recipients were 902 patients and HBsAg-positive recipients, 42. Among HBsAg-positive recipients, HBV reactivation was detected in 7 patients and well controlled by switch or combination therapy. Graft failure developed in only one patient due to chronic rejection regardless of HBV reactivation but no deaths occurred. All patients were alive at the end of follow-up and none developed end-stage liver disease or hepatocellular carcinoma. There was statistically significant difference in graft survival between HBsAg-positive recipients and HBsAg-negative. Multivariate analysis identified increased HBV DNA levels (>5 × 10(4) IU/mL) in the HBsAg-positive kidney transplant recipients as a risk factor for HBV reactivation (P = 0.007). CONCLUSION: Effective viral suppression with antiviral agents in HBsAg-positive renal transplant recipients improves patient outcome and allograft survival. Antiviral therapy may be especially beneficial in patients with high HBV DNA levels prior to transplantation.

9.
J Med Virol ; 86(6): 913-7, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24615989

ABSTRACT

HBV has a relatively high mutation rate in its genome and most of these mutations are associated with the curative effect of nucleoside analogs. In this study, 1,424 patients with HBV-related liver diseases not treated with antiviral drugs, including 197 asymptomatic HBV carriers, 769 chronic hepatitis B patients, 145 acute-on-chronic liver failure (ACLF) patients, 187 HBV-related liver cirrhosis patients, and 126 HBV-related HCC patients, were selected to investigate the distribution and clinical significance of spontaneous YMDD mutations in liver diseases at different stages. Spontaneous YMDD mutations were detected in all stages of liver diseases and the YIDD variant was the dominant mutation type. The mutation rate was higher in genotype C strains than in genotype B strains. The χ(2) subdivision method showed that the spontaneous YMDD mutation rate in HCC was higher than that in other liver diseases. The difference in spontaneous YMDD mutation rates in patients with liver diseases infected with genotype C strains at different stages was statistically significant. Spontaneous YMDD mutation rates in patients with liver diseases infected with genotype C strains at different stages were then compared one to one using the χ(2) subdivision method. The results showed that the spontaneous YMDD mutation rate in HCC was higher than that in other liver diseases. Taken together, these results indicated that spontaneous YMDD mutations are more likely to occur in patients infected with genotype C strains, and genotype C strains with spontaneous YMDD mutations may be a risk factor for HCC.


Subject(s)
Carcinoma, Hepatocellular/epidemiology , Carcinoma, Hepatocellular/virology , DNA-Directed DNA Polymerase/genetics , Hepatitis B virus/genetics , Mutation, Missense , Adolescent , Adult , Aged , Aged, 80 and over , Child , Genotype , Hepatitis B virus/enzymology , Humans , Male , Middle Aged , Risk Factors , Young Adult
10.
Article in English | WPRIM (Western Pacific) | ID: wpr-163741

ABSTRACT

PURPOSE: HBsAg-positive kidney recipients are at increased risk for mortality and graft failure. The aims of this study were to identify the outcomes of HBsAg-positive recipients who received preemptive antiviral agents after successful kidney transplantation and to analyze risk factors for HBV reactivation. METHODS: We retrospectively reviewed the medical records of 944 patients performed kidney transplantation between 1999 and 2010. RESULTS: HBsAg-negative recipients were 902 patients and HBsAg-positive recipients, 42. Among HBsAg-positive recipients, HBV reactivation was detected in 7 patients and well controlled by switch or combination therapy. Graft failure developed in only one patient due to chronic rejection regardless of HBV reactivation but no deaths occurred. All patients were alive at the end of follow-up and none developed end-stage liver disease or hepatocellular carcinoma. There was statistically significant difference in graft survival between HBsAg-positive recipients and HBsAg-negative. Multivariate analysis identified increased HBV DNA levels (>5 x 10(4) IU/mL) in the HBsAg-positive kidney transplant recipients as a risk factor for HBV reactivation (P = 0.007). CONCLUSION: Effective viral suppression with antiviral agents in HBsAg-positive renal transplant recipients improves patient outcome and allograft survival. Antiviral therapy may be especially beneficial in patients with high HBV DNA levels prior to transplantation.


Subject(s)
Humans , Allografts , Antiviral Agents , Carcinoma, Hepatocellular , DNA , Follow-Up Studies , Graft Survival , Hepatitis B virus , Kidney , Kidney Transplantation , Liver Diseases , Medical Records , Mortality , Multivariate Analysis , Retrospective Studies , Risk Factors , Transplantation , Transplants
11.
World J Gastroenterol ; 19(24): 3861-5, 2013 Jun 28.
Article in English | MEDLINE | ID: mdl-23840126

ABSTRACT

AIM: To investigate the relationship between hepatitis B virus (HBV) genotype with spontaneous YMDD mutations and hepatocellular carcinoma (HCC) in HBV-related cirrhosis. METHODS: We investigated 264 liver cirrhosis patients who were not treated with antiviral drugs, including 81 patients with HCC. YMDD mutations were detected by fluorescent hybridization bioprobe polymerase chain reaction (PCR) and melting curve assay using the Diagnosis Kit for HBV YMDD Mutation. Serum HBV genotypes were detected by real-time PCR using genotype-specific TaqMan probes. Statistical analysis was performed according to data type using the t test, χ(2) test and unconditional logistic regression analysis. RESULTS: In the HCC group, genotype C strains, spontaneous YMDD mutations, and genotype C strains with YMDD mutations were detected in 33 (40.74%), 13 (16.05%) and 11 (13.58%) patients, respectively. In the liver cirrhosis (LC) group, HBV genotype C strains, spontaneous YMDD mutations, and genotype C strains with YMDD mutations were detected in 33 (18.03%), 7 (3.83%) and 2 (1.09%) patients, respectively. The differences in genotype C strains, spontaneous YMDD mutations, and genotype C strains with YMDD mutations between the two groups were statistically significant (χ(2) = 15.441, P = 0.000; χ(2) = 11.983, P = 0.001; P = 0.000). In the HCC and LC groups, there were seven patients infected by genotype B strains with YMDD mutations and 13 by genotype C strains with YMDD mutations. Further research revealed that HCC occurred in 2 patients infected by genotype B strains with YMDD mutations and 11 infected by genotype C strains with YMDD mutations. The difference was statistically significant (P = 0.000). Unconditional logistic regression analysis revealed that patients infected by genotype C strains with spontaneous YMDD mutations had a 7.775-fold higher risk for the development of HBV-related HCC than patients infected by other type HBV strains (P = 0.013, 95%CI: 1.540-39.264). CONCLUSION: Genotype C strains with spontaneous YMDD mutations are an independent risk factor for HCC in LC patients and are important for early warning of HCC.


Subject(s)
Carcinoma, Hepatocellular/epidemiology , DNA, Viral/genetics , Genotype , Hepatitis B virus/genetics , Liver Neoplasms/epidemiology , Mutation/genetics , Adult , Aged , Antiviral Agents/therapeutic use , Female , Hepatitis B/complications , Hepatitis B/drug therapy , Humans , Liver Cirrhosis/complications , Liver Cirrhosis/virology , Male , Middle Aged , Risk Factors
12.
Braz. j. infect. dis ; 16(3): 250-255, May-June 2012. tab
Article in English | LILACS | ID: lil-638558

ABSTRACT

OBJECTIVE: This study aimed to determine the natural prevalence of variants of tyrosine-methionine-aspartic acid-aspartic acid (YMDD) motif in patients with chronic hepatitis B (CHB), and to explore its relation with demographic and clinical features, hepatitis B virus (HBV) genotypes, and HBV DNA levels. METHODS: A total of 1,042 antiviral treatment naïve CHB patients (including with lamivudine [LAM]) in the past year were recruited from outpatient and inpatient departments of six centers from December 2008 to June 2010. YMDD variants were analyzed using the HBV drug resistance line probe assay (Inno-Lipa HBV-DR). HBV genotypes were detected with polymerase chain reaction (PCR) microcosmic nucleic acid cross-ELISA, and HBV deoxyribonucleic acid (DNA) was quantitated with real-time PCR. All serum samples underwent tests for HBV, HCV, and HDV with ELISA. RESULTS: YMDD variants were detected in 23.3% (243/1042) of CHB patients. YMDD mutation was accompanied by L180M mutation in 154 (76.9%) patients. Both wild-type HBV and YMDD variant HBV were present in 231 of 243 patients. Interestingly, 12 patients had only YIDD and/or YVDD variants without wild YMDD motif. In addition, 27.2% (98/359) of HbeAg-positive patients had YMDD mutations, which was higher than that in HbeAg-negative patients (21.2%, 145/683). The incidence of YMDD varied among patients with different HBV genotypes, but the difference was not significant. Moreover, the incidence of YMDD in patients with high HBV DNA level was significantly higher than that in those with low HBV DNA level. CONCLUSION: Mutation of YMDD motif was detectable at a high rate in CHB patients in this study. The incidence of YMDD may be correlated with HBeAg and HBV DNA level.


Subject(s)
Adult , Female , Humans , Male , Antiviral Agents/therapeutic use , Aspartic Acid/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , Methionine/genetics , Mutation/genetics , Tyrosine/genetics , Amino Acid Motifs/drug effects , Amino Acid Motifs/genetics , DNA, Viral/analysis , Genotype , Hepatitis B virus/drug effects , Hepatitis B, Chronic/virology , Polymerase Chain Reaction
13.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-427793

ABSTRACT

Objective To explore the use of lamivudine alone induced the poor response,especially the related factors of the occurrence of YMDD.Methods Retrospective analysis of 160 cases of the poor answering cases after lamivudine treatment,the baseline parameter values,the time appearing to the poor answering and the HBVDNA load in treatment were analyzed,to study their relationship with poor response.Results The lamivudine prolonged,the poor response to the probability gradually increase.The mutation rate in the 12nd month was 19.67% and in the 36th month was 49.18% ( P < 0.05 ).Response to the many reasons,the YMDD mutation is the more common one.The relationship among HBVDNA load,ALT level on baseline and the rate of poor response emergence,the YMDD mutation rate was clear.By comparison in groups,the difference was significant (P<0.05).Conclusion The lower baselins of ALT level,the higher of HBVDNA load,the greater probability of the poor response and the YMDD mutation.

14.
Asian J Transfus Sci ; 5(1): 32-4, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21572712

ABSTRACT

BACKGROUND: Lamivudine is an analog nucleoside used for the treatment of chronic hepatitis B virus (CHV) infection. Studies showed that prolonged therapy could induce lamivudine resistance hepatitis B virus (HBV) variants (YMDD motif). In this study, the rate of YMDD motif mutants is determined in lamivudine-treated CHV patients in Iran. MATERIALS AND METHODS: Thirty-three serum specimens of patients with chronic hepatitis who had been treated with lamivudine were included in the study. Serum samples of patients were tested by PCR flash and RFLP as well as tested for HBeAg, HBsAg, and liver enzymes (ALT and AST). RESULTS: Out of the 33 patients enrolled in this study, 82% were male and 18% female, respectively. Mean ALT levels were between 20 and 100 IU/1. HBeAg was positive in 76% of the patients whereas HBs was positive only in 61% of the patients. Furthermore, in 28 patients liver biopsy grade was between 2 and 17 having the stage of 1-6. Moreover, HBsAg negative and HBeAg positive were observed in 30% of the patients. CONCLUSION: During therapy, it was found that patients with lamivudine incidence YMDD mutation were approximately 14%. The ALT levels were also reduced in these patients. This study revealed that there was a significant difference between HBeAg, grade, and YMDD mutation whereas no significant different was observed between HBsAg and HBV DNA PCR. Conclusively, it was found that a significant difference exists between YMDD mutation and lamivudine therapy (17% of patients were HBsAg negative and PCR positive).

15.
Rev. Soc. Bras. Med. Trop ; 43(3): 224-228, May-June 2010. ilus, tab
Article in English | LILACS | ID: lil-548513

ABSTRACT

INTRODUCTION: Lamivudine is a nucleoside analogue that is used clinically for treating chronic hepatitis B infection. However, the main problem with prolonged use of lamivudine is the development of viral resistance to the treatment. Mutations in the YMDD motif of the hepatitis B virus DNA polymerase gene have been associated with resistance to drug therapy. So far, there have not been many studies in Brazil reporting on genotype-dependent development of resistance to lamivudine. Thus, the aim of the present study was to determine the possible correlation between a certain genotype and increased development of resistance to lamivudine among chronic hepatitis B patients. METHODS: HBV DNA in samples from 50 patients under lamivudine treatment was amplified by means of conventional PCR. Samples were collected at Hospital das Clínicas, FMRP-USP. The products were then sequenced and phylogenetic analysis was performed. RESULTS: Phylogenetic analysis revealed that 29 (58 percent) patients were infected with genotype D, 20 (40 percent) with genotype A and one (2 percent) with genotype F. Mutations in the YMDD motif occurred in 20 percent of the patients with genotype A and 27.6 percent of the patients with genotype D. CONCLUSIONS: Despite the small number of samples, our results indicated that mutations in the YMDD motif were 1.38 times more frequent in genotype D than in genotype A.


INTRODUÇÃO: Lamivudina é um análogo de nucleosídeo clinicamente utilizado para o tratamento da infecção crônica pela hepatite B. Entretanto, o principal problema do uso prolongado da lamivudina é o desenvolvimento de resistência viral ao tratamento. Mutações no motivo YMDD no gene da DNA polimerase do vírus da hepatite B estão associados com a resistência a terapia medicamentosa. Até o presente momento, não há muitos estudos no Brasil que descrevem o desenvolvimento genótipo-dependente da resistência à lamivudina. Assim, o intuito do trabalho aqui descrito foi determinar a possível correlação entre um determinado genótipo e o desenvolvimento aumentado da resistência à lamivudina em pacientes com hepatite B crônica. MÉTODOS: O HBV DNA foi amplificado por PCR convencional a partir de 50 amostras coletadas de pacientes submetidos ao tratamento com lamivudina no Hospital das Clínicas- FMRP- USP. Posteriormente, os produtos foram seqüenciados e a análise filogenética foi realizada. RESULTADOS: A análise filogenética mostrou que 29 (58 por cento) pacientes foram infectados com o genótipo D, 20 (40 por cento) com o genótipo A e 1 (2 por cento) com o genótipo F. Mutações no motivo YMDD ocorreu em 20 por cento dos pacientes com genótipo A e 27,6 por cento em pacientes do genótipo D. CONCLUSÕES: Apesar do baixo número de amostras, nossos resultados indicaram que mutações no motivo YMDD são 1,38 X mais frequentes no genótipo D em relação ao genótipo A.


Subject(s)
Humans , Antiviral Agents/therapeutic use , Drug Resistance, Viral/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , Lamivudine/therapeutic use , Mutation/genetics , Base Sequence , DNA, Viral/genetics , Genotype , Hepatitis B virus/drug effects , Hepatitis B, Chronic/virology , Molecular Sequence Data , Phylogeny
16.
Journal of Clinical Hepatology ; (12): 192-194, 2009.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-499038

ABSTRACT

Objective To investigate the clinical significance of YMDD mutation during Lamivudine therapy on chronic hepatitis B.Methods Fluorometric analysis PCR, ELISA were used to estimate the YMDD mutation, HBVDNA quantative level and HBeAg for HBV of 72 cases with chronic hepatitis B before therapy (0 month), and after Lamivudine therapy for 9,12,18 months.Results The YMDD mutation was not observed in these cases before Lamivudine therapy. The mutation was found in 8 cases (11.1%), 17 cases (23.6%) and 28 cases (38.9%) at 9, 12, 18 month for therapy. The YMDD mutation rate rose with the therapy time lasting (P<0.05). Moreover, the YmDD mutation rate in the patients with HBVDNA quantity higher than 108 copies/ml was significantly higher than that in the patients with HBVDNA quantity lower than 108 copies/ml (P<0.005). The YMDD variation rate in patients with HBeAg positive and in patients with HBeAg negative showed no significant difference (P>0.05). The HBeAg negative conversion rate was significantly higher in non-mutation group than that in mutation group (P<0.05).Conclusion The serum virus quantity may be regard as an early estimate indication of the development of YMDD mutation during Lamivudine therapy.

17.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-393318

ABSTRACT

Objective To evaluate the clinical efficacy and safety of bicyelol tablets in treatment of hepatitis B patients infected with YMDD mutation of HBV. Methods Sixty-eight chronic hepatitis patients infected with HBV YMDD mutants and 100 patients with non-mutants HBV were enrolled in the study. All patients received bicyclol tablets orally 150 mg/d, t. i. d, for 24 weeks. Clinical symptoms, signs and adverse effects were observed, and the blood routine, liver function tests, serum HBV markers and HBV DNA loads were examined at 12th and 24th week of the study, Results After treatment for 24 weeks, the normalization rates of ALT and AST in mutant group were 79.4% ( 54/68 ) and 70. 6% (48/68) ; 11 ( 16. 2% ) patients were markedly effective and 14 (20. 6% ) were effective. Clearance rates of HBeAg and HBV DNA were 27.9% ( 17/61 ) and 17.6% ( 12/68 ), while the seroconversion rate of HBeAg was 14. 7% (9/61). The differences of the above indexes were not statistically significant between mutant group and non-mutant group. Conclusion Bicyciol can both protect liver functions and inhibit virus replication in patients infected with HBV YMDD mutants.

18.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-147556

ABSTRACT

The wide use of lamivudine in chronic hepatitis B has produced a monotonic increase in patients with lamivudine resistance. Therefore, treating lamivudine resistance in chronic hepatitis B is a major concern in clinical practice for the treatment of hepatitis B virus (HBV). There is conflicting evidence on the outcome of pegylated interferon alpha (PEG-IFN alpha) therapy against lamivudine-resistant HBV, which is due to mutations in the YMDD motif. We experienced a patient with chronic hepatitis B who was successfully treated with PEG-IFN alpha-2a after the development of virologic and biochemical breakthrough during lamivudine therapy. Virologic breakthrough was associated with the emergence of YMDD mutants 48 months after starting lamivudine therapy. Treatment with PEG-IFN alpha-2a for 12 months resulted in an undetectable serum level of HBV DNA and the resolution of hepatitis, and the virologic response was maintained over 16 months after cessation of PEG-IFN alpha-2a.


Subject(s)
Adult , Humans , Male , Alanine Transaminase/blood , Antiviral Agents/therapeutic use , DNA, Viral/analysis , Drug Resistance, Viral , Hepatitis B, Chronic/diagnosis , Interferon alpha-2/therapeutic use , Lamivudine/therapeutic use , Liver/pathology , Polyethylene Glycols/therapeutic use
19.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-106817

ABSTRACT

PURPOSE: Lamivudine is known to be effective for the treatment of chronic hepatitis B in adults. However, data on lamivudine therapy in pediatrics is limited. The aim of this study was to evaluate the efficacy and durability of lamivudine therapy for chronic hepatitis B in Korean children. METHODS: A total of 44 children (27 males and 17 females, ages 6 months to 14.8 years, mean age 6.7 years) with chronic hepatitis B who received lamivudine (3 mg/kg/day, max 100 mg) for at least 12 months were enrolled. We evaluated the serum AST, ALT and serological HBV markers (HBsAg and anti-HBs, HBeAg and anti HBe, and HBV DNA) periodically. Predictive three year cumulative seroconversion rates were obtained using the Kaplan-Meier method. RESULTS: Twenty one (48%) of 44 children achieved seroconversion of HBeAg by three years, while 23 (42%) children did not. HBV DNA was cleared in 34 (77%) children and the serum ALT levels were normalized in 41 children (93%). The three year cumulative seroconversion rates were 60% for HBeAg, and the clearance rates were 76% for HBV DNA. Eighteen children who discontinued lamivudine after HBeAg seroconversion maintained the therapeutic response for three years (treatment duration 13~58 months mean 24 months). Viral breakthrough developed in 12 children (27%) during the therapy and the YMDD mutation was documented in 11 children (25%). The mean duration for the development of a mutation was 22.7 months. Loss of HBsAg occurred in 6 children (14%). The pretreatment ALT levels were higher in responders; however, the differences were not statistically significant (p>0.05). CONCLUSION: The results of this study showed that lamivudine treatment had a favorable effect and durable therapeutic response in children with chronic hepatitis B. Long term follow-up and alternative therapy are warranted for those patients who do not respond to this treatment.


Subject(s)
Adult , Child , Female , Humans , Male , DNA , Follow-Up Studies , Hepatitis B e Antigens , Hepatitis B Surface Antigens , Hepatitis B, Chronic , Hepatitis, Chronic , Lamivudine , Pediatrics
20.
Braz. j. med. biol. res ; 40(12): 1605-1614, Dec. 2007. graf, tab
Article in English | LILACS | ID: lil-466741

ABSTRACT

Given the loss of therapeutic efficacy associated with the development of resistance to lamivudine (LMV) and the availability of new alternative treatments for chronic hepatitis B patients, early detection of viral genotypic resistance could allow the clinician to consider therapy modification before viral breakthrough and biochemical relapse occur. To this end, 28 LMV-treated patients (44 ± 12 years; 24 men), on their first therapy schedule, were monitored monthly at four Brazilian centers for the emergence of drug resistance using the reverse hybridization-based INNO-LiPA HBV DR assay and occasionally sequencing (two cases). Positive viral responses (HBV DNA clearance) after 6, 12, and 18 months of therapy were achieved by 57, 68, and 53 percent of patients, while biochemical responses (serum alanine aminotransferase normalization) were observed in 82, 82, and 53 percent of cases. All viral breakthrough cases (N = 8) were related to the emergence of YMDD variants observed in 7, 21, and 35 percent of patients at 6, 12, and 18 months, respectively. The emergence of these variants was not associated with viral genotype, HBeAg expression status, or pretreatment serum alanine aminotransferase levels. The detection of resistance-associated mutations was observed before the corresponding biochemical flare (41 ± 14 and 60 ± 15 weeks) in the same individuals. Then, if highly sensitive LMV drug resistance testing is carried out at frequent and regular intervals, the relatively long period (19 ± 2 weeks) between the emergence of viral resistance and the onset of biochemical relapse can provide clinicians with ample time to re-evaluate drug therapy.


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Amino Acid Motifs/genetics , Drug Resistance, Viral/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , Lamivudine/therapeutic use , Reverse Transcriptase Inhibitors/therapeutic use , Alanine Transaminase/blood , DNA, Viral/blood , Follow-Up Studies , Hepatitis B e Antigens/blood , Hepatitis B virus/drug effects , Hepatitis B virus/immunology , Hepatitis B, Chronic/immunology , Hepatitis B, Chronic/virology , Mutation/genetics , Polymerase Chain Reaction , Prospective Studies
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