Hepatitis B viral load and risk for liver cirrhosis and hepatocellular carcinoma in The Gambia, West Africa.
(2009)
Journal - Journal of viral hepatitis
Abstract :
Summary. The main objectives of this study were to define the occurrence and levels of hepatitis B virus (HBV) DNA in asymptomatic HBV carriers, cirrhosis patients and hepatocellular carcinoma (HCC) cases from The Gambia, and to evaluate the risk for cirrhosis or HCC associated with HBV viremia. We used sensitive real-time quantitative PCR assays to measure HBV DNA in samples from a case-control study consisting of 60 asymptomatic HBV carriers, 53 cirrhotic patients and 129 HCC cases. Logistic regression was used to estimate the risks of cirrhosis and HCC associated with HBV-DNA levels and HBV e antigenemia (HBeAg) detection (a surrogate marker for viral replication). Detectable HBV viremia and HBeAg positivity were both significantly associated with cirrhosis (increasing risk by fourfold and 11-fold respectively) and with HCC (increasing risk by sixfold and threefold respectively). HBV-DNA levels were significantly higher in both HCC cases and cirrhotic patients compared to asymptomatic carriers (P < 0.01 for both). High-level HBV DNA (>10 000 copies/mL) was strongly associated with both HCC and cirrhosis (17- and 39-fold increased risk). Lower level HBV viremia (200-10 000 copies/mL) conferred a significant risk of HCC, although the association with cirrhosis was not significant. In conclusion, we find that high HBV-DNA levels are strongly associated with the serious sequelae of HBV infection, independent of HBeAg status. While risk for cirrhosis and for HCC notably increases at HBV-DNA levels >/=10 000 copies/mL, low-level viremia was also associated with significant risk for HCC.
Changes in viral load and HBsAg and HBeAg status with age in HBV chronic carriers in The Gambia.
(2008)
Journal - Virology journal (England )
Abstract :
BACKGROUND: Little is known about changes in hepatitis B viral load (HBV DNA) in relation to age in Africa. The aim of this study is to determine the natural course of HBV chronic infection, particularly in relation to sequential changes in serum HBV DNA levels and hepatitis B surface (HBsAg) antigen/hepatitis e antigen (HBeAg) status by age. METHODS: The study was conducted on 190 HBV chronic carriers, aged 1-19 years who were followed for 19 years. 160, 99 and 123 were traced at 5, 9 and 19 years later. All available samples were tested for HBsAg and HBeAg, whilst 170, 61, 63 and 81 were tested for HBV DNA at the baseline, and at 5, 9 and 19 years following recruitment. RESULTS: In general HBeAg which correlated with high levels of HBV DNA was lost at a much faster rate than HBsAg. 86% of the carriers who were recruited at the age of 1-4 yrs lost HBeAg by the age of 19 years compared to 30% who lost HBsAg. HBeAg negative carriers had serum HBV DNA levels of < 105 copies per mL, HBV DNA positivity declined from 100% in 1-4 yrs old carriers at recruitment to 62.5%,60% and 88% at 5, 9 and 19 years respectively following recruitment. CONCLUSION: After 19 years of follow up, the majority of HBV surface antigen carriers had lost HBeAg positivity and had low levels of viral replication. However small proportions (10-20%) retained HBeAg and continue to have high levels of viral replication.
| ISSN : | 1743-422X |
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| Mesh Heading : | Adolescent Adult Age Factors Carrier State Child Child, Preschool DNA, Viral Female Gambia Hepatitis B Surface Antigens Hepatitis B e Antigens Hepatitis B, Chronic Humans Infant Longitudinal Studies Male blood |
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| Mesh Heading Relevant : | Viral Load virology blood blood virology |
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Application of a novel, rapid, and sensitive oligonucleotide ligation assay for detection of cancer-predicting mutations in the precore and basal core promoter of hepatitis B virus.
(2008)
Journal - Journal of clinical microbiology (United States )
Abstract :
Hepatocellular carcinoma (HCC) and cirrhosis are important causes of mortality worldwide. Persistent hepatitis B virus (HBV) infection is a major cause of these diseases. Double mutations in the basal core promoter (BCP) (A1762T and G1764A) and precore (pre-C) (G1896A) regions of the virus are associated with progression to HCC. The current study is aimed at developing a simple method for screening and detecting BCP and pre-C mutations in HBV carriers. We have developed and validated an oligonucleotide ligation assay (OLA) to detect point mutations in the HBV core gene. We have applied OLA methods to samples from HBV-infected carriers recruited from the Gambia Liver Cancer Study (GLCS) comprising asymptomatic HBsAg carriers, patients with cirrhosis, and patients with HCC. We observed an 89.3% and 95.8% concordance between the OLA and DNA sequencing for BCP and pre-C mutations, respectively. OLA detected the mutations in single-strain infections and in infections with mixtures of wild-type and mutant viruses under conditions where sequencing detected only the single dominant strains. BCP mutations were detected in 75.7% of patients with advanced liver disease (cirrhosis/HCC) compared to 47.6% of asymptomatic carriers, while pre-C mutations were detected in 34.5% of advanced liver disease patients and in 47.6% of asymptomatic HBsAg carriers. There was a significant association between the presence of BCP mutations and advanced liver disease. In conclusion, OLA is a simple, economical, and reliable assay for detection of pre-C and BCP mutations. Its application can lead to improvement in diagnosis and clinical care in regions where HBV is endemic.
| ISSN : | 1098-660X |
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| Mesh Heading : | Carcinoma, Hepatocellular Gambia Hepatitis B Core Antigens Hepatitis B virus Humans Ligation Liver Liver Cirrhosis Oligonucleotide Probes Severity of Illness Index Statistics as Topic diagnosis pathology virology diagnosis virology |
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| Mesh Heading Relevant : | Point Mutation Promoter Regions, Genetic virology genetics genetics methods genetics |
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Envelope protein variability among HBV-Infected asymptomatic carriers and immunized children with breakthrough infections.
(2008)
Journal - Journal of medical virology (United States )
Abstract :
A detailed study of hepatitis B virus (HBV) surface variants and their role in breakthrough infections has been conducted in The Gambia, West Africa. Samples from 1856 vaccinated subjects were tested for hepatitis B surface antigen (HBsAg). Evidence of infection was found in 11% (22/192) of subjects with breakthrough infections and 18 (81.8%) were also positive for HBV DNA following PCR analysis. A cohort of 58 unvaccinated carriers which also included 11 patients with hepatocellular carcinoma was also investigated in order to establish the prevalence of surface variants in the unvaccinated population. Analysis of the S gene from HBV PCR-positive subjects (n = 64) revealed little variation in the S gene of these subjects. Twenty-four S protein sequences (37.5%) were identical and a further 22 sequences differed by only a single amino acid. The K141E variant found in previous work was not detected and little variation was observed in the immunodominant "a" determinant; a single change was found in one vaccinated patient (Q129H) and nine changes detected among six unvaccinated carriers. This study showed that breakthrough HBV infection in vaccinated Gambians is mainly caused by the wild type genoytype E strain and that immune escape mutants are uncommon. However, HBV mutants may play a role in establishing infection later in life when anti-HBs antibodies have begun to decline. Further investigation is required to determine the cause of these breakthrough infections and whether they contribute to the establishment of the carrier state.
| ISSN : | 1096-9071 |
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| Mesh Heading : | Adolescent Adult Amino Acid Substitution Carrier State Child Child, Preschool DNA, Viral Gambia Hepatitis B Hepatitis B Surface Antigens Hepatitis B virus Humans Infant Molecular Sequence Data Mutation, Missense Phylogeny Sequence Analysis, DNA Viral Envelope Proteins genetics epidemiology blood epidemiology epidemiology blood genetics isolation & purification immunology |
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| Mesh Heading Relevant : | immunology virology immunology virology immunology genetics |
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Application of real-time PCR to quantify hepatitis B virus DNA in chronic carriers in The Gambia.
(2006)
Journal - Virology journal (England )
Abstract :
BACKGROUND/AIM: The study aimed at developing a real-time quantitative PCR assay to monitor HBV serum virus load of chronic carriers enrolled in therapeutic trials. METHOD: Quantitative real-time PCR assay was carried out using SYBR-Green signal detection and primers specific to the S gene. Thermal cycling was performed in an ABi 5700 sequence detection system. The assay was calibrated against an international HBV DNA standard and inter- and intra-assay reproducibility determined. Levels of viral load were monitored for 1-year in lamivudine treated carriers. Correlation between HBV DNA levels and HBeAg sero-status was determined in untreated carriers. RESULTS: The qPCR assay showed good intra- and inter-assay reproducibility over a wide dynamic range (1.5 x 103 to 1.5 x 108 copies/mL) and correlated well with those from a commercial assay (r = 0.91, (p < 0.001). Viral load levels dropped dramatically but temporarily during and after a short course of lamivudine therapy. HBV DNA was a more reliable indicator of the presence of virus than HBe antigen and was detected in 77.0% (161/209) of HBeAg negative and in all HBeAg positive carriers. CONCLUSION: This method is reliable, accurate, and reproducible. HBV DNA Quantification by qPCR can be used to monitor the efficacy of HBV therapy and useful in understanding the natural history of HBV in an endemic area.
| ISSN : | 1743-422X |
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| Mesh Heading : | Adolescent Adult Age Factors Aged Antiviral Agents Carrier State Child Child, Preschool DNA Primers DNA, Viral Gambia Hepatitis B Antibodies Hepatitis B Surface Antigens Hepatitis B e Antigens Hepatitis B, Chronic Humans Infant Lamivudine Male Middle Aged Polymerase Chain Reaction Reproducibility of Results Reverse Transcriptase Inhibitors Sensitivity and Specificity Viral Load administration & dosage therapeutic use drug therapy chemistry blood blood blood genetics drug therapy administration & dosage therapeutic use standards administration & dosage therapeutic use |
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| Mesh Heading Relevant : | Hepatitis B virus virology blood virology methods methods |
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Hepatitis B surface antigenaemia and alpha-foetoprotein detection from dried blood spots: applications to field-based studies and to clinical care in hepatitis B virus endemic areas.
(2005)
Journal - Journal of viral hepatitis (England )
Abstract :
In many resource-limited regions with endemic hepatitis B virus (HBV), there is limited infrastructure to collect, process, transport, and store blood samples for identification of persons with chronic HBV infection or with hepatocellular carcinoma (HCC). We describe the application of a simple technique using commercially available kits for detection of HBV surface antigen (HBsAg) and alpha-foetoprotein (AFP) in dried blood spots (DBS) collected on filter paper. Study participants included subjects with and without chronic HBV infection and subjects with HCC or cirrhosis. Three to five blood drops were dried on filter paper. Dried blood (equivalent to 20 muL) was eluted and tested for HBsAg by Determine(TM) HBsAg and for AFP by counter-current immuno-electrophoresis and radio-immunoassay (RIA). The primary analysis focused on comparison of DBS results to serum testing results as the gold standard. The sensitivity of DBS for detecting chronic HBV infection was 96% (98-98) with specificity of 100% (CI 99-100). Sensitivity of DBS in detecting AFP compared with serum RIA was 73% (60-86) with specificity of 90% (81-98). Both HBsAg and AFP recovery were unaffected when DBS were left at room temperature (30-33 degrees C) and under humid conditions for up to 28 days prior to elution. We conclude that DBS can be reliably used as an economical and logical alternative for detection of HBsAg in chronically infected patients and for AFP-based diagnosis of HCC in clinical situations which preclude adequate collection and processing of blood samples. Both research-oriented field studies and routine clinical care may benefit from application of these techniques in resource-limited settings.
| ISSN : | 1352-0504 |
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| Mesh Heading : | Blood Specimen Collection Carcinoma, Hepatocellular Endemic Diseases Female Hepatitis B Surface Antigens Hepatitis B virus Hepatitis B, Chronic Humans Liver Neoplasms Male Sensitivity and Specificity alpha-Fetoproteins isolation & purification epidemiology virology |
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| Mesh Heading Relevant : | methods diagnosis blood diagnosis diagnosis analysis |
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Changes in viral load and HBsAg and HBeAg status with age in HBV chronic carriers in The Gambia
(2008)
Journal - Virology Journal
Abstract :
BackgroundLittle is known about changes in hepatitis B viral load (HBV DNA) in relation to age in Africa. The aim of this study is to determine the natural course of HBV chronic infection, particularly in relation to sequential changes in serum HBV DNA levels and hepatitis B surface (HBsAg) antigen/hepatitis e antigen (HBeAg) status by age.MethodsThe study was conducted on 190 HBV chronic carriers, aged 1–19 years who were followed for 19 years. 160, 99 and 123 were traced at 5, 9 and 19 years later. All available samples were tested for HBsAg and HBeAg, whilst 170, 61, 63 and 81 were tested for HBV DNA at the baseline, and at 5, 9 and 19 years following recruitment.ResultsIn general HBeAg which correlated with high levels of HBV DNA was lost at a much faster rate than HBsAg. 86% of the carriers who were recruited at the age of 1–4 yrs lost HBeAg by the age of 19 years compared to 30% who lost HBsAg. HBeAg negative carriers had serum HBV DNA levels of < 105 copies per mL, HBV DNA positivity declined from 100% in 1–4 yrs old carriers at recruitment to 62.5%,60% and 88% at 5, 9 and 19 years respectively following recruitment.ConclusionAfter 19 years of follow up, the majority of HBV surface antigen carriers had lost HBeAg positivity and had low levels of viral replication. However small proportions (10–20%) retained HBeAg and continue to have high levels of viral replication.
Application of a Novel, Rapid, and Sensitive Oligonucleotide Ligation Assay for Detection of Cancer-Predicting Mutations in the Precore and Basal Core Promoter of Hepatitis B Virus
(2008)
Journal - Journal of Clinical Microbiology
Abstract :
Hepatocellular carcinoma (HCC) and cirrhosis are important causes of mortality worldwide. Persistent hepatitis B virus (HBV) infection is a major cause of these diseases. Double mutations in the basal core promoter (BCP) (A1762T and G1764A) and precore (pre-C) (G1896A) regions of the virus are associated with progression to HCC. The current study is aimed at developing a simple method for screening and detecting BCP and pre-C mutations in HBV carriers. We have developed and validated an oligonucleotide ligation assay (OLA) to detect point mutations in the HBV core gene. We have applied OLA methods to samples from HBV-infected carriers recruited from the Gambia Liver Cancer Study (GLCS) comprising asymptomatic HBsAg carriers, patients with cirrhosis, and patients with HCC. We observed an 89.3% and 95.8% concordance between the OLA and DNA sequencing for BCP and pre-C mutations, respectively. OLA detected the mutations in single-strain infections and in infections with mixtures of wild-type and mutant viruses under conditions where sequencing detected only the single dominant strains. BCP mutations were detected in 75.7% of patients with advanced liver disease (cirrhosis/HCC) compared to 47.6% of asymptomatic carriers, while pre-C mutations were detected in 34.5% of advanced liver disease patients and in 47.6% of asymptomatic HBsAg carriers. There was a significant association between the presence of BCP mutations and advanced liver disease. In conclusion, OLA is a simple, economical, and reliable assay for detection of pre-C and BCP mutations. Its application can lead to improvement in diagnosis and clinical care in regions where HBV is endemic.
Application of real-time PCR to quantify hepatitis B virus DNA in chronic carriers in The Gambia
(2006)
Journal - Virology Journal
Abstract :
Background/AimThe study aimed at developing a real-time quantitative PCR assay to monitor HBV serum virus load of chronic carriers enrolled in therapeutic trials.MethodQuantitative real-time PCR assay was carried out using SYBR-Green signal detection and primers specific to the S gene. Thermal cycling was performed in an ABi 5700 sequence detection system. The assay was calibrated against an international HBV DNA standard and inter- and intra-assay reproducibility determined. Levels of viral load were monitored for 1-year in lamivudine treated carriers. Correlation between HBV DNA levels and HBeAg sero-status was determined in untreated carriers.ResultsThe qPCR assay showed good intra- and inter-assay reproducibility over a wide dynamic range (1.5 × 103 to 1.5 × 108 copies/mL) and correlated well with those from a commercial assay (r = 0.91, (p < 0.001). Viral load levels dropped dramatically but temporarily during and after a short course of lamivudine therapy. HBV DNA was a more reliable indicator of the presence of virus than HBe antigen and was detected in 77.0% (161/209) of HBeAg negative and in all HBeAg positive carriers.ConclusionThis method is reliable, accurate, and reproducible. HBV DNA Quantification by qPCR can be used to monitor the efficacy of HBV therapy and useful in understanding the natural history of HBV in an endemic area.