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Variability of the preC/C region of hepatitis B virus genotype A from a South African cohort predominantly infected with HIV.

ABSTRACT: Hepatitis B virus (HBV) is a serious global health problem, and HBV genotype is an important determinant of disease progression and treatment outcome. The aim of this study was to assess variations of the precore/core (preC/C) region in HBV genotype A. Sequencing of the preC/C and surface (S) genes of HBV was performed on plasma samples from 20 HBV/HIV co-infected and 5 HBV mono-infected individuals. All preC/C study sequences clustered with subgenotype A1, except for two which clustered with subgenotype D4 reference strains. The nucleotide and amino acid variability was far higher in the preC/C region than in the S region. Mutations associated with reduction or failure of HBV e-antigen (HBeAg) production were observed, with a preC start codon mutation being common (24%). Other mutations (e.g., P5H/L and I97L) associated with severe liver disease were also noticed, some of which were located in the major histocompatibility restricted sites. PreC/C intergenotype nucleotide divergence was >7%, while subgenotypes differed by 2.5-7%. Several study sequences were highly divergent from other African subgenotype A1 strains. This study showed that HBeAg-negative chronic hepatitis B is underestimated in subgenotype A1, and also highlighted the variant South African A1 strains. The major advantage of preC/C sequencing is that it informs patient management as HBeAg-negative chronic hepatitis B responds poorly to conventional interferon-α therapy, and some guidelines treat HBeAg-negative chronic hepatitis B differently from HBeAg-positive chronic hepatitis B. These data suggest that subgenotype A1 may be more involved in severe HBV-related diseases.

SUBMITTER: Mayaphi SH

PROVIDER: S-EPMC4559853 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

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Variability of the preC/C region of hepatitis B virus genotype A from a South African cohort predominantly infected with HIV.

Mayaphi Simnikiwe H SH Martin Desmond J DJ Mphahlele M Jeffrey MJ Blackard Jason T JT Bowyer Sheila M SM

Journal of medical virology 20130807 11

Hepatitis B virus (HBV) is a serious global health problem, and HBV genotype is an important determinant of disease progression and treatment outcome. The aim of this study was to assess variations of the precore/core (preC/C) region in HBV genotype A. Sequencing of the preC/C and surface (S) genes of HBV was performed on plasma samples from 20 HBV/HIV co-infected and 5 HBV mono-infected individuals. All preC/C study sequences clustered with subgenotype A1, except for two which clustered with su ...[more]

PMID: 23925707

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Project description:BackgroundHIV-infected individuals have increased risk of developing obstructive lung disease (OLD). Studies from developed countries report high viral load, low CD4 counts, and anti-retroviral therapy (ART) to be associated with OLD; but these findings may not be generalizable to populations in resource-limited settings.MethodsWe conducted a prospective cohort study of lung function in 730 HIV-infected black South African adults. Pre-bronchodilator spirometry was performed at enrollment and repeated annually for three years. Logistic regression models were used to identify factors associated with OLD, defined as FEV1/FVC<0.70, at enrollment. Excess annual declines in FEV1 and FVC were modelled as the product-term of follow-up time and exposures using random effects regression.ResultsMedian (IQR) age at enrollment was 36 (32-41) years, 85% were female and 30% ever-smoked with a median (IQR) exposure of 3 (1-6) pack-years. Median (IQR) CD4 count and viral load at enrollment were 372 (261-518) cells/mm3 and 2655 (91-13,548) copies/mL respectively. Overall, 25% were receiving ART at enrollment, 16% of whom reported at least 6 months of ART receipt. OLD was found in 35 (5%) at enrollment. Increasing age (aOR = 2.08 per 10-years [95%CI 1.22-3.57], p = 0.007), current smoking (aOR = 3.55 [95%CI 1.20-10.53], p = 0.02), and CRP (aOR = 1.01 per unit-increase [95%CI 1.00-1.03], p = 0.04) were significantly associated with OLD at enrollment; while increasing CD4 count (aOR = 1.02 per-100 cells/mm3 [95%CI 0.85-1.22], p = 0.82), viral load (aOR = 0.67 per log-increase [95%CI 0.43-1.10], p = 0.12) and receipt of ART (aOR = 0.57 [95%CI 0.18-1.75], p = 0.32) were not. The median (IQR) follow-up time was 18 (12-24) months. Participants with a history of tuberculosis (TB) had a 35 mL (95%CI 2-68, p = 0.03) and 57 mL (95%CI 19-96, p = 0.003) per year excess loss of FEV1 and FVC respectively.ConclusionPrevalent OLD was associated with older age, current smoking and higher CRP levels, but not CD4 counts and ART, in HIV-infected South African adults. Better understanding of the long-term effects of TB, smoking and inflammation on lung function in HIV-infected populations is urgently needed.

Project description:PurposeSouth Africa's National Health Laboratory Service (NHLS) National HIV Cohort was established in 2015 to facilitate monitoring, evaluation and research on South Africa's National HIV Treatment Programme. In South Africa, 84.8% of people living with HIV know their HIV status; 70.7% who know their status are on ART; and 87.4% on ART are virologically suppressed.ParticipantsThe NHLS National HIV Cohort includes the laboratory data of nearly all patients receiving HIV care in the public sector since April 2004. Patients are included in the cohort if they have received a CD4 count or HIV RNA viral load (VL) test. Using an anonymised unique patient identifier that we have developed and validated to linked test results, we observe patients prospectively through their laboratory results as they receive HIV care and treatment. Patients in HIV care are seen for laboratory monitoring every 6-12 months. Data collected include age, sex, facility location and test results for CD4 counts, VLs and laboratory tests used to screen for potential treatment complications.Findings to dateFrom April 2004 to April 2018, 63 million CD4 count and VL tests were conducted at 5483 facilities. 12.6 million unique patients had at least one CD4 count or VL, indicating they had accessed HIV care, and 7.1 million patients had a VL test indicating they had started antiretroviral therapy. The creation of NHLS National HIV Cohort has enabled longitudinal research on all lab-monitored patients in South Africa's national HIV programme, including analyses of (1) patient health at presentation; (2) care outcomes such as 'CD4 recovery', 'retention in care' and 'viral resuppression'; (3) patterns of transfer and re-entry into care; (4) facility-level variation in care outcomes; and (5) impacts of policies and guideline changes.Future plansContinuous updating of the cohort, integration with available clinical data, and expansion to include tuberculosis and other lab-monitored comorbidities.

Dataset Information

Variability of the preC/C region of hepatitis B virus genotype A from a South African cohort predominantly infected with HIV.

Publications

Variability of the preC/C region of hepatitis B virus genotype A from a South African cohort predominantly infected with HIV.

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