Molecular characterisation of hepatitis B virus in HIV-1 subtype C infected patients in Botswana

BMC Infectious Diseases, Aug 2015

Background Hepatitis B virus (HBV) is a major global health problem especially in sub-Saharan Africa and in East Asia. Ten hepatitis B virus genotypes have been described that differ by geographic distribution, disease progression, and response to treatment. Escape mutations within the surface open reading frame (ORF) affect HBV antigenicity leading to failures in diagnosis, vaccine and hepatitis B immunoglobulin therapy. However, the molecular characteristics of HBV in Botswana, a highly endemic country, are unknown. We describe the molecular characteristics of HBV and prevalence of escape mutants among HIV/HBV coinfected individuals Botswana. Methods DNA was extracted from archived plasma samples from 81 HIV/HBV co-infected participants from various clinical studies at the Botswana Harvard AIDS Institute Partnership. A 415 base pair (bp) fragment of the polymerase gene was amplified by semi-nested PCR. In a subset of samples, a 2100 bp fragment was amplified. The PCR product was genotyped using Big Dye sequencing chemistry and the sequences were analysed for genotypes and mutations. Results Of the 81 samples included, 70 (86 %) samples were successfully genotyped. Genotype A was found in 56 (80 %) participants, D in 13 (18.6 %), and 1 (1.4 %) was genotype E. Escape mutations previously linked with failure of diagnosis or escaping active vaccination and passive immunoglobulin therapy were detected in 12 (17.1 %) participants at positions 100, 119, 122, 123, 124, 126, 129, 130, 133, 134 and 140 of the S ORF. Genotypes and escape mutations were not significantly associated with aspartate aminotransferase (AST), alanine aminotransferase (ALT) and AST platelet ratio index (APRI). Conclusion Genotypes A, D and E were found in this cohort of HIV coinfected patients in Botswana, consistent with the findings from the sub-Saharan Africa region. Some escape mutations which have previously been associated with diagnosis failure, escaping vaccine and immunoglobulin therapy were also observed and are important in guiding future policies related to vaccine implementation, therapeutic guidelines, and diagnostic guidelines. They are also important for identifying patients who are at an increased risk of disease progression and to choose optimal therapy. Future research should focus on determining the clinical significance of the different HBV genotypes and mutations found in this population.

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Molecular characterisation of hepatitis B virus in HIV-1 subtype C infected patients in Botswana

Anderson et al. BMC Infectious Diseases Molecular characterisation of hepatitis B virus in HIV-1 subtype C infected patients in Botswana Motswedi Anderson 1 2 Simani Gaseitsiwe 0 1 Sikhulile Moyo 1 Matthijs J. C. Wessels 1 Terence Mohammed 1 2 Theresa K. Sebunya 2 Eleanor A. Powell 3 Joseph Makhema 0 1 Jason T. Blackard 3 Richard Marlink 0 1 Max Essex 0 1 Rosemary M. Musonda 0 1 0 Department of Immunology and Infectious Diseases, Harvard School of Public Health , Boston , USA 1 Botswana Harvard AIDS Institute Partnership , Gaborone , Botswana 2 Department of Biological Sciences, University of Botswana , Gaborone , Botswana 3 University of Cincinnati College of Medicine , Cincinnati , USA Background: Hepatitis B virus (HBV) is a major global health problem especially in sub-Saharan Africa and in East Asia. Ten hepatitis B virus genotypes have been described that differ by geographic distribution, disease progression, and response to treatment. Escape mutations within the surface open reading frame (ORF) affect HBV antigenicity leading to failures in diagnosis, vaccine and hepatitis B immunoglobulin therapy. However, the molecular characteristics of HBV in Botswana, a highly endemic country, are unknown. We describe the molecular characteristics of HBV and prevalence of escape mutants among HIV/HBV coinfected individuals Botswana. Methods: DNA was extracted from archived plasma samples from 81 HIV/HBV co-infected participants from various clinical studies at the Botswana Harvard AIDS Institute Partnership. A 415 base pair (bp) fragment of the polymerase gene was amplified by semi-nested PCR. In a subset of samples, a 2100 bp fragment was amplified. The PCR product was genotyped using Big Dye sequencing chemistry and the sequences were analysed for genotypes and mutations. Results: Of the 81 samples included, 70 (86 %) samples were successfully genotyped. Genotype A was found in 56 (80 %) participants, D in 13 (18.6 %), and 1 (1.4 %) was genotype E. Escape mutations previously linked with failure of diagnosis or escaping active vaccination and passive immunoglobulin therapy were detected in 12 (17.1 %) participants at positions 100, 119, 122, 123, 124, 126, 129, 130, 133, 134 and 140 of the S ORF. Genotypes and escape mutations were not significantly associated with aspartate aminotransferase (AST), alanine aminotransferase (ALT) and AST platelet ratio index (APRI). Conclusion: Genotypes A, D and E were found in this cohort of HIV coinfected patients in Botswana, consistent with the findings from the sub-Saharan Africa region. Some escape mutations which have previously been associated with diagnosis failure, escaping vaccine and immunoglobulin therapy were also observed and are important in guiding future policies related to vaccine implementation, therapeutic guidelines, and diagnostic guidelines. They are also important for identifying patients who are at an increased risk of disease progression and to choose optimal therapy. Future research should focus on determining the clinical significance of the different HBV genotypes and mutations found in this population. - Background The Hepatitis B virus (HBV) still remains a global health problem especially in sub-Saharan Africa and East Asia despite the availability of a safe and effective vaccine [1]. It is estimated that there are 240 million hepatitis B chronic carriers worldwide [1, 2] and it accounts for 780,000 deaths per year due to acute infections, cirrhosis of the liver, and hepatocellular carcinoma (HCC) [1]. Hepatitis B, a prototype of the family Hepadnaviridae, consists of a 3.2 kb partially double-stranded DNA arranged in four overlapping open reading frames (ORFs) [3, 4]. The open reading frames are the polymerase [3–5], surface [3, 6, 7], precore/core and the X gene [3, 6, 8, 9]. HBV replicates via reverse transcriptase, an enzyme which has no proof-reading capabilities; hence, nucleotide misincorporations are more common than in other DNA viruses [3]. This has led to the emergence of 10 genotypes A–J [10, 11] classified according to whole genome nucleotide divergence of >7.5 % [12–15]. Genotypes A-D and F have been further classified into subgenotypes [16] based on nucleotide divergence of 4 to 7.5 % [12]. These genotypes and subgenotypes have been shown to have a distinct geographic distribution [12, 17] which might be due to human migration after infection [18]. Genotype A is predominant in Western Europe, Africa and Asia; Genotypes B and C in East Asia; D has a worldwide distribution but is mostly in the mediterranean region; E is prevalent in West and Central Africa; F in South and Central America; G and H in Europe and Japan; I in Vietnam and Laos; J in Japan [12, 19–21]. The predominant genotypes in Africa are A, D and E [22]. The clinical significance of the genotypes has also been demonstrated by several studies [23, 24] which might be due to differences in pathogenesis between genotypes [25]. They have been shown to differ ac (...truncated)


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Motswedi Anderson, Simani Gaseitsiwe, Sikhulile Moyo, Matthijs Wessels, Terence Mohammed, Theresa Sebunya, Eleanor Powell, Joseph Makhema, Jason Blackard, Richard Marlink, Max Essex, Rosemary Musonda. Molecular characterisation of hepatitis B virus in HIV-1 subtype C infected patients in Botswana, BMC Infectious Diseases, 2015, pp. 335, 15, DOI: 10.1186/s12879-015-1096-4