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Ogwu, Anthony

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Ogwu

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Anthony

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Ogwu, Anthony

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2010 - 20157

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Author's Publications: search.filters.isAuthorOfPublication.c23f1a94-550e-4d35-9be9-059e23a18534

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    Prevalence and Characteristics of Hepatitis B Virus (HBV) Coinfection among HIV-Positive Women in South Africa and Botswana
    (Public Library of Science, 2015) Matthews, Philippa C.; Beloukas, Apostolos; Malik, Amna; Carlson, Jonathan M.; Jooste, Pieter; Ogwu, Anthony; Shapiro, Roger; Riddell, Lynn; Chen, Fabian; Luzzi, Graz; Jaggernath, Manjeetha; Jesuthasan, Gerald; Jeffery, Katie; Ndung’u, Thumbi; Goulder, Philip J. R.; Geretti, Anna Maria; Klenerman, Paul
    There is progressive concern about the evolving burden of morbidity and mortality caused by coinfection with HIV-1 and hepatitis B virus (HBV) in sub-Saharan Africa, but the epidemiology and impact of this problem are not well defined. We therefore set out to assimilate more information about the nature of HBV/HIV coinfection in this region by undertaking a retrospective observational study of southern African adult women. We used samples from previously recruited HIV-1 positive women attending antenatal clinics in three settings in South Africa and Botswana (n = 950) and added a small cohort of HIV-negative antenatal South African women for comparison (n = 72). We tested for HBsAg and followed up HBsAg-positive samples by testing for HBeAg, HBV DNA, HBV genotype, presence of drug-resistance associated mutations (RAMs) and HDV. We identified HBsAg in 72 individuals (7% of the whole cohort), of whom 27% were HBeAg-positive, and the majority HBV genotypes A1 and A2. We did not detect any HDV coinfection. HBV prevalence was significantly different between geographically distinct cohorts, but did not differ according to HIV status. Among adults from South Africa, HBV/HIV coinfected patients had lower CD4+ T cell counts compared to those with HIV-monoinfection (p = 0.02), but this finding was not replicated in the cohort from Botswana. Overall, these data provide a snapshot of the coinfection problem at the heart of the HIV/HBV co-epidemic, and are important to inform public health policy, resource allocation, education, surveillance and clinical care.
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    HLA-A is a Predictor of Hepatitis B e Antigen Status in HIV-Positive African Adults
    (Oxford University Press, 2015) Matthews, Philippa C.; Carlson, Jonathan M.; Beloukas, Apostolos; Malik, Amna; Jooste, Pieter; Ogwu, Anthony; Shapiro, Roger; Riddell, Lynn; Chen, Fabian; Luzzi, Graz; Jesuthasan, Gerald; Jeffery, Katie; Jojic, Nebojsa; Ndung'u, Thumbi; Carrington, Mary; Goulder, Philip J. R.; Geretti, Anna Maria; Klenerman, Paul
    Outcomes of chronic infection with hepatitis B virus (HBV) are varied, with increased morbidity reported in the context of human immunodeficiency virus (HIV) coinfection. The factors driving different outcomes are not well understood, but there is increasing interest in an HLA class I effect. We therefore studied the influence of HLA class I on HBV in an African HIV-positive cohort. We demonstrated that virologic markers of HBV disease activity (hepatitis B e antigen status or HBV DNA level) are associated with HLA-A genotype. This finding supports the role of the CD8+ T-cell response in HBV control, and potentially informs future therapeutic T-cell vaccine strategies.
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    Antiretroviral Regimens in Pregnancy and Breast-Feeding in Botswana
    (New England Journal of Medicine (NEJM/MMS), 2010) Shapiro, R.L.; Hughes, M.D.; Ogwu, Anthony; Kitch, Doug; Lockman, Shahin; Moffat, C.; Makhema, Joseph; Moyo, Sikhulile; Thior, Ibou; McIntosh, Kenneth; van Widenfelt, E.; Leidner, Jean; Powis, Kathleen; Asmelash, A.; Tumbare, E.; Zwerski, S.; Sharma, Upasna; Handelsman, E.; Mburu, K.; Jayeoba, O.; Moko, E.; Souda, Shashidhar Vaman; Lubega, E.; Akhtar, M.; Wester, C; Tuomola, R.; Snowden, W.; Martinez-Tristani, M.; Mazhani, L.; Essex, Myron
    BACKGROUND: The most effective highly active antiretroviral therapy (HAART) to prevent mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) in pregnancy and its efficacy during breast-feeding are unknown. METHODS: We randomly assigned 560 HIV-1-infected pregnant women (CD4+ count, > or = 200 cells per cubic millimeter) to receive coformulated abacavir, zidovudine, and lamivudine (the nucleoside reverse-transcriptase inhibitor [NRTI] group) or lopinavir-ritonavir plus zidovudine-lamivudine (the protease-inhibitor group) from 26 to 34 weeks' gestation through planned weaning by 6 months post partum. A total of 170 women with CD4+ counts of less than 200 cells per cubic millimeter received nevirapine plus zidovudine-lamivudine (the observational group). Infants received single-dose nevirapine and 4 weeks of zidovudine. RESULTS: The rate of virologic suppression to less than 400 copies per milliliter was high and did not differ significantly among the three groups at delivery (96% in the NRTI group, 93% in the protease-inhibitor group, and 94% in the observational group) or throughout the breast-feeding period (92% in the NRTI group, 93% in the protease-inhibitor group, and 95% in the observational group). By 6 months of age, 8 of 709 live-born infants (1.1%) were infected (95% confidence interval [CI], 0.5 to 2.2): 6 were infected in utero (4 in the NRTI group, 1 in the protease-inhibitor group, and 1 in the observational group), and 2 were infected during the breast-feeding period (in the NRTI group). Treatment-limiting adverse events occurred in 2% of women in the NRTI group, 2% of women in the protease-inhibitor group, and 11% of women in the observational group. CONCLUSIONS: All regimens of HAART from pregnancy through 6 months post partum resulted in high rates of virologic suppression, with an overall rate of mother-to-child transmission of 1.1%.
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    Abacavir Alters the Transcription of Inflammatory Cytokines in Virologically Suppressed, HIV-Infected Women
    (International AIDS Society, 2012) MacLeod, Iain; Rowley, Christopher; Lockman, Shahin; Ogwu, Anthony; Moyo, Sikhulile; van Widenfelt, Erik; Mmalane, Mompati; Makhema, Joseph; Essex, Myron; Shapiro, Roger
    Background: Abacavir (ABC) may be associated with a small, increased risk of myocardial infarction in HIV-infected adults, possibly related to cytokine-mediated inflammation. Methods: To evaluate the induction of inflammatory cytokine transcription by ABC, we used samples from women randomized to receive zidovudine/lamivudine/ABC (Trizivir) or lopinavir/ritonavir and zidovudine/lamividine (Kaletra/Combivir) from the third trimester through six-months postpartum for the prevention of mother-to-child transmission (PMTCT). Women were matched by CD4 count and baseline HIV RNA. All women attained viral suppression (<50 copies/ml) by the time of sampling. Results: Four cytokines showed a difference in expression between the treatment arms, all in a proinflammatory direction for the ABC arm: CD40LG 1.82-fold, (p=.027); IL-8 3.16-fold (p=.020); LTA 2.82-fold, (p=.008); and CCL5 −1.67-fold, (p=.035). At 12-months postpartum, 6-months after antiretroviral discontinuation, cytokine expression was similar by treatment arm. Conclusions: We conclude that ABC may upregulate proinflammatory cytokines at the transcriptional level in this population.
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    Co-Operative Additive Effects between HLA Alleles in Control of HIV-1
    (Public Library of Science, 2012) Matthews, Philippa C.; Listgarten, Jennifer; Carlson, Jonathan M.; Payne, Rebecca; Huang, Kuan-Hsiang Gary; Frater, John; Goedhals, Dominique; Steyn, Dewald; van Vuuren, Cloete; Paioni, Paolo; Jooste, Pieter; Ogwu, Anthony; Shapiro, Roger; Mncube, Zenele; Ndung'u, Thumbi; Walker, Bruce; Heckerman, David; Goulder, Philip J. R.
    Background: HLA class I genotype is a major determinant of the outcome of HIV infection, and the impact of certain alleles on HIV disease outcome is well studied. Recent studies have demonstrated that certain HLA class I alleles that are in linkage disequilibrium, such as HLA-A*74 and HLA-B*57, appear to function co-operatively to result in greater immune control of HIV than mediated by either single allele alone. We here investigate the extent to which HLA alleles - irrespective of linkage disequilibrium - function co-operatively. Methodology/Principal Findings: We here refined a computational approach to the analysis of >2000 subjects infected with C-clade HIV first to discern the individual effect of each allele on disease control, and second to identify pairs of alleles that mediate ‘co-operative additive’ effects, either to improve disease suppression or to contribute to immunological failure. We identified six pairs of HLA class I alleles that have a co-operative additive effect in mediating HIV disease control and four hazardous pairs of alleles that, occurring together, are predictive of worse disease outcomes (q<0.05 in each case). We developed a novel ‘sharing score’ to quantify the breadth of CD8+ T cell responses made by pairs of HLA alleles across the HIV proteome, and used this to demonstrate that successful viraemic suppression correlates with breadth of unique CD8+ T cell responses (p = 0.03). Conclusions/Significance: These results identify co-operative effects between HLA Class I alleles in the control of HIV-1 in an extended Southern African cohort, and underline complementarity and breadth of the CD8+ T cell targeting as one potential mechanism for this effect.
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    Birth Weight for Gestational Age Norms for a Large Cohort of Infants Born to HIV-Negative Women in Botswana Compared with Norms for U.S.-Born Black Infants
    (BioMed Central, 2011) Parekh, Natasha K; Binda, Kelebogile; Souda, Sajini; Essex, Max; Matthews, Lynn; Ribaudo, Heather; Chen, Jennifer Yin-zu; Ogwu, Anthony; Makhema, Joseph; Lockman, Shahin; Shapiro, Roger
    Background: Standard values for birth weight by gestational age are not available for sub-Saharan Africa, but are needed to evaluate incidence and risk factors for intrauterine growth retardation in settings where HIV, antiretrovirals, and other in utero exposures may impact birth outcomes. Methods: Birth weight data were collected from six hospitals in Botswana. Infants born to HIV-negative women between 26-44 weeks gestation were analyzed to construct birth weight for gestational age charts. These data were compared with published norms for black infants in the United States. Results: During a 29 month period from 2007-2010, birth records were reviewed in real-time from 6 hospitals and clinics in Botswana. Of these, 11,753 live infants born to HIV-negative women were included in the analysis. The median gestational age at birth was 39 weeks (1st quartile 38, 3rd quartile 40 weeks), and the median birth weight was 3100 grams (1st quartile 2800, 3rd quartile 3400 grams). We constructed estimated percentile curves for birth weight by gestational age which demonstrate increasing slope during the third trimester and leveling off beyond 40 weeks. Compared with black infants in the United States, Botswana-born infants had lower median birth weight for gestational age from weeks 37 through 42 (p < .02). Conclusions: We present birth weight for gestational age norms for Botswana, which are lower at term than norms for black infants in the United States. These findings suggest the importance of regional birth weight norms to identify and define risk factors for higher risk births. These data serve as a reference for Botswana, may apply to southern Africa, and may help to identify infants at risk for perinatal complications and inform comparisons among infants exposed to HIV and antiretrovirals in utero.
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    HIV-1 Subtype C-Infected Individuals Maintaining High Viral Load as Potential Targets for the “Test-and-Treat” Approach to Reduce HIV Transmission
    (Public Library of Science, 2010) Baum, Marianna; Thior, Ibou; Asmelash, Aida; Campa, Adriana; van Widenfelt, Erik; Mine, Madisa; Moffat, Claire; Mmalane, Mompati; Gilbert, Peter; Novitsky, Vladimir; Wang, Rui; Bussmann, Hermann; Lockman, Shahin; Shapiro, Roger; Wester, Carolyn; Wester, C; Ogwu, Anthony; Musonda, Rosemary; Moyo, Sikhulile; Makhema, Joseph; Marlink, Richard; Seage, George; DeGruttola, Victor; Essex, Myron
    The first aim of the study is to assess the distribution of HIV-1 RNA levels in subtype C infection. Among 4,348 drug-naïve HIV-positive individuals participating in clinical studies in Botswana, the median baseline plasma HIV-1 RNA levels differed between the general population cohorts (4.1–4.2 log10) and cART-initiating cohorts (5.1–5.3 log10) by about one log10. The proportion of individuals with high (≥50,000 (4.7 log10) copies/ml) HIV-1 RNA levels ranged from 24%–28% in the general HIV-positive population cohorts to 65%–83% in cART-initiating cohorts. The second aim is to estimate the proportion of individuals who maintain high HIV-1 RNA levels for an extended time and the duration of this period. For this analysis, we estimate the proportion of individuals who could be identified by repeated 6- vs. 12-month-interval HIV testing, as well as the potential reduction of HIV transmission time that can be achieved by testing and ARV treating. Longitudinal analysis of 42 seroconverters revealed that 33% (95% CI: 20%–50%) of individuals maintain high HIV-1 RNA levels for at least 180 days post seroconversion (p/s) and the median duration of high viral load period was 350 (269; 428) days p/s. We found that it would be possible to identify all HIV-infected individuals with viral load ≥50,000 (4.7 log10) copies/ml using repeated six-month-interval HIV testing. Assuming individuals with high viral load initiate cART after being identified, the period of high transmissibility due to high viral load can potentially be reduced by 77% (95% CI: 71%–82%). Therefore, if HIV-infected individuals maintaining high levels of plasma HIV-1 RNA for extended period of time contribute disproportionally to HIV transmission, a modified “test-and-treat” strategy targeting such individuals by repeated HIV testing (followed by initiation of cART) might be a useful public health strategy for mitigating the HIV epidemic in some communities.