HIV-infected African Adults Research Articles

Association of cellular HIV-1 DNA and virological success of antiretroviral treatment in HIV-infected sub-Saharan African adults

BackgroundHIV-1 DNA persists in infected cells, forming viral reservoirs. Pre-antiretroviral treatment (ART) HIV-1 DNA load was reported to predict ART success in European severely immunocompromised patients. The aim of this study was to determine whether HIV-1 DNA levels are associated with virological success in less severely immunocompromised patients who receive early ART in sub-Saharan Africa.MethodsThe association between pre-ART HIV-1 DNA and the virological response after 30 months on ART was studied in multivariate logistic regression in patients randomised to immediate ART groups in the Temprano trial, which assessed the benefits of early ART in HIV-infected adults in Côte d’Ivoire. HIV-1 DNA was quantified in peripheral blood mononuclear cell (PBMC) using real-time PCR.ResultsHIV-1 DNA levels were measured in 1013 patients. Their medians [IQR] of pre-ART CD4 count, HIV-1 RNA and HIV-1 DNA levels were 465 [379–578]/mm3, 4.7 [4.0–5.3] log10 copies/ml and 2.9 [2.5–3.2] log10 copies/million PBMC, respectively. Pre-ART HIV-1 DNA was significantly correlated with pre-ART HIV-1 RNA (R = 0.59, p < 0.0001). In multivariate analysis, HIV-1 DNA < 3 log10 copies/million PBMC was significantly associated with virological success at M30 after adjustment for other key variables (ART regimen, IPT, sex, age, WHO clinical stage, CD4 and HIV-1 RNA; aOR 1.57; 95% CI 1.08–2.30; p = 0.02).ConclusionLow HIV-1 DNA was statistically associated with virological success in this population of sub-Saharan African adults who started treatment with a median pre-ART CD4 count at 465/mm3. HIV-1 DNA could become a useful tool for guiding some therapeutic decisions in the test-and-treat era.Trial registration TEMPRANO ANRS 12136 ClinicalTrials.gov, number NCT00495651, date of registration 03/07/2007.

Plasma sVCAM-1, antiretroviral therapy and mortality in HIV-1-infected West African adults.

We report the association between pre-antiretroviral therapy (pre-ART) soluble vascular cell adhesion molecule-1 (sVCAM-1) levels and long-term mortality in HIV-infected West African adults participating in a trial of early ART in West Africa (Temprano ANRS 12136 trial). The ART-naïve HIV-infected adults were randomly assigned to start ART immediately or defer ART until the WHO criteria were met. Participants who completed the trial follow-up were invited to participate in a post-trial phase (PTP). The PTP end-point was all-cause death. We used multivariable Cox proportional models to analyse the association between baseline sVCAM-1 and all-cause death, adjusting for ART strategy, sex, CD4 count, plasma HIV-1 RNA and peripheral blood mononuclear cell HIV-1 DNA levels. In all, 954 adults (77% women, median CD4 count of 387 cells/μL) were randomly assigned to start ART immediately (n=477) or to defer initiation of ART (n=477). They were followed for a median of 5.8years [interquartile range (IQR): 5.2-6.3]. In multivariable analysis, the risk of death was significantly associated with baseline sVCAM-1 [≥1458 vs. <1458ng/mL; adjusted hazard ratio = 2.86, 95%confidence interval (CI): 1.60-5.11]. The 6-year probability of death rates were 14.4% (95%CI: 9.1-22.6) and 9.4% (5.4-16.1) in patients with baseline sVCAM-1 ≥ 1458ng/mL randomized to deferred and immediate ART, respectively, and 3.8% (2.2-6.5) and 3.5% (1.9-6.3) in patients with baseline sVCAM-1 <1458ng/mL randomized to deferred and immediate ART. The median difference between pre-ART and 12-month sVCAM-1levels in patients randomized to immediate ART was -252 (IQR: -587 to -61). Pre-ART sVCAM-1levels were significantly associated with mortality, independently of whether ART was started immediately or deferred, but they significantly decreased after 12months of ART.

Estimating the contribution of HIV-infected adults to household pneumococcal transmission in South Africa, 2016-2018: A hidden Markov modelling study.

Human immunodeficiency virus (HIV) infected adults are at a higher risk of pneumococcal colonisation and disease, even while receiving antiretroviral therapy (ART). To help evaluate potential indirect effects of vaccination of HIV-infected adults, we assessed whether HIV-infected adults disproportionately contribute to household transmission of pneumococci. We constructed a hidden Markov model to capture the dynamics of pneumococcal carriage acquisition and clearance observed during a longitudinal household-based nasopharyngeal swabbing study, while accounting for sample misclassifications. Households were followed-up twice weekly for approximately 10 months each year during a three-year study period for nasopharyngeal carriage detection via real-time PCR. We estimated the effect of participant’s age, HIV status, presence of a HIV-infected adult within the household and other covariates on pneumococcal acquisition and clearance probabilities. Of 1,684 individuals enrolled, 279 (16.6%) were younger children (<5 years-old) of whom 4 (1.5%) were HIV-infected and 726 (43.1%) were adults (≥18 years-old) of whom 214 (30.4%) were HIV-infected, most (173, 81.2%) with high CD4+ count. The observed range of pneumococcal carriage prevalence across visits was substantially higher in younger children (56.9–80.5%) than older children (5–17 years-old) (31.7–50.0%) or adults (11.5–23.5%). We estimate that 14.4% (95% Confidence Interval [CI]: 13.7–15.0) of pneumococcal-negative swabs were false negatives. Daily carriage acquisition probabilities among HIV-uninfected younger children were similar in households with and without HIV-infected adults (hazard ratio: 0.95, 95%CI: 0.91–1.01). Longer average carriage duration (11.4 days, 95%CI: 10.2–12.8 vs 6.0 days, 95%CI: 5.6–6.3) and higher median carriage density (622 genome equivalents per millilitre, 95%CI: 507–714 vs 389, 95%CI: 311.1–435.5) were estimated in HIV-infected vs HIV-uninfected adults. The use of ART and antibiotics substantially reduced carriage duration in all age groups, and acquisition rates increased with household size. Although South African HIV-infected adults on ART have longer carriage duration and density than their HIV-uninfected counterparts, they show similar patterns of pneumococcal acquisition and onward transmission.

Virological failure and drug resistance in West African HIV-infected adults who started ART immediately or deferred ART initiation.

Asymptomatic HIV-infected people who start ART early may feel less motivated and neglect compliance. This might promote the emergence of resistance. In the Temprano trial, ART-naive HIV-infected adults with high CD4 counts were randomly assigned to start ART immediately (immediate group) or defer ART until the WHO criteria were met (deferred group). All participants were monitored for 30 months. Those in the deferred group who started ART were monitored for longer, until they had completed 30 months on ART. We compared the rate of virological failure and drug resistance between the immediate and deferred groups 30 months after ART initiation. Of the 2056 participants in Temprano, 1033 were assigned to start ART immediately and 1023 to defer ART. Of the latter, 488 started ART during trial follow-up. Patients in the deferred group who started ART had a lower median CD4 count (280 versus 465 cells/mm3) and a higher median plasma HIV-1 RNA (5.1 versus 4.7 log10 copies/mL) at baseline. During follow-up, participants in both groups had similar antiretroviral drug exposure. Thirty months after ART initiation, patients in the deferred group had a higher rate of virological failure (35.3% versus 29.9%, P = 0.04) and a lower genotypic susceptibility score (P = 0.04). Starting ART early decreases the risk of virological failure and drug resistance in the medium term. This benefit is of particular importance in countries where access to viral load monitoring and the number of antiretroviral drug lines is limited.

Association of Plasma Soluble Vascular Cell Adhesion Molecule-1 and sCD14 With Mortality in HIV-1-Infected West African Adults With High CD4 Counts.

Several biomarkers of inflammation and coagulation were reported to be associated with HIV disease progression in different settings. In this article, we report the association between 11 biomarkers and medium-term mortality in HIV-infected West African adults. In Temprano ANRS 12136, antiretroviral therapy (ART)-naive HIV-infected adults with high CD4 counts were randomly assigned either to start ART immediately or defer ART until the World Health Organization criteria were met. Participants who completed the 30-month trial follow-up were invited to participate in a posttrial phase. The posttrial phase end point was all-cause death. We used multivariate Cox proportional models to analyze the association between baseline plasma biomarkers [IL-1ra, IL-6, soluble vascular cell adhesion molecule 1 (sVCAM-1), sCD14, D-dimer, fibrinogen, IP-10, sCD163, albumin, high-sensitivity C-reactive protein, and 16S rDNA] and all-cause death in the Temprano participants randomized to defer ART. Four hundred seventy-seven patients (median age 35 years, 78% women, and median CD4 count: 379 cells/mm) were randomly assigned to defer starting ART until the World Health Organization criteria were met. The participants were followed for 2646 person-years (median 5.8 years). In the follow-up, 89% of participants started ART and 30 died. In the multivariate analysis adjusted for the study center, sex, baseline CD4 count, isoniazid preventive therapy, plasma HIV-1 RNA, peripheral blood mononuclear cell HIV-1 DNA, and ART, the risk of death was significantly associated with baseline sVCAM-1 (≥1458 vs. <1458: adjusted hazard ratio 2.57, 95% confidence interval: 1.13 to 5.82) and sCD14 (≥2187 vs. <2187: adjusted hazard ratio 2.79, interquartile range 1.29-6.02) levels. In these sub-Saharan African adults with high CD4 counts, pre-ART plasma sVCAM-1 and sCD14 levels were independently associated with mortality.

Incidence of Tuberculosis During the First Year of Antiretroviral Treatment in West African HIV-Infected Adults.

We estimated tuberculosis incidence during the first year on antriretroviral therapy without isoniazid-preventive treatment in 6938 West African HIV-infected adults at 3.33 cases per 100 person-years (95% CI, 2.85–3.80). In multivariate Poisson models, sites in Cote d’Ivoire, male gender, low body mass index, low hemoglobin, low CD4 count, and young age were significantly associated with higher incidence.

Screening for active tuberculosis before isoniazid preventive therapy among HIV-infected West African adults.

TEMPRANO was a multicentre, open-label trial in which human immunodeficiency virus (HIV) infected adults with high CD4 counts were randomised into early or deferred antiretroviral therapy (ART) arms with or without 6-month isoniazid preventive therapy (IPT) in a setting where the World Health Organization (WHO) recommends IPT in HIV-infected patients. Despite the WHO recommendation, IPT coverage remains low due to fear of the presence of undiagnosed active TB before prescribing IPT, and the related risk of drug resistance. To report the frequency of undiagnosed TB in patients enrolled for IPT and describe the results of a 1-month buffer period to avoid prescribing IPT for active TB cases. Patients were screened using a clinical algorithm and chest X-ray at Day 0 and started on isoniazid at Month 1 if no sign/symptom suggestive of TB appeared between Day 0 and Month 1. Of 1030 patients randomised into IPT arms. 10% never started IPT at Month 1. Of these, 23 had active TB, including 16 with prevalent TB. Among the 927 patients who started IPT, 6 had active TB, including 1 with prevalent TB. Only 1 patient with active TB received IPT due to the 1-month buffer period between Day 0 and IPT initiation. In this study, 1.6% of adults considered free of active TB based on clinical screening at pre-inclusion actually had active TB.

Impact of Human Immunodeficiency Virus on the Burden and Severity of Influenza Illness in Malawian Adults: A Prospective Cohort and Parallel Case-Control Study

The impact of human immunodeficiency virus (HIV) infection on influenza incidence and severity in adults in sub-Saharan Africa is unclear. Seasonal influenza vaccination is recommended for HIV-infected persons in developed settings but is rarely implemented in Africa. We conducted a prospective cohort study to compare the incidence of laboratory-confirmed influenza illness between HIV-infected and HIV-uninfected adults in Blantyre, Malawi. In a parallel case-control study, we explored risk factors for severe influenza presentation of severe (hospitalized) lower respiratory tract infection, and mild influenza (influenza-like illness [ILI]). The cohort study enrolled 608 adults, of whom 360 (59%) were HIV infected. Between April 2013 and March 2015, 24 of 229 ILI episodes (10.5%) in HIV-infected and 5 of 119 (4.2%) in HIV-uninfected adults were positive for influenza by means of polymerase chain reaction (incidence rate, 46.0 vs 14.5 per 1000 person-years; incidence rate ratio, 2.75; 95% confidence interval, 1.02-7.44; P = .03; adjusted for age, sex, household crowding, and food security). In the case-control study, influenza was identified in 56 of 518 patients (10.8%) with hospitalized lower respiratory tract infection, and 88 or 642 (13.7%) with ILI. The HIV prevalence was 69.6% and 29.6%, respectively, among influenza-positive case patients and controls. HIV was a significant risk factor for severe influenza (odds ratio, 4.98; 95% confidence interval, 2.09-11.88; P < .001; population-attributable fraction, 57%; adjusted for season, sanitation facility, and food security). HIV is an important risk factor for influenza-associated ILI and severe presentation in this high-HIV prevalence African setting. Targeted influenza vaccination of HIV-infected African adults should be reevaluated, and the optimal mechanism for vaccine introduction in overstretched health systems needs to be determined.

Changes in serum phosphate and potassium and their effects on mortality in malnourished African HIV-infected adults starting antiretroviral therapy and given vitamins and minerals in lipid-based nutritional supplements: secondary analysis from the Nutritional Support for African Adults Starting Antiretroviral Therapy (NUSTART) trial.

Malnourished HIV-infected patients starting antiretroviral therapy (ART) are at high risk of early mortality, some of which may be attributed to altered electrolyte metabolism. We used data from a randomised controlled trial of electrolyte-enriched lipid-based nutritional supplements to assess the association of baseline and time-varying serum phosphate and K concentrations with mortality within the first 12 weeks after starting ART. Baseline phosphate results were available from 1764 patients and there were 9096 subsequent serum phosphate measurements, a median of 6 per patient. For serum K there were 1701 baseline and 8773 subsequent measures, a median of 6 per patient. Abnormally high or low serum phosphate was more common than high or low serum K. Controlling for other factors found to affect mortality in this cohort, low phosphate which had not changed from the previous time interval was associated with increased mortality; the same was not true for high phosphate or for high or low K. Both increases and decreases in serum electrolytes from the previous time interval were generally associated with increased mortality, particularly in the electrolyte-supplemented group. The results suggest that changes in serum electrolytes, largely irrespective of the starting point and the direction of change, were more strongly associated with mortality than were absolute electrolyte levels. Although K and phosphate are required for tissue deposition during recovery from malnutrition, further studies are needed to determine whether specific supplements exacerbate physiologically adverse shifts in electrolyte levels during nutritional rehabilitation of ill malnourished HIV patients.

Bactericidal Immunity to Salmonella in Africans and Mechanisms Causing Its Failure in HIV Infection.

BackgroundNontyphoidal strains of Salmonella are a leading cause of death among HIV-infected Africans. Antibody-induced complement-mediated killing protects healthy Africans against Salmonella, but increased levels of anti-lipopolysaccharide (LPS) antibodies in some HIV-infected African adults block this killing. The objective was to understand how these high levels of anti-LPS antibodies interfere with the killing of Salmonella.Methodology/Principal FindingsSera and affinity-purified antibodies from African HIV-infected adults that failed to kill invasive S. Typhimurium D23580 were compared to sera from HIV-uninfected and HIV-infected subjects with bactericidal activity. The failure of sera from certain HIV-infected subjects to kill Salmonella was found to be due to an inherent inhibitory effect of anti-LPS antibodies. This inhibition was concentration-dependent and strongly associated with IgA and IgG2 anti-LPS antibodies (p<0.0001 for both). IgG anti-LPS antibodies, from sera of HIV-infected individuals that inhibit killing at high concentration, induced killing when diluted. Conversely, IgG, from sera of HIV-uninfected adults that induce killing, inhibited killing when concentrated. IgM anti-LPS antibodies from all subjects also induced Salmonella killing. Finally, the inhibitory effect of high concentrations of anti-LPS antibodies is seen with IgM as well as IgG and IgA. No correlation was found between affinity or avidity, or complement deposition or consumption, and inhibition of killing.Conclusion/SignificanceIgG and IgM classes of anti-S. Typhimurium LPS antibodies from HIV-infected and HIV-uninfected individuals are bactericidal, while at very high concentrations, anti-LPS antibodies of all classes inhibit in vitro killing of Salmonella. This could be due to a variety of mechanisms relating to the poor ability of IgA and IgG2 to activate complement, and deposition of complement at sites where it cannot insert in the bacterial membrane. Vaccine trials are required to understand the significance of lack of in vitro killing by anti-LPS antibodies from a minority of HIV-infected individuals with impaired immune homeostasis.

Culturally Sensitive Approaches to Identification and Treatment of Depression among HIV Infected African American Adults: A Qualitative Study of Primary Care Providers' Perspectives.

Major depressive disorder (MDD) is highly prevalent among HIV-infected (HIV+) individuals, and is associated with non-adherence to antiretroviral therapy (ART), and accelerated disease progression. MDD is underdiagnosed and undertreated among low-income African Americans, who are disproportionately impacted by the HIV epidemic. To improve detection and treatment of depression among African Americans living with HIV/AIDS, it is important to understand culturally and contextually relevant aspects of MDD and attitudes about mental health treatment. A focus group session was conducted with seven providers and staff at a primary care center that serves a largely African-American community heavily impacted by the HIV epidemic in Washington, DC. Data were analyzed using an inductive approach to distill prominent themes, perspectives, and experiences among participating providers. Five themes emerged to characterize the lived experiences of HIV+ African-American patients: (a) Changes in perceptions of HIV over time; (b) HIV is comorbid with mental illness, particularly depression and substance abuse; (c) Stigma is associated with both HIV and depression; (d) Existing mental health services vary and are insufficient and (e) Suggestions for optimal treatment for comorbid HIV and depression. This study reflects the views of providers from one clinic in this community. Substantial economic disadvantage, pervasive childhood adversity, limited education and limited resources jointly put members of this community at risk for acquisition of HIV and for development of depression and addictions. These contextual factors provide an important reminder that any patient-level depression identification or intervention in this community will have to be mindful of such circumstances.

The Impact of Different CD4 Cell-Count Monitoring and Switching Strategies on Mortality in HIV-Infected African Adults on Antiretroviral Therapy: An Application of Dynamic Marginal Structural Models.

In Africa, antiretroviral therapy (ART) is delivered with limited laboratory monitoring, often none. In 2003–2004, investigators in the Development of Antiretroviral Therapy in Africa (DART) Trial randomized persons initiating ART in Uganda and Zimbabwe to either laboratory and clinical monitoring (LCM) or clinically driven monitoring (CDM). CD4 cell counts were measured every 12 weeks in both groups but were only returned to treating clinicians for management in the LCM group. Follow-up continued through 2008. In observational analyses, dynamic marginal structural models on pooled randomized groups were used to estimate survival under different monitoring-frequency and clinical/immunological switching strategies. Assumptions included no direct effect of randomized group on mortality or confounders and no unmeasured confounders which influenced treatment switch and mortality or treatment switch and time-dependent covariates. After 48 weeks of first-line ART, 2,946 individuals contributed 11,351 person-years of follow-up, 625 switches, and 179 deaths. The estimated survival probability after a further 240 weeks for post-48-week switch at the first CD4 cell count less than 100 cells/mm3 or non-Candida World Health Organization stage 4 event (with CD4 count <250) was 0.96 (95% confidence interval (CI): 0.94, 0.97) with 12-weekly CD4 testing, 0.96 (95% CI: 0.95, 0.97) with 24-weekly CD4 testing, 0.95 (95% CI: 0.93, 0.96) with a single CD4 test at 48 weeks (baseline), and 0.92 (95% CI: 0.91, 0.94) with no CD4 testing. Comparing randomized groups by 48-week CD4 count, the mortality risk associated with CDM versus LCM was greater in persons with CD4 counts of <100 (hazard ratio = 2.4, 95% CI: 1.3, 4.3) than in those with CD4 counts of ≥100 (hazard ratio = 1.1, 95% CI: 0.8, 1.7; interaction P = 0.04). These findings support a benefit from identifying patients immunologically failing first-line ART at 48 weeks.

Incomplete recovery of pneumococcal CD4 T cell immunity after initiation of antiretroviral therapy in HIV-infected malawian adults.

HIV-infected African adults are at a considerably increased risk of life-threatening invasive pneumococcal disease (IPD) which persists despite antiretroviral therapy (ART). Defects in naturally acquired pneumococcal-specific T-cell immunity have been identified in HIV-infected adults. We have therefore determined the extent and nature of pneumococcal antigen-specific immune recovery following ART. HIV-infected adults were followed up at 3, 6 and 12 months after initiating ART. Nasopharyngeal swabs were cultured to determine carriage rates. Pneumococcal-specific CD4 T-cell immunity was assessed by IFN-γ ELISpot, proliferation assay, CD154 expression and intracellular cytokine assay. S. pneumoniae colonization was detected in 27% (13/48) of HIV-infected patients prior to ART. The rates remained elevated after 12 months ART, 41% (16/39) (p = 0.17) and significantly higher than in HIV-uninfected individuals (HIVneg 14%(4/29); p = 0.0147). CD4+ T-cell proliferative responses to pneumococcal antigens increased significantly to levels comparable with HIV-negative individuals at 12 months ART (p = 0.0799). However, recovery of the pneumococcal-specific CD154 expression was incomplete (p = 0.0015) as were IFN-γ ELISpot responses (p = 0.0040) and polyfunctional CD4+ T-cell responses (TNF-α, IL-2 and IFN-γ expression) (p = 0.0040) to a pneumolysin-deficient mutant strain. Impaired control of pneumococcal colonisation and incomplete restoration of pneumococcal-specific immunity may explain the persistently higher risk of IPD amongst HIV-infected adults on ART. Whether vaccination and prolonged ART can overcome this immunological defect and reduce the high levels of pneumococcal colonisation requires further evaluation.

Accelerated biological ageing in HIV-infected individuals in South Africa

Objectives:Little is known about the impact of HIV infection on biological ageing in sub-Saharan Africa. The study aimed to assess biological ageing in South African HIV-infected adults and HIV-seronegative individuals using two validated biomarkers, telomere length and CDKN2A expression (a mediator of cellular senescence).Design:A case–control study.Methods:Two hundred and thirty-six HIV-infected adults aged at least 30 years and 250 age and sex frequency matched HIV-seronegative individuals were recruited from clinics in township communities in Cape Town. Biological ageing was evaluated by measurement of telomere length and CDKN2A expression in peripheral blood leukocytes.Results:The median ages of the HIV-infected and HIV-seronegative participants were 39 and 40 years, respectively. Among HIV-infected participants, 87.1% were receiving antiretroviral therapy (ART), their median CD4+ cell count was 468 cells/μl and 84.3% had undetectable viral load. Both biomarkers were validated against chronological age in HIV-seronegative individuals. Telomere length was significantly shorter in HIV-infected individuals than in HIV-seronegative individuals (mean relative T/S ratio ±SE:0.91 ± 0.007 vs. 1.07 ± 0.008, P < 0.0001). CD2NKA expression was higher in HIV-infected participants than in HIV-seronegative individuals (mean expression: 0.45 ± 0.02 vs. 0.36 ± 0.03, P = 0.003). Socioeconomic factors were not associated with biological ageing in HIV-infected participants. However, in participants on ART with undetectable viral load, biomarker levels indicated greater biological ageing in those with lower current CD4+ cell counts.Conclusion:Telomere length and CDKN2A expression were both consistent with increased biological ageing in HIV-infected individuals. Prospective studies of the impact of HIV on biological ageing in sub-Saharan Africa are warranted.

Cost utility of lateral-flow urine lipoarabinomannan for tuberculosis diagnosis in HIV-infected African adults

In-patient hospitals in South Africa and Uganda. To evaluate the cost-effectiveness of a lateral-flow urine lipoarabinomannan (LAM) test when added to existing strategies for tuberculosis (TB) diagnosis in human immunodeficiency virus infected adults (CD4(+) T-cell counts < 100 cells/l) with symptoms of active TB. Decision-analytic cost-utility model, with the primary outcome being the incremental cost-effectiveness ratio, expressed in 2010 US dollars per disability-adjusted life year (DALY) averted from the perspective of a public sector TB control program. For every 1000 patients tested, adding lateral-flow urine LAM generated 80 incremental appropriate anti-tuberculosis treatments and averted 224 DALYs. Estimated cost utility was US$353 per DALY averted (95% uncertainty range $192$1161) in South Africa and $86 per DALY averted (95% uncertainty range $49$239) in Uganda, reflecting the lower treatment costs in Uganda. Cost utility was most sensitive to assay specificity, cost of anti-tuberculosis treatment, life expectancy after TB cure and cohort TB prevalence, but did not rise above $1500 per DALY averted in South Africa under any one-way sensitivity analysis. The probability of acceptability was >99.8% at a per-DALY willingness-to-pay threshold equal to the per capita gross domestic product in South Africa ($7275) and Uganda ($509).

Could Early Antiretroviral Therapy Entail More Risks than Benefits in Sub-Saharan African HIV-Infected Adults? A Model-Based Analysis

Initiation of antiretroviral therapy (ART) in all HIV-infected adults, regardless of CD4⁺ T-cell count, is a proposed strategy for reducing HIV transmission. We investigated the conditions under which starting ART early could entail more risks than benefits for patients with high CD4⁺ T-cell counts. We used a simulation model to compare ART initiation upon entry to care ('immediate ART') to initiation at CD4⁺ T-cell count ≤ 350 cells/μl ('WHO 2010 ART') in African adults with CD4⁺ T-cell counts >500 cells/μl. We varied inputs to determine the combination of parameters (population characteristics, conditions of care, treatment outcomes) that would result in higher 15-year mortality with immediate ART. The 15-year mortality was 56.7% for WHO 2010 ART and 51.8% for immediate ART. In one-way sensitivity analysis, lower 15-year mortality was consistently achieved with immediate ART unless the rate of fatal ART toxicity was >1.0/100 person-years, the rate of withdrawal from care was >1.2-fold higher or the rate of ART failure due to poor adherence was >4.3-fold higher on immediate than on WHO 2010 ART. In multi-way sensitivity analysis, immediate ART led to higher mortality when moderate rates of fatal ART toxicity (0.25/100 person-years) were combined with rates of withdrawal from care >1.1-fold higher and rates of treatment failure >2.1-fold higher on immediate than on WHO 2010 ART. In sub-Saharan Africa, ART initiation at entry into care would improve long-term survival of patients with high CD4⁺ T-cell counts, unless it is associated with increased withdrawal from care and decreased adherence. In early ART trials, a focus on retention and adherence will be crucial.

Purification of antibodies to O antigen of Salmonella Typhimurium from human serum by affinity chromatography

Nontyphoidal Salmonellae (NTS) are a common cause of bacteraemia in children and HIV-infected adults in Sub-Saharan Africa. We have previously shown that antibodies play a key role in both bactericidal and cellular mechanisms of immunity to NTS, but found that high concentrations of antibody to Salmonella Typhimurium O antigen (OAg) in the serum of some HIV-infected African adults is associated with impaired killing of NTS. To further investigate the function of antibodies to the OAg of NTS, we developed a method to purify these antibodies from human serum by affinity chromatography. Purified Salmonella Typhimurium OAg was activated with adipic acid dihydrazide (ADH) via two different chemistries before linking to N-hydroxysuccinamide-Sepharose resin: one ADH molecule was introduced per OAg chain on its terminal 3-deoxy-D-manno-octulosonic acid sugar (OAg–ADH), or multiple ADH molecules were attached along the OAg chain after oxidation with sodium periodate (OAgoxADH). Both resulting columns worked well when tested with commercial polyclonal anti-O:4,5 antibodies from rabbit serum. Over 90% of the applied antibodies bound to the resin and 89% of these antibodies were then eluted as detected by ELISA. OAg–ADH was preferred as the method for OAg derivatisation as it does not modify the saccharide chain and can be applied to OAg from different bacteria. Both columns were able to bind OAg-specific antibodies in human serum, but antibody recovery was initially low. Different elution buffers were tested and different amounts of OAg–ADH were linked to the resin to improve the yield. Optimal recovery (51%) was obtained by loading 1mg of activated OAg per ml of resin and eluting with 0.1M glycine, 0.1M NaCl pH2.4. The column matrix could be regenerated following elution with no detectable loss in performance for over ten uses. This method offers the potential to purify antibodies to Salmonella OAg from polyclonal serum following vaccination or natural exposure to Salmonella and so investigate the functionality and diversity of the antibody response to OAg.

Naturally-Acquired Influenza-Specific CD4+ T-Cell Proliferative Responses Are Impaired in HIV-Infected African Adults

BackgroundSeasonal influenza has been associated with greater morbidity and mortality in AIDS patients. Highly-active antiretroviral therapy (HAART) has led to some reduction in influenza-related complications but the nature of naturally-acquired T-cell immunity to influenza virus in an African setting, and how this changes with immune reconstitution following HAART is unknown. We measured influenza-specific CD4+ T-cell immunity in unimmunized HIV-infected Malawian adults and then investigated immune reconstitution following HAART.MethodsPeripheral blood mononuclear cells were isolated from HIV-infected and HIV-uninfected Malawian adults. CFSE proliferation and CD154 expression flow cytometry-based assays were used to measure influenza-specific CD4+ T-cell immunity.ResultsWe found lower naturally-acquired proliferative influenza-specific CD4+ T-cell responses in AIDS patients that was also present in asymptomatic HIV-infected adults with relatively high CD4 counts (>350 cells/µl). Influenza-specific CD4+ T-cell immune reconstitution in HIV-infected patients on HAART for 12 months was poor despite a marked reduction in viral load and an increase in CD4 count. This poor immune reconstitution was characterised by a low influenza-specific proliferative CD4+ T-cell response and reduced proportions of CD154-expressing influenza-specific CD4+ T-cells in peripheral blood.ConclusionOur data suggest that asymptomatic HIV-infected adults may also be at risk of influenza-related complications and that HAART alone may not circumvent this risk in AIDS patients. This study highlights the need to identify possible interventions early in HIV infection to reduce the risk of influenza and to intensify influenza surveillance in these susceptible African populations.

Common Inherited Mitochondrial Dna Mutations and Nucleoside Reverse Transcriptase Inhibitor-Induced Severe Hyperlactataemia in HIV-Infected Adults: An Exploratory Study

Genetic predisposition to dideoxynucleoside-induced mitochondrial dysfunction might be related to mitochondrial DNA (mtDNA) polymorphisms. Severe hyperlactataemia is probably the best model to assess such a predisposition. For this exploratory study in White European and Black African HIV-infected adults, hypervariable region 1 of mtDNA samples from peripheral blood mononuclear cells or buccal smears of patients who have developed confirmed severe hyperlactataemia was sequenced. Additionally, 21 single nucleotide polymorphisms and a 9 bp deletion were genotyped to assign mtDNA haplogroups. Finally, entire mtDNA sequencing was performed in a subset of European samples. Samples were obtained from Black African cases and controls recruited from a single centre in Johannesburg, South Africa and from white European cases from Amsterdam, London and Zurich. A total of 40 cases and 38 controls from Johannesburg were included. All of the cases and 33 controls were receiving stavudine-based therapy at the time of the index date (P=0.024). The distribution of mtDNA haplotypes was not different between cases and controls (P=0.137), and neither were the predicted haplogroups (P=0.751). In total, 11 of the 12 European cases were on stavudine and/or didanosine at the time of the event. No hypervariable region 1 haplotype was consistently found in the European cases. Sequencing of the entire mtDNA from three of these cases supported the absence of any shared mutations other than major alleles frequently seen in the mtDNA database. We did not find an association between homoplasmic inherited mtDNA polymorphisms and severe hyperlactataemia. Our data do not support the existence of non-synonymous mtDNA mutations that explain an increased predisposition to dideoxynucleoside-induced mitochondrial dysfunction.

Persistent High Burden of Invasive Pneumococcal Disease in South African HIV-Infected Adults in the Era of an Antiretroviral Treatment Program

BackgroundHighly active antiretroviral treatment (HAART) programs have been associated with declines in the burden of invasive pneumococcal disease (IPD) in industrialized countries. The aim of this study was to evaluate trends in IPD hospitalizations in HIV-infected adults in Soweto, South Africa, associated with up-scaling of the HAART program from 2003 to 2008.MethodsLaboratory-confirmed IPD cases were identified from 2003 through 2008 through an existing surveillance program. The period 2003-04 was designated as the early-HAART era, 2005–06 as the intermediate-HAART era and 2007–08 as the established-HAART era. The incidence of IPD was compared between the early-HAART and established-HAART eras in HIV-infected and–uninfected individuals.ResultsA total of 2,567 IPD cases among individuals older than 18 years were reported from 2003 through 2008. Overall incidence of IPD (per 100,000) did not change during the study period in HIV-infected adults (207.4 cases in the early-HAART and 214.0 cases in the established-HAART era; p = 0.55). IPD incidence, actually increased 1.16-fold (95% CI: 1.01; 1.62) in HIV-infected females between the early-and established-HAART eras (212.1 cases and 246.2 cases, respectively; p = 0.03). The incidence of IPD remained unchanged in HIV-uninfected adults across the three time periods.ConclusionDespite a stable prevalence of HIV and the increased roll-out of HAART for treatment of AIDS patients in our setting, the burden of IPD has not decreased among HIV-infected adults. The study indicates a need for ongoing monitoring of disease and HAART program effectiveness to reduce opportunistic infections in African adults with HIV/AIDS, as well as the need to consider alternate strategies including pneumococcal conjugate vaccine immunization for the prevention of IPD in HIV-infected adults.