HLA-A is a Predictor of Hepatitis B e Antigen Status in HIV-Positive African Adults.

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.

Predictors of early breastfeeding cessation among HIV-infected women in Botswana.

OBJECTIVE: Infants born to HIV-infected women receiving antiretroviral treatment (ART) can be breastfed through at least 6 months with very low risk of HIV acquisition. We aimed to identify demographic and cultural factors that may influence mothers' willingness to breastfeed for the recommended duration. METHODS: We evaluated factors associated with early cessation of breastfeeding (i.e. before 5 months post-partum) in a randomized clinical trial evaluating different ART regimens used for prevention of mother-to-child transmission during breastfeeding in Botswana. Univariate and multivariable Cox regressions were used to describe predictors of early exclusive BF cessation. RESULTS: Among 677 women who started breastfeeding, the median time to breastfeeding cessation was 178 days (IQR 150-181) and 25.1% weaned early. In multivariable analysis, urban location (aHR = 1.86 95%CI 1.27-2.73; P = 0.002), salaried employment or being a student (aHR = 2.78 95% CI 1.63-4.75; P < 0.001) and infant hospitalisation before weaning (aHR = 2.04 95% CI 1.21-3.45; P = 0.008) were independently and significantly associated with early BF cessation. CONCLUSIONS: Improved support for breastfeeding among employed mothers, especially in urban settings, may allow HIV-infected women who are receiving ART prophylaxis to breastfeed longer.

Adaptation of HIV-1 to human leukocyte antigen class I.

The rapid and extensive spread of the human immunodeficiency virus (HIV) epidemic provides a rare opportunity to witness host-pathogen co-evolution involving humans. A focal point is the interaction between genes encoding human leukocyte antigen (HLA) and those encoding HIV proteins. HLA molecules present fragments (epitopes) of HIV proteins on the surface of infected cells to enable immune recognition and killing by CD8(+) T cells; particular HLA molecules, such as HLA-B*57, HLA-B*27 and HLA-B*51, are more likely to mediate successful control of HIV infection. Mutation within these epitopes can allow viral escape from CD8(+) T-cell recognition. Here we analysed viral sequences and HLA alleles from >2,800 subjects, drawn from 9 distinct study cohorts spanning 5 continents. Initial analysis of the HLA-B*51-restricted epitope, TAFTIPSI (reverse transcriptase residues 128-135), showed a strong correlation between the frequency of the escape mutation I135X and HLA-B*51 prevalence in the 9 study cohorts (P = 0.0001). Extending these analyses to incorporate other well-defined CD8(+) T-cell epitopes, including those restricted by HLA-B*57 and HLA-B*27, showed that the frequency of these epitope variants (n = 14) was consistently correlated with the prevalence of the restricting HLA allele in the different cohorts (together, P < 0.0001), demonstrating strong evidence of HIV adaptation to HLA at a population level. This process of viral adaptation may dismantle the well-established HLA associations with control of HIV infection that are linked to the availability of key epitopes, and highlights the challenge for a vaccine to keep pace with the changing immunological landscape presented by HIV.

Predictors of suboptimal CD4 response among women achieving virologic suppression in a randomized antiretroviral treatment trial, Africa.

BACKGROUND: A subset of HIV-1 infected patients starting highly active antiretroviral treatment (HAART) experience suboptimal CD4 response (SCR) despite virologic suppression. We studied the rate of and risk factors for SCR among women starting HAART in the ACTG A5208 study conducted in 7 African countries. 741 HAART-naive women with screening CD4 count <200 cells/µL were randomized to start HAART with Tenofovir/Emtricitabine plus either Nevirapine or Lopinavir/Ritonavir. METHODS: This analysis includes the 625 women who remained on-study through 48 weeks without experiencing protocol-defined virologic failure. We defined SCR as<100 CD4 cells/µL increase from baseline and absolute CD4 cell count<350 cells/µL, both at 48 weeks after HAART initiation. RESULTS: The baseline characteristics for the 625 women prior to HAART initiation were: median age 33 years, screening CD4 count 134 cells/µL, and HIV-1 RNA 5.1 log10 copies/mL; 184 (29%) were WHO Stage 3 or 4.Seventy one (11%) of these 625 women experienced SCR. Baseline factors independently associated with increased odds of SCR included older age, lower HIV-1 RNA, positive Hepatitis B surface antigen, and site location. At 96 weeks, only 6% of the SCR group had CD4 ≥ 350 cells/µL compared with 67% in the non SCR group. CONCLUSION: After starting HAART, 11% of women with virologic suppression through 48 weeks experienced SCR. These patients were also less likely to achieve CD4 ≥ 350 cells/µL by 96 weeks. The underlying causes and long term clinical implications of SCR deserve further investigation. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT00089505.

Risk factors for mortality among human immunodeficiency virus-exposed and unexposed infants admitted to a neonatal intensive care unit in Botswana.

AIM: Newborns admitted to neonatal units (NNUs) in resource-limited settings face a high risk of mortality, but the epidemiology of these deaths is poorly understood. We describe risk factors for NNU mortality in an area with high prevalence of human immunodeficiency virus (HIV). METHODS: We performed a prospective cohort study of infants admitted to the NNU at a public referral hospital in Gaborone, Botswana. The primary outcome was neonatal death, defined as death within 28 days of a live delivery. Cox proportional hazard models were used to evaluate risk factors for mortality. RESULTS: From October 2008 to April 2009, 449 neonates were admitted to the NNU. Cumulative mortality was 24.5% (110/449). Factors associated with increased risk of death included lack of enteral feeding (hazard ratio (HR) 18.8, 95% confidence interval (CI) 10.3, 34.2), gestational age <28 weeks (HR 2.0, 95% CI 1.1, 3.8) and Apgar score <7 at 10 min (HR 2.5, 95% CI 1.5, 4.2). Among 348 (78%) infants who were fed, there was no difference in mortality between infants who were breastfed compared with those who were formula fed or had mixed feeding (P = 0.76). There was no significant mortality difference by HIV exposure status; 35 (28%) of 128 HIV-exposed infants died compared with 55 (21%) of 272 HIV-unexposed infants (P = 0.19). CONCLUSIONS: This study identified low Apgar scores, extreme prematurity and lack of enteral feeding as the most important risk factors for mortality in this NNU setting. HIV exposure and formula feeding were not significantly associated with death in neonates who were very ill.

Differential clade-specific HLA-B*3501 association with HIV-1 disease outcome is linked to immunogenicity of a single Gag epitope.

The strongest genetic influence on immune control in HIV-1 infection is the HLA class I genotype. Rapid disease progression in B-clade infection has been linked to HLA-B*35 expression, in particular to the less common HLA-B*3502 and HLA-B*3503 subtypes but also to the most prevalent subtype, HLA-B*3501. In these studies we first demonstrated that whereas HLA-B*3501 is associated with a high viral set point in two further B-clade-infected cohorts, in Japan and Mexico, this association does not hold in two large C-clade-infected African cohorts. We tested the hypothesis that clade-specific differences in HLA associations with disease outcomes may be related to distinct targeting of critical CD8(+) T-cell epitopes. We observed that only one epitope was significantly targeted differentially, namely, the Gag-specific epitope NPPIPVGDIY (NY10, Gag positions 253 to 262) (P = 2 × 10(-5)). In common with two other HLA-B*3501-restricted epitopes, in Gag and Nef, that were not targeted differentially, a response toward NY10 was associated with a significantly lower viral set point. Nonimmunogenicity of NY10 in B-clade-infected subjects derives from the Gag-D260E polymorphism present in ∼90% of B-clade sequences, which critically reduces recognition of the Gag NY10 epitope. These data suggest that in spite of any inherent HLA-linked T-cell receptor repertoire differences that may exist, maximizing the breadth of the Gag-specific CD8(+) T-cell response, by the addition of even a single epitope, may be of overriding importance in achieving immune control of HIV infection. This distinction is of direct relevance to development of vaccines designed to optimize the anti-HIV CD8(+) T-cell response in all individuals, irrespective of HLA type.

HLA-A*7401-mediated control of HIV viremia is independent of its linkage disequilibrium with HLA-B*5703.

The potential contribution of HLA-A alleles to viremic control in chronic HIV type 1 (HIV-1) infection has been relatively understudied compared with HLA-B. In these studies, we show that HLA-A*7401 is associated with favorable viremic control in extended southern African cohorts of >2100 C-clade-infected subjects. We present evidence that HLA-A*7401 operates an effect that is independent of HLA-B*5703, with which it is in linkage disequilibrium in some populations, to mediate lowered viremia. We describe a novel statistical approach to detecting additive effects between class I alleles in control of HIV-1 disease, highlighting improved viremic control in subjects with HLA-A*7401 combined with HLA-B*57. In common with HLA-B alleles that are associated with effective control of viremia, HLA-A*7401 presents highly targeted epitopes in several proteins, including Gag, Pol, Rev, and Nef, of which the Gag epitopes appear immunodominant. We identify eight novel putative HLA-A*7401-restricted epitopes, of which three have been defined to the optimal epitope. In common with HLA-B alleles linked with slow progression, viremic control through an HLA-A*7401-restricted response appears to be associated with the selection of escape mutants within Gag epitopes that reduce viral replicative capacity. These studies highlight the potentially important contribution of an HLA-A allele to immune control of HIV infection, which may have been concealed by a stronger effect mediated by an HLA-B allele with which it is in linkage disequilibrium. In addition, these studies identify a factor contributing to different HIV disease outcomes in individuals expressing HLA-B*5703.

Highly active antiretroviral therapy and adverse birth outcomes among HIV-infected women in Botswana.

BACKGROUND: It is unknown whether adverse birth outcomes are associated with maternal highly active antiretroviral therapy (HAART) in pregnancy, particularly in resource-limited settings. METHODS: We abstracted obstetrical records at 6 sites in Botswana for 24 months. Outcomes included stillbirths (SBs), preterm delivery (PTD), small for gestational age (SGA), and neonatal death (NND). Among human immunodeficiency virus (HIV)-infected women, comparisons were limited to HAART exposure status at conception, and those with similar opportunities for outcomes. Comparisons were adjusted for CD4(+) lymphocyte cell count. RESULTS: Of 33,148 women, 32,113 (97%) were tested for HIV, of whom 9504 (30%) were HIV infected. Maternal HIV was significantly associated with SB, PTD, SGA, and NND. Compared with all other HIV-infected women, those continuing HAART from before pregnancy had higher odds of PTD (adjusted odds ratio [AOR], 1.2; 95% confidence interval [CI], 1.1, 1.4), SGA (AOR, 1.8; 95% CI, 1.6, 2.1) and SB (AOR, 1.5; 95% CI, 1.2, 1.8). Among women initiating antiretroviral therapy in pregnancy, HAART use (vs zidovudine) was associated with higher odds of PTD (AOR, 1.4; 95% CI, 1.2, 1.8), SGA (AOR, 1.5; 95% CI, 1.2, 1.9), and SB (AOR, 2.5; 95% CI, 1.6, 3.9). Low CD4(+) was independently associated with SB and SGA, and maternal hypertension during pregnancy with PTD, SGA, and SB. CONCLUSIONS: HAART receipt during pregnancy was associated with increased PTD, SGA, and SB.

Increased risk of preterm delivery among HIV-infected women randomized to protease versus nucleoside reverse transcriptase inhibitor-based HAART during pregnancy.

BACKGROUND: Protease inhibitor (PI)-based highly active antiretroviral therapy (HAART) use in pregnancy has been associated with preterm deliveries in some observational studies. METHODS: HIV-infected, HAART-naive pregnant women with CD4+ counts ≥200 cells/mm(3) were randomized between 26 and 34 weeks gestation to lopinavir/ritonavir/zidovudine/lamivudine (PI group) or abacavir/zidovudine/lamivudine (NRTI group) in a clinical trial to prevent mother-to-child HIV transmission. Risk factors for preterm delivery (<37 weeks) and differences by randomization arm were evaluated for live infants by logistic regression. RESULTS: Preterm delivery rates were higher among 267 women in the PI group than 263 women in the NRTI group (21.4% vs 11.8%, P = .003). PI-based HAART was the most significant risk factor for preterm delivery [odds ratio = 2.03, 95% confidence interval 1.26-3.27, P = .004]. Mean change in maternal body mass index (BMI) 1 month after HAART initiation was lower in the PI group (P < .001); however, this was not significantly associated with preterm delivery. Neither infant hospitalizations nor mortality through 6 months of life differed by maternal regimen. CONCLUSIONS: PI-based HAART was associated with increased preterm delivery but not increased infant hospitalizations or mortality in a clinical trial setting. The association between PI use and lower increase in BMI in late pregnancy warrants further study.

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.

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.

Comparison of guidelines for HIV viral load monitoring among pregnant and breastfeeding women in sub-Saharan Africa.

BACKGROUND: Intensified viral load monitoring for pregnant and breastfeeding women has been proposed to help address concerns around antiretroviral therapy (ART) adherence, viraemia and transmission risk, but there have been no systematic evaluations of existing policies. METHODS: We used an individual Monte Carlo simulation to describe longitudinal ART adherence and viral load from conception until 2 years' postpartum. We applied national and international guidelines for viral load monitoring to the simulated data. We compared guidelines on the percentage of women receiving viral load monitoring and the percentage of women monitored at the time of elevated viral load. RESULTS: Coverage of viral load monitoring in pregnancy and breastfeeding varied markedly, with between 14% and 100% of women monitored antenatally and 38-98% monitored during breastfeeding. Specific recommendations for testing at either a fixed gestation or a short, fixed period after ART initiation achieved more than 95% testing in pregnancy but this was much lower (14-83%) among guidelines with no special stipulations. By the end of breastfeeding, only a small proportion of simulated episodes of elevated viral load more than 1000 copies/ml were successfully detected by monitoring (range, 20-50%). DISCUSSION: Although further research is needed to understand optimal viral load frequency and timing in this population, these results suggest that current policies yield suboptimal detection of elevated viral load in pregnant and breastfeeding women.

Safety and immunogenicity of a live attenuated pentavalent rotavirus vaccine in HIV-exposed infants with or without HIV infection in Africa.

OBJECTIVE: Although many HIV-infected (HIV+) and HIV-exposed but uninfected (HEU) infants have received live rotavirus vaccines since the WHO recommended universal administration of these vaccines to infants, there has been limited prospective information on their safety and immunogenicity in either group of infants. DESIGN/METHODS: We performed a randomized, double-blinded, placebo-controlled trial of the safety and immunogenicity of oral pentavalent rotavirus vaccine (RV5) administered to HIV+ and HEU infants in four African countries. Ninety-three percent of HIV+ infants were receiving antiretroviral therapy prior to vaccination. Participants were followed for safety. Immune responses were measured 14 days after three doses of RV5, including serum antirotavirus neutralizing and IgA antibodies, IgA antibody in stool, and antirotavirus memory B and T-cell FluoroSpot. Shedding of RV5 in stool was monitored. RESULTS: A total of 76 HIV+ and 126 HEU infants were enrolled from 2009 to 2013. No significant differences were found in adverse event rates, including grade 3 events, between RV5 and placebo recipients, for either HIV+ or HEU infants. The proportion of antirotavirus IgA responders (at least three-fold increase from baseline) after RV5 administration was 81% in both HIV+ and HEU infants, which was approximately 2.5-fold higher than in placebo recipients (P < 0.001). Neutralizing antibody responses to three of five serotypes were significantly higher after RV5 regardless of HIV status, and those of HIV+ infants were equal or greater than responses of HEU infants to all five serotypes. Only one HIV+ RV5 recipient had RV5 isolated from stool. CONCLUSION: RV5 was immunogenic in both HIV+ and HEU infants and no safety signals were observed.

B and T Cell Phenotypic Profiles of African HIV-Infected and HIV-Exposed Uninfected Infants: Associations with Antibody Responses to the Pentavalent Rotavirus Vaccine.

We examined associations between B and T cell phenotypic profiles and antibody responses to the pentavalent rotavirus vaccine (RV5) in perinatally HIV-infected (PHIV) infants on antiretroviral therapy and in HIV-exposed uninfected (PHEU) infants enrolled in International Maternal Pediatric Adolescent AIDS Clinical Trials P1072 study (NCT00880698). Of 17 B and T cell subsets analyzed, PHIV and PHEU differed only in the number of CD4+ T cells and frequency of naive B cells, which were higher in PHEU than in PHIV. In contrast, the B and T cell phenotypic profiles of PHIV and PHEU markedly differed from those of geographically matched contemporary HIV-unexposed infants. The frequency of regulatory T and B cells (Treg, Breg) of PHIV and PHEU displayed two patterns of associations: FOXP3+ CD25+ Treg positively correlated with CD4+ T cell numbers; while TGFß+ Treg and IL10+ Treg and Breg positively correlated with the frequencies of inflammatory and activated T cells. Moreover, the frequencies of activated and inflammatory T cells of PHIV and PHEU positively correlated with the frequency of immature B cells. Correlations were not affected by HIV status and persisted over time. PHIV and PHEU antibody responses to RV5 positively correlated with CD4+ T cell counts and negatively with the proportion of immature B cells, similarly to what has been previously described in chronic HIV infection. Unique to PHIV and PHEU, anti-RV5 antibodies positively correlated with CD4+/CD8+FOXP3+CD25+% and negatively with CD4+IL10+% Tregs. In conclusion, PHEU shared with PHIV abnormal B and T cell phenotypic profiles. PHIV and PHEU antibody responses to RV5 were modulated by typical HIV-associated immune response modifiers except for the association between CD4+/CD8+FOXP3+CD25+Treg and increased antibody production.

PARV4 prevalence, phylogeny, immunology and coinfection with HIV, HBV and HCV in a multicentre African cohort.

Background: The seroprevalence of human parvovirus-4 (PARV4) varies considerably by region. In sub-Saharan Africa, seroprevalence is high in the general population, but little is known about the transmission routes or the prevalence of coinfection with blood-borne viruses, HBV, HCV and HIV.  Methods: To further explore the characteristics of PARV4 in this setting, with a particular focus on the prevalence and significance of coinfection, we screened a cohort of 695 individuals recruited from Durban and Kimberley (South Africa) and Gaborone (Botswana) for PARV4 IgG and DNA, as well as documenting HIV, HBV and HCV status.  Results: Within these cohorts, 69% of subjects were HIV-positive. We identified no cases of HCV by PCR, but 7.4% were positive for HBsAg. PARV4 IgG was positive in 42%; seroprevalence was higher in adults (69%) compared to children (21%) (p<0.0001) and in HIV-positive (52%) compared to HIV-negative individuals (24%) (p<0.0001), but there was no association with HBsAg status. We developed an on-line tool to allow visualization of coinfection data (https://purl.oclc.org/coinfection-viz). We identified five subjects who were PCR-positive for PARV4 genotype-3. Ex vivo CD8+ T cell responses spanned the entire PARV4 proteome and we propose a novel HLA-B*57:03-restricted epitope within the NS protein.  Conclusions: This characterisation of PARV4 infection provides enhanced insights into the epidemiology of infection and co-infection in African cohorts, and provides the foundations for planning further focused studies to elucidate transmission pathways, immune responses, and the clinical significance of this organism.

Prevalence and Characteristics of Hepatitis B Virus (HBV) Coinfection among HIV-Positive Women in South Africa and Botswana.

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.

Vitamin D insufficiency in HIV-infected pregnant women receiving antiretroviral therapy is not associated with morbidity, mortality or growth impairment in their uninfected infants in Botswana.

BACKGROUND: Low maternal 25(OH)D (vitamin D) values have been associated with higher mortality and impaired growth among HIV-exposed uninfected (HEU) infants of antiretroviral (ART)-naive women. These associations have not been studied among HEU infants of women receiving ART. METHODS: We performed a nested case-control study in the Botswana Mma Bana Study, a study providing ART to women during pregnancy and breastfeeding. Median maternal vitamin D values, and the proportion with maternal vitamin D insufficiency, were compared between women whose HEU infants experienced morbidity/mortality during 24 months of follow-up and women with nonhospitalized HEU infants. Growth faltering was assessed for never hospitalized infants attending the 24-month-of-life visit. Multivariate logistic regression models determined associations between maternal vitamin D insufficiency and infant morbidity/mortality and growth faltering. RESULTS: Delivery plasma was available and vitamin D levels assayable from 119 (86%) of 139 cases and 233 (84%) of 278 controls, and did not differ significantly between cases and controls [median: 36.7 ng/mL, interquartile range (IQR): 29.1-44.7 vs. 37.1 ng/mL, IQR: 30.0-47.2, P = 0.32]. Vitamin D insufficiency (<32 ng/mL) was recorded among 112 (31.8%) of 352 women at delivery and occurred most frequently among women delivering in winter. Multivariate logistic regression models adjusted for maternal HIV disease progression did not show associations between maternal vitamin D insufficiency at delivery and child morbidity/mortality, or 24-month-of-life growth faltering. CONCLUSIONS: Vitamin D insufficiency was common among ART-treated pregnant women in Botswana, but was not associated with morbidity, mortality or growth impairment in their HIV-uninfected children.

Therapeutic levels of lopinavir in late pregnancy and abacavir passage into breast milk in the Mma Bana Study, Botswana.

BACKGROUND: Pharmacokinetic data for lopinavir in late pregnancy and in breastfeeding are limited, and no data for abacavir in breast milk are available. METHODS: Women in the Mma Bana Study initiated HAART from 18 to 34 weeks of gestation. We determined trough plasma and whole breast milk concentrations of lopinavir (LPV), abacavir (ABC), nevirapine (NVP), lamivudine (3TC) and zidovudine (ZDV) among separate subsets of pregnant and breastfeeding women, and in plasma of exposed infants. Lopinavir was measured 1 month after starting HAART or 1 month postpartum, and other drugs were measured 1 month postpartum. RESULTS: Sampling occurred a median of 14 h (range 11-17) from last maternal drug ingestion. Although 50% higher median LPV levels were seen in postpartum than antepartum plasma (8.29 µg/ml versus 5.51 µg/ml; P = 0.02), antepartum levels with standard LPV dosing were therapeutic for all women (> 1.0 µg/ml). Very low LPV levels (< 0.25 µg/ml) were detected in breast milk. Median ABC levels in breast milk were 85% of those in plasma (0.057 µg/ml versus 0.067 µg/ml). Breast milk concentrations of NVP and 3TC were 27% and 74% of plasma levels, respectively. At these trough maternal time points, only NVP was detectable in potentially inhibitory levels in breastfeeding infants, and most infants had non-detectable levels of LPV, ABC, ZDV and 3TC via maternal breast milk. CONCLUSIONS: Standard LPV dosing achieved therapeutic levels in pregnancy and no appreciable concentrations in breast milk. ABC is detectable in breast milk at similar concentrations to plasma, but does not result in appreciable infant exposure.

HIV transmission and 24-month survival in a randomized trial of HAART to prevent MTCT during pregnancy and breastfeeding in Botswana.

OBJECTIVES: HAART for prevention of mother-to-child HIV transmission (MTCT) may impact long-term survival of women and children. DESIGN: Randomized clinical trial. METHODS: HIV-infected pregnant women with CD4+ cell count at least 200 cells/µl were randomly assigned to abacavir, zidovudine, lamivudine (arm A) or lopinavir­ritonavir, zidovudine­lamivudine (arm B) from week 26 to 34 gestation through planned weaning by 6 months postpartum. Women with baseline CD4+ cell count less than 200 cells/µl received nevirapine­zidovudine­lamivudine indefinitely (Obs arm), as did randomized women later qualifying for treatment. RESULTS: Among 560 randomized and 170 observational women enrolled, there were 14 deaths (1.9%) ­ one antenatally (Obs), three from delivery to 6 months postpartum (1 arm A, 2 Obs), and 10 from 6 to 24 months postpartum (5 arm A, 3 arm B, 2 Obs). Time to death or CD4+ cell count below 200 cells/µl was shorter in arm A vs. B (P = 0.03). Of the 709 live-born children, 97% breastfed for a median of 5.8 months. Of 37 (5.2%) deaths by 24 months, nine were before breastfeeding initiated (3 arm A, 2 arm B, 4 Obs); six while breastfeeding (1 arm A, 2 arm B, 3 Obs); and 22 after weaning (9 arm A, 11 arm B, 2 Obs). Only eight children (1.1%) were HIV-infected at 24 months (6 arm A, 1 arm B, 1 Obs), all before 6 months. CONCLUSION: Low MTCT was maintained through extended follow-up in all arms. Disease progression appeared slower after discontinuing protease inhibitor-based HAART, but a concerning number of maternal deaths occurred after stopping either regimen. Strategies to improve maternal and child survival in the postintervention period are required.

Nef-specific CD8+ T cell responses contribute to HIV-1 immune control.

Recent studies in the SIV-macaque model of HIV infection suggest that Nef-specific CD8+ T-cell responses may mediate highly effective immune control of viraemia. In HIV infection Nef recognition dominates in acute infection, but in large cohort studies of chronically infected subjects, breadth of T cell responses to Nef has not been correlated with significant viraemic control. Improved disease outcomes have instead been associated with targeting Gag and, in some cases, Pol. However analyses of the breadth of Nef-specific T cell responses have been confounded by the extreme immunogenicity and multiple epitope overlap within the central regions of Nef, making discrimination of distinct responses impossible via IFN-gamma ELISPOT assays. Thus an alternative approach to assess Nef as an immune target is needed. Here, we show in a cohort of >700 individuals with chronic C-clade infection that >50% of HLA-B-selected polymorphisms within Nef are associated with a predicted fitness cost to the virus, and that HLA-B alleles that successfully drive selection within Nef are those linked with lower viral loads. Furthermore, the specific CD8+ T cell epitopes that are restricted by protective HLA Class I alleles correspond substantially to effective SIV-specific epitopes in Nef. Distinguishing such individual HIV-specific responses within Nef requires specific peptide-MHC I tetramers. Overall, these data suggest that CD8+ T cell targeting of certain specific Nef epitopes contributes to HIV suppression. These data suggest that a re-evaluation of the potential use of Nef in HIV T-cell vaccine candidates would be justified.

High viral load and elevated angiogenic markers associated with increased risk of preeclampsia among women initiating highly active antiretroviral therapy in pregnancy in the Mma Bana study, Botswana.

BACKGROUND: Risk factors associated with preeclampsia in HIV-infected women remain largely unknown. Systemic angiogenic imbalance contributes to preeclampsia in HIV-uninfected women, but changes in angiogenic markers after highly active antiretroviral therapy (HAART) initiation have not been studied. METHODS: The Mma Bana study randomized 560 HIV-infected, HAART-naive pregnant women with CD4 counts ≥ 200 cells per cubic millimeter between 26 and 34 weeks gestation to lopinavir/ritonavir/zidovudine/lamivudine or abacavir/zidovudine/lamivudine. Another 170 participants with CD4 counts less than 200 cells per cubic millimeter initiated nevirapine/zidovudine/lamivudine between 18 and 34 weeks gestation. Characteristics of 11 women who developed preeclampsia were compared with the remaining 722 Mma Bana participants who delivered using logistic regression. Plasma samples drawn at HAART initiation and 1 month later from 60 women without preeclampsia and at HAART initiation for all 11 preeclamptic women were assayed for placental growth factor (PlGF) and soluble FMS toll-like tyrosine kinase-1 (sFlt-1). RESULTS: Pre-HAART viral load greater than 100,000 copies per milliliter was associated with preeclampsia (odds ratio: 5.8, 95% confidence interval: 1.8 to 19.4, P = 0.004). Median pre-HAART PlGF level was lower and sFlt-1 was higher in women who developed preeclampsia vs those who did not (130 vs 992 pg/mL, P = 0.001; 17.5 vs 9.4 pg/mL, P = 0.03, respectively). In multivariate analysis, PlGF and viral load remained significantly associated with preeclampsia. No significant changes in angiogenic factors were noted after 1 month of HAART treatment among non-preeclamptic women. CONCLUSIONS: Pre-HAART viral load greater than 100,000 copies per milliliter and PlGF predicted preeclampsia among women starting HAART in pregnancy. Among non-preeclamptic women, HAART treatment did not significantly alter levels of PlGF or sFlt-1 after 1 month of treatment.