CD8+ T Cell Breadth and Ex Vivo Virus Inhibition Capacity Distinguish between Viremic Controllers with and without Protective HLA Class I Alleles.

UNLABELLED: The mechanisms of viral control and loss of viral control in chronically infected individuals with or without protective HLA class I alleles are not fully understood. We therefore characterized longitudinally the immunological and virological features that may explain divergence in disease outcome in 70 HIV-1 C-clade-infected antiretroviral therapy (ART)-naive South African adults, 35 of whom possessed protective HLA class I alleles. We demonstrate that, over 5 years of longitudinal study, 35% of individuals with protective HLA class I alleles lost viral control compared to none of the individuals without protective HLA class I alleles (P = 0.06). Sustained HIV-1 control in patients with protective HLA class I alleles was characteristically related to the breadth of HIV-1 CD8(+) T cell responses against Gag and enhanced ability of CD8(+) T cells to suppress viral replication ex vivo In some cases, loss of virological control was associated with reduction in the total breadth of CD8(+) T cell responses in the absence of differences in HIV-1-specific CD8(+) T cell polyfunctionality or proliferation. In contrast, viremic controllers without protective HLA class I alleles possessed reduced breadth of HIV-1-specific CD8(+) T cell responses characterized by reduced ability to suppress viral replication ex vivo These data suggest that the control of HIV-1 in individuals with protective HLA class I alleles may be driven by broad CD8(+) T cell responses with potent viral inhibitory capacity while control among individuals without protective HLA class I alleles may be more durable and mediated by CD8(+) T cell-independent mechanisms. IMPORTANCE: Host mechanisms of natural HIV-1 control are not fully understood. In a longitudinal study of antiretroviral therapy (ART)-naive individuals, we show that those with protective HLA class I alleles subsequently experienced virologic failure compared to those without protective alleles. Among individuals with protective HLA class I alleles, viremic control was associated with broad CD8(+) T cells that targeted the Gag protein, and CD8(+) T cells from these individuals exhibited superior virus inhibition capacity. In individuals without protective HLA class I alleles, HIV-1-specific CD8(+) T cell responses were narrow and poorly inhibited virus replication. These results suggest that broad, highly functional cytotoxic T cells (cytotoxic T lymphocytes [CTLs]) against the HIV-1 Gag protein are associated with control among those with protective HLA class I alleles and that loss of these responses eventually leads to viremia. A subset of individuals appears to have alternative, non-CTL mechanisms of viral control. These controllers may hold the key to an effective HIV vaccine.

Neurodevelopmental outcomes of HIV/antiretroviral drug perinatally exposed uninfected children aged 3-6 years.

OBJECTIVE: Given the roll out of maternal antiretroviral therapy (ART) for prevention-of-perinatal-HIV-transmission, increasing numbers of children are perinatally HIV/antiretroviral exposed but uninfected (CAHEU). Some studies suggest CAHEU may be at increased risk for neurodevelopmental (ND) deficits. We aimed to assess ND performance among preschool CAHEU. DESIGN: This cross-sectional study assessed ND outcomes among 3-6-year-old CAHEU at entry into a multicountry cohort study. METHODS: We used the Mullen Scales of Early Learning (MSEL) and Kaufman Assessment Battery for Children (KABC-II) to assess ND status among 3-6-year-old CAHEU at entry into the PROMISE Ongoing Treatment Evaluation (PROMOTE) study conducted in Uganda, Malawi, Zimbabwe and South Africa. Statistical analyses (Stata 16.1) was used to generate group means for ND composite scores and subscale scores, compared to standardized test score means. We used multivariable analysis to adjust for known developmental risk factors including maternal clinical/socioeconomic variables, child sex, growth-for-age measurements, and country. RESULTS: 1647 children aged 3-6 years had baseline ND testing in PROMOTE; group-mean unadjusted Cognitive Composite scores on the MSEL were 85.8 (standard deviation [SD]: 18.2) and KABC-II were 79.5 (SD: 13.2). Composite score group-mean differences were noted by country, with South African and Zimbabwean children having higher scores. In KABC-II multivariable analyses, maternal age >40 years, lower education, male sex, and stunting were associated with lower composite scores. CONCLUSIONS: Among a large cohort of 3-6 year old CAHEU from eastern/southern Africa, group-mean composite ND scores averaged within the low-normal range; with differences noted by country, maternal clinical and socioeconomic factors.

Contraceptive choices, pregnancy rates, and outcomes in a microbicide trial.

OBJECTIVE: Women who become pregnant during the conduct of biomedical human immunodeficiency virus prevention trials are taken off the study product for safety reasons. High pregnancy rates can compromise statistical integrity in these trials. The comprehensive contraceptive curriculum developed for the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial was evaluated for its ability to enhance contraceptive uptake, reduce pregnancy rates, and preserve statistical integrity. METHODS: Contraceptive- and pregnancy-related eligibility criteria were specified in the protocol. We enrolled women who opted for a nonbarrier method of contraceptive and provided hormonal contraceptives onsite at no cost. At each monthly study visit, we provided pregnancy prevention counseling and performed pregnancy testing. Study product was withheld on pregnancy diagnosis, but women continued with monthly follow-up. RESULTS: Contraceptive use was high throughout the study with 100% uptake at baseline and 94.71% use after a mean of 18 months follow-up at exit. Injectable progestins, particularly medroxyprogesterone acetate, remained the preferred choice of contraceptive. After 30 months of follow-up, 54 pregnancies were reported out of 889 participants, giving a pregnancy incidence rate of 3.95 per 100 woman-years (95% confidence interval 2.96-5.17). Of all pregnancies, two thirds (64.81%) resulted in a full-term live birth, whereas 18.52% and 11.11% pregnancies culminated as miscarriage and terminated pregnancies, respectively. There were no congenital anomalies in the early neonatal period. Pregnancies resulted in 1.56% of woman-years of study follow-up lost as a result of temporary product withdrawal. CONCLUSION: The CAPRISA 004 contraceptive curriculum was an effective strategy for maintaining low pregnancy rates, thereby minimizing product withdrawal and loss of follow-up time. LEVEL OF EVIDENCE: III.

Co-enrollment in multiple HIV prevention trials - experiences from the CAPRISA 004 Tenofovir gel trial.

BACKGROUND: In settings where multiple HIV prevention trials are conducted in close proximity, trial participants may attempt to enroll in more than one trial simultaneously. Co-enrollment impacts on participant's safety and validity of trial results. We describe our experience, remedial action taken, inter-organizational collaboration and lessons learnt following the identification of co-enrolled participants. EXPERIENCES: Between February and April 2008, we identified 185 of the 398 enrolled participants as ineligible. In violation of the study protocol exclusion criteria, there was simultaneous enrollment in another HIV prevention trial (ineligible co-enrolled, n=135), and enrollment of women who had participated in a microbicide trial within the past 12 months (ineligible not co-enrolled, n=50). Following a complete audit of all enrolled participants, ineligible participants were discontinued via study exit visits from trial follow-up. Custom-designed education program on co-enrollment impacting on participants' safety and validity of the trial results was implemented. Shared electronic database between research units was established to enable verification of each volunteer's trial participation and to prevent future co-enrollments. LESSONS LEARNT: Interviews with ineligible enrolled women revealed that high-quality care, financial incentives, altruistic motives, preference for sex with gel, wanting to increase their likelihood of receiving active gel, perceived low risk of discovery and peer pressure are the reasons for their enrollment in the CAPRISA 004 trial. CONCLUSION: Instituting education programs based on the reasons reported by women for seeking enrollment in more than one trial and using a shared central database system to identify co-enrollments have effectively prevented further co-enrollments.

Recruitment of high risk women for HIV prevention trials: baseline HIV prevalence and sexual behavior in the CAPRISA 004 tenofovir gel trial.

BACKGROUND: Young women in sub-Saharan Africa bear a disproportionate burden of HIV infection compared to men but have limited options to reduce their HIV risk. Microbicides could fill an important HIV prevention gap for sexually active women who are unable to successfully negotiate mutual monogamy or condom use. PURPOSE: This paper describes the baseline sample characteristics in the CAPRISA 004 trial which assessed the safety and effectiveness of the vaginal microbicide, 1% tenofovir gel for HIV prevention in South Africa. METHODS: This analysis assessed the baseline demographic, clinical and sexual behavior data of women screened and enrolled into the trial. The characteristics were summarized using descriptive summary measures; expressed as means and percent for categorical variables. RESULTS: HIV prevalence at screening was 25.8% [95% Confidence Interval (CI):23.9-27.7). Of the 889 eligibly enrolled women who contributed follow-up data, rural participants recruited from a family planning (FP) clinic were younger, more likely to be living apart from their regular partner, reported lower coital frequency, had lower condom use (p < 0.001). In contrast, urban participants recruited from a sexually transmitted disease (STD) clinic reported higher numbers of lifetime sexual partners, new partners in the last 30 days and receiving money in exchange for sex (p < 0.001). CONCLUSION: The populations selected provide suitable diverse target groups for HIV prevention intervention studies. TRIAL REGISTRATION: ClinicalTrials.gov: NCT 00441298.