HIV Sexual Risk and Syndemics among Women in Three Urban Areas in the United States: Analysis from HVTN 906.

Limited data are available on the longitudinal occurrence of syndemic factors among women at risk for HIV infection in the USA and how these factors relate to sexual risk over time. HVTN 906 was a longitudinal study enrolling 799 HIV-uninfected women in three cities. Assessments were done at baseline, 6, 12, and 18 months to assess syndemic factors (low education, low income, unemployment, lack of health insurance, housing instability, substance use, heavy alcohol use, partner violence, incarceration) and sexual risk outcomes. For each sexual risk outcome, a GEE model was fit with syndemic factors or syndemic score (defined as sum of binary syndemics, ranging from 0 to 9), visit, study site, age and race/ethnicity as predictors to examine the multivariable association between syndemic factors and outcomes over time. Odds of unprotected sex while drunk or high were significantly higher when women reported lack of health insurance, substance and heavy alcohol use and partner violence. Housing instability, substance and heavy alcohol use, partner violence and recent incarceration were associated with higher odds of having multiple sexual partners. Odds of sex exchange were significantly higher in the presence of unemployment, housing instability, low education, lack of health insurance, substance and heavy alcohol use, partner violence and incarceration. Housing instability, substance and heavy alcohol use, and partner violence were significantly associated with higher odds of unprotected anal sex. Odds of having a recent STI were significantly higher when women reported housing instability and partner violence. There were significantly higher odds of the reporting of any risk outcomes during follow-up with higher syndemic score. This study highlights a group of women experiencing multiple poor social and health outcomes who need to be the focus of comprehensive interventions.

Feasibility of identifying a cohort of US women at high risk for HIV infection for HIV vaccine efficacy trials: longitudinal results of HVTN 906.

BACKGROUND: Identifying cohorts of US women with HIV infection rates sufficient for inclusion in vaccine efficacy trials has been challenging. Using geography and sexual network characteristics to inform recruitment strategies, HVTN 906 determined the feasibility of recruiting a cohort of women at high risk for HIV acquisition. METHODS: HIV uninfected women who reported unprotected sex in the prior 6 months, resided or engaged in risk behavior in local geographical high-risk pockets and/or had a male partner who had been incarcerated, injected drugs, or had concurrent partners were eligible. Behavioral risk assessment, HIV counseling and testing, and pregnancy testing were done at baseline, 6, 12, and 18 months. RESULTS: Among 799 women, 71% were from local high-risk pockets and had high-risk male partners. Median age was 37 years; 79% were Black; and 15% Latina. Over half (55%) reported a new partner in the prior 6 months, 57% reported a male partner who had concurrent female sexual partners, and 37% reported a male partner who had been incarcerated. Retention at 18 months was 79.5%. Annual pregnancy incidence was 12%. Annual HIV incidence was 0.31% (95% confidence interval: 0.06% to 0.91%). Risk behaviors decreased between screening and 6 months with smaller changes thereafter. DISCUSSION: This cohort of women recruited using new strategies based on geography and sexual network characteristics did not have an HIV incidence high enough for HIV vaccine efficacy trials, despite high baseline levels of risk and a high pregnancy rate. New strategies to identify cohorts of US women for efficacy trials are needed.

Recruitment of urban US women at risk for HIV infection and willingness to participate in future HIV vaccine trials.

Enrollment of US women with sufficient risk of HIV infection into HIV vaccine efficacy trials has proved challenging. A cohort of 799 HIV-negative women, aged 18-45, recruited from three US cities was enrolled to assess recruitment strategies based on geographic risk pockets, social and sexual networks and occurrence of sexual concurrency and to assess HIV seroincidence during follow-up (to be reported later). Among enrolled women, 90 % lived or engaged in risk behaviors within a local risk pocket, 64 % had a male partner who had concurrent partners and 50 % had a male partner who had been recently incarcerated. Nearly half (46 %) were recruited through peer referral. At enrollment, 86 % of women said they were willing to participate in a vaccine efficacy trial. Results indicate that participant and partner risk behaviors combined with a peer referral recruitment strategy may best identify an at-risk cohort willing to participate in future trials.

Mucosal HIV-binding antibody and neutralizing activity in high-risk HIV-uninfected female participants in a trial of HIV-vaccine efficacy.

BACKGROUND: This study investigated gp120-binding antibody and neutralizing activity, at the gingival- and cervical-mucosal levels, in response to a bivalent gp120 candidate vaccine. METHODS: Women who met the study's inclusion criteria for documented high-risk behaviors participated in a nested substudy of the multicenter phase 3 trial of human immunodeficiency virus (HIV)-vaccine efficacy, VAX004. Gingival, cervicovaginal lavage, and plasma specimens were collected at 6-month intervals for 3 years. Binding-antibody and neutralizing-activity assays quantified the presence of anti-HIV activity in mucosal specimens. RESULTS: Vaccine recipients were more likely than placebo recipients to have IgG binding antibodies in all 3 compartments tested and to have only IgA binding antibody in plasma (P<.0001). The relationship between vaccine and cervicovaginal IgG achieved significance (odds ratio [OR], 6.6 [P=.01]) but was weakened by the presence of cervicovaginal leukocytes. There was no relationship between immunization and the presence of neutralizing activity, in either bivariate or multivariate modeling (OR, 6.0 [P=.29]). CONCLUSIONS: Vaccination is associated with the presence of both gp120-binding IgG in all compartments and plasma IgA but not with neutralizing activity. There is a role for the measurement of mucosal immunity in response to candidate vaccines and, in particular, for a determination of HIV-specific neutralizing antibodies.

Cervicovaginal levels of lactoferrin, secretory leukocyte protease inhibitor, and RANTES and the effects of coexisting vaginoses in human immunodeficiency virus (HIV)-seronegative women with a high risk of heterosexual acquisition of HIV infection.

Innate immune factors in mucosal secretions may influence human immunodeficiency virus type 1 (HIV-1) transmission. This study examined the levels of three such factors, genital tract lactoferrin [Lf], secretory leukocyte protease inhibitor [SLPI], and RANTES, in women at risk for acquiring HIV infection, as well as cofactors that may be associated with their presence. Women at high risk for HIV infection meeting established criteria (n = 62) and low-risk controls (n = 33) underwent cervicovaginal lavage (CVL), and the CVL fluid samples were assayed for Lf and SLPI. Subsets of 26 and 10 samples, respectively, were assayed for RANTES. Coexisting sexually transmitted infections and vaginoses were also assessed, and detailed behavioral information was collected. Lf levels were higher in high-risk (mean, 204 ng/ml) versus low-risk (mean, 160 ng/ml, P = 0.007) women, but SLPI levels did not differ, and RANTES levels were higher in only the highest-risk subset. Lf was positively associated only with the presence of leukocytes in the CVL fluid (P < 0.0001). SLPI levels were lower in women with bacterial vaginosis [BV] than in those without BV (P = 0.04). Treatment of BV reduced RANTES levels (P = 0.05). The influence, if any, of these three cofactors on HIV transmission in women cannot be determined from this study. The higher Lf concentrations observed in high-risk women were strongly associated with the presence of leukocytes, suggesting a leukocyte source and consistent with greater genital tract inflammation in the high-risk group. Reduced SLPI levels during BV infection are consistent with an increased risk of HIV infection, which has been associated with BV. However, the increased RANTES levels in a higher-risk subset of high-risk women were reduced after BV treatment.

Mucosal innate immune factors in secretions from high-risk individuals immunized with a bivalent gp120 vaccine.

This study examined the effect of an HIV vaccine on mucosal innate factor expression. Serum, gingival fluid, and genital mucosal secretions were collected from high-risk women and men enrolled in an HIV-1 efficacy vaccine trial and from low-risk women and men. Samples were tested by standard ELISA for lactoferrin, myeloid-related protein-8/14, and secretory leukocyte protease inhibitor. No consistent significant changes in innate factor levels were found in serum or secretions from vaccinees compared to placebo recipients or from high-risk compared to low-risk individuals. Because of the importance of innate immunity in host defense, evaluation of the mucosal innate immune system should be included in future HIV prevention trials.

Human cervicovaginal lavage fluid contains an inhibitor of HIV binding to dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin.

A small percentage of women at high risk for human immunodeficiency virus (HIV) exposure remain uninfected for long periods, protected by unknown mechanisms. We hypothesized that one mechanism could be inhibition of interactions between HIV and dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) in the genital tract. In an analysis of 95 cervicovaginal lavage samples, we found that 12 (12.6%) strongly inhibited the binding of laboratory-adapted and primary HIV-1 isolates to B-THP-1/DC-SIGN cells in a dose-dependent manner, independently of the donor's risk of exposure. Three of 5 primary isolates were also blocked from binding to primary DCs. The inhibitor has a high molecular weight, is heat stable, and is resistant to trypsin. It is sensitive to pronase and periodate, indicating that it is likely a glycoprotein. Mannosidase digestion and concanavalin A adsorption indicate that the terminal residues of the carbohydrate are not mannose. Mechanistic experiments indicate that the inhibitor acts via binding to DC-SIGN. Further study of such inhibitors may help to elucidate the role played by DC-SIGN in HIV transmission.

Induction of tumor necrosis factor- alpha secretion and toll-like receptor 2 and 4 mRNA expression by genital mucosal fluids from women with bacterial vaginosis.

BACKGROUND: Bacterial vaginosis (BV) is associated with complications of pregnancy and increased susceptibility to human immunodeficiency virus (HIV) sexual transmission. METHODS: The ability of genital mucosal fluids from women with BV and of microbial flora associated with BV to induce tumor necrosis factor (TNF)- alpha secretion and Toll-like receptor (TLR) 2 and TLR4 mRNA expression was assessed. RESULTS: Primary peripheral-blood mononuclear cells and THP-1 monocytic cells secreted TNF- alpha in response to cervicovaginal lavage (CVL) samples from women with BV. Mycoplasma hominis and Gardnerella vaginalis also stimulated TNF- alpha secretion. Strikingly, CVL samples from women with BV induced up to 60-fold increases in TLR4 mRNA expression, compared with CVL samples from women without BV and with bacteria not associated with BV. Anti-TNF- alpha antibody blocked increases in TLR4 mRNA expression induced by CVL samples from women with BV, indicating that TNF- alpha plays a critical role in induction of TLR4. Both TLR2 and TLR4 mRNA expression were approximately 60-fold higher in cells isolated from the lumen of the genital tract than in cervical mucosal tissue, but lumen TLR mRNA levels did not change significantly after BV treatment. CONCLUSIONS: These experiments show that genital mucosal fluids and certain bacteria from women with BV stimulate TNF- alpha secretion and TLR4 mRNA expression, suggesting mechanisms whereby BV affects pregnancy and HIV transmission.

Trichomonas vaginalis infection activates cells through toll-like receptor 4.

While Trichomonas vaginalis infection can cause inflammation and influx of leukocytes into the female genital tract, the molecular pathways important in inducing these effects are not known. This study determined if infection with T. vaginalis activates cells through toll-like receptor 4 (TLR4). Genital tract secretions from infected women stimulated TNF-alpha production by cells with functional TLR4 (350 pg/ml) but significantly less by cells that are unresponsive to TLR4 ligands (44 pg/ml, P = 0.001). Secretions collected after clearance of infection also induced significantly lower responses by cells with functional TLR4 (136 pg/ml, P = 0.008). TNF-alpha responses were not reduced by Polymyxin B and did not correlate with beta(2)-defensin levels, indicating that stimulation of cells was not through lipopolysaccharide or beta(2)-defensin. These studies show that T. vaginalis infection results in the appearance in the genital tract of substance(s) that stimulate cells through TLR4, suggesting a mechanism for the inflammation caused by this infection.