Longitudinal Assessment of Systemic and Genital Tract Inflammatory Markers and Endogenous Genital Tract E. coli Inhibitory Activity in HIV-Infected and Uninfected Women

PROBLEM

Stability over time of systemic and mucosal immunity and their associations with bacterial vaginosis (BV) and HIV-specific parameters were assessed.

METHOD OF STUDY

Immune mediators and HIV viral load in plasma and cervicovaginal lavage (CVL), E. coli inhibition, and Nugent score were measured at three semiannual visits among 94 participants in the Women's Interagency HIV Study. Mixed models identified the factors associated with immune mediators.

RESULTS

There was higher E. coli inhibition and lower inflammation over time in the genital tract and systemically. BV was consistently associated with higher CVL inflammatory mediators and lower CVL E. coli inhibition. HIV-infected women with higher CD4 counts had lower systemic and genital inflammatory mediators, and genital HIV shedding was associated with higher CVL inflammatory mediators. Use of antiretroviral therapy (ART) was associated with lower plasma and CVL mediators, but higher E. coli inhibition.

CONCLUSION

HIV and BV are linked to inflammation, and ART may be associated with improved vaginal health.

Loss of Innate Host Defense Following Unprotected Vaginal Sex

BACKGROUND

Multiple host defense mechanisms protect the female genital tract from pathogens, but the impact of sexual intercourse on defense is unknown.

METHODS

As part of a hypothesis-generating study, 17 women provided cervicovaginal lavage (CVL) specimens at baseline (all had abstained from sexual intercourse, masturbation, and vaginal product use for 72 hours prior to screening), 2-6 hours and 10-14 hours after vaginal intercourse with a male condom, and 2-6 hours and 10-14 hours after vaginal intercourse without a male condom (5 visits total, including the baseline visit). Vaginal pH, concentrations of immune molecules, and antimicrobial activity at postcoital visits were compared to baseline values.

RESULTS

Vaginal pH and the transforming growth factor β1 level increased, but human beta-defensin 2 (HBD-2), HBD-3, and interleukin 8 levels decreased after unprotected sex. Median Escherichia coli inhibitory activity in CVL specimens decreased significantly from baseline at the visit 2-6 hours after unprotected sex (63% [range, -34% to 99%] vs 5% [range, -51% to 100%]; P = .02) and remained low at the visit 10-14 hours after unprotected sex (6% [range, -19% to 92%]; P = .02). Pooled human seminal plasma enhanced E. coli growth in vitro in a dose-dependent manner and, when added to CVL samples with high anti-E. coli activity, reversed the inhibition.

CONCLUSIONS

Unprotected vaginal sex results in a reduction in endogenous anti-E. coli activity, which may reflect, in part, enhancement of bacterial growth by seminal plasma. This finding may contribute to the risk of E. coli vaginal colonization following sexual intercourse.

Screening for Human Papillomavirus-Associated Cervical Disease in HIV-Infected Women

HIV-infected women have higher rates of persistence of human papillomavirus (HPV) infection, of abnormal cervical cytology results, and of cervical cancer than uninfected women. It is currently recommended that HIV-infected, sexually active women have a Papanicolaou (Pap) test performed at the time of initial diagnosis of HIV infection, followed by annual Pap testing if the previous test result is normal. Women whose test results show abnormalities greater than atypical squamous cells of undetermined significance (ASCUS) should be referred for colposcopy. Those with ASCUS should undergo immediate colposcopy or repeat cervical cytology in 6 months to 12 months, and those whose repeat cervical cytology results show ASCUS or greater abnormalities should undergo colposcopy. Recent findings indicate that screening intervals can be lengthened for HIV-infected women whose Pap test results are persistently normal and who are engaged in routine care, and that HPV DNA testing may have a role in screening. This article summarizes a presentation by Marla J. Keller, MD, at the IAS-USA continuing education program, Improving the Management of HIV Disease, held in Atlanta, Georgia, in March 2015.

Cervical Precancer Risk in HIV-Infected Women Who Test Positive for Oncogenic Human Papillomavirus Despite a Normal Pap Test

BACKGROUND

Determining cervical precancer risk among human immunodeficiency virus (HIV)-infected women who despite a normal Pap test are positive for oncogenic human papillomavirus (oncHPV) types is important for setting screening practices.

METHODS

A total of 2791 HIV-infected and 975 HIV-uninfected women in the Women's Interagency HIV Study were followed semiannually with Pap tests and colposcopy. Cumulative risks of cervical intraepithelial neoplasia grade 2 or greater (CIN-2+; threshold used for CIN treatment) and grade 3 or greater (CIN-3+; threshold to set screening practices) were measured in HIV-infected and HIV-uninfected women with normal Pap tests, stratified by baseline HPV results, and also in HIV-infected women with a low-grade squamous intraepithelial lesion (LSIL; benchmark indication for colposcopy).

RESULTS

At baseline, 1021 HIV-infected and 518 HIV-uninfected women had normal Pap tests, of whom 154 (15%) and 27 (5%), respectively, tested oncHPV positive. The 5-year CIN-2+ cumulative risk in the HIV-infected oncHPV-positive women was 22% (95% confidence interval [CI], 9%-34%), 12% (95% CI, 0%-22%), and 14% (95% CI, 2%-25%) among those with CD4 counts <350, 350-499, and ≥500 cells/µL, respectively, whereas it was 10% (95% CI, 0%-21%) in those without HIV. For CIN-3+, the cumulative risk averaged 4% (95% CI, 1%-8%) in HIV-infected oncHPV-positive women, and 10% (95% CI, 0%-23%) among those positive for HPV type 16. In HIV-infected women with LSIL, CIN-3+ risk was 7% (95% CI, 3%-11%). In multivariate analysis, HIV-infected HPV16-positive women had 13-fold (P = .001) greater CIN-3+ risk than oncHPV-negative women (referent), and HIV-infected women with LSIL had 9-fold (P < .0001) greater risk.

CONCLUSIONS

HIV-infected women with a normal Pap result who test HPV16 positive have high precancer risk (similar to those with LSIL), possibly warranting immediate colposcopy. Repeat screening in 1 year may be appropriate if non-16 oncHPV is detected.

Nevirapine Concentration in Hair Samples Is a Strong Predictor of Virologic Suppression in a Prospective Cohort of HIV-Infected Patients

Effective antiretroviral (ARV) therapy depends on adequate drug exposure, yet methods to assess ARV exposure are limited. Concentrations of ARV in hair are the product of steady-state pharmacokinetics factors and longitudinal adherence. We investigated nevirapine (NVP) concentrations in hair as a predictor of treatment response in women receiving ARVs. In participants of the Women’s Interagency HIV Study, who reported NVP use for >1 month from 2003–2008, NVP concentrations in hair were measured via liquid-chromatography-tandem mass-spectrometry. The outcome was virologic suppression (plasma HIV RNA below assay threshold) at the time of hair sampling and the primary predictor was nevirapine concentration categorized into quartiles. We controlled for age, race/ethnicity, pre-treatment HIV RNA, CD4 cell count, and self-reported adherence over the 6-month visit interval (categorized ≤ 74%, 75%–94% or ≥ 95%). We also assessed the relation of NVP concentration with changes in hepatic transaminase levels via multivariate random intercept logistic regression and linear regression analyses. 271 women contributed 1089 person-visits to the analysis (median 3 of semi-annual visits). Viral suppression was least frequent in concentration quartile 1 (86/178 (48.3%)) and increased in higher quartiles (to 158/204 (77.5%) for quartile 4). The odds of viral suppression in the highest concentration quartile were 9.17 times (95% CI 3.2–26, P < 0.0001) those in the lowest. African-American race was associated with lower rates of virologic suppression independent of NVP hair concentration. NVP concentration was not significantly associated with patterns of serum transaminases. Concentration of NVP in hair was a strong independent predictor of virologic suppression in women taking NVP, stronger than self-reported adherence, but did not appear to be strongly predictive of hepatotoxicity.

TLR7 induces anergy in human CD4(+) T cells

The recognition of microbial patterns by Toll-like receptors (TLRs) is critical for activation of the innate immune system. Although TLRs are expressed by human CD4(+) T cells, their function is not well understood. Here we found that engagement of TLR7 in CD4(+) T cells induced intracellular calcium flux with activation of an anergic gene-expression program dependent on the transcription factor NFATc2, as well as unresponsiveness of T cells. As chronic infection with RNA viruses such as human immunodeficiency virus type 1 (HIV-1) induces profound dysfunction of CD4(+) T cells, we investigated the role of TLR7-induced anergy in HIV-1 infection. Silencing of TLR7 markedly decreased the frequency of HIV-1-infected CD4(+) T cells and restored the responsiveness of those HIV-1(+) CD4(+) T cells. Our results elucidate a previously unknown function for microbial pattern-recognition receptors in the downregulation of immune responses.

Long-term cumulative detection of human papillomavirus among HIV seropositive women

OBJECTIVE

To estimate the effects of infection by HIV on the type-specific cumulative detection of cervicovaginal infection by human papillomavirus (HPV).

DESIGN

Retrospective assessment of prospectively collected data in a multicenter US cohort.

METHODS

HIV-seropositive and at-risk seronegative participants in the Women's Interagency HIV Study were followed semiannually for up to 11 years. HPV typing was determined from cervicovaginal lavage specimens by PCR; types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68 were considered carcinogenic.

RESULTS

Among the 3438 women enrolled (2543 HIV-seropositive, 895 seronegative), the cumulative detection of any HPV infection rose among HIV-seropositive women from 53% at baseline to 92% at 8 years, and among seronegative women from 22 to 66% (P < 0.0001 for HIV-seropositive vs. seronegative women). The 8-year cumulative detection of carcinogenic and noncarcinogenic HPV was 67 and 89% among HIV-seropositive, and 36 and 56% among seronegative women (P = 0.001 for both carcinogenic and noncarcinogenic HPV). The 8-year cumulative detection of HPV16 and HPV18 was 15.2 and 15.0% in HIV-seropositive, and 6.7 and 6.1% in HIV-seronegative women (P < 0.0001 for both). In multivariable regression analyses, lower CD4(+) cell count, age under 30 years, and smoking, but not number of lifetime sexual partners, were significant correlates of cumulative HPV detection.

CONCLUSION

More than 90% of the HIV-seropositive women have HPV detected during a long follow-up. The rates are lower among at-risk HIV-seronegative women, though most also develop HPV infections.

Plasmodium falciparum Infection Does Not Affect Human Immunodeficiency Virus Viral Load in Coinfected Rwandan Adults

In contrast to prior studies, mild malaria infection had no impact on HIV Viral Loads(VL) in Rwanda. Over fifty percent of patients prescribed ARV had detectable VL; 25% had genotypic resistance. Eleven percent of patients with mild malaria were newly diagnosed with HIV.

Background

 Plasmodium falciparum infection has been reported to increase human immunodeficiency virus (HIV) viral load (VL), which can facilitate HIV transmission. We prospectively studied the impact of mild P falciparum coinfection on HIV VL in Rwanda.

Methods

 We measured plasma HIV VL at presentation with malaria infection and weekly for 4 weeks after artemether-lumefantrine treatment in Rwandan adults infected with HIV with P falciparum malaria. Regression analyses were used to examine associations between malaria infection and HIV VL changes. Samples with detectable virus underwent genotypic drug-resistance testing.

Results

 We enrolled 28 HIV-malaria coinfected patients and observed 27 of them for 5 weeks. Three patients (11%) were newly diagnosed with HIV. Acute P falciparum infection had no significant effect on HIV VL slope over 28 days of follow-up. Ten patients with VL <40 copies/mL at enrollment maintained viral suppression throughout. Seventeen patients had a detectable VL at enrollment including 9 (53%) who reported 100% adherence to ARVs; 3 of these had detectable genotypic drug resistance.

Conclusions

 Unlike studies from highly malaria-endemic areas, we did not identify an effect of P falciparum infection on HIV VL; therefore, malaria is not likely to increase HIV-transmission risk in our setting. However, routine HIV testing should be offered to adults presenting with acute malaria in Rwanda. Most importantly, we identified a large percentage of patients with detectable HIV VL despite antiretroviral (ARV) therapy. Some of these patients had HIV genotypic drug resistance. Larger studies are needed to define the prevalence and factors associated with detectable HIV VL in patients prescribed ARVs in Rwanda.

Use of the dye stain assay and ultraviolet light test for assessing vaginal insertion of placebo-filled applicators before and after sex

BACKGROUND

Applicator dye staining and ultraviolet (UV) light have been used in trials to measure adherence, but not in the setting of before and after sex gel dosing (BAT-24). This study was designed to determine if semen or presex gel dosing impacts the sensitivity and specificity of a dye stain assay (DSA) for measuring vaginal insertion of placebo-filled applicators with BAT-24 dosing.

METHODS

Healthy monogamous couples received Microlax-type applicators (Tectubes, Åstorp, Sweden) filled with hydroxyethylcelluose placebo gel. Women were instructed to vaginally insert 1 dose of gel before and a second dose after sex and to return applicators within 48 hours after sex. Applicators were stained to detect semen, followed by UV then DSA, and scored by 2 readers. Positive and negative controls were randomly included in applicator batches.

RESULTS

Fifteen couples completed the study. Each woman returned at least 6 applicators over a 30-day period. The sensitivity for insertion of postsex applicators was higher for UV (97%) compared with DSA (90%), and the specificity was similar (≥96%). For presex applicators, the sensitivity and specificity were higher for DSA (100%) compared with UV testing (87% sensitivity, 96% specificity). Among returned postsex applicators, 95% tested positive by UV compared with 87% by DSA. Agreement between readers was significantly better on the presex applicators for DSA than for UV, and for postsex readings, agreement was less than half that for UV, although the results were not statistically significant.

CONCLUSIONS

Applicator tests are feasible for measuring adherence in trials with gel dosing before and after sex.

Evaluation of 3 approaches for assessing adherence to vaginal gel application in clinical trials

BACKGROUND

Accurate measurement of adherence to product use is an ongoing challenge in microbicide trials.

METHODS

We compared adherence estimates using 2 applicator tests (a dye stain assay [DSA] and an ultraviolet light assay [UVA]), the Wisebag (an applicator container that electronically tracks container openings), and self-reported adherence (ability, frequency, and percent missed doses). Healthy, HIV-negative, nonpregnant US women aged 23 to 45 years received a Wisebag and 32 applicators filled with placebo gel were instructed to insert 1 applicator daily for 30 days, returned the Wisebag and all applicators, and completed an exit interview. Emptied applicators were tested by UVA and then DSA, and scored by 2 blinded readers. Positive and negative controls were randomly included in applicator batches.

RESULTS

Among 42 women enrolled, 39 completed the study. Both DSA and UVA yielded similar sensitivity (97% and 95%) and specificity (79% and 79%). Two participants had fully inoperable Wisebags, and 9 had partially inoperable Wisebags. The proportion of participants considered to have high adherence (≥80%) varied: 43% (Wisebag), 46% (UVA), 49% (DSA), and 62% to 82% (self-reports). For estimating high adherence, Wisebag had a sensitivity of 76% (95% confidence interval, 50%-93%) and a specificity of 85% (95% confidence interval, 62%-97%) compared with DSA. Although 28% of participants reported forgetting to open the Wisebag daily, 59% said that it helped them remember gel use.

CONCLUSIONS

Dye stain assay and UVA performed similarly. Compared with these tests, self-reports overestimated and Wisebag underestimated adherence. Although Wisebag may encourage gel use, the applicator tests currently seem more useful for measuring use in clinical trials.

Trends in contraceptive use among women with human immunodeficiency virus

OBJECTIVE

To estimate trends in contraceptive use, especially long-acting reversible contraceptives (LARCs) and condoms, among human immunodeficiency virus (HIV)-seropositive and HIV-seronegative women.

METHODS

Human immunodeficiency virus-seropositive and HIV-seronegative women in a multicenter longitudinal cohort were interviewed semiannually between 1998 and 2010 about sexual behaviors and contraceptive use. Trends in contraceptive use by women aged 18-45 years who were at risk for unintended pregnancy but not trying to conceive were analyzed using generalized estimating equations.

RESULTS

Condoms were the dominant form of contraception for HIV-seropositive women and showed little change across time. Less than 15% of these women used no contraception. Between 1998 and 2010, LARC use increased among HIV-seronegative women from 4.8% (6 of 126) to 13.5% (19 of 141, P=.02), but not significantly among seropositive women (0.9% [4 of 438] to 2.8% [6 of 213], P=.09). Use of highly effective contraceptives, including pills, patches, rings, injectable progestin, implants, and intrauterine devices, ranged from 15.2% (53 of 348) in 1998 to 17.4% (37 of 213) in 2010 (P=.55). Human immunodeficiency virus-seronegative but not HIV-seropositive LARC users were less likely than nonusers to use condoms consistently (hazard ratio 0.51, 95% confidence interval [CI] 0.32-0.81, P=.004 for seronegative women; hazard ratio 1.09, 95% CI 0.96-1.23 for seropositive women).

CONCLUSION

Although most HIV-seropositive women use contraception, they rely primarily on condoms and have not experienced the increase in LARC use seen among seronegative women. Strategies to improve simultaneous use of condoms and LARC are needed to minimize risk of unintended pregnancy as well as HIV transmission and acquisition of sexually transmitted infections.

LEVEL OF EVIDENCE

II.

Lactobacillus proteins are associated with the bactericidal activity against E. coli of female genital tract secretions

BACKGROUND

Female genital tract secretions are bactericidal for Escherichia (E.) coli ex vivo. However, the intersubject variability and molecules that contribute to this activity have not been defined.

METHODS

The bactericidal activity and concentration of immune mediators in cervicovaginal lavage (CVL) collected from 99 healthy women were determined.

RESULTS

CVL reduced the number of E. coli colonies by 68% [-26, 100] (median [range]). CVL were active against laboratory and clinical isolates of E. coli, but were inactive against Lactobacillus species. Bactericidal activity correlated with the concentration of protein recovered (p<0.001), but not with cytokines, chemokines or antimicrobial peptides. Four CVL with>90% inhibitory activity (active) and two with<30% activity were subjected to MS/MS proteomic analysis. 215 proteins were identified and six were found exclusively in active samples. Four of these corresponded to Lactobacillus crispatus or jensenii proteins. Moreover, culture supernatants from Lactobacillus jensenii were bactericidal for E. coli.

CONCLUSION

Both host and commensal microbiota proteins contribute to mucosal defense. Identification of these proteins will facilitate the development of strategies to maintain a healthy vaginal microbiome and prevent colonization with pathogenic bacteria such as E. coli that increase the risk for urinary tract infections, preterm labor and perinatal infection.

Phase I randomized safety study of twice daily dosing of acidform vaginal gel: candidate antimicrobial contraceptive

Background

Acidform gel, an acid-buffering product that inactivates spermatozoa, may be an effective topical non-hormonal contraceptive. This study was designed to evaluate the safety of vaginal dosing and effects of Acidform on mucosal immune mediators, antimicrobial properties of genital secretions, and vaginal microbiota.

Methods

Thirty-six sexually abstinent U.S. women were randomized to apply Acidform or hydroxyethylcellulose (HEC) placebo gel twice daily for 14 consecutive days. Safety was assessed by symptoms and pelvic examination. The impact of gel on mucosal immunity was assessed by quantifying cytokines, chemokines, antimicrobial proteins and antimicrobial activity of genital secretions collected by cervicovaginal lavage (CVL) at screening, 2 hours after gel application, and on days 7, 14 and 21. Vaginal microbiota was characterized at enrollment and day 14 using species-specific quantitative PCR assays.

Results

The median vaginal and cervical pH was significantly lower 2 hours after application of Acidform and was associated with an increase in the bactericidal activity of CVL against E. coli. However, 65% of women who received Acidform had at least one local adverse event compared with 11% who received placebo (p = 0.002). While there was no increase in inflammatory cytokines or chemokines, CVL concentrations of lactoferrin and interleukin-1 receptor antagonist (IL-1ra), an anti-inflammatory protein, were significantly lower following Acidform compared to HEC placebo gel application. There were no significant changes in Lactobacillus crispatus or Lactobacillus jensenii in either group but there was a decrease in Gardnerella vaginalis in the Acidform group (p = 0.08).

Conclusions

Acidform gel may augment mucosal defense as evidenced by an increase in bactericidal activity of genital secretions against E. coli and a decrease in Gardnerella vaginalis colonization. However, Acidform was associated with more irritation than placebo and lower levels of antimicrobial (lactoferrin) and anti-inflammatory (IL-1ra) proteins. These findings indicate the need for additional safety studies of this candidate non-hormonal contraceptive.

Trial Registration

ClinicalTrials.gov NCT00850837

Risk of cervical precancer and cancer among HIV-infected women with normal cervical cytology and no evidence of oncogenic HPV infection

CONTEXT

US cervical cancer screening guidelines for human immunodeficiency virus (HIV)-uninfected women 30 years or older have recently been revised, increasing the suggested interval between Papanicolaou (Pap) tests from 3 years to 5 years among those with normal cervical cytology (Pap test) results who test negative for oncogenic human papillomavirus (HPV). Whether a 3-year or 5-year screening interval could be used in HIV-infected women who are cytologically normal and oncogenic HPV-negative is unknown.

OBJECTIVE

To determine the risk of cervical precancer or cancer defined cytologically (high-grade squamous intraepithelial lesions or greater [HSIL+]) or histologically (cervical intraepithelial neoplasia 2 or greater [CIN-2+]), as 2 separate end points, in HIV-infected women and HIV-uninfected women who at baseline had a normal Pap test result and were negative for oncogenic HPV.

DESIGN, SETTING, AND PARTICIPANTS

Participants included 420 HIV-infected women and 279 HIV-uninfected women with normal cervical cytology at their enrollment in a multi-institutional US cohort of the Women's Interagency HIV Study, between October 1, 2001, and September 30, 2002, with follow-up through April 30, 2011. Semiannual visits at 6 clinical sites included Pap testing and, if indicated, cervical biopsy. Cervicovaginal lavage specimens from enrollment were tested for HPV DNA using polymerase chain reaction. The primary analysis was truncated at 5 years of follow-up.

MAIN OUTCOME MEASURE

Five-year cumulative incidence of cervical precancer and cancer.

RESULTS

No oncogenic HPV was detected in 369 (88% [95% CI, 84%-91%]) HIV-infected women and 255 (91% [95% CI, 88%-94%]) HIV-uninfected women with normal cervical cytology at enrollment. Among these oncogenic HPV-negative women, 2 cases of HSIL+ were observed; an HIV-uninfected woman and an HIV-infected woman with a CD4 cell count of 500 cells/μL or greater. Histologic data were obtained from 4 of the 6 clinical sites. There were 6 cases of CIN-2+ in 145 HIV-uninfected women (cumulative incidence, 5% [95% CI, 1%-8%]) and 9 cases in 219 HIV-infected women (cumulative incidence, 5% [95% CI, 2%-8%]). This included 1 case of CIN-2+ in 44 oncogenic HPV-negative HIV-infected women with CD4 cell count less than 350 cells/μL (cumulative incidence, 2% [95% CI, 0%-7%]), 1 case in 47 women with CD4 cell count of 350 to 499 cells/μL (cumulative incidence, 2% [95% CI, 0%-7%]), and 7 cases in 128 women with CD4 cell count of 500 cells/μL or greater (cumulative incidence, 6% [95% CI, 2%-10%]). One HIV-infected and 1 HIV-uninfected woman had CIN-3, but none had cancer.

CONCLUSION

The 5-year cumulative incidence of HSIL+ and CIN-2+ was similar in HIV-infected women and HIV-uninfected women who were cytologically normal and oncogenic HPV-negative at enrollment.

Altered biomarkers of mucosal immunity and reduced vaginal Lactobacillus concentrations in sexually active female adolescents

BACKGROUND

Genital secretions collected from adult women exhibit in vitro activity against herpes simplex virus (HSV) and Escherichia coli (E. coli), but prior studies have not investigated this endogenous antimicrobial activity or its mediators in adolescent females.

METHODOLOGY/PRINCIPAL FINDINGS

Anti-HSV and anti-E.coli activity were quantified from cervicovaginal lavage (CVL) specimens collected from 20 sexually active adolescent females (15-18 years). Soluble immune mediators that may influence this activity were measured in CVL, and concentrations of Lactobacillus jensenii and crispatus were quantified by PCR from vaginal swabs. Results for adolescents were compared to those obtained from 54 healthy, premenopausal adult women. Relative to specimens collected from adults, CVL collected from adolescent subjects had significantly reduced activity against E. coli and diminished concentrations of protein, IgG, and IgA but significantly increased anti-HSV activity and concentrations of interleukin (IL)-1α, IL-6 and IL-1 receptor antagonist. Vaginal swabs collected from adolescent subjects had comparable concentrations of L. crispatus but significantly reduced concentrations of L. jensenii, relative to adult swabs.

CONCLUSIONS/SIGNIFICANCE

Biomarkers of genital mucosal innate immunity may differ substantially between sexually active adolescents and adult women. These findings warrant further study and may have significant implications for prevention of sexually transmitted infections in adolescent females.

Safety and pharmacokinetics of aciclovir in women following release from a silicone elastomer vaginal ring

OBJECTIVES

Systemic aciclovir and its prodrug valaciclovir are effective in treating and reducing recurrences of genital herpes simplex virus (HSV) and reducing transmission. Local aciclovir delivery, if it can achieve and maintain comparable intracellular genital tract levels, may be equally effective in the treatment and suppression of genital HSV. Intravaginal ring (IVR) delivery of aciclovir may provide pre-exposure prophylaxis against HSV acquisition.

METHODS

Tolerability and pharmacokinetics were evaluated in six HIV-negative women with recurrent genital HSV who switched their daily oral valaciclovir suppression to an aciclovir IVR for 7 days (n = 3) or 14 days (n = 3). Blood and cervicovaginal lavage (CVL) were collected after oral and IVR dosing to measure aciclovir concentrations and genital swabs were obtained to quantify HSV shedding by PCR.

RESULTS

The rings were well tolerated. Median plasma aciclovir concentrations were 110.2 ng/mL (IQR, 85.9-233.5) 12-18 h after oral valaciclovir. Little or no drug was detected in plasma following IVR dosing. Median (IQR) CVL aciclovir levels were 127.3 ng/mL (21-660.8) 2 h after oral valaciclovir, 154.4 ng/mL (60.7-327.5) 12-18 h after oral valaciclovir and 438 ng/mL (178.5-618.5) after 7 days and 393 ng/mL (31.6-1615) after 14 days of aciclovir ring use. Median CVL aciclovir levels 2 h after oral dosing were similar to levels observed 7 (P = 0.99) and 14 (P = 0.75) days after ring use. HSV DNA was not detected in genital swabs and there was no significant change in inflammatory mediators.

CONCLUSIONS

This first-in-human study demonstrated that an IVR could safely deliver mucosal levels of aciclovir similar to oral valaciclovir without systemic absorption. More intensive site-specific pharmacokinetic studies are needed to determine whether higher local concentrations are needed to achieve optimal drug distribution within the genital tract.

Topical prophylaxis for HIV prevention in women: becoming a reality

Strategies to protect against sexual transmission of HIV include the development of products formulated for topical application, which limit the toxicities associated with systemic oral pre-exposure prophylaxis. Following several clinical trial failures, attention is now focused on antiretroviral (ARV) agents. Highly potent ARV topical formulations provide a female-controlled, targeted, and feasible option for HIV prevention. A recently completed tenofovir gel trial was the first to demonstrate significant protection against HIV acquisition. Topical ARVs have the advantage of delivering high concentration of drug at the site of transmission of HIV, with low systemic absorption. Sustained-release formulations, such as intravaginal rings, will likely improve adherence and can be designed to provide controlled and continuous delivery of ARV combinations. Further studies to test alternative dosing strategies and pharmacokinetic/pharmacodynamic relationships in the genital tract will provide valuable information as the field strives to improve upon the promising tenofovir gel trial results.

A randomized trial to assess anti-HIV activity in female genital tract secretions and soluble mucosal immunity following application of 1% tenofovir gel

Background

Preclinical and early phase clinical microbicide studies have not consistently predicted the outcome of efficacy trials. To address this gap, candidate biomarkers of microbicide pharmacodynamics and safety were evaluated in a double-blind, placebo-controlled trial of tenofovir gel, the first microbicide to demonstrate significant protection against HIV acquisition.

Methods

30 women were randomized to apply a single daily dose of tenofovir or placebo gel for 14 consecutive days. Anti-HIV activity was measured in cervicovaginal lavage (CVL) on Days 0, 3, 7, 14 and 21 by luciferase assay as a surrogate marker of pharmacodynamics. Endogenous activity against E. coli and HSV-2 and concentrations of immune mediators were quantified in CVL as candidate biomarkers of safety. Tenofovir levels were measured in CVL and blood.

Results

A significant increase in anti-HIV activity was detected in CVL from women who applied tenofovir gel compared to their endogenous anti-HIV activity in genital tract secretions on Day 0 and compared to activity in CVL from women in the placebo group. The activity correlated significantly with CVL concentration of tenofovir (r = 0.6, p<0.001) and fit a sigmoid E_max pharmacodynamic model. Anti-HIV activity in CVL from women who applied tenofovir persisted when virus was introduced in semen, whereas endogenous anti-HIV activity decreased. Tenofovir did not trigger an inflammatory response or induce sustained loss in endogenous antimicrobial activity or immune mediators.

Conclusions

Tenofovir gel had no deleterious impact on soluble mucosal immunity. The increased anti-HIV activity in CVL, which persisted in the presence of semen and correlated with tenofovir concentration, is consistent with the efficacy observed in a recent clinical trial. These results promote quantified CVL anti-HIV activity as a surrogate of tissue pharmacodynamics and as a potential biomarker of adherence to product. This simple, feasible and inexpensive bioassay may promote the development of models more predictive of microbicide efficacy.

Trial Registration

ClinicalTrials.gov NCT00594373

Female genital tract secretions and semen impact the development of microbicides for the prevention of HIV and other sexually transmitted infections

Pharmacologic strategies for the prevention of HIV include vaccines, post-exposure prophylaxis with antiretroviral therapy, and topical microbicides. Vaginal microbicides have the potential to augment innate defenses in the genital tract but may also disrupt endogenous protection and increase HIV acquisition risk, as observed in clinical trials of nonoxynol-9. The initially disappointing results of microbicide clinical trials stimulated the development of more sensitive and comprehensive pre-clinical safety studies, which include dual-chamber culture systems to model the epithelial barrier and post-coital studies to evaluate the effects of semen and sexual intercourse on microbicide efficacy. This review discusses the key factors that contribute to a healthy female genital tract environment, the impact of semen on mucosal defense, and how our understanding of these mediators informs the development of effective vaginal microbicides.

Elevated osteoprotegerin is associated with abnormal ankle brachial indices in patients infected with HIV: a cross-sectional study

Background

Patients infected with HIV have an increased risk for accelerated atherosclerosis. Elevated levels of osteoprotegerin, an inflammatory cytokine receptor, have been associated with a high incidence of cardiovascular disease (including peripheral arterial disease, or PAD), acute coronary syndrome, and cardiovascular mortality. The objective of this study was to determine whether PAD is prevalent in an HIV-infected population, and to identify an association with HIV-specific and traditional cardiovascular risk factors, as well as levels of osteoprotegerin.

Methods

One hundred and two patients infected with HIV were recruited in a cross-sectional study. To identify the prevalence of PAD, ankle-brachial indices (ABIs) were measured. Four standard ABI categories were utilized: ≤ 0.90 (definite PAD); 0.91-0.99 (borderline); 1.00-1.30 (normal); and >1.30 (high). Medical history and laboratory measurements were obtained to determine possible risk factors associated with PAD in HIV-infected patients.

Results

The prevalence of PAD (ABI ≤ 0.90) in a young HIV-infected population (mean age: 48 years) was 11%. Traditional cardiovascular risk factors, including advanced age and previous cardiovascular history, as well as elevated C-reactive protein levels, were associated with PAD. Compared with patients with normal ABIs, patients with high ABIs had significantly elevated levels of osteoprotegerin [1428.9 (713.1) pg/ml vs. 3088.6 (3565.9) pg/ml, respectively, p = 0.03].

Conclusions

There is a high prevalence of PAD in young HIV-infected patients. A number of traditional cardiovascular risk factors and increased osteoprotegerin concentrations are associated with abnormal ABIs. Thus, early screening and aggressive medical management for PAD may be warranted in HIV-infected patients.