Cell-associated genital tract virus and vertical transmission of human immunodeficiency virus type 1 in antiretroviral-experienced women

Pregnancy Management in HIV Viral Controllers: Twenty Years of Experience

(1) Background: The evidence base for the management of spontaneous viral controllers in pregnancy is lacking. We describe the management outcomes of pregnancies in a series of UK women with spontaneous HIV viral control (<100 copies/mL 2 occasions before or after pregnancy off ART). (2) Methods: A multi-centre, retrospective case series (1999-2021) comparing pre- and post-2012 when guidelines departed from zidovudine-monotherapy (ZDVm) as a first-line option. Demographic, virologic, obstetric and neonatal information were anonymised, collated and analysed in SPSS. (3) Results: A total of 49 live births were recorded in 29 women, 35 pre-2012 and 14 post. HIV infection was more commonly diagnosed in first reported pregnancy pre-2012 (15/35) compared to post (2/14), p = 0.10. Pre-2012 pregnancies were predominantly managed with ZDVm (28/35) with pre-labour caesarean section (PLCS) (24/35). Post-2012 4/14 received ZDVm and 10/14 triple ART, p = 0.002. Post-2012 mode of delivery was varied (5 vaginal, 6 PLCS and 3 emergency CS). No intrapartum ZDV infusions were given post-2012 compared to 11/35 deliveries pre-2012. During pregnancy, HIV was detected (> 50 copies/mL) in 14/49 pregnancies (29%) (median 92, range 51-6084). Neonatal ZDV post-exposure prophylaxis was recorded for 45/49 infants. No transmissions were reported. (4) Conclusion: UK practice has been influenced by the change in guidelines, but this has had little impact on CS rates.

Brief Report: Vaginal Viral Shedding With Undetectable Plasma HIV Viral Load in Pregnant Women Receiving 2 Different Antiretroviral Regimens: A Randomized Clinical Trial

BACKGROUND

Pregnant women using antiretrovirals (ARVs) may have persistent vaginal viral shedding, which could be associated with sexual and perinatal HIV transmission. However, there are scant data on vaginal viral load (VVL) in pregnant women with undetectable plasma viral load (PVL).

METHODS

This study was a post hoc analysis of an open-label randomized trial to evaluate the virologic response of 2 ART regimens. The participants were ART-naive women living with HIV initiating ART regimens between 20 and 36 weeks of pregnancy recruited at 19 clinical sites in 6 countries. Participants were randomized to receive 400 mg of raltegravir 2 times a day or 600 mg of efavirenz 4 times a day in addition to 150 mg of lamivudine and 300 mg of zidovudine 2 times a day. VVL and PVL tests were performed at every study visit. The primary outcome measures were HIV-1 PVL and VVL at maternal study week 4 and rates of perinatal HIV transmission.

RESULTS

A total of 408 were enrolled, of whom 323 had VVL samples 4 weeks after enrollment and were included in this analysis. Among women with undetectable/nonquantifiable PVL during ART, the overall rate of quantifiable VVL at week 4 was 2.54% (7/275). Of the 275 with nonquantifiable PVL, 99.1% (115/116) and 96.2% (153/159) had nonquantifiable VVL in the efavirenz and raltegravir arms, respectively. None of the 7 women with quantifiable VVL at the week 4 study visit transmitted HIV to their infants.

CONCLUSIONS

Detectable VVL in pregnant women with undetectable/nonquantifiable PVL while receiving ART was rare and not associated with perinatal HIV transmission.

Genital Human Immunodeficiency Virus-1 RNA and DNA Shedding in Virologically Suppressed Individuals Switching From Triple- to Dual- or Monotherapy: Pooled Results From 2 Randomized, Controlled Trials

BACKGROUND

Increasingly, people living with human immunodeficiency virus (HIV) benefit from lower drug regimens (LDRs). Exploring viral genital shedding during LDRs is crucial to ensure their safety.

METHODS

We pooled genital sub-studies from 2 clinical trials in this area. Patients were randomized 1:1 to continue abacavir/lamivudine/dolutegravir or switch to dolutegravir (MONCAY trial), or to continue tenofovir/emtricitabine + a third agent or switch to tenofovir/emtricitabine (TRULIGHT trial). Participants whose plasma HIV-RNA remained <50 copies/mL had sperm or cervicovaginal lavage collected between Weeks 24 and 48. HIV-RNA and HIV-DNA were amplified by ultrasensitive polymerase chain reaction. The main objective was to measure the proportion of participants who had no detectable HIV in genital fluids, both according to each strategy and then in an aggregated analysis (LDR versus triple therapies).

RESULTS

There were 64 participants (35 males, 29 females) included: 16 received dual therapies and 16 received triple therapies in TRULIGHT; and 16 received monotherapies and 16 received triple therapies in MONCAY. In TRULIGHT, 13/15 (87%) of evaluable participants on dual therapy had no detectable HIV in their genital fluid, versus 14/15 (93%) under triple therapy (P = 1.0). In MONCAY, these figures were 12/15 (80%) on monotherapy versus 13/16 (81%) on triple therapy (P = 1.0). In the pooled analysis, a similar proportion of participants in the LDR and triple therapy groups had no detectable HIV: 25/30 (83%) and 27/31 (87%), respectively (P = .73).

CONCLUSIONS

There was no evidence of increased HIV-RNA and/or -DNA shedding in the genital fluids of people who maintained undetectable plasma HIV-RNA during LDRs.

CLINICAL TRIALS REGISTRATION

NCT02302547 and NCT02596334.

HIV and SIV in Body Fluids: From Breast Milk to the Genitourinary Tract

HIV-1 is present in many secretions including oral, intestinal, genital, and breast milk. However, most people exposed to HIV-1 within these mucosal compartments do not become infected despite often frequent and repetitive exposure over prolonged periods of time. In this review, we discuss what is known about the levels of cell-free HIV RNA, cell-associated HIV DNA and cell-associated HIV RNA in external secretions. Levels of virus are usually lower than contemporaneously obtained blood, increased in settings of inflammation and infection, and decreased in response to antiretroviral therapy. Additionally, each mucosal compartment has unique innate and adaptive immune responses that affect the composition and presence of HIV-1 within each external secretion. We discuss the current state of knowledge about the types and amounts of virus present in the various excretions, touch on innate and adaptive immune responses as they affect viral levels, and highlight important areas for further study.

The Role of Immune Responses in HIV Mother-to-Child Transmission

HIV mother-to-child transmission (MTCT) represents a success story in the HIV/AIDS field given the significant reduction in number of transmission events with the scale-up of antiretroviral treatment and other prevention methods. Nevertheless, MTCT still occurs and better understanding of the basic biology and immunology of transmission will aid in future prevention and treatment efforts. MTCT is a unique setting given that the transmission pair is known and the infant receives passively transferred HIV-specific antibodies from the mother while in utero. Thus, infant exposure to HIV occurs in the face of HIV-specific antibodies, especially during delivery and breastfeeding. This review highlights the immune correlates of protection in HIV MTCT including humoral (neutralizing antibodies, antibody-dependent cellular cytotoxicity, and binding epitopes), cellular, and innate immune factors. We further discuss the future implications of this research as it pertains to opportunities for passive and active vaccination with the ultimate goal of eliminating HIV MTCT.

Managing Mother-to-Child Transmission of HIV Infection in Developed-Country Settings

This article reviews current understanding of the management of mother-to-child transmission of HIV-1 infection in the context of developed-country settings. The advent of highly active antiretroviral therapy has facilitated the virtual elimination of mother-to-child transmission of HIV infection in developed countries, reducing transmission rates to approximately 1–2%. This review describes the epidemiology of HIV infection among women of child-bearing age and the risk factors, timing and mechanisms of mother-to-child transmission, followed by a discussion of the identification of pregnant HIV-infected women and their therapeutic and obstetric management.

Characteristics and quantities of HIV host cells in human genital tract secretions

Human immunodeficiency virus (HIV)-infected leukocytes have been detected in genital secretions from HIV-infected men and women and may play an important role in the sexual transmission of HIV. However, they have been largely overlooked in studies on mechanisms of HIV transmission and in the design and testing of HIV vaccine and microbicide candidates. This article describes the characteristics and quantities of leukocytes in male and female genital secretions under various conditions and also reviews evidence for the involvement of HIV-infected cells in both horizontal and vertical cell-associated HIV transmission. Additional research is needed in this area to better target HIV prevention strategies.

Modeling mucosal cell-associated HIV type 1 transmission in vitro

Human immunodeficiency virus type 1 (HIV-1) can efficiently spread by direct cell-to-cell contact, a mechanism termed cell-associated HIV transmission. By some estimates, cell-associated HIV transmission is 10-1000-fold more effective than cell-free HIV infection. Mucosal cell-associated HIV transmission may occur when HIV-bearing cells in mucosal secretions from an HIV-infected donor transfer virus directly to recipient target cells in or below the mucosal epithelium, or through HIV transcytosis across the mucosal epithelium of a noninfected host. This mechanism may play an important role in the sexual and vertical transmission of HIV-1, yet most in vitro tests of vaccine and microbicide efficacy assess cell-free virus transmission. This article reviews in vitro assays that have been used to model mucosal cell-associated transmission, including microscopy, immune cell cocultures, use of HIV-infected cells in epithelial cell transcytosis assays, and cell-associated infection of mucosal tissue explants. Assays that authentically simulate mucosal cell-associated HIV transmission could provide valuable insight into mechanisms and molecules that can potentially be targeted for HIV prevention, as well as critical models for testing novel HIV prevention strategies for efficacy against cell-associated HIV transmission.

The role of cell-associated virus in mother-to-child HIV transmission

Mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) continues to contribute to the global burden of disease despite great advances in antiretroviral (ARV) treatment and prophylaxis. In this review, we discuss the proposed mechanisms of MTCT, evidence for cell-free and cell-associated transmission in different routes of MTCT, and the impact of ARVs on virus levels and transmission. Many population-based studies support a role for cell-associated virus in transmission and in vitro studies also provide some support for this mode of transmission. However, animal model studies provide proof-of-principle that cell-free virus can establish infection in infants, and studies of ARVs in HIV-infected pregnant women show a strong correlation with reduction in cell-free virus levels and protection. ARV treatment in MTCT potentially provides opportunities to better define the infectious form of virus, but these studies will require better tools to measure the infectious cell reservoir.

Co-occurrence of Trichomonas vaginalis and bacterial vaginosis and vaginal shedding of HIV-1 RNA

BACKGROUND

Trichomonas vaginalis (TV) and bacterial vaginosis (BV) are independently associated with increased risk of vaginal shedding in HIV-positive women. Because these 2 conditions commonly co-occur, this study was undertaken to examine the association between TV/BV co-occurrence and vaginal shedding of HIV-1 RNA.

METHODS

HIV-positive women attending outpatient HIV clinics in 3 urban US cities underwent a clinical examination; were screened for TV, BV, Neisseria gonorrhoeae, Chlamydia trachomatis, and vulvovaginal candidiasis; and completed a behavioral survey. Women shedding HIV-1 RNA vaginally (≥50 copies/mL) were compared with women who had an undetectable (<50 copies/mL) vaginal viral load to determine if women who were TV positive and BV positive or had co-occurrence of TV/BV had higher odds of shedding vaginally when compared with women who did not have these conditions.

RESULTS

In this sample of 373 HIV-positive women, 43.1% (n = 161) had co-occurrence of TV/BV and 33.2% (n = 124) were shedding HIV-1 RNA vaginally. The odds of shedding HIV vaginally in the presence of TV alone or BV alone and when TV/BV co-occurred were 4.07 (95% confidence interval [CI], 1.78-9.37), 5.65 (95% CI, 2.64-12.01), and 18.63 (95% CI, 6.71-51.72), respectively, when compared with women with no diagnosis of TV or BV, and after adjusting for age, antiretroviral therapy status, and plasma viral load.

CONCLUSIONS

T. vaginalis and BV were independently and synergistically related to vaginal shedding of HIV-1 RNA. Screening and prompt treatment of these 2 conditions among HIV-positive women are important not only clinically but for HIV prevention, as well.

Antiretroviral therapy and mother-to-child transmission of HIV-1

The advent of highly active antiretroviral therapy has facilitated the virtual elimination of mother-to-child transmission of HIV infection in developed countries, reducing transmission rates to approximately 1 to 2%. In these settings, highly active antiretroviral therapy has also transformed pediatric HIV infection into a chronic disease; although there are associated costs in terms of side effects and the heavy pill burden. In less developed settings, easier-to-use adaptations of antiretroviral therapy regimens, such as short-course and single-dose antiretroviral strategies or neonatal postexposure prophylaxis can also substantially prevent mother-to-child transmission, although to a lesser degree than highly active antiretroviral therapy. However, postnatal transmission of infection through breastfeeding significantly reduces the longer-term efficacy of these strategies. Ongoing research is focusing on the use of antiretroviral therapy in the breastfeeding period.

Maximizing the impact of HIV prevention efforts: interventions for couples

Despite efforts to increase access to HIV testing and counseling services, population coverage remains low. As a result, many people in sub-Saharan Africa do not know their own HIV status or the status of their sex partner(s). Recent evidence, however, indicates that as many as half of HIV-positive individuals in ongoing sexual relationships have an HIV-negative partner and that a significant proportion of new HIV infections in generalized epidemics occur within serodiscordant couples. Integrating couples HIV testing and counseling (CHTC) into routine clinic- and community-based services can significantly increase the number of couples where the status of both partners is known. Offering couples a set of evidence-based interventions once their HIV status has been determined can significantly reduce HIV incidence within couples and if implemented with sufficient scale and coverage, potentially reduce population-level HIV incidence as well. This article describes these interventions and their potential benefits.

As good as it gets? The problem of HIV persistence despite antiretroviral drugs

Human immunodeficienty virus (HIV) infection is suppressed but not eliminated by antiretroviral drugs. Viral persistence in the face of therapy has been explained by viral latency, lowered effectiveness of drugs in some anatomical sites and cell types, and cell-to-cell spread. These mechanisms allow for drug-sensitive virus to persist despite treatment. Understanding the persistence mechanism at work at different times after infection, including the time of initial infection immediately following transmission when reservoirs are first formed, will reveal if we are at the limit of what can be achieved with the current therapy paradigm of suppressing ongoing virus replication with drugs. We discuss some of the possible reasons why HIV persists at different points on the infection timeline, focusing on the role ongoing replication may have in maintaining the infection despite drugs at early times postexposure.

Selective impact of HIV disease progression on the innate immune system in the human female reproductive tract

BACKGROUND

We have previously demonstrated intrinsic anti-HIV activity in cervicovaginal lavage (CVL) from HIV-infected women with high CD4 counts and not on antiretroviral therapy. However, the impact of HIV disease progression on CVL innate immune responses has not been delineated.

METHODS

CVL from 57 HIV-infected women not on antiretroviral therapy were collected by washing the cervicovaginal area with 10 ml of sterile normal saline. We characterized subject HIV disease progression by CD4 count strata: >500 cells/µl, 200-500 cells/µl, or <200 cells/µl of blood. To assess CVL anti-HIV activity, we incubated TZM-bl cells with HIV plus or minus CVL. Antimicrobials, cytokines, chemokines and anti-gp160 HIV IgG antibodies were measured by ELISA and Luminex.

RESULTS

CVL exhibited broad anti-HIV activity against multiple laboratory-adapted and transmitted/founder (T/F) viruses, with anti-HIV activity ranging from 0 to 100% showing wide variation between viral strains. Although there was broad CVL inhibition of most both laboratory-adapted and T/F virus strains, there was practically no inhibition of T/F strain RHPA.c, which was isolated from a woman newly infected via heterosexual intercourse. HIV disease progression, measured by declining CD4 T cell counts, resulted in a selective reduction in intrinsic anti-HIV activity in CVL that paralleled CVL decreases in human beta-defensin 2 and increases in Elafin and secretory leukocyte protease inhibitor. HIV disease progress predicted decreased CVL anti-HIV activity against both laboratory-adapted and T/F strains of HIV. Anti-HIV activity exhibited close associations with CVL levels of fourteen cytokines and chemokines.

CONCLUSIONS

Amid a multifaceted immune defense against HIV-1 and other sexually transmitted pathogens, HIV disease progression is associated with selective disturbances in both CVL anti-HIV activity and specific innate immune defenses in the human female reproductive tract (FRT). Overall, these studies indicate that innate immune protection in the FRT is compromised as women progress to AIDS.

Pharmacokinetics of antiretroviral drugs in anatomical sanctuary sites: the male and female genital tract

HIV resides within anatomical 'sanctuary sites', where local drug exposure and viral dynamics may differ significantly from the systemic compartment. Suboptimal antiretroviral concentrations in the genital tract may result in compartmentalized viral replication, selection of resistant mutations and possible re-entry of wild-type/resistant virus into the systemic circulation. Therefore, achieving adequate antiretroviral exposure in the genital tract has implications for the prevention of sexual and vertical transmission of HIV. Penetration of antiretrovirals in the genital tract is expressed by accumulation ratios derived from the measurement of drug concentrations in time-matched seminal plasma/cervicovaginal fluid and plasma samples. Penetration varies by gender and may be drug (as opposed to class) specific with high interindividual variability. Concentrations in seminal plasma are highest for nucleoside analogues and lowest for protease inhibitors and efavirenz. Seminal accumulation of newer agents, raltegravir and maraviroc, is moderate (rank order of accumulation is nucleoside/nucleotide reverse transcriptase inhibitors [lamivudine/zidovudine/tenofovir/didanosine > stavudine/abacavir] > raltegravir > indinavir/maraviroc/nevirapine >> efavirenz/protease inhibitors [amprenavir/atazanavir/darunavir > lopinavir/ritonavir > saquinavir] > enfuvirtide). In the female genital tract, the nucleoside analogues exhibit high accumulation ratios, whereas protease inhibitors have limited penetration; however, substantial variability exists between individuals and study centres. Second generation non-nucleoside reverse transcriptase inhibitor etravirine, and maraviroc and raltegravir, demonstrate effective accumulation in cervicovaginal secretions (rank order of accumulation is nucleoside/nucleotide reverse transcriptase inhibitor [zidovudine/lamivudine/didanosine > emtricitabine/tenofovir] > indinavir > maraviroc/raltegravir/darunavir/etravirine > nevirapine/abacavir > protease inhibitors [amprenavir/atazanavir/ritonavir] > lopinavir/stavudine/efavirenz > saquinavir).

Post-natal anaemia and iron deficiency in HIV-infected women and the health and survival of their children

Prenatal iron supplementation may improve pregnancy outcomes and decrease the risk of child mortality. However, little is known about the importance of post-natal maternal iron status for child health and survival, particularly in the context of HIV infection. We examined the association of maternal anaemia and hypochromic microcytosis, an erythrocyte morphology consistent with iron deficiency, with child health and survival in the first two to five years of life. Repeated measures of maternal anaemia and hypochromic microcytosis from 840 HIV-positive women enrolled in a clinical trial of vitamin supplementation were prospectively related to child mortality, HIV infection and CD4 T-cell count. Median duration of follow-up for the endpoints of child mortality, HIV infection and CD4 cell count was 58, 17 and 23 months, respectively. Maternal anaemia and hypochromic microcytosis were associated with greater risk of child mortality [hazard ratio (HR) for severe anaemia = 2.58, 95% confidence interval (CI): 1.66-4.01, P trend < 0.0001; HR for severe hypochromic microcytosis = 2.36, 95% CI: 1.27-4.38, P trend = 0.001]. Maternal anaemia was not significantly associated with greater risk of child HIV infection (HR for severe anaemia = 1.46, 95% CI: 0.91, 2.33, P trend = 0.08) but predicted lower CD4 T-cell counts among HIV-uninfected children (difference in CD4 T-cell count/µL for severe anaemia: -93, 95% CI: -204-17, P trend = 0.02). The potential child health risks associated with maternal anaemia and iron deficiency may not be limited to the prenatal period. Efforts to reduce maternal anaemia and iron deficiency during pregnancy may need to be expanded to include the post-partum period.

Residual HIV-1 RNA and HIV-1 DNA production in the genital tract reservoir of women treated with HAART: the prospective ANRS EP24 GYNODYN study

BACKGROUND

The female genital tract constitutes a reservoir for HIV providing active production of both cell-free HIV RNA and cell-associated DNA within the cervicovaginal secretions. The objective of this study was to prospectively assess residual HIV-1 RNA and HIV-1 DNA production in the genital tract reservoir of women initiating HAART over an 18-month period.

METHODS

Paired blood and cervicovaginal lavage samples were collected at inclusion and 1, 6, 12 and 18 months after HAART initiation, in 23 women in first-line HAART and six women in virological failure, for measurement of HIV-1 RNA and HIV-1 DNA shedding and/or drug concentrations.

RESULTS

A dramatic decrease of HIV-1 RNA and HIV-1 DNA occurred in both blood and cervicovaginal samples over the first 6 months on HAART, followed by a shelf up to 18 months, independently of the drugs' genital pharmacokinetics. While cervicovaginal HIV-1 RNA became undetectable in >90% of women from 6 months on HAART, genital HIV-1 DNA remained frequently detectable (27-50%). Nearly 40% of women with sustained undetectable plasma HIV-1 RNA after 6-18 months on HAART harboured transient HIV-1 RNA (15% of women) or HIV-1 DNA (31% of women) in their genital secretions.

CONCLUSIONS

Low-level cervicovaginal HIV-1 shedding is frequently evidenced in HAART-treated women with transient HIV-1 RNA and persistent HIV-1 DNA despite a systemic control of viral replication, resulting in possible residual genital infectivity.

Patient-delivered partner treatment and Trichomonas vaginalis repeat infection among human immunodeficiency virus-infected women

BACKGROUND

Repeat infections with Trichomonas vaginalis (TV) among human immunodeficiency virus (HIV)-infected women are common and may increase the risk of HIV transmission. Patient delivered partner treatment (PDPT) has been shown to reduce repeat infections of other sexually transmitted diseases. The purpose of this study was to evaluate adherence to PDPT and possible causes of repeat TV infection among HIV-infected women.

METHODS

A multicentered cohort study was conducted in 3 US cities. Women coinfected with HIV and TV were treated with metronidazole and given treatment to deliver to all reported sex partners. A test-of-cure visit was conducted 6 to 12 days post index treatment completion and behavioral data were collected.

RESULTS

Of 252 women (mean age = 40 years, s.d. 9.1) enrolled, 92.5% were black, 26.2% had CD4 cell counts <200/mm(3), 34.1% had plasma viral loads >10,000 copies, 58.3% were taking antiretrovial therapy, and 15.1% had multiple partners. Of the 183 women with partners at baseline, 75.4% provided PDPT to all partners and 61.7% reported they were sure all of their partners took the medication. Factors associated with not giving medications to all partner(s) were multiple sex partners, being single, and having at least one partner unaware of the index woman's HIV status. At test-of-cure, 10.3% were TV-positive and 16.7% reported having sex since baseline. Of the 24 repeat infections, 21 (87.5%) reported adherence to medication and no sexual exposure.

CONCLUSION

HIV-infected women with TV reported high adherence to PDPT, and treatment failure was the most common probable cause of repeat infection.

Various viral compartments in HIV-1-infected mothers contribute to in utero transmission of HIV-1

Perinatal HIV transmission occurs in utero or intrapartum. The mechanisms and timing of transmission are not clearly understood. To compare the genetic sequences of the V3 envelope region of infant's plasma HIV to that of the mother's plasma, peripheral blood mononuclear cells (PBMC) and vaginal secretions, and correlate with timing of transmission. All 3 infants had a positive HIV PCR in the first days of life, thus classified as in utero infections. In the first mother-infant pair, two different variants were present in the infant, one correlating with maternal PBMC virus and highly homologous to virus from vaginal secretions and the other identical to sequences in maternal plasma. In the second pair, the infant plasma virus was similar to that of maternal PBMC. In the third pair, the cord blood and infant plasma virus were highly similar to maternal vaginal virus. The presence of more than one HIV variant from the maternal blood and from the vaginal compartment in the cord blood of infants presumably infected in utero could point to more than one episode of transmission or, alternatively, to transmission of PBMC virus.

A randomized treatment trial: single versus 7-day dose of metronidazole for the treatment of Trichomonas vaginalis among HIV-infected women

OBJECTIVE

To determine if the metronidazole (MTZ) 2-gm single dose (recommended) is as effective as the 7-day 500 mg twice a day dose (alternative) for treatment of Trichomonas vaginalis (TV) among HIV+ women.

METHODS

Phase IV randomized clinical trial; HIV+ women with culture confirmed TV were randomized to treatment arm: MTZ 2-gm single dose or MTZ 500 mg twice a day 7-day dose. All women were given 2-gm MTZ doses to deliver to their sex partners. Women were recultured for TV at a test-of-cure (TOC) visit occurring 6-12 days after treatment completion. TV-negative women at TOC were again recultured at a 3-month visit. Repeat TV infection rates were compared between arms.

RESULTS

Two hundred seventy HIV+/TV+ women were enrolled (mean age = 40 years, ±9.4; 92.2% African American). Treatment arms were similar with respect to age, race, CD4 count, viral load, antiretroviral therapy status, site, and loss-to-follow up. Women in the 7-day arm had lower repeat TV infection rates at TOC [8.5% (11 of 130) versus 16.8% (21 of 125) (relative risk: 0.50, 95% confidence interval = 0.25, 1.00; P < 0.05)] and at 3 months [11.0% (8 of 73) versus 24.1% (19 of 79) (relative risk: 0.46, 95% confidence interval = 0.21, 0.98; P = 0.03)] compared with the single-dose arm.

CONCLUSIONS

The 7-day MTZ dose was more effective than the single dose for the treatment of TV among HIV+ women.

Mother-to-child transmission of HIV: pathogenesis, mechanisms and pathways

More than 400,000 children were infected with (HIV-1) worldwide in 2008, or more than 1000 children per day. Mother-to-child transmission (MTCT) of HIV-1 is the most important mode of HIV acquisition in infants and children. MTCT of HIV-1 can occur in utero, intrapartum, and postnatally through breastfeeding. Great progress has been made in preventing such transmission, through the use of antiretroviral prophylactic regimens to the mother during gestation and labor and delivery and to either mother or infant during breast feeding. The timing and mechanisms of transmission, however, are multifactorial and remain incompletely understood. This article summarizes what is known about the pathogenetic mechanisms and routes of MTCT of HIV-1, and includes virologic, immunologic, genetic, and mucosal aspects of transmission.

Fetal immune activation to malaria antigens enhances susceptibility to in vitro HIV infection in cord blood mononuclear cells

Mother-to-child-transmission (MTCT) of human immunodeficiency virus (HIV) remains a significant cause of new HIV infections in many countries. To examine whether fetal immune activation as a consequence of prenatal exposure to parasitic antigens increases the risk of MTCT, cord blood mononuclear cells (CBMCs) from Kenyan and North American newborns were examined for relative susceptibility to HIV infection in vitro. Kenyan CBMCs were 3-fold more likely to be infected with HIV than were North American CBMCs (P=.03). Kenyan CBMCs with recall responses to malaria antigens demonstrated enhanced susceptibility to HIV when compared with Kenyan CBMCs lacking recall responses to malaria (P=.03). CD4(+) T cells from malaria-sensitized newborns expressed higher levels of CD25 and human leukocyte antigen DR ex vivo, which is consistent with increased immune activation. CD4(+) T cells were the primary reservoir of infection at day 4 after virus exposure. Thus, prenatal exposure and in utero priming to malaria may increase the risk of MTCT.

Acute HIV infection among pregnant women in Malawi

There are limited data on acute HIV infection (AHI) prevalence during pregnancy. Malawian pregnant women admitted in the third trimester and meeting eligibility criteria underwent dual HIV rapid antibody testing. AHI prevalence was retrospectively detected through HIV RNA pooling of seronegative plasma. Among 3,825 pregnant women screened, dual HIV rapid testing indicated that 30.2% were HIV positive, 69.7% were HIV negative, and 0.1% were indeterminate. Sensitivity and specificity of dual rapid testing was 99.0% and 98.7%, respectively. Of 2,666 seronegative specimens, 2,327 had samples available for HIV RNA pooling; 5 women (0.21%) (95% confidence interval, 0.03-0.40%) had AHI with a median peripartum viral load of 1,324,766 copies/mL. Pregnant women are at risk for AHI, warranting counseling of all women and their sexual partners about incident HIV during pregnancy. Dual HIV rapid tests have high sensitivity and specificity. HIV testing should be repeated in the third trimester and/or at delivery.

German-Austrian recommendations for HIV1-therapy in pregnancy and in HIV1-exposed newborn, update 2008

In Germany during the last years about 200-250 HIV1-infected pregnant women delivered a baby each year, a number that is currently increasing. To determine the HIV-status early in pregnancy voluntary HIV-testing of all pregnant women is recommended in Germany and Austria as part of prenatal care. In those cases, where HIV1-infection was known during pregnancy, since 1995 the rate of vertical transmission of HIV1 was reduced to 1-2%. - This low transmission rate has been achieved by the combination of anti-retroviral therapy of pregnant women, caesarean section scheduled before onset of labour, anti-retroviral post exposition prophylaxis in the newborn and refraining from breast-feeding by the HIV1-infected mother. To keep pace with new results in research, approval of new anti-retroviral drugs and changes in the general treatment recommendations for HIV1-infected adults, in 1998, 2001, 2003 and 2005 an interdisciplinary consensus meeting was held. Gynaecologists, infectious disease specialists, paediatricians, pharmacologists, virologists and members of the German AIDS Hilfe (NGO) were participating in this conference to update the prevention strategies. A fifth update became necessary in 2008. The updating process was started in January 2008 and was terminated in September 2008. The guidelines provide new recommendations on the indication and the starting point for HIV-therapy in pregnancies without complications, drugs and drug combinations to be used preferably in these pregnancies and updated information on adverse effects of anti-retroviral drugs. Also the procedures for different scenarios and risk constellations in pregnancy have been specified again. - With these current guidelines in Germany and Austria the low rate of vertical HIV1-transmission should be further maintained.

Strategies for harm reduction among HIV-affected couples who want to conceive

As effective HIV treatments become more widespread, HIV-infected individuals are living longer, healthier lives. Many HIV-affected couples (sero-discordant and sero-concordant) are considering options for safer reproduction. A large body of evidence suggests that reproductive technologies can help HIV-affected couples to safely conceive with minimal risk of HIV transmission to their partner. However, for most couples such technologies are neither geographically nor economically accessible. This paper addresses the options for safer procreation among HIV-affected couples who cannot access reproductive technologies.

Genital tract, cord blood, and amniotic fluid exposures of seven antiretroviral drugs during and after pregnancy in human immunodeficiency virus type 1-infected women

The objective of the study was to measure antiretroviral exposures in four physiological compartments during pregnancy, delivery, and postpartum. This prospective, open-label, longitudinal study collected paired blood plasma (BP) and genital tract (GT) aspirates antepartum, at delivery, and up to 12 weeks postpartum. Antiretroviral cord BP and amniotic fluid concentrations were also measured. Drug concentrations were analyzed by validated high-performance liquid chromatography/UV and liquid chromatography/tandem mass spectrometry methods, with secondary compartment concentrations presented as the percentage of BP. Fourteen women taking lamivudine plus zidovudine and either lopinavir-ritonavir (n = 7), nelfinavir (n = 6), or nevirapine (n = 1) were enrolled; four also received tenofovir. GT penetration relative to BP was highest for the nucleoside reverse transcriptase inhibitors compared to the protease inhibitors and nevirapine. Only antepartum nelfinavir GT penetration was significantly higher than in the second trimester (geometric mean ratio [GMR], 179.3) or third trimester (GMR, 41.9). Compared to nonpregnant historical controls, antepartum GT penetration was significantly lower (P < 0.05) for zidovudine (GMR, 0.25) and lopinavir (GMR, 0.03); postpartum lopinavir GT penetration continued to be significantly lower (GMR, 0.27). Cord BP exposures were highest for lamivudine and tenofovir (> or = 100%), with cord BP levels of the remaining drugs ranging from 49 to 86% of that of the respective BP level. Amniotic exposures for lamivudine, zidovudine, tenofovir, and nelfinavir were > or = 100%, nevirapine exposure was 53%, and lopinavir and ritonavir exposures were < or = 6% that of BP. We conclude that GT, cord BP, and amniotic fluid exposures vary within and between antiretroviral drug classes and biologic sites. Measurement of antiretroviral exposure in maternal genital secretions, cord BP, and amniotic fluid may be needed to identify signals of subtherapeutic or supratherapeutic drug exposure.

Association between HLA-G 3'UTR 14-bp polymorphism and HIV vertical transmission in Brazilian children

OBJECTIVES

The aim of our study was to verify the possible association between an HLA-G 14-bp deletion/insertion polymorphism and perinatal HIV transmission in Brazilian children.

DESIGN

We analyzed the 14-bp deletion/insertion polymorphisms in seronegative (i.e., exposed uninfected, N = 71) and seropositive (exposed infected, N = 175) Brazilian children born from HIV-positive mothers and in healthy controls (n = 175).

METHODS

HLA-G 14-bp deletion/insertion polymorphism (rs16375) was detected by PCR amplification of the target sequence followed by agarose gel electrophoresis. All the samples were also analyzed by direct sequencing in order to validate the genotyping results.

RESULTS

HIV-exposed uninfected children showed significant differences in their allele and genotype frequencies of the HLA-G 14-bp polymorphism when compared to both seropositive children and healthy controls. The 14-bp-deleted (D) allele was more frequent in exposed uninfected children (79%) than in healthy controls (60%) and HIV-positive children (58%); the higher percentage of the D allele found in the exposed uninfected children with respect to HIV-positive individuals was significantly associated with a reduced risk of vertical transmission. This effect was ascribable to the presence of the D/D homozygous genotype.

CONCLUSION

Our findings support the possible role for the HLA-G 14-bp deletion/insertion polymorphism in the HIV vertical transmission in Brazilian children. The presence of the D allele and D/D genotype is associated with a protective effect toward HIV perinatal infection.

Increased levels of HIV-1-infected cells in endocervical secretions after the luteinizing hormone surge

Levels of HIV-1 RNA in endocervical specimens fluctuate with the menstrual cycle, suggesting that cell-free HIV-1 levels may vary during the cycle, which could influence infectivity. Here, we examined daily changes in endocervical HIV-1-infected cells during 1 cycle. There were significant positive associations between the number of days from the luteinizing hormone surge and the number of HIV-1 DNA copies/swab (P = 0.001) and the number of total cells/swab (P < 0.001) in endocervical specimens. These data suggest that sampling of cell-associated endocervical HIV-1 increases after the periovulatory period, which could result in increased exposure to HIV-1-infected cells during sexual contact.

Temporal and lateral dynamics of HIV shedding and elevated sodium in breast milk among HIV-positive mothers during the first 4 months of breast-feeding

OBJECTIVE

To better understand the dynamics of breast milk HIV shedding and its relation to postnatal HIV transmission, we investigated the temporal and lateral relations of breast milk viral shedding and sodium concentrations in HIV-positive women.

DESIGN

This was a longitudinal cohort study in Lusaka, Zambia.

METHOD

We examined patterns of HIV shedding in breast milk over the first 4 months of breast-feeding and their correlations with postnatal HIV transmission among 138 breast-feeding mothers. Sodium concentration in breast milk was also examined in the same samples and in breast milk from 23 HIV-negative controls.

RESULTS

Higher breast milk viral load at 1 week, 1 month, and 4 months and consistent viral shedding in breast milk were significantly associated with increased risk of HIV transmission. Elevated breast milk sodium concentration (> or =13 mmol/L) at 4 months was associated with HIV transmission, low maternal CD4 cell count, and high maternal plasma viral load. Elevated sodium concentration at 1 week postpartum was common and was not associated with any of these parameters.

CONCLUSIONS

Consistent viral shedding and high breast milk viral load are strong predictors of mother-to-child HIV transmission. Although sodium concentrations later in breast-feeding correlate with breast milk viral load, increased breast milk sodium is normal in early lactation and does not predict HIV transmission.

No association between antepartum serologic and genital tract evidence of herpes simplex virus-2 coinfection and perinatal HIV-1 transmission

OBJECTIVE

The purpose of this study was to assess the risk of perinatal HIV-1 transmission in women who are coinfected with herpes simplex virus-2 (HSV-2).

STUDY DESIGN

We performed a nested case-control study of 26 women whose HIV-1 was transmitted to their infants and 52 control subjects whose HIV-1 was not transmitted. We assessed antepartum serologic evidence of HSV-2 by HSV-2 serostatus and genital tract evidence of HSV-2 by presence of HSV-2 DNA.

RESULTS

There was no significant association between antepartum serologic evidence of HSV-2 coinfection and the risk of perinatal HIV-1 transmission. There was also no association between antepartum genital tract evidence of HSV-2 coinfection and risk of perinatal HIV-1 transmission.

CONCLUSION

Women who were infected with HIV-1 with antepartum serologic and genital tract evidence of HSV-2 coinfection did not appear to have an increased risk of perinatal HIV-1 transmission. However, further investigations are needed to assess HSV-2 reactivation and the risk of perinatal HIV-1 transmission at the time of delivery.

Antiretroviral drug concentrations and HIV RNA in the genital tract of HIV-infected women receiving long-term highly active antiretroviral therapy

OBJECTIVE

Our objective was to determine antiretroviral drug concentrations and human immunodeficiency virus (HIV) RNA rebound in cervicovaginal fluid (CVF) in relation to blood plasma (BP) in women receiving suppressive highly active antiretroviral therapy (HAART).

METHODS

Thirty-four HIV-infected women who had plasma HIV RNA levels < or =80 copies/mL for at least 6 months were enrolled. Sixty-eight paired CVF and BP drug concentrations and HIV RNA levels were determined before and 3-4 h after drug administration. For each woman and antiretroviral drug, the CVF:BP drug concentration ratios before and after drug administration were calculated. The nonparametric Wilcoxon rank sum test was used to determine if these ratios were different from 1.0.

RESULTS

Lamivudine (administered to 20 patients) and tenofovir (administered to 16) had significantly higher concentrations in CVF than in BP before drug administration, with mean CVF:BP concentration ratios of 3.19 (95% confidence interval, 1.2-8.5) and 5.2 (95% confidence interval, 1.2-22.6), respectively. Efavirenz (administered to 13 patients) and lopinavir (administered to 6) had significantly lower concentrations in CVF, with mean CVF:BP concentration ratios of 0.01 (95% confidence interval, 0.00-0.03) and 0.03 (0.01-0.11), respectively. During the study visit (median time after enrollment, 6 months), BP and CVF detectable HIV RNA levels were observed 7 patients (20.6%) and 1 patient (2.9%), respectively.

CONCLUSION

Despite lower CVF concentrations of key HAART components, such as efavirenz and lopinavir, virologic rebound was rare. The high concentrations of tenofovir and lamivudine in CVF may have implications for the prevention of sexual transmission during HAART and for pre-exposure or postexposure prophylaxis.

[Why are HIV-infected infants still being born in Spain?]

INTRODUCTION

Despite the success of preventive measures against mother-to-child transmission (MTCT) of human immunodeficiency virus-1 and -2 (HIV-1 and -2) in developed countries, HIV-infected infants continue to be born. The aim of this study was to evaluate failures in the prevention of MTCT and the clinical characteristics of infected infants.

METHODS

The Foundation for the Investigation and Prevention of AIDS in Spain (FIPSE) Cohort in Madrid prospectively follows up children at risk of MTCT HIV born in eight public hospitals in Madrid. From May 2000 to December 2005, 632 children born to HIV-infected mothers were evaluated. Data from pregnancy follow-up, antiretroviral therapy (ART), and symptoms at diagnosis in infected infants were analyzed.

RESULTS

Nine infants were infected. The rate of vertical transmission was 1.42 (95% CI 0.7-2.68). Of the nine mothers, seven had not received ART during pregnancy (and five had not received ART at delivery). Of the mothers who received ART, one had only done so for the last month of pregnancy. Two infants were given three drugs as prevention of MTCT, one received bitherapy and six received monotherapy. The median age at diagnosis was 2.4 months (range 7 days-2 years). The mean plasma viral load at diagnosis was 276,000 copies/ml (range: 11,900-1,000,000). Five of the infants were symptomatic at diagnosis (P. jirovaci pneumonia in two, sepsis in one, recurrent bacterial infections in one, hepatosplenomegaly in one). Four of the nine infants had been admitted to hospital prior to HIV diagnosis.

DISCUSSION

Missed opportunities for the prevention of MTCT were identified in eight of the nine HIV-infected infants (89%). Administration of AZT during labor in HIV-infected mothers and triple therapy for the prevention of MTCT in high risk infants is not universal. Hospital admission in young infants at risk might lead to suspicion of infection in infants born to HIV-infected mothers. Improved implementation of all the preventive measures for MTCT should be encouraged.

Intrapartum transmission after mucosal exposure to HIV was not observed with single-dose nevirapine for mother and child

BACKGROUND

Intrapartum transmission of HIV has been reported to be associated with HIV in oropharyngeal secretions (OPSs) of the child. In this study, we analyze the frequency of intrapartum transmission after mucosal exposure to HIV after administration of single-dose nevirapine.

METHODS

Eighty mothers and their children participating in a prevention of mother-to-child transmission of HIV program in Uganda who took a single dose of nevirapine according to the HIVNET012 protocol participated in the study. HIV-1 was quantified by polymerase chain reaction (PCR) in the mothers' and children's plasma, in cervicovaginal secretions (CVSs), and in the children's OPSs. Intrapartum transmission was defined as a positive HIV-1 RNA PCR result at week 1 or 2 after birth and a previously negative PCR result.

RESULTS

Ninety-seven percent of children had detectable nevirapine in their OPS (median = 592 ng/mL). Fifty-seven (81%) children had HIV-negative OPSs, and 13 (19%) had HIV-positive OPSs. All children of mothers with HIV-negative CVSs had HIV-negative OPSs. HIV-1 levels of OPSs and CVSs correlated (r = 0.33, P = 0.027). None of the babies with detectable HIV-1 in the OPSs became infected by means of intrapartum transmission.

CONCLUSION

Intrapartum HIV infection was not observed after mucosal exposure to HIV-1 after administration of a single dose of nevirapine to the mother and child.

Biological mechanisms of vertical human immunodeficiency virus (HIV-1) transmission

In the absence of interventions, 30-45% of exposed infants acquire human immunodeficiency virus type 1 (HIV-1) through mother-to-child transmission. It remains unclear why some infants become infected while others do not, despite significant exposure to HIV-1 in utero, during delivery and while breastfeeding. Here we discuss the correlates of vertical transmission with an emphasis on factors that increase maternal HIV-1 levels, either systemically or locally in genital secretions and breast milk. Immune responses may influence maternal viral load, and data suggest that maternal neutralising antibodies reduce infection rates. In addition, infants may be capable of mounting HIV-specific cellular immune responses. We propose that both humoral and cellular responses are necessary to reduce infection because cell-free as well as cell-associated virus appears to play a role in vertical transmission. These distinct forms of the virus may be targeted most effectively by different components of the immune system. We also discuss the use of antiretrovirals to reduce transmission, focusing on the mechanisms of action of regimens currently used in developing country settings. We conclude that prevention relies not only on reducing maternal HIV-1 levels within blood, genital tract and breast milk, but also on pre- and/or post-exposure prophylaxis to the infant. However, HIV-1 has the capacity to mutate under drug pressure and rapidly acquires mutations conferring antiretroviral resistance. This review concludes with data on persistence of low-level resistance after delivery as well as recent guidelines for maternal and infant regimens designed to limit resistance.

Relationship between plasma selenium concentrations and lower genital tract levels of HIV-1 RNA and interleukin type 1beta

OBJECTIVE

To examine the relationship between selenium nutritional status and intermediates of human immunodeficiency virus (HIV)-1 transmission.

DESIGN

Prospective cohort study.

SETTING

A study clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania.

SUBJECTS

A total of 340 HIV-1-infected pregnant women with gestational ages 12-27 weeks.

METHODS

Women's plasma selenium concentrations were determined at enrollment and modeled as tertiles (tertile 1: <114 microg/l (reference); tertile 2: 114-131 microg/l; tertile 3: >131 microg/l). Cervicovaginal lavage specimens were obtained at 36 weeks of gestation to determine HIV-1 RNA and interleukin-1beta (IL-1beta) levels. In subgroup analyses, 123 women with genital tract infections at enrollment were excluded.

RESULTS

Plasma selenium concentrations >or=114 microg/l were related to increased risk of lower-genital shedding of HIV-1 RNA. Excluding women with genital tract infections strengthened the associations (relative risk (RR) tertile 2: 1.46, 95% confidence interval (CI)=1.10, 1.92; RR tertile 3: 1.39, 95% CI=1.05, 1.84). There was evidence for an association between plasma selenium concentrations >or=114 microg/l and increased HIV-1 RNA levels among the entire cohort and after excluding women with genital tract infections. There was no association between plasma selenium and IL-1beta concentrations.

CONCLUSIONS

High selenium status may lead to increased risk of genital HIV-1 shedding, but data from other studies indicate that the evidence is mixed. Results from ongoing selenium trials are awaited to clarify the impact of selenium on HIV-1-related transmission endpoints.

SPONSORSHIP

National Institute of Child Health and Human Development (NICHD R01 32257) and the Fogarty International Center (NIH D43 TW00004).

Quantification of genital human immunodeficiency virus type 1 (HIV-1) DNA in specimens from women with low plasma HIV-1 RNA levels typical of HIV-1 nontransmitters

Studies of human immunodeficiency virus type 1 (HIV-1) transmission suggest that genital HIV-1 RNA and DNA may both be determinants of HIV-1 infectivity. Despite its potential role in HIV-1 transmission, there are limited quantitative data on genital HIV-1 DNA. Here we validated an in-house real-time PCR method for quantification of HIV-1 DNA in genital specimens. In reactions with 100 genomes to 1 genome isolated from a cell line containing one HIV-1 provirus/cell, this real-time PCR assay is linear and agrees closely with a commercially available real-time PCR assay specific for a cellular housekeeping gene. In mock genital samples spiked with low numbers of HIV-1-infected cells such that the expected HIV-1 DNA copy number/reaction was 100, 10, or 5, the average copy number/reaction was 80.2 (standard deviation [SD], 28.3), 9.1 (SD, 5.4), or 3.1 (SD, 2.1), respectively. We used this method to examine genital HIV-1 DNA levels in specimens from women whose low plasma HIV-1 RNA levels are typical of HIV-1 nontransmitters. The median HIV-1 DNA copy number in endocervical secretions from these women (1.8 HIV-1 DNA copies/10,000 cells) was lower than that for women with higher plasma HIV-1 RNA levels (16.6 HIV-1 DNA copies/10,000 cells) (P=0.04), as was the median HIV-1 DNA copy number in vaginal secretions (undetectable versus 1.0 HIV-1 DNA copies/10,000 cells). These data suggest that women with low plasma HIV-1 RNA and thus a predicted low risk of HIV-1 transmission have low levels of genital HIV-1 cell-associated virus. The assay described here can be utilized in future efforts to examine the role of cell-associated HIV-1 in transmission.

Trichomonas vaginalis lipophosphoglycan triggers a selective upregulation of cytokines by human female reproductive tract epithelial cells

Trichomonas vaginalis is one of the most common nonviral sexually transmitted human infections and, worldwide, has been linked to increased incidence of human immunodeficiency virus type 1 transmission, preterm delivery, low birth weight, cervical cancer, and vaginitis. The molecular pathways that are important in initiating host inflammatory and immune responses to T. vaginalis are poorly understood. Here we report interactions of human cervicovaginal epithelial cells with the most abundant cell surface glycoconjugate of the parasite, the T. vaginalis lipophosphoglycan (LPG). Purified LPG mediated the adhesion of parasites to human vaginal epithelial cells in a dose-dependent manner. Furthermore, T. vaginalis LPG (but not LPG from Tritrichomonas foetus, the causative agent of bovine trichomoniasis) induced a selective upregulation of chemotactic cytokines by human endocervical, ectocervical, and vaginal epithelial cells, which do not express Toll-like receptor 4/MD2. The T. vaginalis LPG triggered interleukin 8 (IL-8), which promotes the adhesion and transmigration of neutrophils across the endothelium, and macrophage inflammatory protein 3alpha, which is a chemoattractant for immune cells and is essential for dendritic cell maturation. These effects were dose dependent and sustained in the absence of cytotoxicity and IL-1beta release and utilized, at least in part, a signaling pathway independent from the Toll-like/IL-1 receptor adaptor protein MyD88.