Lower levels of HIV-2 than HIV-1 in the female genital tract: correlates and longitudinal assessment of viral shedding

Mother-to-child HIV-2 transmission: comparison with HIV-1 and evaluation of factors influencing the rate of transmission. A systematic review

A review and collection of data on HIV-2 mother-to-child transmission (MTCT) is absent in the literature. This systematic review and meta-analysis aims to provide a pooled estimate of the rate of HIV-2 MTCT and to identify factors influencing the rate of transmission. PubMed and EMBASE were used to identify eligible publications using a sensitive search strategy. All publications until February 2021 were considered; 146 full-text articles were assessed. Observational studies describing the rate of HIV-2 MTCT in a defined HIV-2 infected study population were included. Other publication types and studies describing HIV-1 or dually infected populations were excluded. Nine studies consisting of 901 mother-child pairs in West Africa, France and Portugal were included in the meta-analysis. The pooled rate estimate of HIV-2 MTCT for antiretroviral therapy-naïve women was 0.2% (95% CI 0.03 to 1.47%), considerably lower than that for HIV-1. The levels of maternal HIV RNA and CD4 cell count were positively related to the vertical transmission rate. Maternal HIV-2 infection did not significantly affect perinatal mortality. It was concluded that the vertical transmission of HIV-2 is lower than that of HIV-1. Maternal viral load and CD4 cell count appear to influence the rate of HIV-2 MTCT.

The first case of HIV-2 in Scotland

HIV-1 infects an estimated 37 million people worldwide, while the rarer HIV-2 infects 1–2 million worldwide. HIV-2 is mainly restricted to West African countries. The majority of patients in Scotland are diagnosed with HIV-1, but in 2013 the West of Scotland Specialist Virology Centre (WoSSVC) diagnosed Scotland’s first HIV-2 positive case in a patient from Côte d’Ivoire. HIV-2 differs from HIV-1 in terms of structural viral proteins, viral transmissibility, prolonged period of latency, intrinsic resistance to certain antivirals and how to monitor the effectiveness of treatment. Over the course of 5 years the patient has required several changes in treatment due to both side effects and pill burden. This case highlights the complexity of HIV-2 patient management over time.

A Trial of a Single-tablet Regimen of Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir Disoproxil Fumarate for the Initial Treatment of Human Immunodeficiency Virus Type 2 Infection in a Resource-limited Setting: 48-Week Results From Senegal, West Africa

Background

There is an urgent need for safe and effective antiretroviral therapy (ART) for human immunodeficiency virus type 2 (HIV-2) infection. We undertook the first clinical trial of a single-tablet regimen containing elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (E/C/F/TDF) to assess its effectiveness in HIV-2-infected individuals in Senegal, West Africa.

Methods

HIV-2-infected, ART-naive adults with World Health Organization stage 3-4 disease or CD4 count <750 cells/μL were eligible for this 48-week, open-label trial. We analyzed HIV-2 viral loads (VL), CD4 counts, clinical and adverse events, mortality, and loss to follow-up.

Results

We enrolled 30 subjects who initiated E/C/F/TDF. Twenty-nine subjects completed 48 weeks of follow-up. The majority were female (80%). There were no deaths, no new AIDS-associated clinical events, and 1 loss to follow-up. The median baseline CD4 count was 408 (range, 34-747) cells/μL, which increased by a median 161 (range, 27-547) cells/μL at week 48. Twenty-five subjects had baseline HIV-2 VL of <50 copies/mL of plasma. In those with detectable HIV-2 VL, the median was 41 (range, 10-6135) copies/mL. Using a modified intent-to-treat analysis (US Food and Drug Administration Snapshot method), 28 of 30 (93.3%; 95% confidence interval, 77.9%-99.2%) had viral suppression at 48 weeks. The 1 subject with virologic failure had multidrug-resistant HIV-2 (reverse transcriptase mutation: K65R; integrase mutations: G140S and Q148R) detected at week 48. There were 8 grade 3-4 adverse events; none were deemed study related. Adherence and acceptability were good.

Conclusions

Our data suggest that E/C/F/TDF, a once-daily, single-tablet-regimen, is safe, effective, and well tolerated. Our findings support the use of integrase inhibitor-based regimens for HIV-2 treatment.

Clinical Trials Registration

NCT02180438.

T-cell and B-cell perturbations are similar in ART-naive HIV-1 and HIV-1/2 dually infected patients

BACKGROUND

HIV-2 may slow progression of a subsequently acquired HIV-1 infection through cross-neutralizing antibodies and polyfunctional CD8 T cells. We hypothesized that HIV-1/2 dually infected patients compared with HIV-1-infected patients had more preserved immune maturation subsets and less immune activation of T and B cells.

METHODS

ART-naive patients with HIV-1 (n = 83) or HIV-1/2 dual (n = 27) infections were included in this cross-sectional study at an HIV clinic in Guinea-Bissau. Peripheral blood mononuclear cells (PBMCs) were analyzed by flow cytometry according to T-cell maturation and activation, regulatory T-cell fraction, and B-cell maturation and activation.

RESULTS

HIV-1/2 dually infected patients had lower levels of HIV-1 RNA compared with patients with HIV-1 infection, but the levels of total HIV RNA (HIV-1 and HIV-2) were similar in the two patient groups. T-cell maturation, and proportions of regulatory T cells (FoxP3+) were also similar in the two groups. HIV-1/2 dually infected patients had higher proportions of CD4 and CD8 T cells positive for the activation marker CD38, but there was no difference in other T-cell activation markers (CD28, CTLA-4, PD-1). HIV-1/2 dually infected patients also had higher proportions of IgM-only B cells and plasmablasts.

CONCLUSION

HIV-1/2 was not associated with less immune perturbations than for HIV-1 infection.

90-90-90 for HIV-2? Ending the HIV-2 epidemic by enhancing care and clinical management of patients infected with HIV-2

Distinct from HIV-1 and often neglected in the global campaign to end the AIDS epidemic, HIV-2 presents unique and underappreciated challenges in diagnosis, clinical care, antiretroviral therapy (ART), and HIV programmatic management. Here, we review the epidemiology and natural history of HIV-2, diagnostics and algorithms for accurately diagnosing and differentiating HIV-2 from HIV-1, the unique features of HIV-2 ART and drug resistance, and the clinical care and management of patients infected with HIV-2 in both developed and resource-limited settings. Ultimately, further research is needed to address the gaps in our knowledge of HIV-2 infection, increased resources are needed to specifically target HIV-2 as part of the UNAIDS/WHO 90-90-90 campaign to end AIDS, and increased determination is needed to better advocate for inclusion of people living with HIV-2 in global HIV/AIDS initiatives.

Antiretroviral treatment of HIV-2 infection

HIV-2 is a neglected virus despite estimates of 1–2 million people being infected worldwide. AIDS develops more slowly in HIV-2 than HIV-1. Outside endemic regions, HIV-2 is mostly found in immigrants from west Africa or their sex partners. There are four major caveats when treating HIV-2. First, some antiretrovirals are not or only partially active against HIV-2. Second, CD4 declines in HIV-2 occur slowly, but CD4 recovery is smaller with antiretroviral treatment. Third, both virological failure and rapid emergence of drug resistance occur more frequently in HIV-2 than HIV-1. Finally, misdiagnosis of HIV-2 in patients wrongly considered as infected with HIV-1 or in those dually infected may result in treatment failures with undetectable HIV-1 RNA. Integrase inhibitors, and especially dolutegravir, should be part of any preferred HIV-2 antiretroviral combination nowadays.

HIV type 2 epidemic in Spain: challenges and missing opportunities

: HIV type 2 (HIV-2) is a neglected virus despite estimates of 1-2 million people infected worldwide. HIV-2 is less efficiently transmitted than HIV-1 by sex and from mother to child. Although AIDS may develop in HIV-2 carriers, it takes longer than in HIV-1-infected patients. In contrast with HIV-1 infection, there is no global pandemic caused by HIV-2, as the virus is largely confined to West Africa. In a less extent and due to socioeconomic ties and wars, HIV-2 is prevalent in Portugal and its former colonies in Brazil, India, Mozambique and Angola. Globally, HIV-2 infections are steadily declining over time. A total of 338 cases of HIV-2 infection had been reported at the Spanish HIV-2 registry until December 2016, of whom 63% were men. Overall 72% were sub-Saharan Africans, whereas 16% were native Spaniards. Dual HIV-1 and HIV-2 coinfection was found in 9% of patients. Heterosexual contact was the most likely route of HIV-2 acquisition in more than 90% of cases. Roughly one-third presented with CD4 cell counts less than 200 cells/μl and/or AIDS clinical events. Plasma HIV-2 RNA was undetectable at baseline in 40% of patients. To date, one-third of HIV-2 carriers have received antiretroviral therapy, using integrase inhibitors 32 individuals. New diagnoses of HIV-2 in Spain have remained stable since 2010 with an average of 15 cases yearly. Illegal immigration from Northwestern African borders accounts for over 75% of new HIV-2 diagnoses. Given the relatively large community of West Africans already living in Spain and the continuous flux of immigration from endemic regions, HIV-2 infection either alone or as coinfection with HIV-1 should be excluded once in all HIV-seroreactive persons, especially when showing atypical HIV serological profiles, immunovirological disconnect (CD4 cell count loss despite undetectable HIV-1 viremia) and/or high epidemiological risks (birth in or sex partners from endemic regions).

ART influences HIV persistence in the female reproductive tract and cervicovaginal secretions

The recently completed HIV prevention trials network study 052 is a landmark collaboration demonstrating that HIV transmission in discordant couples can be dramatically reduced by treating the infected individual with antiretroviral therapy (ART). However, the cellular and virological events that occur in the female reproductive tract (FRT) during ART that result in such a drastic decrease in transmission were not studied and remain unknown. Here, we implemented an in vivo model of ART in BM/liver/thymus (BLT) humanized mice in order to better understand the ability of ART to prevent secondary HIV transmission. We demonstrated that the entire FRT of BLT mice is reconstituted with human CD4+ cells that are shed into cervicovaginal secretions (CVS). A high percentage of the CD4+ T cells in the FRT and CVS expressed CCR5 and therefore are potential HIV target cells. Infection with HIV increased the numbers of CD4+ and CD8+ T cells in CVS of BLT mice. Furthermore, HIV was present in CVS during infection. Finally, we evaluated the effect of ART on HIV levels in the FRT and CVS and demonstrated that ART can efficiently suppress cell-free HIV-RNA in CVS, despite residual levels of HIV-RNA+ cells in both the FRT and CVS.

Infection with human retroviruses other than HIV-1: HIV-2, HTLV-1, HTLV-2, HTLV-3 and HTLV-4

HIV-1 is the most prevalent retrovirus, with over 30 million people infected worldwide. Nevertheless, infection caused by other human retroviruses like HIV-2, HTLV-1, HTLV-2, HTLV-3 and HTLV-4 is gaining importance. Initially confined to specific geographical areas, HIV-2, HTLV-1 and HTLV-2 are becoming a major concern in non-endemic countries due to international migration flows. Clinical manifestations of retroviruses range from asymptomatic carriers to life-threatening conditions, such as AIDS in HIV-2 infection or adult T-cell lymphoma/leukemia or tropical spastic paraparesis in HTLV-1 infection. HIV-2 is naturally resistant to some antiretrovirals frequently used to treat HIV-1 infection, but it does have effective antiretroviral therapy options. Unfortunately, HTLV still has limited therapeutic options. In this article, we will review the epidemiological, clinical, diagnostic, pathogenic and therapeutic aspects of infections caused by these human retroviruses.

The association between HPV, intraepithelial lesions and HIV-1 shedding in anogenital specimens in two contrasting populations: Senegalese women and American MSM

In light of observational evidence showing an association between human papillomavirus (HPV) and HIV acquisition risk, the potential of HPV vaccination as a HIV prevention strategy is being considered. However, the relationship between HPV and HIV infectiousness is unclear. In this analysis, the relationship between HPV and anogenital HIV shedding (a proxy for transmissibility) was assessed in two diverse populations: HIV-infected Senegalese women and American men who have sex with men (MSM). Data from two longitudinal studies with similar protocols were analysed. In both studies, anogenital specimens underwent cytologic, HPV DNA, and HIV-1 RNA testing. Analyses utilised multivariable generalised estimating equations that controlled for age, hormonal contraceptive use (women only), plasma viral load, CD4 count and treatment status. Among Senegalese women, cervical lesions were significantly associated with the detection of HIV RNA (aRR = 1.16 [1.05, 1.28]) and log10 cervicovaginal fluids viral load (adjusted β = 0.56 [0.12, 1.01]). No association was detected between HPV (of any type) and cervicovaginal HIV shedding (aRRDetection = 0.90 [0.77, 1.06]; βQuantity = -0.31 [-0.78, 0.16]). Among MSM, having multiple HPV infections (versus no HPV infection) was associated with anal HIV shedding (aRRDetection = 1.05 [1.01, 1.09]; βQuantity = 0.11 [0.01, 0.21]). Anal lesions were not associated with anal HIV shedding (aRRLESIONS = 0.99 [0.96, 1.03], βLESIONS = -0.05 [-0.13, 0.03]). Although HPV and intraepithelial lesions were associated with anogenital HIV shedding in crude analyses, the measures of effect were attenuated in adjusted analyses. Our data suggest that the prevention of HPV through vaccination is unlikely to substantially affect HIV infectiousness among persons living with HIV.

Changes in plasma viral load and penile viral shedding after circumcision among HIV-positive men in Kisumu, Kenya

BACKGROUND

We conducted a prospective cohort study of HIV-positive men aged 18-35 years in Kisumu, Kenya to determine if medical circumcision of ART-naive HIV-positive men leads to increased viral load and penile viral shedding.

METHODS

From 108 HIV-positive men circumcised by forceps-guided method and followed up weekly for 6 weeks, 29 men were evaluated for penile viral shedding. HIV-1 RNA was measured in plasma from 19 men and in penile lavage samples from 29 men. Samples were collected before circumcision and at weekly intervals for 6 weeks or until the circumcision wound was healed. CD4 T-cell counts from 102 HIV-positive men were determined at baseline and at 2 weeks thereafter. Wounds with healthy scar, no scab or opening, and no suture tracks were deemed healed.

RESULTS

Among 65 ART-naive men, mean CD4 T-cell count increased from 417 cells per cubic millimeter at baseline to 456 cells per cubic millimeter after 2 weeks (P = 0.04), but did not change in the 37 men on ART (P = 0.81). There was no change in HIV plasma viral load (P = 0.36), but penile viral shedding rose significantly within 1 week after circumcision then declined to undetectable levels by 6 weeks (multivariate analysis of variance; P < 0.001). In 28 of 29 men (96.6%), there was no detectable viral shedding after certification of wound healing.

CONCLUSIONS

Medical circumcision among ART-naive HIV-infected men results in a transitory rise in penile viral shedding before complete wound healing, which should pose no additional risk of HIV transmission if men adhere to 6 weeks postcircumcision sexual abstinence and use condoms consistently.

The Neonatal Fc receptor (FcRn) enhances human immunodeficiency virus type 1 (HIV-1) transcytosis across epithelial cells

The mechanisms by which human immunodeficiency virus type 1 (HIV-1) crosses mucosal surfaces to establish infection are unknown. Acidic genital secretions of HIV-1-infected women contain HIV-1 likely coated by antibody. We found that the combination of acidic pH and Env-specific IgG, including that from cervicovaginal and seminal fluids of HIV-1-infected individuals, augmented transcytosis across epithelial cells as much as 20-fold compared with Env-specific IgG at neutral pH or non-specific IgG at either pH. Enhanced transcytosis was observed with clinical HIV-1 isolates, including transmitted/founder strains, and was eliminated in Fc neonatal receptor (FcRn)-knockdown epithelial cells. Non-neutralizing antibodies allowed similar or less transcytosis than neutralizing antibodies. However, the ratio of total:infectious virus was higher for neutralizing antibodies, indicating that they allowed transcytosis while blocking infectivity of transcytosed virus. Immunocytochemistry revealed abundant FcRn expression in columnar epithelia lining the human endocervix and penile urethra. Acidity and Env-specific IgG enhance transcytosis of virus across epithelial cells via FcRn and could facilitate translocation of virus to susceptible target cells following sexual exposure.

HIV-1 causes a sexually transmitted disease. However, the mechanisms employed by the virus to cross genital tract tissue and establish infection are uncertain. Since cervicovaginal fluid is acidic and HIV-1 in cervicovaginal fluid is likely coated with antibodies, we explored the effect of low pH and HIV-1-specific antibodies on transcytosis, the movement of HIV-1 across tight-junctioned epithelial cells. We found that the combination of HIV-1-specific antibodies and low pH enhanced transcytosis as much as 20-fold. Virus that underwent transcytosis under these conditions was infectious, and infectivity was highly influenced by whether or not the antibody neutralized the virus. We observed enhanced transcytosis using antibody from cervicovaginal and seminal fluids and using transmitted/founder strains of HIV-1. We also found that the enhanced transcytosis was due to the Fc neonatal receptor (FcRn), which binds immune complexes at acidic pH and releases them at neutral pH. Finally, staining of human tissue revealed abundant FcRn expression on columnar epithelial cells of penile urethra and endocervix. Our findings reveal a novel mechanism wherein HIV-1 may facilitate its own transmission by usurping the antibody response directed against itself. These results have important implications for HIV vaccine development and for understanding the earliest events in HIV transmission.

HIV-1 outcompetes HIV-2 in dually infected Senegalese individuals with low CD4⁺ cell counts

OBJECTIVE

Dual infection with HIV-1 and HIV-2, which is not uncommon in West Africa, has implications for transmission, progression, and antiretroviral therapy (ART). Few studies have examined viral dynamics in this setting. Our objective was to directly compare HIV-1 and HIV-2 viral loads and to examine whether this relationship is associated with CD4⁺ cell count.

STUDY DESIGN

This is a retrospective analysis of data from observational cohort studies.

METHODS

We compared HIV-1 and HIV-2 viral loads from 65 dually infected, ART-naive Senegalese individuals. Participants provided blood, oral fluid, and cervicovaginal lavage (CVL) or semen samples for virologic and immunologic testing. We assessed relationships between HIV-1 and HIV-2 levels using linear regression with generalized estimating equations to account for multiple study visits.

RESULTS

After adjusting for CD4⁺ cell count, age, sex, and commercial sex work, HIV-1 RNA levels were significantly higher than HIV-2 levels in semen, CVL, and oral fluids. Despite similar peripheral blood mononuclear cell DNA levels among individuals with CD4⁺ cell counts above 500 cells/μl, individuals with CD4⁺ cell counts below 500 cells/μl had higher HIV-1 and lower HIV-2 DNA levels. Individuals with high CD4⁺ cell counts had higher mean HIV-1 plasma RNA viral loads than HIV-2, with HIV-1 levels significantly higher and HIV-2 levels trending toward lower mean viral loads among individuals with low CD4⁺ cell counts.

CONCLUSION

Our data are consistent with the hypothesis that with disease progression, HIV-1 outcompetes HIV-2 in dually infected individuals. This finding helps explain differences in prevalence and outcomes between HIV-1, HIV-2, and HIV-dual infection.

Characteristics of HIV-2 and HIV-1/HIV-2 Dually Seropositive Adults in West Africa Presenting for Care and Antiretroviral Therapy: The IeDEA-West Africa HIV-2 Cohort Study

Background

HIV-2 is endemic in West Africa. There is a lack of evidence-based guidelines on the diagnosis, management and antiretroviral therapy (ART) for HIV-2 or HIV-1/HIV-2 dual infections. Because of these issues, we designed a West African collaborative cohort for HIV-2 infection within the framework of the International epidemiological Databases to Evaluate AIDS (IeDEA).

Methods

We collected data on all HIV-2 and HIV-1/HIV-2 dually seropositive patients (both ARV-naive and starting ART) and followed-up in clinical centres in the IeDEA-WA network including a total of 13 clinics in five countries: Benin, Burkina-Faso Côte d’Ivoire, Mali, and Senegal, in the West Africa region.

Results

Data was merged for 1,754 patients (56% female), including 1,021 HIV-2 infected patients (551 on ART) and 733 dually seropositive for both HIV-1 and HIV 2 (463 on ART). At ART initiation, the median age of HIV-2 patients was 45.3 years, IQR: (38.3–51.7) and 42.4 years, IQR (37.0–47.3) for dually seropositive patients (p = 0.048). Overall, 16.7% of HIV-2 patients on ART had an advanced clinical stage (WHO IV or CDC-C). The median CD4 count at the ART initiation is 166 cells/mm³, IQR (83–247) among HIV-2 infected patients and 146 cells/mm³, IQR (55–249) among dually seropositive patients. Overall, in ART-treated patients, the CD4 count increased 126 cells/mm³ after 24 months on ART for HIV-2 patients and 169 cells/mm³ for dually seropositive patients. Of 551 HIV-2 patients on ART, 5.8% died and 10.2% were lost to follow-up during the median time on ART of 2.4 years, IQR (0.7–4.3).

Conclusions

This large multi-country study of HIV-2 and HIV-1/HIV-2 dual infection in West Africa suggests that routine clinical care is less than optimal and that management and treatment of HIV-2 could be further informed by ongoing studies and randomized clinical trials in this population.

Population dynamics of HIV-2 in rural West Africa: comparison with HIV-1 and ongoing transmission at the heart of the epidemic

OBJECTIVES

To compare the population dynamics of HIV-2 and HIV-1, and to characterize ongoing HIV-2 transmission in rural Guinea-Bissau.

DESIGN

Phylogenetic and phylodynamic analyses using HIV-2 gag and env, and HIV-1 env sequences, combined with epidemiological data from a community cohort.

METHODS

Samples were obtained from surveys in 1989-1991, 1996-1997, 2003 and 2006-2007. Phylogenies were reconstructed using sequences from 103 HIV-2-infected and 56 HIV-1-infected patients using Bayesian Evolutionary Analysis by Sampling Trees (BEAST), a relaxed molecular clock and a Bayesian skyline coalescent model.

RESULTS

Bayesian skyline plots showed a strong increase in the 1990s of the HIV-1 effective population size (Ne) in the same period that the Ne of HIV-2 came into a plateau phase. The population dynamics of both viruses were remarkably similar following initial introduction. Incident infections were found more often in HIV-2 transmission clusters, with 55-58% of all individuals contributing to ongoing transmission. Some phylogenetically linked sexual partners had discordant viral loads (undetectable vs. detectable), suggesting host factors dictate the risk of disease progression in HIV-2. Multiple HIV-2 introductions into the cohort are evident, but ongoing transmission has occurred predominantly within the community.

CONCLUSION

Comparison of HIV-1 and HIV-2 phylodynamics in the same community suggests both viruses followed similar growth patterns following introduction, and is consistent with the hypothesis that HIV-1 may have played a role in the decline of HIV-2 via competitive exclusion. The source of ongoing HIV-2 transmission in the cohort appears to be new HIV-2 cases, rather than the pool of older infections established during the early growth of HIV-2.

Trends of HIV-1, HIV-2 and dual infection in women attending outpatient clinics in Senegal, 1990-2009

We assessed trends in the relative prevalences of HIV-1, HIV-2 and dual HIV-1/HIV-2 infection in 10,321 women attending outpatient clinics in Senegal between 1990 and 2009. The relative prevalence of HIV-1 (defined as the proportion of seropositive subjects having HIV-1) rose sharply from 38% in 1990 until 1993 (P < 0.001), whereupon it continued to rise, but at a slower rate, reaching 72% of HIV infections in 2009. As compared with HIV-1, the relative prevalence of HIV-2 decreased sharply from 54% in 1990 until 1993 (P < 0.001) and continued to decrease at a slower rate through 2009. The relative prevalence of dual infection, as compared with HIV-1, was stable from 1990 to 1993, but decreased slightly thereafter (P < 0.001). These study findings indicate that during the early 1990s, the relative prevalence of HIV-1 increased markedly, while the relative prevalence of HIV-2 decreased and the relative prevalence of dual infection remained stable in Senegal. From 1993 to 2009, the relative prevalence of HIV-1 increased at a slower rate, while the relative prevalences of HIV-2 and dual infection decreased. These results confirm trends in HIV prevalence observed in other West African populations and provide a critical update on HIV transmission risk among women in Senegal.

HIV shedding in the oral cavity: an assessment of HIV type, immunovirologic, demographic and oral factors

OBJECTIVE

To quantify the prevalence and burden of HIV type 2 (HIV-2) and HIV-1 RNA in the oral cavity of antiretroviral therapy-naive HIV-infected Senegalese individuals and to identify correlates of oral HIV viral loads.

DESIGN

A cross-sectional study of 163 HIV-1 and 27 HIV-2-infected antiretroviral therapy-naive Senegalese adults.

METHODS

Participants received clinical and oral exams and provided blood and oral wash samples for viral load and plasma CD4 count ascertainment. Logistic and interval regression models were used to identify univariate and multivariable associations between presence and level of oral HIV RNA and various immunovirologic, local and demographic factors.

RESULTS

Presence of detectable oral HIV RNA was less common in HIV-2-infected compared with HIV-1-infected study participants (33% vs 67%, OR 0.25, 95% CI 0.11 to 0.59). HIV type was no longer associated with oral shedding of HIV when plasma viral load was considered. Detection of oral HIV RNA was associated with increased plasma viral load in both HIV-1-infected and HIV-2-infected individuals (HIV-1, OR 1.89, 95% CI 1.24 to 2.61; HIV-2, OR 1.93, 95% CI 1.1 to 3.39). Oral HIV-1 detection was also associated with periodontal disease (OR 3.02, 95% CI 1.16 to 7.87).

CONCLUSIONS

Oral shedding of HIV-2 RNA is less common than HIV-1 RNA, a likely consequence of lower overall viral burden. Both systemic and local factors may contribute to shedding of HIV in the oral cavity.

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.

Innate immune factors associated with HIV-1 transmission

PURPOSE OF REVIEW

Relatively little is known with regards to the mechanisms of HIV-1 transmission across a mucosal surface and more specifically what effects host factors have on influencing infection and early viral dissemination. The purpose of this review is to summarize which factors of the innate immune response can influence mucosal transmission of HIV-1.

RECENT FINDINGS

A large array of cell types reside at the mucosal surface ranging from Langerhans cells, dendritic cells, macrophages as well as CD4⁺ lymphocytes, all of which interact with the virus in a unique and different way and which can contribute to risk of HIV-1 transmission. Numerous factors present in bodily secretions as well as the carrier fluids of HIV-1 (breast milk, vaginal secretions, semen and intestinal mucus) can influence transmission and early virus replication. These range from cytokines, chemokines, small peptides, glycoproteins as well as an array of host intracellular molecules which can influence viral uncoating, reverse transcription as well as egress from the infected cell.

SUMMARY

Better understanding the cellular mechanisms of HIV-1 transmission and how different host factor can influence infection will aide in the future development of vaccines, microbicides, and therapies.

HIV-2 integrase variation in integrase inhibitor-naïve adults in Senegal, West Africa

Background

Antiretroviral therapy for HIV-2 infection is hampered by intrinsic resistance to many of the drugs used to treat HIV-1. Limited studies suggest that the integrase inhibitors (INIs) raltegravir and elvitegravir have potent activity against HIV-2 in culture and in infected patients. There is a paucity of data on genotypic variation in HIV-2 integrase that might confer intrinsic or transmitted INI resistance.

Methods

We PCR amplified and analyzed 122 HIV-2 integrase consensus sequences from 39 HIV-2–infected, INI-naive adults in Senegal, West Africa. We assessed genetic variation and canonical mutations known to confer INI-resistance in HIV-1.

Results

No amino acid-altering mutations were detected at sites known to be pivotal for INI resistance in HIV-1 (integrase positions 143, 148 and 155). Polymorphisms at several other HIV-1 INI resistance-associated sites were detected at positions 72, 95, 125, 154, 165, 201, 203, and 263 of the HIV-2 integrase protein.

Conclusion

Emerging genotypic and phenotypic data suggest that HIV-2 is susceptible to the new class of HIV integrase inhibitors. We hypothesize that intrinsic HIV-2 integrase variation at “secondary” HIV-1 INI-resistance sites may affect the genetic barrier to HIV-2 INI resistance. Further studies will be needed to assess INI efficacy as part of combination antiretroviral therapy in HIV-2–infected patients.

Prevalence and risk determinants of HIV-1 and HIV-2 infections in pregnant women in Bissau

OBJECTIVES

To analyse the risk determinants of HIV-1 and HIV-2 infections in pregnant women in Bissau.

METHODS

Pregnant women attending the antenatal clinics of Bissau between January 2002 and June 2006 were consecutively tested unless they opted out.

RESULTS

Among 23,869 tested women the overall prevalence of HIV-1 was 5.7%, that of HIV-2 was 2.4%, and these included the 0.7% prevalence of HIV-1 and HIV-2 duals. The main factors associated with the risk of HIV-1 infection were older age, occupation and number of sexual partners. Beafada and Mandinga ethnic groups were at greater risk of presenting HIV-1, and Bijago and Papel at lower risk. The factors associated with the risk of HIV-2 were age, literacy and occupation; the Beafada were at greater risk than the other ethnic groups.

CONCLUSIONS

The prevalence of HIV-2 infection decreased overtime, whereas that of HIV-1 infection remained substantially stable, but was higher than that observed in previous studies. The rapid decline in the rates of HIV-2 infection suggests that many of the factors that allowed its exponential growth in the past have now been partially removed, and that sexual and vertical transmission have not been sufficient to maintain and extend the epidemic.