David N. Burns

Prevention of HIV-1 Infection with Early Antiretroviral Therapy

BACKGROUND Antiretroviral therapy that reduces viral replication could limit the transmission of human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples. METHODS In nine countries, we enrolled 1763 couples in which one partner was HIV-1-positive and the other was HIV-1-negative; 54% of the subjects were from Africa, and 50% of infected partners were men. HIV-1-infected subjects with CD4 counts between 350 and 550 cells per cubic millimeter were randomly assigned in a 1:1 ratio to receive antiretroviral therapy either immediately (early therapy) or after a decline in the CD4 count or the onset of HIV-1-related symptoms (delayed therapy). The primary prevention end point was linked HIV-1 transmission in HIV-1-negative partners. The primary clinical end point was the earliest occurrence of pulmonary tuberculosis, severe bacterial infection, a World Health Organization stage 4 event, or death. RESULTS As of February 21, 2011, a total of 39 HIV-1 transmissions were observed (incidence rate, 1.2 per 100 person-years; 95% confidence interval [CI], 0.9 to 1.7); of these, 28 were virologically linked to the infected partner (incidence rate, 0.9 per 100 person-years, 95% CI, 0.6 to 1.3). Of the 28 linked transmissions, only 1 occurred in the early-therapy group (hazard ratio, 0.04; 95% CI, 0.01 to 0.27; P<0.001). Subjects receiving early therapy had fewer treatment end points (hazard ratio, 0.59; 95% CI, 0.40 to 0.88; P=0.01). CONCLUSIONS The early initiation of antiretroviral therapy reduced rates of sexual transmission of HIV-1 and clinical events, indicating both personal and public health benefits from such therapy. (Funded by the National Institute of Allergy and Infectious Diseases and others; HPTN 052 ClinicalTrials.gov number, NCT00074581.).

Preexposure Chemoprophylaxis for HIV Prevention in Men Who Have Sex with Men

BACKGROUND Antiretroviral chemoprophylaxis before exposure is a promising approach for the prevention of human immunodeficiency virus (HIV) acquisition. METHODS We randomly assigned 2499 HIV-seronegative men or transgender women who have sex with men to receive a combination of two oral antiretroviral drugs, emtricitabine and tenofovir disoproxil fumarate (FTC-TDF), or placebo once daily. All subjects received HIV testing, risk-reduction counseling, condoms, and management of sexually transmitted infections. RESULTS The study subjects were followed for 3324 person-years (median, 1.2 years; maximum, 2.8 years). Of these subjects, 10 were found to have been infected with HIV at enrollment, and 100 became infected during follow-up (36 in the FTC-TDF group and 64 in the placebo group), indicating a 44% reduction in the incidence of HIV (95% confidence interval, 15 to 63; P=0.005). In the FTC-TDF group, the study drug was detected in 22 of 43 of seronegative subjects (51%) and in 3 of 34 HIV-infected subjects (9%) (P<0.001). Nausea was reported more frequently during the first 4 weeks in the FTC-TDF group than in the placebo group (P<0.001). The two groups had similar rates of serious adverse events (P=0.57). CONCLUSIONS Oral FTC-TDF provided protection against the acquisition of HIV infection among the subjects. Detectable blood levels strongly correlated with the prophylactic effect. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT00458393.).

Uptake of pre-exposure prophylaxis, sexual practices, and HIV incidence in men and transgender women who have sex with men: a cohort study

BACKGROUND The effect of HIV pre-exposure prophylaxis (PrEP) depends on uptake, adherence, and sexual practices. We aimed to assess these factors in a cohort of HIV-negative people at risk of infection. METHODS In our cohort study, men and transgender women who have sex with men previously enrolled in PrEP trials (ATN 082, iPrEx, and US Safety Study) were enrolled in a 72 week open-label extension. We measured drug concentrations in plasma and dried blood spots in seroconverters and a random sample of seronegative participants. We assessed PrEP uptake, adherence, sexual practices, and HIV incidence. Statistical methods included Poisson models, comparison of proportions, and generalised estimating equations. FINDINGS We enrolled 1603 HIV-negative people, of whom 1225 (76%) received PrEP. Uptake was higher among those reporting condomless receptive anal intercourse (416/519 [81%] vs 809/1084 [75%], p=0·003) and having serological evidence of herpes (612/791 [77%] vs 613/812 [75%] p=0·03). Of those receiving PrEP, HIV incidence was 1·8 infections per 100 person-years, compared with 2·6 infections per 100 person-years in those who concurrently did not choose PrEP (HR 0·51, 95% CI 0·26-1·01, adjusted for sexual behaviours), and 3·9 infections per 100 person-years in the placebo group of the previous randomised phase (HR 0·49, 95% CI 0·31-0·77). Among those receiving PrEP, HIV incidence was 4·7 infections per 100 person-years if drug was not detected in dried blood spots, 2·3 infections per 100 person-years if drug concentrations suggested use of fewer than two tablets per week, 0·6 per 100 person-years for use of two to three tablets per week, and 0·0 per 100 person-years for use of four or more tablets per week (p<0·0001). PrEP drug concentrations were higher among people of older age, with more schooling, who reported non-condom receptive anal intercourse, who had more sexual partners, and who had a history of syphilis or herpes. INTERPRETATION PrEP uptake was high when made available free of charge by experienced providers. The effect of PrEP is increased by greater uptake and adherence during periods of higher risk. Drug concentrations in dried blood spots are strongly correlated with protective benefit. FUNDING US National Institutes of Health.

Antiretroviral therapy for the prevention of HIV-1 transmission

BACKGROUND An interim analysis of data from the HIV Prevention Trials Network (HPTN) 052 trial showed that antiretroviral therapy (ART) prevented more than 96% of genetically linked infections caused by human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples. ART was then offered to all patients with HIV-1 infection (index participants). The study included more than 5 years of follow-up to assess the durability of such therapy for the prevention of HIV-1 transmission. METHODS We randomly assigned 1763 index participants to receive either early or delayed ART. In the early-ART group, 886 participants started therapy at enrollment (CD4+ count, 350 to 550 cells per cubic millimeter). In the delayed-ART group, 877 participants started therapy after two consecutive CD4+ counts fell below 250 cells per cubic millimeter or if an illness indicative of the acquired immunodeficiency syndrome (i.e., an AIDS-defining illness) developed. The primary study end point was the diagnosis of genetically linked HIV-1 infection in the previously HIV-1-negative partner in an intention-to-treat analysis. RESULTS Index participants were followed for 10,031 person-years; partners were followed for 8509 person-years. Among partners, 78 HIV-1 infections were observed during the trial (annual incidence, 0.9%; 95% confidence interval [CI], 0.7 to 1.1). Viral-linkage status was determined for 72 (92%) of the partner infections. Of these infections, 46 were linked (3 in the early-ART group and 43 in the delayed-ART group; incidence, 0.5%; 95% CI, 0.4 to 0.7) and 26 were unlinked (14 in the early-ART group and 12 in the delayed-ART group; incidence, 0.3%; 95% CI, 0.2 to 0.4). Early ART was associated with a 93% lower risk of linked partner infection than was delayed ART (hazard ratio, 0.07; 95% CI, 0.02 to 0.22). No linked infections were observed when HIV-1 infection was stably suppressed by ART in the index participant. CONCLUSIONS The early initiation of ART led to a sustained decrease in genetically linked HIV-1 infections in sexual partners. (Funded by the National Institute of Allergy and Infectious Diseases; HPTN 052 ClinicalTrials.gov number, NCT00074581 .).

Determinants of HIV-1 shedding in the genital tract of women

BACKGROUND Plasma HIV-1 RNA concentration has been the best predictor for risk of heterosexual and perinatal transmission. However, direct contact with HIV-1 present locally in the genital tract might be necessary for transmission. We aimed to assess the relation between HIV-1 shedding (RNA or culturable virus) in female genital secretions and other factors that might affect HIV-1 shedding. METHODS This was a cross-sectional study within the Womens Interagency HIV Study (WIHS), a prospective longitudinal cohort study of HIV-infected women. We enrolled 311 HIV positive women from Jan 30, 1997 to July 1, 1998. We did clinical assessments, cultured HIV-1, and measured RNA in peripheral blood mononuclear cells (PBMC) and genital secretions. We compared the results with univariate and multivariate analyses. Presence of HIV-1 RNA or culturable virus in genital secretions was defined as HIV-1 shedding. FINDINGS HIV-1 RNA was present in genital secretions of 57% (152/268) of women whereas infectious virus was detected only in 6% (17/271). Genital tract HIV-1 shedding was found in 80% (130/163) of women with detectable plasma RNA and 78% (116/148) of women with positive PBMC cultures. 33% (27/83) of women with less than 500 copies/mL plasma RNA and 39% (35/90) of those with negative PBMC cultures also had genital tract shedding. INTERPRETATION Plasma RNA concentration, both qualitatively and quantitatively, was the most important factor in predicting genital HIV-1 shedding, even among women receiving potent antiretroviral therapy. However, HIV-1 shedding did occur in women with less than 500 copies/mL plasma HIV-1 RNA. This finding suggests that a separate reservoir of HIV-1 replication may exist in some women.

Prevalence and predictors of squamous cell abnormalities in papanicolaou smears from women infected with HIV-1

Background Cervical neoplasia occurs with increased frequency among women infected with HIV-1. Objective To characterize prevalence of and risk factors for abnormal cervical cytology among women with HIV and to compare them to uninfected women. Methods Baseline cervical cytology was obtained from 1713 women seropositive for HIV and 482 at-risk control women who were enrolled in the Womens Interagency HIV Study, a multicenter prospective cohort study conducted in six U.S. cities. Associations with sociodemographic, medical, and sexual variables were assessed by Fishers exact test, Mantel extension test, and logistic regression analysis. Results Cervical cytology was abnormal in 38.3% of HIV-infected women (atypical squamous cells of uncertain significance [ASCUS] 20.9%, low-grade squamous cells of uncertain significance [LSIL] 14.9%, high-grade squamous cells of uncertain significance [HSIL] 2.3%, cancer 0.2%) and 16.2% of HIV-uninfected women (ASCUS 12.7%, LSIL 2.3%, HSIL 1.2%, cancer 0.0%). Risk factors for any abnormal cytology in multivariate analysis included HIV infection, CD4 cell count, HIV RNA level, detection of human papillomavirus (HPV), a prior history of abnormal cytology, employment, and number of male sex partners within 6 months of enrollment. Prior abortion was associated with a decreased risk of cytologic abnormality. Conclusions Cervical cytologic abnormalities were frequent among women infected with HIV, although high-grade changes were found in only 2.5%. Factors linked to sexual and reproductive history, HPV infection, and HIV disease all influenced risk.

Effect of menstrual cycle on HIV-1 levels in the peripheral blood and genital tract.

ObjectiveTo assess the variation in HIV-1 over the menstrual cycle, including RNA levels in the female genital tract, plasma HIV-1-RNA levels, CD4 cell counts, and culturable virus. DesignA prospective analysis of 55 HIV-1-infected women. MethodsBlood and genital tract specimens were collected weekly over 8 weeks, spanning two complete menstrual cycles. Applying repeated-measures models that used menses as the reference level, the variation in viral RNA levels was compared in endocervical canal fluid and cells (collected by Sno-strips and cytobrush, respectively) and ectocervicovaginal lavage (CVL) fluid. Repeated-measures models were also used to assess the variation in plasma CD4 cell counts and viral load. ResultsShedding patterns differed among the three sampling methods, independent of genital tract co-infections. Genital tract HIV-1-RNA levels from CVL fluid and endocervical canal cytobrush specimens were highest during menses and lowest immediately thereafter (P = 0.001 and P = 0.04). The HIV-1-RNA level in endocervical canal fluid was highest in the week preceding menses (P = 0.003). The menstrual cycle had no effect on blood levels of RNA (P = 0.62), culturable virus (P = 0.34), or CD4 cell counts (P = 0.55). HIV-1-RNA levels were higher in endocervical canal fluid than in peripheral blood plasma during the late luteal phase (P = 0.03). ConclusionHIV-1-RNA levels vary with the menstrual cycle in the female genital tract but not the blood compartment. HIV-1-RNA levels are higher in endocervical canal fluid than in blood plasma. These findings may have important implications for sex-specific pathogenesis, heterosexual transmission, and contraceptive hormone interventions in HIV-1-infected women.

Cigarette smoking, bacterial pneumonia, and other clinical outcomes in HIV-1 infection

Cigarette smoking has been associated with impaired immune defenses and an increased risk of certain infectious and neoplastic diseases in HIV-1 seronegative populations. We examined the relationship between cigarette smoking and clinical outcome in a prospective cohort of 3221 HIV-1-seropositive men and women enrolled in the Terry Beirn Community Programs for Clinical Research on AIDS. Differences in clinical outcomes between never, former, and current cigarette smokers were assessed using proportional hazards regression analysis. After adjustment for CD4+ cell count, prior disease progression, use of antiretroviral therapy, and other covariates, there was no difference between current smokers and never smokers in the overall risk of opportunistic diseases [relative hazard (RH) = 1.05; 95% confidence interval (CI) 0.90-1.23; p = 0.52] or death (RH = 1.00; 95% CI 0.86-1.18; p = 0.97). However, current smokers were more likely than never smokers to develop bacterial pneumonia (RH = 1.57; 95% CI 1.14-2.15; p = 0.006), oral candidiasis (RH = 1.37; 95% CI 1.16-1.62; p = 0.0002), and AIDS dementia complex (RH = 1.80; 95% CI 1.11-2.90; p = 0.02). In addition, current smokers were less likely to develop Kaposis sarcoma (RH = 0.58; 95% CI 0.39-0.88; p = 0.01) and several other non-respiratory tract diseases. If confirmed by other studies, these findings have important clinical implications.

Effect of HIV infection on menstrual cycle length.

Summary: HIV serostatus and menstrual function were examined using prospectively collected menstrual data from 802 HIV‐seropositive and 273 HIV‐seronegative women, ages 20 to 44, enrolled in two cohort studies of HIV infection in North American women. The associations between HIV serostatus and the probabilities of having a cycle lasting >40 days (n = 541 cycles), >90 days (n = 67 cycles), <18 days (n = 316 cycles) and mean length and variability of 18 to 40 day cycles (n = 3634) were assessed. After adjustment for demographic characteristics, body mass index, and substance use, seropositivity increased the odds of having a very short cycle (<18 days, odds ratio [OR], 1.45; 95% confidence interval [CI], 1.00‐2.11) and a very long cycle (>90 days, OR, 1.32; 95% CI, 0.68‐2.58) slightly, although the latter CIs include one. Seropositivity did not increase the odds of having a moderately long cycle (>40 days, OR, 1.14) or affect mean cycle length or variability (&bgr;, 0.30 ± 0.20; between‐woman standard deviation [SD], 2.2 days [HIV‐seronegative] and 1.9 days [HIV‐seropositive]; within‐woman SD, 3.5 days for both). Although seropositivity may slightly increase the probability of very short cycles, HIV serostatus has little overall effect on amenorrhea, menstrual cycle length, or variability. Among HIV‐seropositive women, higher viral loads and lower CD4+ counts were associated with increased cycle variability and polymenorrhea.

The impact of the ovulatory cycle on cytokine production: evaluation of systemic, cervicovaginal, and salivary compartments.

To understand the impact of the menstrual cycle on immunologic parameters, we measured the level of cytokines and chemokines from plasma, cervicovaginal lavage (CVL), and saliva samples of 6 premenopausal women during the follicular and luteal phases of the ovulatory cycle. We demonstrate that the level of plasma interleukin-8 (IL-8) was 4-fold higher during the follicular phase than the luteal phase (p = 0.004), whereas plasma IL-1beta, IL-4, IL-6, IL-10, interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-1alpha (MIP-1alpha), and TNF receptor II (TNFR II) were not altered during the ovulatory cycle. In the vaginal compartment, as measured from CVL samples, the levels of IL-6 and IL-1beta were both 5-fold higher in the follicular than the luteal phase (p = 0.0002 and 0.03, respectively). Salivary cytokine and chemokine samples were similar when measured during the luteal and the follicular phases. Additional analysis of lymphocyte subsets for phenotypic and functional markers indicated that they were not influenced by the ovulatory cycle. Collectively, these data suggest that IL-6, IL-8, and IL-1beta are differentially regulated during the ovulatory cycle.