Antibody-mediated control of HIV-1 infection through an alternative pathway No abstract available

The antagonism of folate receptor by dolutegravir: developmental toxicity reduction by supplemental folic acid Objective: Maternal folate (vitamin B9) status is the largest known modifier of neural tube defect risk, so we evaluated folate-related mechanisms of action for dolutegravir (DTG) developmental toxicity. Design: Folate receptor 1 (FOLR1) was examined as a target for DTG developmental toxicity using protein and cellular interaction studies and an animal model. Methods: FOLR1 competitive binding studies were used to test DTG for FOLR1 antagonism. Human placenta cell line studies were used to test interactions with DTG, folate, and cations. Zebrafish were selected as an animal model to examine DTG-induced developmental toxicity and rescue strategies. Results: FOLR1 binding studies indicate DTG is a noncompetitive FOLR1 antagonist at therapeutic concentrations. In-vitro testing indicates calcium (2 mmol/l) increases FOLR1-folate interactions and alters DTG-FOLR1-folate interactions and cytotoxicity. DTG does not inhibit downstream folate metabolism by dihydrofolate reductase. Early embryonic exposure to DTG is developmentally toxic in zebrafish, and supplemental folic acid can mitigate DTG developmental toxicity. Conclusion: Folates and FOLR1 are established modifiers of risk for neural tube defects, and binding data indicates DTG is a partial antagonist of FOLR1. Supplemental folate can ameliorate increased developmental toxicity due to DTG in zebrafish. The results from these studies are expected to inform and guide future animal models and clinical studies of DTG-based antiretroviral therapy in women of childbearing age.

Long-term evolution of transmitted CXCR4-using HIV-1 under effective antiretroviral therapy Objective: To study the long-term evolution of the transmitted CXCR4-using viruses. CCR5-using viruses (R5 viruses) predominate during primary HIV-1 infections (PHI) while CXCR4-using viruses are isolated in less than 10% of PHI. Design: Six patients infected with an R5X4 virus, detected by a sensitive phenotypic assay during PHI, were matched with six patients infected with a pure R5 virus for sex, Fiebig stage, time of antiretroviral initiation and duration of follow-up. Methods: We used MiSeq ultra-deep sequencing to determine the composition of the virus quasispecies during PHI and at the end of follow-up (median time of follow-up: 12.5 years). Results: X4 viruses were detected by genetic analysis in three of six samples from the R5X4 group, accounting for 1.3–100% of the virus quasispecies, during PHI, and in four of six samples (accounting for 6.7–100%) at the end of follow-up. No X4 virus was detected in the R5 group during PHI and in only one patient (accounting for 1.2%) at the end of follow-up. The complexity of the virus quasispecies at the stage of PHI was higher in the R5X4 group than in the R5 group. Complexity increased from PHI to the end of follow-up in the R5 group but remained stable in the R5X4 group. Conclusion: CXCR4-using viruses persisted in the peripheral blood mononuclear cells of several patients on suppressive antiretroviral therapy for a median duration of 12.5 years after PHI. The genetic complexity of HIV-1 evolved differently post-PHI in patients infected with R5X4 viruses from those infected with R5 viruses.

Viro-immunological outcomes after 13-valent pneumococcal vaccination in HIV-1-infected individuals on stable virological suppression Background: Very limited data are available on the immunovirological outcomes after 13-valent pneumococcal conjugate vaccine (PCV13) in antiretroviral therapy (ART)-treated patients. The aim of this study was to assess the immune-virological outcomes in HIV-1-infected ART-treated patients on stable virological suppression who underwent pneumococcal conjugate vaccination. Methods: Retrospective, cohort study on ART-treated HIV-1-infected individuals, age at least 18 years, with three consecutive determinations of HIV-RNA less than 50 copies/ml before the administration of PCV13 (baseline) at San Raffaele Hospital and with at least two HIV-RNA values after vaccination. Results: Overall 1197 patients underwent PCV13 vaccination. During 6-month of follow-up (594 person-years of follow-up, PYFU), 12 confirmed virological failure and 35 viral blips were observed; the overall incidence rate of confirmed virological failure was 2.02 (95% confidence interval: 0.88–3.16) per 100-PYFU and the incidence rate of viral blips was 5.89 (95% confidence interval: 3.94–7.84) per 100-PYFU. Median CD4+ cell count change from baseline at 6 months was +10 cells/μl (interquartile range −67, +111; P = 0.0002). Median change in CD4+/CD8+ ratio was +0.02 (interquartile range −0.06, +0.11; P < 0.001). Conclusion: Viral blips and confirmed virological failures were rarely observed in patients on stable virological suppression in the first 6 months following vaccination with PCV13. In addition, no decrease of CD4+ cell count and CD4+/CD8+ ratio was recorded.

A pharmacokinetic and pharmacogenetic evaluation of contraceptive implants and antiretroviral therapy among women in Kenya and Uganda Objectives: To evaluate pharmacokinetics and pharmacogenetics of contraceptive implant progestin concentrations in HIV-positive women initiating efavirenz (EFV)-containing or nevirapine (NVP)-containing antiretroviral therapy (ART). Design: We analyzed stored samples from women self-reporting implant use in the Partners PrEP Study. Methods: Plasma samples collected every 6 months were analyzed for levonorgestrel and etonogestrel concentrations. Progestin concentrations from samples collected after ART initiation were compared with pre-ART concentrations for intraindividual comparisons. We used adjusted linear mixed models to compare hormone concentrations between individuals on EFV and NVP to a no ART group. We then evaluated whether possessing certain alleles with known or possible influences on EFV, NVP, or progestin metabolism were associated with changes in progestin concentrations or modified the association between ART use and progestin concentrations. Results: Our analysis included 11 women who initiated EFV, 13 who initiated NVP, and 36 who remained ART-naive. In the EFV group, the adjusted geometric mean ratio (aGMR) of levonorgestrel was 0.39 [90% confidence intervals (0.31, 0.49); P < 0.001] and the etonogestrel aGMR was 0.51 (0.34, 0.76; P = 0.006) compared with the control group. No difference was observed in the NVP group compared with controls [levonorgestrel 0.93 (0.74, 1.18); P = 0.64; etonogestrel 1.07 (0.77, 1.50); P = 0.73]. Possession of four allele variants were found to result in further reductions in progestin concentrations among those receiving EFV. Conclusion: Concomitant use of EFV significantly reduces levonorgestrel or etonogestrel concentrations by 61 and 49%, respectively, compared with no ART use. We also report allelic variants in hepatic enzymes that influenced the extent of the observed drug-interaction between progestins and EFV.

Low-level viremia and virologic failure in persons with HIV infection treated with antiretroviral therapy Background: The clinical management of low-level viremia (LLV) remains unclear. The objective of this study was to investigate the association of blips and LLV with virologic failure. Methods: We enlisted patients who newly enrolled into the HIV Research Network between 2005 and 2015, had HIV-1 RNA more than 200 copies/ml, and were either antiretroviral therapy (ART)-naive or ART-experienced and not on ART. Patients were included who achieved virologic suppression (≤50 on two consecutive viral loads) and had at least two viral loads following suppression. Blips and LLV (≥2 consecutive >51 copies/ml) were categorized separately into three categories: no blips/LLV, 51–200, 201–500. Cox proportional hazards regression was used to assess association between rates of blips/LLV and virologic failure (two consecutive >500). Results: The 2795 patients were mostly male (75.4%), black (50.3%), and MSM (52.9%). Median age was 38 years old (interquartile range 29–48). Most patients (88.8%) were ART-naive at study entry. Overall, 283 (10.1%) patients experienced virologic failure. A total of 152 (5.4%) patients experienced LLV to 51–200 and 110 (3.9%) patients experienced LLV to 201–500. Both LLV 51–200 [adjusted hazard ratio (aHR) 1.83 (1.10,3.04)] and LLV 201–500 [aHR 4.26 (2.65,6.86)] were associated with virologic failure. In sensitivity analysis excluding ART-experienced patients, the association between LLV 51 and 200 and virologic failure was not statistically significant. Conclusion: LLV between 201 and 500 was associated with virologic failure, as was LLV between 51 and 200, particularly among ART-experienced patients. Patients with LLV below the current Department of Health and Human Services threshold for virologic failure (persistent viremia ≥200) may require more intensive monitoring because of increased risk for virologic failure.

Uptake and effectiveness of two-drug compared with three-drug antiretroviral regimens among HIV-positive individuals in Europe Objective: To assess the use of two-drug antiretroviral regimens (2DR) and virologic and immunologic outcomes compared with three-drug regimens (3DR) in the EuroSIDA cohort. Design: Multicentre, prospective cohort study. Methods: Logistic regression was used to analyse the uptake and outcomes among HIV-positive individuals who started or switched to a 2DR compared with those on a 3DR. Virologic outcomes were assessed on-treatment as the proportion of individuals with controlled viral load (<400 copies/ml), or with a composite modified FDA snapshot endpoint (mFDA), with mFDA success defined as controlled viral load at 6 months or 12 months for individuals with a known viral load, no regimen changes, AIDS or death. Immunologic response was defined as a 100 cells/μl or a 25% increase in CD4+ cell counts from baseline. Results: Between 1 July 2010 and 31 December 2016, 423 individuals started or switched to a 2DR (eight antiretroviral-naive) and 4347 started a 3DR (566 naive). Individuals on 2DR tended to have suppressed viral load, higher CD4+ cell counts and more comorbidities at baseline compared with those on 3DR. There were no differences in the proportions of individuals who obtained on-treatment or mFDA success, and no significant differences in the adjusted odds ratios for mFDA success or immunologic responses between the 2DR and 3DR groups at 6 months or 12 months. Conclusion: In routine clinical practice, 2DR were largely used for virologically suppressed individuals with higher cumulative exposure to antiretrovirals and comorbidities. Virologic and immunologic outcomes were similar among those on 2DR or 3DR, although confounding by indication cannot be fully excluded due to the observational nature of the study.

Contributions of HIV, hepatitis C virus, and traditional vascular risk factors to peripheral artery disease in women Objectives: HIV and hepatitis C virus (HCV) have been associated with cardiovascular disease (CVD), but it is unclear whether HIV and HCV are also associated with peripheral artery disease (PAD). We examined the association of HIV, HCV, and traditional CVD risk factors with PAD in the Women's Interagency HIV Study, a multicenter US cohort. Methods: In this cross-sectional study, ankle–brachial index was estimated using Doppler ultrasound and manual sphygmomanometer in 1899 participants aged more than 40 years with HIV/HCV coinfection, HCV or HIV monoinfection, or neither infection. Multivariable logistic regression was used to estimate the odds of PAD (ankle–brachial index ≤0.9) after controlling for demographic, behavioral, and CVD risk factors. Results: Over two-thirds were African-American, median age was 50 years, and PAD prevalence was 7.7% with little difference by infection status. After multivariable adjustment, neither HIV nor HCV infection was associated with greater odds of PAD. Factors associated with PAD included older age [adjusted odds ratio (aOR): 2.01 for age 61–70 vs. 40–50 years; 95% confidence interval (CI): 1.04, 3.87], Black race (aOR: 2.30; 95% CI: 1.15, 4.63), smoking (aOR: 1.27 per 10-pack-year increment; 95% CI: 1.09, 1.48), and higher SBP (aOR: 1.14 per 10 mmHg; 95% CI: 1.01, 1.28). Conclusion: The high PAD prevalence in this nationally representative cohort of women with or at risk for HIV is on par with general population studies in individuals a decade older than our study's median age. HIV and HCV infection are not associated with greater PAD risk relative to uninfected women with similar risk factors. Modifiable traditional CVD risk factors may be important early intervention targets in women with and at risk for HIV.

The use of molecular markers for cervical screening of women living with HIV in South Africa Objective: To determine the performance of molecular screening strategies for detection of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) in comparison with cytology screening in women living with HIV. Design: Post-hoc analysis using data from a South African study cohort. Methods: Cytology and human papillomavirus (HPV)-based strategies were evaluated, including single test and FAM19A4/miR124-2 methylation triage strategies. Participants underwent cytology screening and a colposcopy-directed biopsy. Valid results on cytology, HPV status, 16/18 genotyping and histology were available for 318 women. Detection of HPV and FAM19A4/miR124-2 hypermethylation was performed on DNA from cervical scrapes. Histological diagnosis of CIN3+ was used as outcome. Results: Cytology provided highest specificity (91.6%), but lowest sensitivity (59.3%), whereas a single HPV test provided highest sensitivity (83.1%), but lowest specificity (66.4%). Combining cytology with methylation did not improve the performance compared with cytology alone: a slight increase in sensitivity was seen, at the cost of a decrease in specificity. Triage of high-risk HPV positive women with methylation increased specificity (76.1%) compared with a single HPV or cytology test, while maintaining acceptable sensitivity (72.9%). Similar performance was observed for HPV16/18 with methylation triage (sensitivity 79.7%, specificity 74.8%). The number of women needed to refer to detect one CIN3+ ranged from 1.5 (cytology) to 2.6 (single HPV test). Conclusion: Molecular screening strategies using HPV, with or without HPV16/18 genotyping, and FAM19A4/miR124-2 methylation have higher sensitivity with an acceptable loss in specificity compared with current cytology screening and are efficient for the detection of CIN3+ in South African women living with HIV.

Inflammatory biomarkers prior to antiretroviral therapy as prognostic markers of 12-month mortality in South Africa and Uganda Objective: The aim of this study was to determine the utility of biomarkers of immune activation, systemic inflammation and coagulopathy prior to antiretroviral therapy to predict mortality during the first year of antiretroviral therapy (ART) in sub-Saharan Africa. Design: A prospective, observational cohort. Methods: We measured soluble CD14, interleukin-6 and D-dimer in nonpregnant individuals initiating ART in South Africa and Uganda in the Measuring Early Treatment Adherence (META) Study. We used survival analysis methods to estimate their association with 12-month mortality, and fit receiver operator curves (ROC) to assess the prognostic value of each biomarker. Results: Six-hundred and sixty individuals were enrolled and had pretreatment biomarkers measured. Approximately 60% were women, with a median CD4+ cell count of 187 cells/μl [interquartile range (IQR) 111–425] and approximately half were enrolled each from South Africa and Uganda. We observed 34 deaths for a crude mortality of 5.3 deaths/100 person-years (py) (95% confidence interval 3.8–7.4), which ranged from 0/100 py to 13.7/100 py in the lowest and highest tertile of pretreatment sCD14, respectively. In Cox models, all three biomarkers were strongly predictive of the hazard of death (adjusted hazard ratio 3–6, all P < 0.01). In multivariable models including biomarkers, both pretreatment CD4+ cell count and pretreatment viral load became borderline or nonsignificantly associated with mortality. The c-statistic for area under ROC was higher for all three biomarkers than for CD4+ cell count (P < 0.01). Conclusion: Biomarkers of immune activation, systemic inflammation and coagulopathy prior to ART initiation are strongly predictive of early death on treatment after adjustment for CD4+ cell count. Such biomarkers might serve as important prognostic indicators for patient triage in this population.