Pharmacokinetics of antiretroviral drugs in anatomical sanctuary sites: the fetal compartment (placenta and amniotic fluid)

Disturbances in the IgG Antibody Profile in HIV-Exposed Uninfected Infants Associated with Maternal Factors

Over the last 20 years, the incidence of vertical HIV transmission has decreased from 25%-42% to less than 1%. Although there are no signs of infection, the health of HIV-exposed uninfected (HEU) infants is notoriously affected during the first months of life, with opportunistic infections being the most common disease. Some studies have reported effects on the vertical transfer of antibodies, but little is known about the subclass distribution of these antibodies. We proposed to evaluate the total IgG concentration and its subclasses in HIV+ mothers and HEU pairs and to determine which maternal factors condition their levels. In this study, plasma from 69 HEU newborns, their mothers, and 71 control pairs was quantified via immunoassays for each IgG isotype. Furthermore, we followed the antibody profile of HEUs throughout the first year of life. We showed that mothers present an antibody profile characterized by high concentrations of IgG1 and IgG3 but reduced IgG2, and HEU infants are born with an IgG subclass profile similar to that of their maternal pair. Interestingly, this passively transferred profile could remain influenced even during their own antibody production in HEU infants, depending on maternal conditions such as CD4+ T-cell counts and maternal antiretroviral treatment. Our findings indicate that HEU infants exhibit an altered IgG subclass profile influenced by maternal factors, potentially contributing to their increased susceptibility to infections.

Haematopoietic stem-cell transplantation in an HIV endemic area: time to consider donors exposed to or living with HIV

South Africa has more than 8 million people living with HIV. However, the number of patients undergoing haematopoietic stem-cell transplantation (HSCT) in South Africa is far below the target number. Donor numbers are insufficient to meet demand. Both HSCT and solid organ transplantation have proved successful in people living with HIV. Solid organ transplantation also has good outcomes when both donors and recipients have HIV. This Personal View explores the possible inclusion of people living with HIV and umbilical cord blood from HIV-negative infants exposed to HIV as donor sources for HSCT. Beyond the risk of HIV transmission, additional complications must be considered, such as delayed or inadequate immune reconstitution and an increased risk of haematological abnormalities and malignancies. Interactions between antiretroviral drugs and drugs used in the conditioning regimen, as well as the need to maintain virological suppression when gastrointestinal absorption deteriorates, are additional complicating factors. The process also requires more stringent ethical processes to be in place to minimise physical and emotional harm. However, in an HIV endemic country, people living with HIV or donors exposed to HIV must be considered as part of a multidisciplinary collaborative effort to provide more patients with the opportunity to have a life-saving HSCT.

Human immunodeficiency virus and antiretroviral therapy-mediated immune cell metabolic dysregulation in children born to HIV-infected women: potential clinical implications

Commencing lifelong antiretroviral therapy (ART) immediately following HIV diagnosis (Option B+) has dramatically improved the health of HIV-infected women and their children, with the majority being of HIV-exposed children born uninfected (HEU). This success has led to an increasing population of HIV-infected women receiving ART during pregnancy and children exposed to ART in utero. Nonetheless, a small proportion of children are still infected with HIV (HEI) each year. HEI children suffer from reduced immunocompetence and host-defence, due to CD4+ T lymphocyte depletion, but also dysregulation of other immune cells including CD8+ T lymphocytes, natural killer (NK) cells, macrophages including B lymphocytes. Furthermore, although HEU children are uninfected, altered immune responses are observed and associated with increased vulnerability to infections. The mechanisms underlying immune dysregulation in HEU children remain poorly described. Building on early studies, emerging data suggests that HIV/ART exposure early in life affects cell metabolic function of HEU children. Prenatal HIV/ART exposure has been associated with dysregulation of mitochondria, including impaired DNA polymerase activity. Furthermore, dysregulation of oxidative phosphorylation (OXPHOS) causes a decreased generation of adenosine triphosphate (ATP) and increased production of reactive oxygen species (ROS), resulting in oxidative stress. These altered metabolic processes can affect immune cell viability and immune responses. Recent studies have indicated that immune-metabolic dysregulation may contribute to HIV-associated pathogenesis and clinical observations associated with HIV and ART exposure in HEU/HEI children. Given the critical role metabolic processes in immune cell functioning, immune-metabolic dysregulation in HEU and HEI children may have implications in effective host-defence responses against pathogens, as well as efficacy of standard ART regimens and future novel HIV cure approaches in HEI children. At the same time, targeting metabolic pathways of immune cells may provide safer and novel approaches for HIV cure strategies. Here, we review the current literature investigating immune-metabolic dysregulation in paediatric HIV pathogenesis.

Umbilical Cord Blood-Derived Exosomes in Maternal-Fetal Disease: a Review

The nutrients and other factors transported by umbilical cord blood, which is vital for fetal survival, play crucial roles in fetal development. There are various communication modes between the fetal-placental system and the maternal-placental system, and these communication modes are all mediated by umbilical cord blood. During the process of umbilical cord blood transportation, the changes of some nutrients and factors may play a key role in fetal development. Exosomes, which are members of the extracellular vesicle family, are present in the umbilical cord blood and play roles in information transmission as a result of their efficient cellular communication activity. The study of umbilical cord blood-derived exosomes provides a new approach for research on the etiology of maternal-fetal diseases and they may be useful for the development of intrauterine treatments. This review summarizes specific functions and research directions regarding umbilical cord blood-derived exosomes, and their potential associations with pregnancy complications.

Higher Hospitalization Rates in Children Born HIV-exposed Uninfected in British Columbia, Canada, Between 1990 and 2012

BACKGROUND

Compared with children who are HIV-unexposed and uninfected (CHUU), children who are HIV-exposed and uninfected (CHEU) experience more clinical complications. We investigated hospitalizations among CHEU by antenatal antiretroviral therapy (ART) exposure, in British Columbia, Canada.

METHODS

This retrospective controlled cohort study used administrative health data from 1990 to 2012. CHEU and CHUU were matched 1:3 for age, sex and maternal geographical area of residence. We determined adjusted odds ratios (aORs) via conditional logistic regression, adjusting for maternal risk factors.

RESULTS

A total of 446 CHEU and 1333 CHUU were included. Compared with CHUU, more CHEU experienced one or more lifetime hospitalization (47.3% vs. 29.8%), one or more neonatal hospitalization (40.4% vs. 27.6%), and any intensive care unit admission (28.5% vs. 9.2%). In adjusted analyses, CHEU experienced higher odds of any lifetime hospitalization (aOR 2.30, 95% confidence interval 1.81-2.91) and neonatal hospitalization (aOR 2.14, 95% confidence interval 1.68-2.73), compared with CHUU. There was, however, no difference in infection-related hospitalizations (9.0% vs. 7.5%), which were primarily respiratory tract infections among both CHEU and CHUU. CHEU whose mothers-initiated ART preconception showed lower odds of infection-related hospitalizations than children whose mothers initiated ART during pregnancy or received no ART.

CONCLUSIONS

CHEU experienced increased odds of hospitalization relative to CHUU. A substantial number of CHEU hospitalizations occurred within the neonatal period and were ICU admissions. Initiating ART preconception may reduce the risk of infection-related hospitalizations. These findings reinforce the benefit of ART in pregnancy and the need for ongoing pediatric care to reduce hospitalizations.

Placental transfer of doravirine, a recent HIV-1 NNRTI in the ex vivo human cotyledon perfusion model

BACKGROUND

The recent HIV-1 NNRTI doravirine is likely to be used in pregnant women despite the complete lack of data on safety and exposure in the fetus. The objective of this study was to determine its placental transfer.

METHODS

Maternal-to-fetal transfer was investigated using the open-circuit ex vivo dually perfused human cotyledon model. Doravirine was added to a maternal perfusate (theoretical doravirine concentration of 250 ng/mL) containing 2 g/L human albumin and 20 g/L antipyrine, a marker to validate the cotyledon's viability, and cotyledons were dually perfused for up to 90 min.

RESULTS

In five experiments, the median (IQR) doravirine concentrations in the maternal and fetal compartments were, respectively, 303 (178-420) and 40 (30-54) ng/mL, the fetal-to-maternal ratio was 16% (12%-18%) and the clearance index (in comparison with antipyrine transfer) was 48% (35%-64%). The median accumulation index in cotyledon tissue was 39% (range 10%-66%).

CONCLUSIONS

Doravirine both crosses and accumulates in the placenta. This may be useful as pre/post-exposure prophylaxis to reduce the risk of vertical HIV transmission but carries the potential for fetal toxicities. Further investigation is required to determine the safety and efficacy of this new antiretroviral agent in pregnancy.

HIV in pregnancy: Mother-to-child transmission, pharmacotherapy, and toxicity

An estimated 1.3 million pregnant women were living with HIV in 2018. HIV infection is associated with adverse pregnancy outcomes and all HIV-positive pregnant women, regardless of their clinical stage, should receive a combination of antiretroviral drugs to suppress maternal viral load and prevent vertical fetal infection. Although antiretroviral treatment in pregnant women has undoubtedly minimized mother-to-child transmission of HIV, several uncertainties remain. For example, while pregnancy is accompanied by changes in pharmacokinetic parameters, relevant data from clinical studies are lacking. Similarly, long-term adverse effects of exposure to antiretrovirals on fetuses have not been studied in detail. Here, we review current knowledge on HIV effects on the placenta and developing fetus, recommended antiretroviral regimens, and pharmacokinetic considerations with particular focus on placental transport. We also discuss recent advances in antiretroviral research and potential effects of antiretroviral treatment on placental/fetal development and programming.

Preterm Birth and Antiretroviral Exposure in Infants HIV-exposed Uninfected

BACKGROUND

Infants HIV-exposed and uninfected (IHEU) who are born to women living with HIV are at an increased risk of preterm birth (PTB). Antenatal exposure to certain maternal antiretroviral therapy (ART) regimens has been associated with PTB, although existing studies in this domain are limited and report discordant findings. We determined odds of PTB among IHEU by antenatal ART regimens and timing of exposure, adjusting for maternal risk factors.

METHODS

We retrospectively studied IHEU born in British Columbia (BC), Canada between 1990 and 2012 utilizing provincial health administrative databases. We included data from a control group of infants HIV-unexposed and uninfected (IHUU) matched ~3:1 for each IHEU on age, sex and geocode.

RESULTS

A total of 411 IHEU and 1224 IHUU were included in univariable analysis. PTB was more frequent among IHEU (20%) compared with IHUU (7%). IHEU were more often antenatally exposed to alcohol, tobacco, as well as prescription, nonprescription, and illicit drugs (IHEU: 36%, 8% and 35%; vs. IHUU: 3%, 1% and 9%, respectively). After adjusting for maternal substance use and smoking exposure, IHEU remained at increased odds of PTB [adjusted odds ratio (aOR) (95% CI): 2.66; (1.73, 4.08)] compared with matched IHUU controls. ART-exposed IHEU (excluding those with NRTIs only ART) had lower adjusted odds of PTB compared with IHEU with no maternal ART exposure, regardless of regimen [aOR range: 0.16-0.29 (0.02-0.95)]. Odds of PTB between IHEU exposed to ART from conception compared with IHEU exposed to ART postconception did not differ [aOR: 0.91 (0.47, 1.76)]; however, both groups experienced lower odds of PTB compared with IHEU with no maternal ART [preconception: aOR: 0.28 (0.08, 0.89); postconception: aOR 0.30 (0.11, 0.83)].

CONCLUSIONS

BC IHEU were over twice as likely to be born preterm compared with demographically matched controls. Maternal substance use in pregnancy modulated this risk; however, we found no adverse associations of PTB with exposure to antenatal ART.

Mini review: Prevention of mother-child transmission of HIV: 25 years of continuous progress toward the eradication of pediatric AIDS?

Prevention of mother-to-child transmission with antiretrovirals is extraordinarily effective. When medically well followed, a mother living with human immunodeficiency virus can now expect to avoid transmitting the virus to her child. Despite the immense difficulties inherent in the global implementation of this treatment, the virtual disappearance of pediatric AIDS can be considered in the long term.

Elevated Blood Mitochondrial DNA in Early Life Among Uninfected Children Exposed to Human Immunodeficiency Virus and Combination Antiretroviral Therapy in utero

BACKGROUND

Combination antiretroviral therapy (cART) during pregnancy prevents vertical transmission, but many antiretrovirals cross the placenta and several can affect mitochondria. Exposure to maternal human immunodeficiency virus (HIV) and/or cART could have long-term effects on children who are HIV exposed and uninfected (CHEU). Our objective was to compare blood mitochondrial DNA (mtDNA) content in CHEU and children who are HIV unexposed and uninfected (CHUU), at birth and in early life.

METHODS

Whole-blood mtDNA content at birth and in early life (age 0-3 years) was compared cross-sectionally between CHEU and CHUU. Longitudinal changes in mtDNA content among CHEU was also evaluated.

RESULTS

At birth, CHEU status and younger gestational age were associated with higher mtDNA content. These remained independently associated with mtDNA content in multivariable analyses, whether considering all infants, or only those born at term. Longitudinally, CHEU mtDNA levels remained unchanged during the first 6 months of life, and gradually declined thereafter. A separate age- and sex-matched cross-sectional analysis (in 214 CHEU and 214 CHUU) illustrates that the difference in mtDNA between the groups remains detectable throughout the first 3 years of life.

CONCLUSION

The persistently elevated blood mtDNA content observed among CHEU represents a long-term effect, possibly resulting from in utero stresses related to maternal HIV and/or cART. The clinical impact of altered mtDNA levels is unclear.

Therapeutic drug monitoring of darunavir/ritonavir in pregnancy

BACKGROUND

Physiological changes during pregnancy can have a significant impact on antiretroviral pharmacokinetics (PK), which may result in reduced drug efficacy. Here we describe the PK of darunavir/ritonavir (DRV/r) 800/100 once daily in a cohort of pregnant women undergoing routine therapeutic drug monitoring (TDM) as well as transplacental passage of DRV by measuring and comparing cord blood and maternal blood samples at delivery.

METHODS

Pregnant HIV-positive women received DRV/r as part of routine pre-natal care. Demographic and clinical data were collected. DRV plasma concentrations [DRV] were determined in the first (T1), second (T2) and third (T3) trimester and at postpartum (PP). The target concentration was 550 ng/ml. Where possible, paired maternal and cord blood samples were taken at delivery.

RESULTS

A total of 33 women were enrolled. Samples were taken 14-20 h post-dose and measured concentrations were extrapolated to 24 h post-dose. At the time nearest to delivery, all but four had undetectable plasma viral loads (pVL). [DRV] were determined in 1 (T1); 14 (T2); 32 (T3) and 29 (PP). 1 sample was <550 ng/ml at T2, 6 at T3 and 3 at PP. [DRV] were significantly lower at T2/T3 relative to PP.

CONCLUSIONS

[DRV] in T2 and T3 were 36-55% when compared with PP. However, DRV PK in pregnancy were not associated with a lack of virological suppression at delivery as of the 33 patients enrolled in this study, 31 had no HIV transmission from mother to child. Data regarding two candidates were not available as they delivered in a separate health-care facility.

Pharmacokinetics, Placental and Breast Milk Transfer of Antiretroviral Drugs in Pregnant and Lactating Women Living with HIV

BACKGROUND

Remarkable progress has been achieved in the identification of HIV infection in pregnant women and in the prevention of vertical HIV transmission through maternal antiretroviral treatment (ART) and neonatal antiretroviral drug (ARV) prophylaxis in the last two decades. Millions of women globally are receiving combination ART throughout pregnancy and breastfeeding, periods associated with significant biological and physiological changes affecting the pharmacokinetics (PK) and pharmacodynamics (PD) of ARVs. The objective of this review was to summarize currently available knowledge on the PK of ARVs during pregnancy and transport of maternal ARVs through the placenta and into the breast milk. We also summarized main safety considerations for in utero and breast milk ARVs exposures in infants.

METHODS

We conducted a review of the pharmacological profiles of ARVs in pregnancy and during breastfeeding obtained from published clinical studies. Selected maternal PK studies used a relatively rich sampling approach at each ante- and postnatal sampling time point. For placental and breast milk transport of ARVs, we selected the studies that provided ratios of maternal to the cord (M:C) plasma and breast milk to maternal plasma (M:P) concentrations, respectively.

RESULTS

We provide an overview of the physiological changes during pregnancy and their effect on the PK parameters of ARVs by drug class in pregnancy, which were gathered from 45 published studies. The PK changes during pregnancy affect the dosing of several protease inhibitors during pregnancy and limit the use of several ARVs, including three single tablet regimens with integrase inhibitors or protease inhibitors co-formulated with cobicistat due to suboptimal exposures. We further analysed the currently available data on the mechanism of the transport of ARVs from maternal plasma across the placenta and into the breast milk and summarized the effect of pregnancy on placental and of breastfeeding on mammal gland drug transporters, as well as physicochemical properties, C:M and M:P ratios of individual ARVs by drug class. Finally, we discussed the major safety issues of fetal and infant exposure to maternal ARVs.

CONCLUSIONS

Available pharmacological data provide evidence that physiological changes during pregnancy affect maternal, and consequently, fetal ARV exposure. Limited available data suggest that the expression of drug transporters may vary throughout pregnancy and breastfeeding thereby possibly impacting the amount of ARV crossing the placenta and secreted into the breast milk. The drug transporter's role in the fetal/child exposure to maternal ARVs needs to be better understood. Our analysis underscores the need for more pharmacological studies with innovative study design, sparse PK sampling, improved study data reporting and PK modelling in pregnant and breastfeeding women living with HIV to optimize their treatment choices and maternal and child health outcomes.

Rilpivirine Plasma and Cervicovaginal Concentrations in Women During Pregnancy and Postpartum

BACKGROUND

Concentrations of antiretrovirals in the genital tract play a key role in preexposure prophylaxis. This study aims to describe rilpivirine (Edurant) concentrations in the genital tract in pregnant and postpartum women.

METHODS

International Maternal Pediatric Adolescent AIDS Clinical Trials Protocol P1026s is an ongoing, prospective study of antiretroviral pharmacokinetics in HIV-infected pregnant women that include a cohort receiving rilpivirine combination regimen. Intensive pharmacokinetics evaluations were performed at steady state during the second and third trimester, and postpartum. Plasma and directly aspirated cervicovaginal fluid (CVF) samples were collected at 4 time points around an observed dose and measured using high-performance liquid chromatography with ultraviolet detection, [plasma; lower limit of quantification (LLQ) = 10 ng/mL] or liquid chromatography-tandem mass spectrometry (CVF; LLQ = 1 ng/mL).

RESULTS

A total of 24 women were included in the analysis. For all time points combined, median (interquartile range) rilpivirine concentrations were 70 ng/mL (23-121) in CVF and 92 ng/mL (49-147) in plasma. The CVF to plasma AUC(0-4) ratios were significantly higher in the second (0.90, 90% CI: 0.61 to 1.46) and third trimesters of pregnancy compared with postpartum (0.40, 90% CI: 0.19 to 0.87). Three of 189 (1.6%) plasma samples in 2 women were below the LLQ and the corresponding CVF concentrations. Seventeen additional CVF concentrations (10.6%) were below LLQ in 13 participants. No major safety concerns were noted.

CONCLUSIONS

Rilpivirine concentrations were higher in the CVF during pregnancy compared with postpartum. CVF Rilpivirine is likely to achieve inhibitory concentrations effective for preventing peripartum HIV transmission.

Prediction of Fetal Darunavir Exposure by Integrating Human Ex-Vivo Placental Transfer and Physiologically Based Pharmacokinetic Modeling

Background

Fetal antiretroviral exposure is usually derived from the cord-to-maternal concentration ratio. This static parameter does not provide information on the pharmacokinetics in utero, limiting the assessment of a fetal exposure–effect relationship.

Objective

The aim of this study was to incorporate placental transfer into a pregnancy physiologically based pharmacokinetic model to simulate and evaluate fetal darunavir exposure at term.

Methods

An existing and validated pregnancy physiologically based pharmacokinetic model of maternal darunavir/ritonavir exposure was extended with a feto-placental unit. To parameterize the model, we determined maternal-to-fetal and fetal-to-maternal darunavir/ritonavir placental clearance with an ex-vivo human cotyledon perfusion model. Simulated maternal and fetal pharmacokinetic profiles were compared with observed clinical data to qualify the model for simulation. Next, population fetal pharmacokinetic profiles were simulated for different maternal darunavir/ritonavir dosing regimens.

Results

An average (±standard deviation) maternal-to-fetal cotyledon clearance of 0.91 ± 0.11 mL/min and fetal-to-maternal clearance of 1.6 ± 0.3 mL/min was determined (n = 6 perfusions). Scaled placental transfer was integrated into the pregnancy physiologically based pharmacokinetic model. For darunavir 600/100 mg twice a day, the predicted fetal maximum plasma concentration, trough concentration, time to maximum plasma concentration, and half-life were 1.1, 0.57 mg/L, 3, and 21 h, respectively. This indicates that the fetal population trough concentration is higher or around the half-maximal effective darunavir concentration for a resistant virus (0.55 mg/L).

Conclusions

The results indicate that the population fetal exposure after oral maternal darunavir dosing is therapeutic and this may provide benefits to the prevention of mother-to-child transmission of human immunodeficiency virus. Moreover, this integrated approach provides a tool to prevent fetal toxicity or enhance the development of more selectively targeted fetal drug treatments.

Electronic supplementary material

The online version of this article (doi:10.1007/s40262-017-0583-8) contains supplementary material, which is available to authorized users.

Multiple Drug Transporters Contribute to the Placental Transfer of Emtricitabine

Emtricitabine (FTC) is a first-line antiviral drug recommended for the treatment of AIDS during pregnancy. We hypothesized that transporters located in the placenta contribute to FTC transfer across the blood-placenta barrier. BeWo cells, cell models with stable or transient expression of transporter genes, primary human trophoblast cells (PHTCs), and small interfering RNAs (siRNAs) were applied to demonstrate which transporters were involved. FTC accumulation in BeWo cells was reduced markedly by inhibitors of equilibrative nucleoside transporters (ENTs), concentrative nucleoside transporters (CNTs), organic cation transporters (OCTs), and organic cation/carnitine transporter 1 (OCTN1) and increased by inhibitors of breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins (MRPs). ENT1, CNT1, OCTN1, MRP1/2/3, and BCRP, but not ENT2, CNT3, OCTN2, or multidrug resistance protein 1 (MDR1), were found to transport FTC. FTC accumulation in PHTCs was decreased significantly by inhibitors of ENTs and OCTN1. These results suggest that ENT1, CNT1, and OCTN1 probably contribute to FTC uptake from maternal circulation to trophoblasts and that ENT1, CNT1, and MRP1 are likely involved in FTC transport between trophoblasts and fetal blood, whereas BCRP and MRP1/2/3 facilitate FTC transport from trophoblasts to maternal circulation. Coexistence of tenofovir or efavirenz with FTC in the cell medium did not influence FTC accumulation in BeWo cells or PHTCs.

Umbilical cord blood-based gene signatures related to prenatal major depressive disorder

BACKGROUND

Prenatal exposure to depression has been considered as a risk factor for adverse childhood, while it is accompanied by unknown molecular mechanisms. The aim of this study was to identify differentially expressed genes (DEGs) and associated biological processes between cord blood samples from neonates born to mothers who exposed to major depressive disorder (MDD) and healthy mothers.

METHODS

The microarray data GSE114852 were downloaded to analyze the mRNA expression profiles of umbilical cord blood with 31 samples exposed to prenatal MDD and 62 samples with healthy mothers. Kyoto Encyclopedia of Genes and Genomes pathway and Gene ontology enrichment analyses were conducted to identify associated biochemical pathways and functional categories of the DEGs. The protein-protein interaction network was constructed and the top 10 hub genes in the network were predicted.

RESULTS

The results showed several immunity related processes, such as "phagosome", "Epstein-Barr virus infection", "proteasome", "positive regulation of I-kappaB kinase/NF-kappaB signaling", "interferon-gamma-mediated signaling pathway", and "tumor necrosis factor" presented significant differences between two groups. Most of the hub genes (for example PSMD2, PSMD6, PSMB8, PSMB9) were also associated with immune pathways.

CONCLUSION

This bioinformatic analysis demonstrated immune-mediated mechanisms might play a fatal role in abnormalities in fetal gene expression profiles caused by prenatal MDD.

Risk of cancer in children exposed to antiretroviral nucleoside analogues in utero: The french experience

All nucleoside analogues for treating HIV infection, due to their capacity to integrate into and alter human DNA, are experimentally genotoxic to some extent. The long-term oncogenic risk after in utero exposure remains to be determined. Cancer incidence in uninfected children exposed to nucleos(t)ide reverse transcriptase inhibitors (NRTIs) was evaluated, by cross-checking against the National Cancer Registry, in the French perinatal study of children born to HIV⁺ mothers. Twenty-one cancers were identified in 15,163 children (median age: 9.9 years [interquartile range (IQR): 5.8-14.2]) exposed to at least one NRTI in utero between 1990 and 2014. Five of these children were exposed to zidovudine monotherapy, and 15 to various combinations, seven of which included didanosine. Overall, the total number of cases was not significantly different from that expected for the general population (SIR = 0.8[0.47-1.24]), but the number of cases after didanosine exposure was twice that expected (SIR = 2.5 [1.01-5.19]). Didanosine accounted for only 10% of prescriptions but was associated with one-third of cancers. In multivariate analysis, didanosine exposure was significantly associated with higher risk (HR = 3.0 [0.9-9.8]). This risk was specifically linked to first-trimester exposure (HR = 5.5 [2.1-14.4]). Three cases of pineoblastoma, a very rare cancer, were observed, whereas 0.03 were expected. Two were associated with didanosine exposure. Despite reassuring data overall, there is strong evidence to suggest that didanosine displays transplacental oncogenicity. These findings cannot be extrapolated to other NRTIs, but they highlight the need for comprehensive evaluations of the transplacental genotoxicity of this antiretroviral class. Environ. Mol. Mutagen., 60:404-409, 2019. © 2017 Wiley Periodicals, Inc.

Improving the clinical relevance of a mouse pregnancy model of antiretroviral toxicity; a pharmacokinetic dosing-optimization study of current HIV antiretroviral regimens

Animal models can be useful tools for the study of HIV antiretroviral (ARV) safety/toxicity in pregnancy and the mechanisms that underlie ARV-associated adverse events. The utility and translatability of animal model-based ARV safety/toxicity data is improved if ARVs are tested in clinically relevant concentrations. The objective of this work was to improve the clinical relevance of our mouse pregnancy model of ARV toxicity, by determining the doses of currently prescribed ARV regimens that would yield human therapeutic plasma concentrations. Pregnant mice were administered increasing doses of ARV combinations by oral gavage, followed by measurement of drug concentrations in the maternal plasma and amniotic fluid. Concentrations of ten different ARVs in maternal plasma and amniotic fluid samples of pregnant mice are presented, with dosing optimization to yield human pregnancy-relevant plasma drug concentrations. We have proposed optimal dosing for different regimen component drugs to achieve human therapeutic plasma levels, so that a clinically relevant standard dosing is established. A review of related ARV pharmacokinetic studies in (pregnant/non-pregnant) rodents and human pregnancy is also shown. We hope these data will inform and encourage the use of mouse pregnancy models in the study of ARV safety/toxicity.

Leukocyte Telomere Length at Birth and During the Early Life of Children Exposed to but Uninfected With HIV After In Utero Exposure to Antiretrovirals

Background

Maternal combination antiretroviral therapy (cART) during pregnancy could impact the health of human immunodeficiency virus (HIV)-exposed, HIV-uninfected (HEU) children, because some antiretrovirals cross the placenta and can inhibit telomerase. Our objective was to compare leukocyte telomere length (LTL) in HEU children and HIV-unexposed, HIV-uninfected (HUU) children at birth and in early life and to investigate any relationship with cART exposure.

Methods

HEU and HUU children's blood LTL was compared cross-sectionally at birth, and during the first three years of life. Longitudinal HEU LTL dynamics was evaluated over that same period.

Results

At birth, the LTL in HEU children (n = 114) was not shorter than that in HUU children (n = 86), but female infants had longer LTL than male infants. Maternal cART (duration or type) showed no association with shorter infant LTL. Among 214 HEU children age- and sex-matched at a 1:1 ratio to HUU children, LTL declined similarly in both groups. In a longitudinal analysis, LTL attrition in HEU children was rapid from birth to 1 year of age and gradual thereafter. Zidovudine prophylaxis did not significantly alter LTL.

Conclusions

Our results indicate that from birth to 3 years of age, the LTL in HEU children is not negatively affected by exposure to maternal HIV infection and cART, at least not to the regimens used within this Canadian cohort, a reassuring finding.

Development of a Novel Maternal-Fetal Physiologically Based Pharmacokinetic Model I: Insights into Factors that Determine Fetal Drug Exposure through Simulations and Sensitivity Analyses

Determining fetal drug exposure (except at the time of birth) is not possible for both logistical and ethical reasons. Therefore, we developed a novel maternal-fetal physiologically based pharmacokinetic (m-f-PBPK) model to predict fetal exposure to drugs and populated this model with gestational age-dependent changes in maternal-fetal physiology. Then, we used this m-f-PBPK to: 1) perform a series of sensitivity analyses to quantitatively demonstrate the impact of fetoplacental metabolism and placental transport on fetal drug exposure for various drug-dosing regimens administered to the mother; 2) predict the impact of gestational age on fetal drug exposure; and 3) demonstrate that a single umbilical venous (UV)/maternal plasma (MP) ratio (even after multiple-dose oral administration to steady state) does not necessarily reflect fetal drug exposure. In addition, we verified the implementation of this m-f-PBPK model by comparing the predicted UV/MP and fetal/MP AUC ratios with those predicted at steady state after an intravenous infusion. Our simulations yielded novel insights into the quantitative contribution of fetoplacental metabolism and/or placental transport on gestational age-dependent fetal drug exposure. Through sensitivity analyses, we demonstrated that the UV/MP ratio does not measure the extent of fetal drug exposure unless obtained at steady state after an intravenous infusion or when there is little or no fluctuation in MP drug concentrations after multiple-dose oral administration. The proposed m-f-PBPK model can be used to predict fetal exposure to drugs across gestational ages and therefore provide the necessary information to assess the risk of drug toxicity to the fetus.

Pharmacokinetics and Placental Transfer of Elvitegravir, Dolutegravir, and Other Antiretrovirals during Pregnancy

The integrase inhibitors elvitegravir (EVG) and dolutegravir (DTG) rapidly decrease the plasma HIV-1 viral load, a key factor in the prevention of maternal-to-fetal transmission of HIV-1. No data have been reported on the concentrations of these drugs in cord blood, maternal peripheral blood mononuclear cells (PBMCs), or placental tissue in pregnant women. We present in vivo pharmacokinetic data on antiretrovirals (ARV) within maternal and cord blood and within placentae from HIV-1-infected pregnant women. Maternal blood and cord blood were obtained from women receiving EVG, cobicistat, tenofovir disoproxil fumarate, and emtricitabine as a single fixed-dose combination formulation or DTG as part of a combination regimen. Plasma and PBMCs from maternal and cord blood were obtained along with villous placental samples. Drug concentrations were simultaneously determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Utilizing medians and ranges to interpret our data, we compared the drug concentration ratios between different matrices (maternal and cord blood plasma, PBMCs, and placenta). All five agents transferred from maternal into fetal circulation via the placenta. Concentration ratios for EVG, cobicistat, tenofovir, and emtricitabine (n = 10) and DTG (n = 3) were determined between cord plasma and placenta, cord and maternal plasma, and cord PBMCs and maternal PBMCs. TFV moves from maternal plasma through the placenta to the cord blood and then into cord PBMCs, where it is phosphorylated into its active forms (TFV diphosphate). These five ARVs were detected in each of the compartments, highlighting transfer of these agents from the maternal into the fetal circulation.

Impact of endotoxin on the expression of drug transporters in the placenta of HIV-1 transgenic (HIV-Tg) rats

BACKGROUND

Inflammatory responses in HIV (+) patients may be exacerbated due to reports of subclinical endotoxemia and existing immune dysregulation. As inflammation has been reported to mediate changes in the expression of transporters, this could be potentiated in pregnant HIV (+) women. Similar to humans, the HIV-Tg rat model develops immune dysregulation and chronic AIDS-like conditions. Our objective was to examine the expression of placental drug transporters in HIV-Tg rats in response to low-dose endotoxin.

METHODS

Pregnant HIV-Tg rats or wild-type littermates (WT) were treated with low dose bacterial endotoxin 0.1mg/kg (n=8) or 0.25mg/kg (n=4-6) on GD18 and placentas were harvested 18h later. Placental and hepatic expression of transporters and cytokines were examined using qRT-PCR and Western blotting.

RESULTS

As compared to WT, endotoxin administration increased the hepatic and placental expression of IL-6 and TNF-α to a greater extent in HIV-Tg rats (p<0.05). The placental mRNA and protein expression of Abcb1a and Slco2b1 was significantly decreased in endotoxin-treated HIV-Tg but not WT rats and downregulation of Slco4a1 mRNA was more pronounced in the HIV-Tg group (p<0.05). These changes significantly correlated with the placental expression of pro-inflammatory cytokines. Abcc3 mRNA expression was increased in the placenta of endotoxin treated WT rats only, while placental expression of Abcc1, Abcc2 and Abcc4 was not significantly affected in both WT and HIV rats. Endotoxin imposed a pronounced downregulation in the hepatic expression of Abcb1a, Abcc2, Abcc4, Abcg2, Slco1a1, Slco1b2 and Slc29a1 in both HIV-Tg and WT rats; however, Abcb1b expression was increased in HIV but not WT rats.

CONCLUSION

Our results indicate that low-dose endotoxin resulted in an augmented inflammatory response in HIV-Tg rats accompanied with significant changes in the placental expression of several drug transporters. Our data suggests that subclinical endotoxemia and other co-existing infections may alter the placental transfer of drugs in the HIV population.

Risk of cancer in children exposed to didanosine in utero

BACKGROUND

Evaluation of long-term tolerance to antiretroviral exposure during pregnancy is required. An increased risk of cancer has been suggested in children exposed in utero to didanosine.

METHODS

Updated evaluation of cancer incidence in uninfected children exposed to nucleos(t)ide reverse transcriptase inhibitors (NRTIs) in the French perinatal study of children born to HIV+ mothers, by cross-checking with the National Cancer Registry. Associations between cancer risk and exposure to NRTIs were evaluated by univariate survival analysis and Cox proportional hazard models. Standardized incidence ratios (SIR) were used for comparison with the general population.

RESULTS

A total of 21 cancers were identified in 15 163 children (median age: 9.9 years [interquartile range (IQR): 5.8-14.2]) exposed to at least one NRTI in utero, between 1990 and 2014. Five children were exposed to zidovudine monotherapy, and 16 to various combinations, seven including didanosine. Didanosine accounted for only 10% of prescriptions but was associated with one-third of cancers. In a multivariate analysis, didanosine exposure was significantly associated with higher risk [hazard ratio = 3.0 (0.9-9.8)]. The risk was specifically linked with first-trimester exposure [hazard ratio = 5.5 (2.1-14.4)]. Overall, the total number of cases was not significantly different from that expected for the general population [SIR = 0.8 (0.47-1.24)], but was twice that expected after didanosine exposure [SIR = 2.5 (1.01-5.19)].

CONCLUSION

There are strong arguments to suggest that didanosine displays transplacental oncogenicity. Although not extrapolable to other NRTIs, they stress the need for comprehensive evaluation of the transplacental genotoxicity of this antiretroviral class.

Meconium aspiration syndrome in infants of HIV-positive women: a case-control study

OBJECTIVE

Our aim was to determine whether maternal HIV infection in the current era is associated with an increased incidence of meconium aspiration syndrome (MAS) in their infants.

METHODS

Infants born to 149 HIV-positive women at our hospital over a 5-year period were compared with infants born to HIV-negative women in a retrospective case-control study. Charts of all 298 patients included in the study were reviewed for maternal and infant demographics, HIV treatment, vertical transmission and untoward events at delivery or during the hospital course.

RESULTS

When compared with HIV-negative women, a greater proportion of HIV-positive women had meconium-stained amniotic fluid (MSAF), 33% vs. 13%, P<0.001; and thick MSAF, 17% vs. 5%, P<0.001, respectively. Seven of 298 infants were admitted to the neonatal intensive care unit for MAS; all seven were born to HIV-positive women (P=0.015). Although in utero exposure to illicit drugs is a reported risk factor for meconium staining of the amniotic fluid and such drug exposure was more common among our HIV-positive sample, controlling for this and other possible covariates did not greatly reduce the association of HIV status with meconium-related complications of delivery.

CONCLUSIONS

Infants born to HIV-positive women had significantly more MSAF and MAS than infants born to non-infected women. It is unclear whether this association results from maternal HIV infection itself or from anti-retroviral therapy. Maternal and infant care providers should be prepared for this complication when attending to the deliveries of HIV-positive women.

Residual inflammation and viral reservoirs: alliance against an HIV cure

PURPOSE OF REVIEW

HIV persists in cellular and anatomical reservoirs during antiretroviral therapy (ART). Viral persistence is ensured by a variety of mechanisms including ongoing viral replication and proliferation of latently infected cells. In this review, we summarize recent findings establishing a link between the unresolved levels of inflammation observed in virally suppressed individuals on ART and the mechanisms responsible for HIV persistence.

RECENT FINDINGS

Residual levels of viral replication during ART are associated with persistent low levels of immune activation, suggesting that unresolved inflammation can promote the replenishment of the HIV reservoir in tissues. In addition, the recent findings that the latent HIV reservoir is maintained by continuous proliferation of latently infected cells provide another mechanism by which residual inflammation could contribute to HIV persistence.

SUMMARY

Residual inflammation during ART is likely to be a critical parameter contributing to HIV persistence. Therefore, reducing inflammation may be an efficient way to interfere with the maintenance of the HIV reservoir in virally suppressed individuals on ART.

Prediction of human fetal pharmacokinetics using ex vivo human placenta perfusion studies and physiologically based models

AIMS

Pregnant women can be exposed to numerous drugs during the gestational period. For obvious ethical reasons, in vivo studies of fetal exposure to drugs are limited. Information about the transplacental transfer of drugs prior to their administration to pregnant women would be highly useful. In the present study, a novel approach was developed quantitatively predict or to predict the fetal exposure to drugs administered to the mother quantitatively.

METHODS

Transplacental parameters estimated from ex vivo human placenta perfusion experiments were implemented in pregnancy-physiologically based pharmacokinetic (p-PBPK) models in order to predict fetal PK. Thereafter, fetal PK profiles for two antiretroviral drugs, tenofovir (TFV) and emtricitabine (FTC) were simulated. These predictions were then compared to observed cord blood concentrations, to validate these models.

RESULTS

Parameters obtained from the ex vivo experiments enabled a good prediction of observed cord blood concentrations without additional a scaling factor. Moreover, a sensitivity analysis showed that fetal predictions were sensitive to changes in transplacental parameters values obtained ex vivo.

CONCLUSION

The integration of ex vivo human placental perfusion parameters in a p-PBPK model should be a promising new approach for predicting human fetal exposure to xenobiotics.

Pharmacokinetics of Once Versus Twice Daily Darunavir in Pregnant HIV-Infected Women

OBJECTIVE

To describe darunavir (DRV) pharmacokinetics with once-and twice-daily dosing during pregnancy and postpartum in HIV-infected women.

DESIGN

Women were enrolled in International Maternal Pediatric Adolescent AIDS Clinical Trials Network Protocol P1026s, a prospective nonblinded study of antiretroviral pharmacokinetics in HIV-infected pregnant women that included separate cohorts receiving DRV/ritonavir dosed at either 800 mg/100 mg once daily or 600 mg/100 mg twice daily.

METHODS

Intensive steady-state 12- or 24-hour pharmacokinetic profiles were performed during the second trimester, third trimester, and postpartum. DRV was measured using high-performance liquid chromatography (detection limit: 0.09 μg/mL).

RESULTS

Pharmacokinetic data were available for 64 women (30 once daily and 34 twice daily dosing). Median DRV area under the concentration-time curve (AUC) and maximum concentration were significantly reduced during pregnancy with both dosing regimens compared with postpartum, whereas the last measurable concentration (Clast) was also reduced during pregnancy with once daily DRV. DRV AUC with once daily dosing was reduced by 38% during the second trimester and by 39% during the third trimester. With twice daily dosing, DRV AUC was reduced by 26% in both trimesters. The median (range) ratio of cord blood/maternal delivery DRV concentration in 32 paired samples was 0.18 (range: 0-0.82).

CONCLUSIONS

DRV exposure is reduced by pregnancy. To achieve DRV plasma concentrations during pregnancy equivalent to those seen in nonpregnant adults, an increased twice daily dose may be necessary. This may be especially important for treatment-experienced women who may have developed antiretroviral resistance mutations.

A case series of third-trimester raltegravir initiation: Impact on maternal HIV-1 viral load and obstetrical outcomes

OBJECTIVE

To describe the impact of initiating raltegravir (RAL)-containing combination antiretroviral therapy (cART) regimens on HIV viral load (VL) in pregnant women who have high or suboptimal VL suppression late in pregnancy.

METHODS

HIV-infected pregnant women who started RAL-containing cART after 28 weeks' gestation from 2007 to 2013 were identified in two university hospital centres.

RESULTS AND DISCUSSION

Eleven HIV-infected women started RAL at a median gestational age of 35.7 weeks (range 31.1 to 38.0 weeks). Indications for RAL initiation were late presentation in pregnancy (n=4) and suboptimal VL suppression secondary to poor adherence or viral resistance (n=7). Mean VL at the time of RAL initiation was 73,959 copies/mL (range <40 to 523,975 copies/mL). Patients received RAL for a median of 20 days (range one to 71 days). The mean decline in VL from the time of RAL initiation to delivery was 1.93 log, excluding one patient who received only one RAL dose and one patient with undetectable VL at the time of RAL initiation. After eight days on RAL, 50% of the women achieved a VL <1000 copies/mL (the threshold for recommended Caesarean section to reduce the risk for perinatal transmission). There were no cases of perinatal HIV transmission.

CONCLUSION

The present study provides preliminary data to support the use of RAL-containing cART to expedite HIV-1 VL reduction in women who have a high VL or suboptimal VL suppression late in pregnancy, and to decrease the risk of HIV perinatal transmission while avoiding Caesarean section. Further assessment of RAL safety during pregnancy is warranted.

Tenofovir: What We Have Learnt After 7.5 Million Person-Years of Use

Tenofovir was licensed for use in patients with HIV in 2001 and since then has become a firmly established anti-retroviral in both guidelines and routine practice. Data have been presented from many pivotal studies—informing on its efficacy, use, and adverse features—and there are also over 7.5 million patient-years of experience to date. We explore the data on this nucleotide reverse transcriptase inhibitor in HIV presented since 2008—focusing on efficacy, side effects, and utility.

Smart nanoparticles as targeting platforms for HIV infections

While Human Immunodeficiency Virus (HIV) infections are reducing in incidence with the advent of Highly Active Anti-retroviral Therapy (HAART), there remain a number of challenges including the existence of reservoirs, drug resistance and anatomical barriers to antiretroviral therapy. To overcome these, smart nanoparticles with stimuli responsive release are proposed for delivery of anti-retroviral agents. The paper highlights the strategic similarities between the design of smart antiretroviral nanocarriers and those optimized for cancer chemotherapy. This includes the development of nanoparticles capable of passive and active targeting as well as those that are responsive to various internal and external triggers. For antiretroviral therapy, the relevant triggers for stimuli responsive release of drugs include semen, enzymes, endosomal escape, temperature and magnetic field. Deriving from the experience of cancer chemotherapy, additional potential triggers are light and ultrasound which remain hitherto unexplored in HIV therapy. In addition, the roles of nanomicrobicides (nanogels) and virus mimetic nanoparticles are discussed from the point of view of prevention of HIV transmission. The challenges associated with translation of smart nanoparticles for HIV infections to realize the Millennium Development Goal of combating HIV infections are discussed.

In utero exposure to zidovudine and heart anomalies in the ANRS French perinatal cohort and the nested PRIMEVA randomized trial

BACKGROUND

Antiretroviral (ARV) regimens during pregnancy are highly effective in preventing mother-to-child transmission of human immunodeficiency virus (HIV). Congenital heart defects (CHDs) and anomalies in cardiac function have been reported in zidovudine (ZDV)-exposed uninfected children. We explored these associations in a large observational cohort and a randomized clinical trial.

METHODS

Since 1986, the French Perinatal Cohort prospectively enrolled all HIV-infected women in 90 centers and collected follow-up on their children through 2 years of age. All CHDs were reviewed by a specialist blinded to exposures. Additionally, in a randomized trial (PRIMEVA ANRS 135) of 2 ARV regimens during pregnancy, 1 of which was without nucleoside reverse transcriptase inhibitors, infants had a specific follow-up including echocardiography at 1 month and 12 months.

RESULTS

Among 12 888 children included, ZDV exposure in the first trimester was significantly associated with CHD (1.5% vs 0.7%; adjusted odds ratio, 2.2 [95% confidence interval, 1.3-3.7]; P < .001). This association was significant for ventricular septal defects (1.1% vs 0.6%; P = .001) and other CHDs (0.31% vs 0.11%; P = .02). In the randomized trial, among 50 infants, girls (but not boys) exposed in utero to ZDV/lamivudine/ritonavir-boosted lopinavir (LPV/r) had a higher left ventricular shortening fraction at 1 month (40% vs 36%; P = .008), and an increased posterior wall thickness at 1 year (5.4 mm vs 4.4 mm; P = .01) than the LPV/r group.

CONCLUSIONS

This study confirms a specific association between in utero exposure to ZDV and CHDs, and a long-lasting postnatal myocardial remodeling in girls. A potential common mechanism, including the involvement of mitochondrial dysfunction, must be explored, and long-term consequences on cardiac function warrant specific attention.

CLINICAL TRIALS REGISTRATION

NCT00424814.

Pharmacokinetics of antiretrovirals in mucosal tissue

INTRODUCTION

In the absence of an HIV vaccine or cure, antiretroviral (ARV)-based prevention strategies are being investigated to reduce HIV incidence. These prevention strategies depend on achieving effective drug concentrations at the site of HIV exposure, which is most commonly the mucosal tissue of the lower gastrointestinal tract and the female genital tract.

AREAS COVERED

This article collates all known data regarding drug exposure in these vulnerable mucosal tissues and reviews important mechanisms of ARV drug distribution. Research papers and abstracts describing ARV pharmacokinetics (PK) in the female genital tract and lower gastrointestinal mucosal tissues available in MEDLINE® or presented at scientific conferences prior to December 2014 are reviewed in detail. Important influences on ARV mucosal tissue distribution, including protein binding, active drug transport and endogenous hormones are also reviewed.

EXPERT OPINION

ARVs exhibit highly variable PK in mucosal tissues. In general, ARV exposure is higher in the lower gastrointestinal tract compared with the female genital tract, but concentrations required for protective efficacy are largely unknown. The expected site of HIV exposure represents an important consideration when designing and optimizing ARV-based prevention strategies.

Tolerance of the newborn to antiretroviral drug exposure in utero

INTRODUCTION

The prevention of mother-to-child HIV-1 transmission by antiretroviral drug treatment is remarkably effective. The risk of transmission to the child is now almost zero for women optimally treated during pregnancy. The rapid expansion of this prophylactic treatment has led the World Health Organization to aspire to the virtual elimination of mother-to-child transmission and pediatric AIDS over the next few years. In 2014, more than 900,000 women worldwide were treated with antiretroviral drugs during pregnancy. The issue of fetal and neonatal antiretroviral drug tolerance is therefore extremely important.

AREAS COVERED

This review focuses on the possible impact of in utero exposure to antiretroviral drug on newborn health. To restrict analysis to this period is justified by the specificities of transplacental drug exposure and fetal vulnerability. Relevant data are available from trials and observational cohorts. The significance of various bio-markers detectable at birth is still unresolved, but merits a careful evaluation. Long-term assessment is associated with various logistical difficulties.

EXPERT OPINION

The health of 'exposed but not infected' children poses no major problem in the immense majority of cases, but a series of biological, clinical and imaging-based warning signs have emerged indicating the need for careful attention to be paid to this issue. Some effects that are straightforward to manage in industrialized countries may have more severe consequences in countries in which access to effective healthcare is limited. Nucleoside/nucleotide analogs are potentially genotoxic to mitochondrial and nuclear DNA, and the principal question to be addressed concerns their potential long-term effects.

Placental transfer of rilpivirine in an ex vivo human cotyledon perfusion model

Placental transfers of the HIV nonnucleoside reverse transcriptase inhibitor rilpivirine were investigated in 8 term human cotyledons perfused with rilpivirine (400 ng/ml) in the maternal-to-fetal direction. The mean fetal transfer rate (FTR) (fetal/maternal concentration at steady state from 15 to 90 min) was 26% ± 8% (mean ± standard deviation), and the clearance index (rilpivirine FTR/antipyrine FTR) was 61% ± 20%. This shows that rilpivirine crosses the placenta at a relatively high rate, suggesting that the fetus is exposed to the compound during treatment of the mother.

Darunavir pharmacokinetics throughout pregnancy and postpartum

Introduction

Antiretroviral therapy is recommended during pregnancy for prevention of mother-to-child transmission (MTCT) of HIV. Physiological changes during pregnancy are known to affect the pharmacokinetics (PK) of protease inhibitors (PIs), leading to lower exposures in pregnant women. Here we examine the PK of DRV/r 800/100 mg once daily (OD) over the course of pregnancy and postpartum (PP).

Material and Methods

In this prospective open-labelled study, HIV-positive pregnant women receiving darunavir/ritonavir as part of their routine maternity care were enrolled. DRV plasma trough concentrations [DRV] were determined in the first (T1) and/or second (T2) and/or third (T3) trimester and PP using a validated HPLC-MS/MS methodology (Lab21, Cambridge UK). Where possible paired maternal and cord blood samples were taken at delivery.

Results

To date 20 women (12 black African, 8 Caucasian) have been enrolled. Median (range) baseline CD4 count was 338 cells/µL (108–715), and median baseline plasma viral load was 555 copies/mL (<40–8,188,943). All but 2 women were virally suppressed at time of delivery (114 and 176 copies/mL; 1 sub-therapeutic at T3) and median CD4 count was 410 cells/µL (92–947). There were 20 live births, all term deliveries and there were no cases of MTCT. [DRV] (geometric mean; 95% CI) was 3790 ng/mL at T1 (n=1); 1288 ng/mL (663–1913) at T2 (n=9); 1086 ng/mL (745–1428) at T3 (n=18, 1 undetectable) and 2324 ng/mL (1369–3279) at PP (n=14, 1 undetectable). There was no significant difference in [DRV] between T2 and PP (p=0.158); however, there was between T3 and PP (p=0.021). Nineteen of twenty (95%) and 16 of 20 (80%) women achieved [DRV] above the estimated MEC for WT (55 ng/mL) and PI resistant HIV-1 (550 ng/mL) throughout pregnancy. Maternal and cord [DRV] were available for 10 mother–baby pairs. Mean maternal [DRV] at delivery was 2235 ng/mL (±1557 ng/mL), while mean cord [DRV] was 337 ng/mL (±217 ng/mL). The median cord to maternal blood ratio (C/M) was 0.11 (0.06–0.49).

Conclusions

In most cases examined, DRV/r 800/100 mg once daily was effective at achieving adequate therapeutic drug levels (>550 ng/ml) during pregnancy. However, reduced DRV plasma concentrations in the second/third trimesters highlights the need for TDM in this population and warrants further study of pregnancy-associated changes in DRV pharmacokinetics. The low C/M ratios reported here are consistent with previous reports [1] and suggest low transplacental transfer of DRV.

Increase in transaminase levels following the use of raltegravir in a woman with a high HIV viral load at 35 weeks of pregnancy

BACKGROUND

Despite the efficacy of raltegravir in reducing viral load in HIV-infected patients, evidence for its safety in late pregnancy is lacking. A high rate of placental transfer was recently demonstrated.

CASE

A treatment-naïve 34-year-old HIV-1-positive woman of African origin began treatment with zidovudine/lamivudine, lopinavir/ritonavir, and raltegravir at 35 weeks of pregnancy. After 11 days of treatment with raltegravir, a substantial reduction in viral load was achieved. Concurrently, she had a 23-fold increase in serum alanine aminotransferase and a 10-fold increase in serum aspartate aminotransferase, both of which returned to normal when raltegravir treatment was discontinued. A healthy boy was delivered at term. The infant's tests for HIV were negative at five months, and he had no health problems at eight months.

CONCLUSION

This is the first case report, to our knowledge, of increased maternal serum transaminase levels following the use of raltegravir in a woman at a late stage of pregnancy.

Atazanavir exposure is effective during pregnancy regardless of tenofovir use

BACKGROUND

We studied the effect of pregnancy on atazanavir pharmacokinetics in the presence and absence of tenofovir.

METHODS

This was a non-randomized, open-label, multicentre Phase IV study in HIV-infected pregnant women recruited from European HIV treatment centres. HIV-infected pregnant women treated with boosted atazanavir (300/100 mg or 400/100 mg atazanavir/ritonavir) as part of their combination antiretroviral therapy (cART) were included in the study. 24 h pharmacokinetic curves were recorded in the third trimester and postpartum. Collection of a cord blood and maternal sample at delivery was optional.

RESULTS

31 patients were included in the analysis, 21/31 patients used tenofovir as part of cART. Median (range) gestational age at delivery was 39 weeks (36-42). Approaching delivery 81% (25 patients) had an HIV viral load <50 copies/ml, all <1,000 copies/ml. Least squares means ratios (90% CI) of atazanavir pharmacokinetic parameters third trimester/postpartum were: 0.66 (0.57, 0.75) for AUC0-24h, 0.70 (0.61, 0.80) for Cmax and 0.59 (0.48, 0.72) for C24h. No statistical difference in pharmacokinetic parameters was found between patients using tenofovir versus no tenofovir. None of the patients showed atazanavir concentrations <0.15 mg/l (target for treatment-naive patients). One baby had a congenital abnormality, which was not likely to be related to atazanavir/ritonavir use. None of the children were HIV-infected.

CONCLUSIONS

Despite 34% lower atazanavir exposure during pregnancy, atazanavir/ritonavir 300/100 mg once daily generates effective concentrations for protease inhibitor (PI)-naive patients, even if co-administered with tenofovir. For treatment-experienced patients (with relevant PI resistance mutations) therapeutic drug monitoring of atazanavir should be considered to adapt the atazanavir/ritonavir dose on an individual basis.
 ClinicalTrials.gov number NCT00825929.

[HIV and pregnancy: 2013 guidelines from the French expert working group]

With effective antiretroviral therapy, the risk of mother to child transmission (MTCT) is now under 1%. The 2013 French guidelines emphasize early antiretroviral lifelong antiretroviral therapy. Thus, the current trend for women living with HIV is to take antiretroviral therapy before, during and after their pregnancies. A major issue today is the choice of antiretroviral drugs, to maximize the benefits and minimize the risks of fetal exposure. This requires interdisciplinary care. The use of effective therapies permits gradual but profound changes in obstetric practice. When maternal plasma viral load is controlled (<50 copies/ml), obstetrical care can be more similar to standards in HIV-negative women. Prophylactic cesarean section is recommended when the viral load in late pregnancy is above 400 copies/mL. Intravenous zidovudine during labor is recommended only if the last maternal viral load is>400 copies/mL or in case of complications such as preterm delivery, bleeding or chorio-amnionitis during labor. In case of premature rupture of membranes before 34 weeks, a multidisciplinary decision should be made, based on gestational age and control of maternal viral load; if the woman is under antiretroviral therapy and especially if her viral load is undetectable, steroids and antibiotics should be offered and pregnancy can be continued except in case of signs or symptoms of chorio-amnionitis. Breastfeeding is not recommended in women living with HIV in France, as in industrialized countries. Prophylaxis in the newborn is usually zidovudine for 1 month. In case of significant exposure to HIV perinatally, in particular when, maternal viral load is>1000 copies/mL, prophylactic combination therapy is recommended. Monitoring of the child is necessary to determine whether or not it is free of HIV infection and to monitor possible adverse effects of perinatal exposure to antiretroviral drugs.

Pharmacological considerations on the use of antiretrovirals in pregnancy

PURPOSE OF REVIEW

Treatment with combination antiretroviral therapy during pregnancy reduces the chance of mother to child transmission of HIV. Physiological changes during pregnancy can lead to lower exposure to antiretrovirals, possibly resulting in virological failure. For most antiretrovirals, data on exposure during pregnancy and transplacental passage are limited. This review summarizes the most recent information on pharmacokinetics (including transplacental passage), efficacy, as well as the safety of antiretrovirals during pregnancy.

RECENT FINDINGS

Intensive-sampling pharmacokinetic studies as well as observational studies using sparse sampling were performed to explore the exposure to antiretrovirals during pregnancy. Transplacental passage, efficacy (viral load at delivery and infection status of the newborn) and safety information were evaluated for several antiretrovirals.

SUMMARY

For most nucleoside/nucleotide reverse transcriptase inhibitors and protease inhibitors, recent research shows a decreased exposure during pregnancy. However, the advantage of a general dose increase during pregnancy still remains unclear. For newer compounds and efavirenz, limited or no data on pharmacokinetics during pregnancy or transplacentally are available, while the mechanisms of transplacental passage also remain unknown. For safety reasons, it will be important to monitor pregnancy outcomes in resource-limited settings during the implementation of the WHO guidelines (including the use of efavirenz during pregnancy).

HIV-exposed uninfected children: a growing population with a vulnerable immune system?

Through the successful implementation of policies to prevent mother-to-child-transmission (PMTCT) of HIV-1 infection, children born to HIV-1-infected mothers are now much less likely to acquire HIV-1 infection than previously. Nevertheless, HIV-1-exposed uninfected (HEU) children have substantially increased morbidity and mortality compared with children born to uninfected mothers (unexposed uninfected, UU), predominantly from infectious causes. Moreover, a range of phenotypical and functional immunological differences between HEU and UU children has been reported. As the number of HEU children continues to increase worldwide, two questions with clear public health importance need to be addressed: first, does exposure to HIV-1 and/or ART in utero or during infancy have direct immunological consequences, or are these poor outcomes simply attributable to the obvious disadvantages of being born into an HIV-affected household? Secondly, can we expect improved maternal care and ART regimens during and after pregnancy, together with optimized infant immunization schedules, to reduce the excess morbidity and mortality of HEU children?

Cesarean section for HIV-infected women in the combination antiretroviral therapies era, 2000-2010

OBJECTIVE

Elective cesarean section (CS) is a proven method to prevent mother-to-child transmission (MTCT), but is no longer recommended for women with antiretroviral therapy resulting in a low viral load (VL): <400 copies/mL in French and <1000 copies/mL in US guidelines. We sought to describe mode of delivery practices in human immunodeficiency virus (HIV)-infected women and their association with MTCT and postpartum complications.

STUDY DESIGN

All deliveries from HIV-1-infected women in the French Perinatal Cohort (Agence Nationale de Recherches sur le Sida/Enquête Périnatale Française) 2000 through 2010 (N = 8977) were analyzed, with additional details for 2005 through 2010 (n = 4717).

RESULTS

Vaginal deliveries increased from 25% in 2000 to 53% in 2010. Over 2005 through 2010, 4300 women had VL before delivery <400 copies/mL; among them only 49.3% delivered vaginally, 22.0% had nonelective CS, and 28.7% had elective CS. Elective CS were performed for scarred uterus in 45.4%, other obstetrical indications in 37.1%, and solely because of HIV in 15.7%. Of the 417 women with VL ≥400 copies/mL, 48.9% had elective CS as recommended, 25.9% had nonelective CS, and 25.2% had vaginal delivery. The MTCT rate did not differ according to the mode of delivery in term deliveries (≥37 gestational weeks) in 2000 through 2010: 0.3% after both vaginal delivery and elective CS with VL <50 copies/mL, 4.0% vs 5.3%, respectively, with VL ≥10,000 copies/mL. In case of preterm delivery, MTCT rates tended to be higher with vaginal delivery. Postpartum complications were more frequent following CS than vaginal deliveries (6.5% vs 2.9, P < .01).

CONCLUSION

Our findings suggest that HIV-infected women on antiretroviral therapy with low VL can safely opt for vaginal delivery in the absence of obstetrical risk factors.

Potential effect of pharmacogenetics on maternal, fetal and infant antiretroviral drug exposure during pregnancy and breastfeeding

Mother-to-child-transmission rates of HIV in the absence of any intervention range between 20 and 45%. However, the provision of antiretroviral drugs (ARVs) during pregnancy, delivery and breastfeeding can reduce HIV transmission to less than 2%. Physiological changes during pregnancy can influence ARV disposition. Associations between SNPs in genes coding for metabolizing enzymes, and/or transporters, and ARVs disposition are well described; however, relatively little is known about the influence of these SNPs on ARV pharmacokinetics during pregnancy and lactation as well as their effect on distribution into the fetal compartment and breast milk excretion. Differences in maternal, fetal and infant ARV exposure due to SNPs may affect the efficacy and safety of ARVs used to prevent mother-to-child-transmission. The aim of this review is to provide an update on the effect of pregnancy-induced changes on the pharmacokinetics of ARVs and highlight the potential role of pharmacogenetics.

NRTI backbone in HIV treatment: will it remain relevant?

Nucleoside reverse transcriptase inhibitors (NRTIs) remain a critical component of therapy for HIV-infected patients. The drugs are effective, relatively inexpensive and an important component of antiretroviral therapy (ART), particularly in areas where the introduction of effective therapy has been delayed. They are an essential part of initial therapy for HIV and for prevention of mother-to-child transmission; however, toxicities and resistance may limit their use. The role for pre-exposure prophylaxis (PrEP) to reduce sexual transmission of HIV is still undefined, but this use may have a significant impact on NRTI resistance worldwide, most particularly in areas where subtype C predominates. With increasing prevalence of resistant HIV, the approval of new agents that are effective against resistant virus, and those that use novel cellular targets, are essential. Large studies are now in progress examining the safety and efficacy of NRTI-sparing regimens, but results are not currently available. NRTIs may lose relevance in the not distant future unless steps are put in place to reduce the development and spread of NRTI-resistant viruses, and new NRTIs with minimal toxicity are developed that have a novel resistance profile. This article describes the principal NRTIs, their mechanism of action, and resistance and selected toxicities of the class and of the individual drugs.

Maraviroc intensification of stable antiviral therapy in HIV-1-infected patients with poor immune restoration: MARIMUNO-ANRS 145 study

OBJECTIVE

To address the ability of a 24-week Maraviroc (MVC) intensification of a stable antiretroviral therapy (cART) to significantly increase the CD4 cell count slope.

METHODS

Patients were eligible if they had CD4 <350 cells/mm, a CD4 slope <50 cells/mm per year, and sustained plasma HIV-RNA <50 copies/mL over the last 2 years, while receiving a stable cART. Patients harboring pure X4-using viruses by a phenotypic tropism assay were excluded. MVC was added to cART for 24 weeks, at the recommended dosage per drug-drug interactions. The primary endpoint was a significant positive difference in CD4 slopes (with MVC- pre-MVC, paired t test).

RESULTS

Sixty patients (55 men), with median age 51 years, baseline CD4 238 cells/mm, and slope before intensification +14.1 cells/mm per year were included. CD4 nadir was <50/mm in 47% of the population. The full set of patients (N = 57) completed week 24, and the on-treatment patients (N = 48) did not discontinue MVC. The median CD4 slope difference from baseline was +22.6 cells/mm per year (P = 0.08) in full set and +22.6 cells/mm per year (P = 0.04) in on-treatment. Slope evolution was not different according to baseline tropism, CD4 nadir, or ongoing cART regimen. No drug-related severe adverse events were recorded during intensification. MVC plasma concentrations were significantly different depending on drug-drug interaction with ongoing cART regimen and tended to be correlated with CD4 cells increase.

CONCLUSION

In this study, MVC intensification of stable cART over 24 weeks was able to enhance CD4 cell slopes in patients with prior insufficient immune restoration despite long-term virological control.