Lower Insulin Sensitivity Through 36 Months of Life With in Utero HIV and Antiretroviral Exposure in Botswana: Results From the Tshilo Dikotla Study

BACKGROUND

There are little data on changes in insulin sensitivity during the first few years of life following in utero human immunodeficiency virus (HIV) and antiretroviral (ARV) exposure.

METHODS

The Tshilo Dikotla study enrolled pregnant persons with HIV (PWH) (receiving tenofovir/emtricitabine or lamivudine plus dolutegravir or efavirenz) and pregnant individuals without HIV, as well as their liveborn children. Newborns were randomized to receive either zidovudine (AZT) or nevirapine (NVP) postnatal prophylaxis. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was assessed at birth and 1, 18, 24, and 36 months of life. We fit linear mixed-effects models to evaluate the association between in utero HIV/ARV exposure and average HOMA-IR from birth through 36 months of life, adjusting for confounders.

RESULTS

A total of 419 children were included (287 with in utero HIV/ARV exposure and uninfected [CHEU] and 132 without in utero HIV/ARV exposure [CHUU]). CHEU were born to older women (29.6 vs 25.3 years of age) with higher gravidity (3 vs 1). HOMA-IR was persistently higher in CHEU versus CHUU in adjusted analyses (mean difference of 0.07 in log10 HOMA-IR, P  = .02) from birth through 36 months of life. Among CHEU, no differences in HOMA-IR were observed from birth through 36 months by in utero ARV exposure status or between AZT and NVP infant prophylaxis arms.

CONCLUSIONS

In utero HIV/ARV exposure was associated with lower insulin sensitivity throughout the first 36 months of life, indicating persistent early life metabolic disturbances which may raise concern for poorer metabolic health later in life.

Psychiatric disorders in perinatally HIV-exposed, uninfected children: a systematic review

The population of perinatally HIV-exposed but uninfected (HEU) children is growing rapidly globally. However, perinatal HIV and antiretroviral (ARV) medicine exposure in HIV-uninfected children has raised concerns about HEU children's mental well-being. The objective of this study was to systematically review the literature on psychiatric disorders in HEU children. The PRISMA guideline was used as a methodical frame of reference. A systematic search was conducted in 5 databases. Data from the included studies were extracted, and the results were summarized qualitatively. The search identified 1,976 articles of which 105 were eligible for full-text analysis. 13 studies met the inclusion criteria. Eight studies compared psychiatric disorder prevalence in perinatally HIV-infected children with HEU children, and only one study found a difference between the two groups. Three studies found that HEU children had a higher prevalence of psychiatric disorders compared with HIV-unexposed, uninfected (HUU) children. These findings indicate that factors such as psychosocial stress, socioeconomic status, and stigma contribute to the increased risk of mental disorders in HEU children. More research is needed comparing HEU children with HUU children adjusting for potential confounders that might partially explain the higher rates seen in the HIV-exposed population.Prospero ID: CRD42020212420.

The prenatal environment and its influence on maternal and child mitochondrial DNA copy number and methylation: A review of the literature

Mitochondrial DNA (mtDNA) is sensitive to environmental stressors and associated with human health. We reviewed epidemiological literature examining associations between prenatal environmental, dietary, and social exposures and alterations in maternal/child mtDNA copy number (mtDNAcn) and mtDNA methylation. Evidence exists that prenatal maternal exposures are associated with alterations in mtDNAcn for air pollution, chemicals (e.g. metals), cigarette smoke, human immunodeficiency virus (HIV) infection and treatment. Evidence for their associations with mtDNA methylation was limited. Given its potential implications as a disease pathway biomarker, studies with sufficient biological specificity should examine the long-term implications of prenatal and early-life mtDNA alterations in response to prenatal exposures.

Immune and Metabolic Alterations in Children with Perinatal HIV Exposure

With the global rollout of mother-to-child prevention programs for women living with HIV, vertical transmission has been all but eliminated in many countries. However, the number of children who are exposed in utero to HIV and antiretroviral therapy (ART) is ever-increasing. These children who are HIV-exposed-but-uninfected (CHEU) are now well recognized as having persistent health disparities compared to children who are HIV-unexposed-and-uninfected (CHUU). Differences reported between these two groups include immune dysfunction and higher levels of inflammation, cognitive and metabolic abnormalities, as well as increased morbidity and mortality in CHEU. The reasons for these disparities remain largely unknown. The present review focuses on a proposed link between immunometabolic aberrations and clinical pathologies observed in the rapidly expanding CHEU population. By drawing attention, firstly, to the significance of the immune and metabolic alterations observed in these children, and secondly, the impact of their healthcare requirements, particularly in low- and middle-income countries, this review aims to sensitize healthcare workers and policymakers about the long-term risks of in utero exposure to HIV and ART.

Distinct cord blood C-peptide, adipokine, and lipidomic signatures by in utero HIV exposure

BACKGROUND

Early-life metabolic derangements in HIV-exposed uninfected (HEU) infants have been reported.

METHODS

Pregnant women with HIV and HIV-uninfected pregnant women were enrolled with their newborns in a US cohort from 2011 to 2015. We measured cord insulin, C-peptide, and metabolic cytokines of HEU and HIV-unexposed uninfected (HUU) newborns using ELISA and metabolites, lipid subspecies, and eicosanoids via liquid chromatography/mass spectrometry. Linear regression was employed to assess the association of intrauterine HIV/ART with insulin and C-peptide. Graphical lasso regression was used to identify differences between metabolite/lipid subspecies networks associated with C-peptide.

RESULTS

Of 118 infants, 56 were HEU, ART exposed. In adjusted analyses, mean cord insulin (β = 0.295, p = 0.03) and C-peptide (β = 0.522, p < 0.01) were significantly higher in HEU vs. HUU newborns. HEU neonates exhibited primarily positive associations between complex lipids and C-peptide, indicative of fuel storage, and augmented associations between cord eicosanoids and cytokines. HUU neonates exhibited negative associations with lipids and C-peptide indicative of increased fuel utilization.

CONCLUSION

Higher cord insulin and C-peptide in HEU vs. HUU newborns as well as differences in cord metabolites, metabolic-related cytokines, and eicosanoids may reflect a propensity for fuel storage and an inflammatory milieu suggestive of fetal metabolic changes associated with in utero HIV/ART exposure.

IMPACT

There is a paucity of studies assessing cord blood and neonatal metabolic health in HIV-exposed uninfected (HEU) newborns, an increasing population worldwide. Compared to HIV-unexposed uninfected (HUU) newborns, HEU newborns exhibit alterations in fuel homeostasis and an inflammatory milieu associated with in utero HIV/antiretroviral therapy (ART) exposure. The long-term implications of these neonatal findings are as yet unknown, but merit continued evaluation as this important and growing population ages into adulthood.

Prediction and prevention of preterm birth in pregnant women living with HIV on antiretroviral therapy

INTRODUCTION

The rate of spontaneous preterm-birth among pregnant women living with HIV on antiretroviral therapy (ART) is 3- to 4-fold higher when compared to HIV-negative women. The pathophysiology of preterm-birth related to HIV or ART remains unknown, especially as women living with HIV are often excluded from preterm birth studies.

AREAS COVERED

This review discusses the currently available evidence on the prediction and prevention of preterm-birth in pregnant women living with HIV. A review of the literature was conducted of primary articles between 2005 and 2021 measuring the association or lack thereof between combination ART and preterm birth, as well as of other predisposing factors to preterm birth in women living with HIV, including cervical length, vaginal microbiome, and cervico-vaginal biomarkers.

EXPERT OPINION

Further research into the effect of ART exposure on preterm-birth risk is critical, and development of preterm-birth predictive tools in this population should be a priority. Vaginal progesterone supplementation deserves further investigation as a therapeutic option to prevent recurrent preterm birth in pregnant women living with HIV. The ProSPAR study, a multicenter randomized controlled trial studying progesterone supplementation in pregnant women on protease inhibitor-based regimens, has been designed but is not yet recruiting patients.

Emerging methods for and novel insights gained by absolute quantification of mitochondrial DNA copy number and its clinical applications

The past thirty years have seen a surge in interest in pathophysiological roles of mitochondria, and the accurate quantification of mitochondrial DNA copy number (mCN) in cells and tissue samples is a fundamental aspect of assessing changes in mitochondrial health and biogenesis. Quantification of mCN between studies is surprisingly variable due to a combination of physiological variability and diverse protocols being used to measure this endpoint. The advent of novel methods to quantify nucleic acids like digital polymerase chain reaction (dPCR) and high throughput sequencing offer the ability to measure absolute values of mCN. We conducted an in-depth survey of articles published between 1969 -- 2020 to create an overview of mCN values, to assess consensus values of tissue-specific mCN, and to evaluate consistency between methods of assessing mCN. We identify best practices for methods used to assess mCN, and we address the impact of using specific loci on the mitochondrial genome to determine mCN. Current data suggest that clinical measurement of mCN can provide diagnostic and prognostic value in a range of diseases and health conditions, with emphasis on cancer and cardiovascular disease, and the advent of means to measure absolute mCN should improve future clinical applications of mCN measurements.

Mitochondrial DNA Parameters in Blood of Infants Receiving Lopinavir/Ritonavir or Lamivudine Prophylaxis to Prevent Breastfeeding Transmission of HIV-1

Children who are human immunodeficiency virus (HIV)-exposed but uninfected (CHEU) accumulate maternal HIV and antiretroviral exposures through pregnancy, postnatal prophylaxis, and breastfeeding. Here, we compared the dynamics of mitochondrial DNA (mtDNA) parameters in African breastfed CHEU receiving lopinavir/ritonavir (LPV/r) or lamivudine (3TC) pre-exposure prophylaxis during the first year of life. The number of mtDNA copies per cell (MCN) and the proportion of deleted mtDNA (MDD) were assessed at day 7 and at week 50 post-delivery (PrEP group). mtDNA depletion was defined as a 50% or more decrease from the initial value, and mtDNA deletions was the detection of mtDNA molecules with large DNA fragment loss. We also performed a sub-analysis with CHEU who did not receive a prophylactic treatment in South Africa (control group). From day seven to week 50, MCN decreased with a median of 41.7% (interquartile range, IQR: 12.1; 64.4) in the PrEP group. The proportion of children with mtDNA depletion was not significantly different between the two prophylactic regimens. Poisson regressions showed that LPV/r and 3TC were associated with mtDNA depletion (reference: control group; LPV/r: PR = 1.75 (CI95%: 1.15–2.68), p < 0.01; 3TC: PR = 1.54 (CI95%: 1.00–2.37), p = 0.05). Moreover, the proportion of children with MDD was unexpectedly high before randomisation in both groups. Long-term health impacts of these mitochondrial DNA parameters should be investigated further for both CHEU and HIV-infected children receiving LPV/r- or 3TC- based regimens.

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.

Investigation of factors associated with spontaneous preterm birth in pregnant women living with HIV

OBJECTIVE

To investigate factors contributing to preterm birth (PTB), including cART use and clinical and social determinants of health, in women living with HIV (WLWH) from British Columbia, Canada.

DESIGN

Retrospective observational cohort.

METHODS

We investigated the effect of cART use and other clinical and demographic factors on spontaneous PTB (sPTB) rates (<37 weeks gestational age) among 631 singleton pregnancies between 1997 and 2018. Exposure to cART was modelled in comparison to no exposure, exposure in the first trimester, and between regimens. Differences in sPTB risk were estimated using time-dependent Cox's proportional hazards models.

RESULTS

Overall, the sPTB rate was 16%. Cumulative cART use was associated with lower risk of PTB (Wald test P = 0.02; hazard ratio = 0.98, 95% CI = 0.96-0.99) and specific cART regimens were not associated with increased risk of sPTB. Exposure in the first trimester was not associated with sPTB and for each week of cART exposure, the risk of sPTB decreased by 2%. In a multivariable model, HIV viral load and substance use remained associated with risk of sPTB, but not cART exposure.

CONCLUSION

The sPTB rate among pregnant WLWH was more than three times higher than in the general population. However, sPTB was not related specifically to use of cART; in fact, cART appeared to reduce the risk of sPTB. Uncontrolled HIV replication and substance use were associated with increased risk of sPTB among pregnant WLWH. This emphasizes the important role of prenatal care, access to cART, and smoking cessation and harm reduction to reduce the risk of sPTB in WLWH.

Mitochondrial DNA content of peripheral blood mononuclear cells in ART untreated & stavudine/zidovudine treated HIV-1-infected patients

Background & objectives:

Nucleoside reverse transcriptase inhibitors (NRTIs) are known to cause mitochondrial toxicity. This study was done to estimate mitochondrial DNA (mtDNA) content of peripheral blood mononuclear cells (PBMCs) among human immunodeficiency virus (HIV) infected, NRTI treated and antiretroviral therapy (ART)-naïve patients and evaluate the utility of mtDNA content as a biomarker of mitochondrial toxicity.

Methods:

mtDNA content in PBMCs of 57 HIV-infected ART untreated and 30 ART treated with stavudine (d4T) or zidovudine (AZT) containing regimen were compared against 24 low-risk healthy controls (LoRHC).

Results:

There was a significant (P=0.01) reduction in mtDNA content among HIV-infected (104; 80-135) compared to LoRHC (127; 110-167), and it was the same in both the treated (104.8; 88-130) and untreated patients (104.7; 78-142). mtDNA significantly (P=0.014) declined in ART treated patients symptomatic for toxicity (97; 74-111) than the asymptomatic patients (128; 103- 153).

Interpretation & conclusions:

mtDNA depletion in PBMCs was evident among HIV-infected individuals on ART. Moreover, as mtDNA content was reduced among the patients symptomatic for toxicity than the asymptomatic in both the HIV-infected groups, the current study supports mtDNA content of PBMCs to serve as a biomarker of mitochondrial dysfunction induced by NRTI and HIV. Longitudinal studies with a large sample need to be done to confirm these findings.

Cardiac and mitochondrial function in HIV-uninfected fetuses exposed to antiretroviral treatment

BACKGROUND

Mitochondrial toxicity related to maternal combined antiretroviral treatment (cART) may have an impact on the heart of HIV-exposed uninfected (HEU) fetuses. Our objective was to evaluate fetal cardiovascular and mitochondrial biomarkers in HIV pregnancies.

METHODS

Prospective cohort including 47 HIV-infected and 47 non HIV-infected pregnancies. Fetal echocardiography was performed at 26-32 weeks of pregnancy. Umbilical cord blood and placental tissue were collected to study mitochondrial DNA content (mtDNA) (ratio 12SrRNA/RNAseP) and mitochondrial function (cytochrome c oxidase, COX, enzymatic activity) normalized by mitochondrial content (citrate synthase, CS).

RESULTS

HEU fetuses showed hypertrophic hearts (left myocardial wall thickness: HIV mean 3.21 mm (SD 0.81) vs. non-HIV 2.72 (0.42), p = 0.012), with signs of systolic and diastolic dysfunction (isovolumic relaxation time: HIV 52.2 ms (8.85) vs. non-HIV 42.5 ms (7.30); p<0.001). Cord blood mitochondrial content was significantly increased in HIV-exposed fetuses (CS activity: HIV 82.9 nmol/min.mg of protein (SD 40.5) vs. non-HIV 56.7 nmol/min.mg of protein (28.4); p = 0.007), with no differences in mtDNA content and COX activity. Both myocardial and mitochondrial mass parameters were significantly associated with zidovudine exposure.

CONCLUSIONS

HEU fetuses showed signs of increased myocardial and mitochondrial mass associated with maternal zidovudine treatment, suggesting a fetal adaptive response to cART toxicity.

HIV in pregnancy: Identification of intrapartum and perinatal HIV exposures

The benefits of human immunodeficiency virus (HIV) testing in pregnancy, when combined with appropriate maternal antiretroviral therapy and intrapartum and postnatal prophylaxis, are well established. The vertical rate of transmission of HIV in North America is now well below 2%. Efforts must continue to ensure that these benefits are sustained. Women who have received little or no prenatal care and those who present for delivery with unknown HIV status need immediate testing. As more infants are exposed to antiretroviral agents, strategies need to be implemented to ensure adequate follow-up of these infants. Issues relating to the identification of HIV-exposed infants are highlighted.

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.

Blood Mitochondrial DNA Content in HIV-Exposed Uninfected Children with Autism Spectrum Disorder

Long-term outcomes of perinatal exposure to maternal antiretroviral therapy in HIV-exposed uninfected (HEU) children are unknown. However, both HIV antiretroviral therapy and autism spectrum disorder (ASD) have been associated with mitochondrial alterations. Leukocyte mitochondrial DNA (mtDNA) content can serve as a marker for mitochondrial dysfunction. In this cross-sectional, nested case-control study, HEU children with ASD were matched approximately 1:3 on age, sex, and ethnicity to HEU children without ASD, HIV-unexposed uninfected (HUU) controls, and HUU children with ASD. Leukocyte mtDNA content was measured using quantitative PCR. Among 299 HEU in this study, 14 (4.7%) were diagnosed with ASD, which is higher than the general population prevalence estimates. HEU children without ASD and HUU children with ASD had higher mtDNA content than HUU controls. HEU children with ASD had significantly higher mtDNA content than all other study groups. Our results suggest a clear association between elevated leukocyte mtDNA content and both HEU and ASD status. This may implicate mitochondrial dysfunction as a contributor to the high ASD prevalence observed in our cohort.

Lower mitochondrial DNA and altered mitochondrial fuel metabolism in HIV-exposed uninfected infants in Cameroon

OBJECTIVE

Evaluate blood mitochondrial DNA (mtDNA) content in HIV/antiretroviral-exposed uninfected (HEU) vs. HIV-unexposed uninfected (HUU) infants and investigate differences in mitochondrial-related metabolites by exposure group.

DESIGN

We enrolled a prospective cohort of HIV-infected and HIV-uninfected pregnant woman/infant pairs in Cameroon.

METHODS

Dried blood spot mtDNA : nuclear DNA ratio was measured by monochrome multiplex quantitative polymerase chain reaction in HEU infants exposed to in-utero antiretrovirals and postnatal zidovudine (HEU-Z) or nevirapine (HEU-N), and in HUU infants at 6 weeks of life. Acylcarnitines and branch-chain amino acids (BCAAs) were measured via tandem mass spectrometry and consolidated into seven uncorrelated components using principal component analysis. Linear regression models were fit to assess the association between in-utero/postnatal HIV/antiretroviral exposure and infant mtDNA, adjusting for confounders and principal component analysis-derived acylcarnitine/BCAA component scores.

RESULTS

Of 364 singleton infants, 38 were HEU-Z, 117 HEU-N, and 209 HUU. Mean mtDNA content was lowest in HEU-Z infants (140 vs. 160 in HEU-N vs. 174 in HUU, P = 0.004). After adjusting for confounders, HEU-Z infants remained at increased risk for lower mtDNA content compared with HUU infants (β: -4.46, P = 0.045), whereas HEU-N infants did not, compared with HUU infants (β: -1.68, P = 0.269. Furthermore, long-chain acylcarnitines were associated with lower (β: -2.35, P = 0.002) and short-chain and BCAA-related acylcarnitines were associated with higher (β: 2.96, P = 0.001) mtDNA content.

CONCLUSION

Compared with HUU infants, HEU infants receiving postnatal zidovudine appear to be at increased risk for decreased blood mtDNA content which may be associated with altered mitochondrial fuel utilization in HEU-Z infants.

Disclosing in utero HIV/ARV exposure to the HIV-exposed uninfected adolescent: is it necessary?

Introduction

The tremendous success of antiretroviral therapy has resulted in a diminishing population of perinatally HIV-infected children on the one hand and a mounting number of HIV-exposed uninfected (HEU) children on the other. As the oldest of these HEU children are reaching adolescence, questions have emerged surrounding the implications of HEU status disclosure to these adolescents. This article outlines the arguments for and against disclosure of a child's HEU status.

Discussion

Disclosure of a child's HEU status, by definition, requires disclosure of maternal HIV status. It is necessary to weigh the benefits and harms which could occur with disclosure in each of the following domains: psychosocial impact, long-term physical health of the HEU individual and the public health impact. Does disclosure improve or worsen the psychological health of the HEU individual and extended family unit? Do present data on the long-term safety of in utero HIV/ARV exposure reveal potential health risks which merit disclosure to the HEU adolescent? What research and public health programmes or systems need to be in place to afford monitoring of HEU individuals and which, if any, of these require disclosure?

Conclusions

At present, it is not clear that there is sufficient evidence on whether long-term adverse effects are associated with in utero HIV/ARV exposures, making it difficult to mandate universal disclosure. However, as more countries adopt electronic medical record systems, the HEU status of an individual should be an important piece of the health record which follows the infant not only through childhood and adolescence but also adulthood. Clinicians and researchers should continue to approach the dialogue around mother–child disclosure with sensitivity and a cogent consideration of the evolving risks and benefits as new information becomes available while also working to maintain documentation of an individual's perinatal HIV/ARV exposures as a vital part of his/her medical records. As more long-term adult safety data on in utero HIV/ARV exposures become available these decisions may become clearer, but at this time, they remain complex and multi-faceted.

Decreased Mitochondrial Function Among Healthy Infants Exposed to Antiretrovirals During Gestation, Delivery and the Neonatal Period

BACKGROUND

Antiretroviral (ARV)-associated mitochondrial toxicity in HIV/ARV-exposed healthy infants is a concern. Clinically relevant toxicity is rare. Hyperlactatemia is common but nonspecific, both increased and decreased mitochondrial DNA (mtDNA) level has been reported. Mitochondrial function has scarcely been investigated.

METHODS

In a prospective observational study of 133 HIV/ARV-exposed infants, mtDNA content was measured with quantitative real-time polymerase chain reaction, and mitochondrial respiratory chain enzymatic activity of complex IV (CIV) and mitochondrial mass (MM) were assessed spectrophotometrically from cryopreserved peripheral blood mononuclear cells obtained at 6 weeks and 3, 6 and 12 months of age and compared with a control group.

RESULTS

Most mothers (88%) received combined ARV therapy during pregnancy, and 92% of infants received zidovudine monotherapy. No infant had clinical evidence of mitochondrial disease during follow-up. Nonsignificant higher MM and lower mtDNA levels (normalized by MM) were observed over time in HIV/ARV-exposed infants. MM-normalized CIV activity was consistently lower in HIV/ARV-exposed children than in controls over time (0.09 vs. 0.35, 0.12 vs. 0.38, 0.13 vs. 0.24 and 0.14 vs. 0.24 nmol/min/mg at 6 weeks and 3, 6 and 12 months; P = 0.014, P < 0.0001, P = 0.065 and P = 0.011, respectively) and showed a linear trend toward normalization with age (P < 0.01). In HIV/ARV-exposed infants, an inverse correlation between CIV activity and mtDNA levels was observed until 6 months of age (r = -0.327, P = 0.016; r = -0.311, P = 0.040 and r = -0.275, P = 0.046).

CONCLUSIONS

Mitochondrial-encoded CIV activity was consistently lower among HIV/ARV-exposed healthy infants and inversely correlated with mtDNA levels, suggesting upregulation of the latter.

Evidence of Subclinical mtDNA Alterations in HIV-Infected Pregnant Women Receiving Combination Antiretroviral Therapy Compared to HIV-Negative Pregnant Women

Introduction

Combination antiretroviral therapy (cART) can effectively prevent vertical transmission of HIV but there is potential risk of adverse maternal, foetal or infant effects. Specifically, the effect of cART use during pregnancy on mitochondrial DNA (mtDNA) content in HIV-positive (HIV+) women is unclear. We sought to characterize subclinical alterations in peripheral blood mtDNA levels in cART-treated HIV+ women during pregnancy and the postpartum period.

Methods

This prospective longitudinal observational cohort study enrolled both HIV+ and HIV-negative (HIV-) pregnant women. Clinical data and blood samples were collected at three time points in pregnancy (13-<23 weeks, 23-<30 weeks, 30–40 weeks), and at delivery and six weeks post-partum in HIV+ women. Peripheral blood mtDNA to nuclear DNA (nDNA) ratio was measured by qPCR.

Results

Over a four year period, 63 HIV+ and 42 HIV- women were enrolled. HIV+ women showed significantly lower mtDNA/nDNA ratios compared to HIV- women during pregnancy (p = 0.003), after controlling for platelet count and repeated measurements using a multivariable mixed-effects model. Ethnicity, gestational age (GA) and substance use were also significantly associated with mtDNA/nDNA ratio (p≤0.02). Among HIV+ women, higher CD4 nadir was associated with higher mtDNA/nDNA ratios (p<0.0001), and these ratio were significantly lower during pregnancy compared to the postpartum period (p<0.0001).

Conclusions

In the context of this study, it was not possible to distinguish between mtDNA effects related to HIV infection versus cART therapy. Nevertheless, while mtDNA levels were relatively stable over time in both groups during pregnancy, they were significantly lower in HIV+ women compared to HIV- women. Although no immediate clinical impact was observed on maternal or infant health, lower maternal mtDNA levels may exert long-term effects on women and children and remain a concern. Improved knowledge of such subclinical alterations is another step toward optimizing the safety and efficacy of cART regimens during pregnancy.

Research into a functional cure for HIV in neonates: the need for ethical foresight

In 2013, researchers announced that a newborn child from Mississippi, USA might have been functionally cured of HIV by being given combination antiretroviral therapy within hours of birth. Public and media attention has since been captured by the possibility of finding a cure for HIV transmitted from mother to child. Research into the strategy used for the Mississippi patient is crucially important to establish whether it can be replicated and shown to work in diverse populations. At the same time, any ethical issues likely to arise in such studies should be addressed and not ignored in the pursuit of a functional cure. In this Personal View we identify ethical issues that could arise in research towards achievment of a functional cure for HIV in neonates, including difficult trade-offs associated with choosing the study population and questions about the broader social implications of the research, and propose ways to resolve them.

Metabolic complications of in utero maternal HIV and antiretroviral exposure in HIV-exposed infants

BACKGROUND

Despite a wide body of literature supporting the use of antenatal antiretrovirals (ARV) for the prevention of mother-to-child transmission, there remains a need for continued monitoring as the intrauterine interval is a critical period during which fetal programming influences the future health and development of the child.

METHODS

We conducted a systematic review of the current literature addressing potential metabolic complications of in utero HIV and ARV exposure. We describe studies evaluating metabolic outcomes such as intrauterine and early postnatal growth, bone health and mitochondrial toxicity.

RESULTS

Overall, infants exposed to HIV/ARV do not appear to exhibit vastly compromised intrauterine or early postnatal growth. However, some studies on the effect of combination antiretroviral therapy on small for gestational age and low birth weight outcomes in low-middle income countries show a risk for small for gestational age/low birth weight while those in the United States do not. Postnatal growth to 1 year does not appear to be affected by intrauterine tenofovir exposure in African studies, but a US study found statistically significant differences in length for age z scores (LAZ) at 1 year. Little data exists on long-term bone health. Mitochondrial toxicity including abnormal mitochondrial morphology and DNA content, as well as neurologic deficits and death, have been demonstrated in HIV/ARV-exposed infants.

CONCLUSION

Although gross measures of metabolic well-being appear to be reassuring, careful vigilance of even small risks for potential serious adverse effects to infants exposed to intrauterine HIV/ARVs is warranted as intrauterine fetal metabolic programming may substantially impact the future health of the child.

Role of mitochondria in HIV infection and associated metabolic disorders: focus on nonalcoholic fatty liver disease and lipodystrophy syndrome

Highly active antiretroviral therapy (HAART) has considerably improved the prognosis of HIV-infected patients. However, prolonged use of HAART has been related to long-term adverse events that can compromise patient health such as HIV-associated lipodystrophy syndrome (HALS) and nonalcoholic fatty liver disease (NAFLD). There is consistent evidence for a central role of mitochondrial dysfunction in these pathologies. Nucleotide reverse transcriptase inhibitors (NRTIs) have been described to be mainly responsible for mitochondrial dysfunction in adipose tissue and liver although nonnucleoside transcriptase inhibitors (NNRTIs) or protease inhibitors (PIs) have also showed mitochondrial toxicity, which is a major concern for the selection and the long-term adherence to a particular therapy. Several mechanisms explain these deleterious effects of HAART on mitochondria, and evidence points to other mechanisms beyond the “Pol-γ hypothesis.” HIV infection has also direct effects on mitochondria. In addition to the negative effects described for HIV itself and/or HAART on mitochondria, HIV-infected patients are more prone to develop a premature aging and, therefore, to present an increased oxidative state that could lead to the development of these metabolic disturbances observed in HIV-infected patients.

Quantification of mitochondrial toxicity in HIV-infected individuals by quantitative PCR compared to flow cytometry

BACKGROUND

Non-invasive diagnostic assays to evaluate mitochondrial toxicity could have significant clinical utility for HIV-infected individuals on antiretroviral therapy (ART).

METHODS

This study compared the ratio of mitochondrial to nuclear DNA determined by quantitative polymerase chain reaction (qPCR) to the ratio of mitochondrial to nuclear-encoded proteins by flow cytometry, in peripheral blood mononuclear cells from 73 HIV-infected individuals with and without risk factors for mitochondrial toxicity.

RESULTS

PCR detected similar mitochondrial/nuclear DNA in HIV-infected individuals without a history of ART, and those receiving ART with lipodystrophy, lipoatrophy, or a history of suspected lactic acidosis. However, the ratio was significantly greater in ART-untreated compared to those receiving either stavudine or didanosine. In contrast, flow cytometry did not detect any differences in mitochondrial/nuclear protein (Lin et al., Cytometry B 2009;76B:181-190). There was no correlation between the assays (rho = -0.05, P = 0.65).

CONCLUSIONS

Assessment of the mitochondrial/nuclear DNA ratio by qPCR performed better than the mitochondrial/nuclear-encoded protein ratio by flow cytometry to detect adverse effects of nucleoside analogs on mitochondria.

Blood mitochondrial DNA mutations in HIV-infected women and their infants exposed to HAART during pregnancy

OBJECTIVES

Nucleo(s/t)ide reverse transcriptase inhibitors given to HIV-infected pregnant women to prevent vertical transmission may adversely affect mitochondrial DNA (mtDNA). We hypothesized that HAART-exposed/HIV-uninfected infants may show higher blood mtDNA mutation burden than controls born to HIV-uninfected mothers.

METHODS

Blood was collected from in-utero HIV/HAART-exposed infants and controls, as well as from a subset of their mothers. The presence of mtDNA A→C/T→G (AC/TG) mutations was measured by cloning and sequencing D-loop PCR amplicons. Relationships with maternal characteristics were examined.

RESULTS

No significant difference was found between the percentage of HIV/HAART-exposed infants with AC/TG mutations (N = 15/57, 26.3%) and controls (N = 10/70, 14.3%) before (P = 0.090) or after controlling for covariates (P = 0.058), although a tendency was observed. However, significantly more HIV/HAART-exposed mothers (N = 18/42, 42.9%) harboured AC/TG mutations compared with controls (N = 7/39, 17.9%) before (P = 0.015) and after (P = 0.012) controlling for covariates. AC/TG mutations were more prevalent in HIV/HAART-exposed mothers than in their infants (N = 42, 42.9 vs. 23.8%, P = 0.033), however, this difference disappeared after controlling for covariates. No difference was seen between control mothers and their infants (N = 39, both 17.9%). In HIV/HAART-exposed mothers, only a detectable HIV plasma viral load near delivery predicted AC/TG mutations.

CONCLUSION

Our results suggest that HIV and/or HAART exposure are associated with increased prevalence of AC/TG mtDNA mutations in mothers and show a similar tendency in infants exposed during pregnancy. As accumulation of mtDNA mutations has been linked with aging and age-associated diseases, this may raise concerns in the long term for HIV and HAART-exposed populations.

Perinatal outcomes, mitochondrial toxicity and apoptosis in HIV-treated pregnant women and in-utero-exposed newborn

OBJECTIVE

Highly active antiretroviral therapy (HAART) has decreased the risk of HIV mother-to-child transmission. However, HIV and HAART have been associated with adverse perinatal outcome. HAART has been associated with mitochondrial dysfunction in nonpregnant adults, and HIV, additionally, to apoptosis. We determined whether mitochondrial toxicity and apoptosis are present in HIV-pregnant women and their newborns and could be the basis of adverse pregnancy outcome.

DESIGN

Single-site, cross-sectional, controlled observational study without intervention.

METHODS

We studied mitochondrial and apoptotic parameters in mononuclear cells from maternal peripheral blood and infant cord blood at delivery in 27 HIV-infected and treated pregnant women, and 35 uninfected controls and their infants, to correlate clinical outcome with experimental findings: mitochondrial number (CS), mtDNA content (ND2/18SrRNA), mitochondrial protein synthesis (COX-II/V-DAC), mitochondrial function (enzymatic activities) and apoptotic rate (caspase-3/β-actin).

RESULTS

Global adverse perinatal outcome, preterm births and small newborn for gestational age were significantly increased in HIV pregnancies [odds ratio (OR) 7.33, 5.77 and 9.71]. Mitochondrial number was unaltered. The remaining mitochondrial parameters were reduced in HIV mothers and their newborn; especially newborn mtDNA levels, maternal and fetal mitochondrial protein synthesis and maternal glycerol-3-phosphate + complex III function (38.6, 25.8, 13.6 and 31.2% reduced, respectively, P < 0.05). All materno-fetal mitochondrial parameters significantly correlated, except mtDNA content. Apoptosis was exclusively increased in infected pregnant women, but not in their newborn. However, adverse perinatal outcome did not correlate mitochondrial or apoptotic findings.

CONCLUSIONS

Transplacental HAART toxicity may cause subclinical mitochondrial damage in HIV-pregnant women and their newborn. Trends to increased maternal apoptosis may be due to maternal-restricted HIV infection. However, we could not demonstrate mitochondrial or apoptotic implication in adverse perinatal outcome.

Effects of in utero antiretroviral exposure on mitochondrial DNA levels, mitochondrial function and oxidative stress

OBJECTIVES

HIV and antiretroviral (ART) exposure in utero may have deleterious effects on the infant, but uncertainty still exists. The objective of this study was to evaluate aspects of mitochondrial DNA (mtDNA) content, mitochondrial function and oxidative stress simultaneously in placenta, umbilical cord blood and infant blood in HIV/ART-exposed infants compared with uninfected controls.

METHODS

HIV-1-infected pregnant women and HIV-1-uninfected healthy pregnant controls were enrolled in the study prospectively. Placenta and umbilical cord blood were obtained at delivery and infant blood was obtained within 48 h of delivery. mtDNA content was determined for each specimen. Nuclear [subunit IV of cytochrome c-oxidase (COX IV)]- and mitochondrial (COX II)-encoded polypeptides of the oxidative phosphorylation enzyme cytochrome c-oxidase were quantified in cord and infant blood. Placental mitochondria malondialdehyde (MDA) concentrations were measured as a marker of oxidative stress.

RESULTS

Twenty HIV-positive/HIV-exposed and 26 control mother-infant pairs were enrolled in the study. All HIV-infected women and their infants received ART. Placental MDA concentration and mtDNA content in placenta and cord blood were similar between groups. The cord blood COX II:IV ratio was lower in the HIV-positive group than in the controls, whereas the infant peripheral blood mtDNA content was higher in the HIV-exposed infants, but the infant peripheral blood COX II:IV ratio was similar. No infant had clinical evidence of mitochondrial disease or acquired HIV infection. In multivariable regression analyses, the significant findings in cord and infant blood were both most associated with HIV/ART exposure.

CONCLUSIONS

HIV-exposed infants showed reduced umbilical cord blood mitochondrial enzyme expression with increased infant peripheral blood mitochondrial DNA levels, the latter possibly reflecting a compensatory mechanism to overcome HIV/ART-associated mitochondrial toxicity.

Antiretroviral drugs for preventing mother-to-child transmission of HIV: a review of potential effects on HIV-exposed but uninfected children

The provision of antiretroviral drugs for the prevention of mother-to-child HIV transmission has been rising sharply in low- and middle-income countries. Changes to the World Health Organization guidelines support further extension of these programs. The result will be a greatly expanded population of HIV-exposed but uninfected children with substantial exposure to antiretroviral drugs, both in utero and while breastfeeding. There are limited data on possible toxicities in this burgeoning population, and the large number of confounding factors limits any conclusions. Although the evidence on birth defects and mitochondrial toxicity remains equivocal, considerable data link protease inhibitors to preterm delivery and low birth-weight. Transient hematologic toxicities are also likely. The drug impact later in life is an open question. Larger and longer cohort studies are necessary to properly balance the risks and benefits of large-scale infant exposure to antiretroviral agents.

Mitochondrial interference by anti-HIV drugs: mechanisms beyond Pol-γ inhibition

The combined pharmacological approach to the treatment of HIV infection, known as highly active antiretroviral therapy (HAART), has dramatically reduced AIDS-related morbidity and mortality. However, its use has been associated with serious adverse reactions, of which those resulting from mitochondrial dysfunction are particularly widespread. Nucleos(t)ide-reverse transcriptase inhibitors (NRTIs) have long been considered the main source of HAART-related mitochondrial toxicity due to their ability to inhibit Pol-γ, the DNA polymerase responsible for the synthesis of mitochondrial DNA. Nevertheless, accumulating evidence points to a more complex relationship between these organelles and NRTIs. Also, alternative pathways by which other groups of anti-HIV drugs (non-nucleoside reverse transcriptase inhibitors and protease inhibitors) interfere with mitochondria have been suggested, although their implications, both pharmacological and clinical, are open to debate. This review aims to provide a comprehensive overview of the mechanisms and factors which influence the mitochondrial involvement in the toxicity of all three major classes of anti-HIV drugs.

Short communication: transplacental nucleoside analogue exposure and mitochondrial parameters in HIV-uninfected children

Transplacental nucleoside analogue exposure can affect infant mitochondrial DNA (mtDNA). We evaluated mitochondria in peripheral blood mononuclear cells of children with and without clinical signs of mitochondrial dysfunction (MD) and antiretroviral (ARV) exposure. We previously identified 20 children with signs of MD (cases) among 1037 HIV-uninfected children born to HIV-infected women. We measured mtDNA copies/cell and oxidative phosphorylation (OXPHOS) NADH dehydrogenase (complex I) and cytochrome c oxidase (complex IV) protein levels and enzyme activities, determined mtDNA haplogroups and deletions in 18 of 20 cases with stored samples and in sex- and age-matched HIV-uninfected children, both ARV exposed and unexposed, (1) within 18 months of birth and (2) at the time of presentation of signs of MD. In specimens drawn within 18 months of birth, mtDNA levels were higher and OXPHOS protein levels and enzyme activities lower in cases than controls. In contrast, at the time of MD presentation, cases and ARV-exposed controls had lower mtDNA levels, 214 and 215 copies/cell, respectively, than ARV-unexposed controls, 254 copies/cell. OXPHOS protein levels and enzyme activities were lower in cases than exposed controls, and higher in cases than unexposed controls, except for complex IV activity, which was higher in cases. Haplotype H was less frequent among cases (6%) than controls (31%). No deletions were found. The long-term significance of these small but potentially important alterations should continue to be studied as these children enter adolescence and adulthood.

Quality assessment of human mitochondrial DNA quantification: MITONAUTS, an international multicentre survey

Mitochondrial DNA quantification by qPCR is used in the context of many diseases and toxicity studies but comparison of results between laboratories is challenging. Through two multigroup distributions of DNA samples from human cell lines, the MITONAUTS group anonymously compared mtDNA/nDNA quantification across nine laboratories involved in HIV research worldwide. Eight of the nine sites showed significant correlation between them (mean raw data R(2)=0.664; log(10)-transformed data R(2)=0.844). Although mtDNA/nDNA values were well correlated between sites, the inter-site variability on the absolute measurements remained high with a mean (range) coefficient of variation of 71 (37-212) %. Some variability appeared cell line-specific, probably due to chromosomal alterations or pseudogenes affecting the quantification of certain genes, while within cell line variability was likely due to differences in calibration of the standard curves. The use of two mtDNA and two single copy nDNA genes with highly specific primers to quantify each genome would help address copy number variants. Our results indicate that sample shipment must be done frozen and that absolute mtDNA/nDNA ratio values cannot readily be compared between laboratories, especially if assessing cultured cell mtDNA content. However, within laboratory and relative mtDNA/nDNA comparisons between laboratories should be reliable.

Antiretroviral medications during pregnancy for therapy or prophylaxis

The use of combination antiretroviral therapy during pregnancy has enabled us to decrease perinatal HIV transmission to less than 1%, in areas with adequate resources. Questions remain regarding the safety of these medications for the mother, fetus, and child. Recent publications present conflicting data about associations between antiretrovirals and prematurity and other adverse pregnancy outcomes, and if highly active antiretroviral therapy (HAART) is necessary for all pregnant women. The pharmacokinetics of some antiretroviral medications are altered significantly during pregnancy; placental transfer to the fetus is variable. The well-documented benefit of HAART for preventing mother-to-child transmission generally outweighs the potential risks to the fetus, infant, and mother. However, potential adverse effects are of concern, and questions remain as to the optimal treatment strategy. More data on the effects of antiretrovirals during pregnancy are needed.