Serum lactate levels in infants exposed peripartum to antiretroviral agents to prevent mother-to-child transmission of HIV: Agence Nationale de Recherches Sur le SIDA et les Hépatites Virales 1209 study, Abidjan, Ivory Coast

HIV in Neonates and Infants

Advances in perinatal HIV management have averted a significant number of infections in neonates and have made the possibility of elimination of mother-to-child transmission a reality; however, significant gaps in implementation of early testing programs as well as the expansion of therapeutic strategies to neonates are hindering prevention efforts and access to safer, more effective and easier to administer treatment. This article provides insights on the current state of perinatal HIV, recent advances, and future needs.

Health Outcomes at School Age among Children Who Are HIV-Exposed but Uninfected with Detected Mitochondrial DNA Depletion at One Year

Infant antiretroviral (ARV) prophylaxis given to children who are human immunodeficiency virus (HIV)-exposed but uninfected (CHEU) to prevent HIV transmission through breastfeeding previously proved its efficacy in the fight against the pediatric epidemic. However, few studies have investigated the short- and long-term safety of prophylactic regimens. We previously reported a decrease of mitochondrial DNA (mtDNA) content among CHEU who received one year of lamivudine (3TC) or lopinavir-boosted ritonavir (LPV/r) as infant prophylaxis. We aimed to describe mtDNA content at six years of age among these CHEU, including those for whom we identified mtDNA depletion at week 50 (decrease superior or equal to 50% from baseline), and to compare the two prophylactic drugs. We also addressed the association between mtDNA depletion at week 50 with growth, clinical, and neuropsychological outcomes at year 6. Quantitative PCR was used to measure mtDNA content in whole blood of CHEU seven days after birth, at week 50, and at year 6. Among CHEU with identified mtDNA depletion at week 50 (n = 17), only one had a persistent mtDNA content decrease at year 6. No difference between prophylactic drugs was observed. mtDNA depletion was not associated with growth, clinical, or neuropsychological outcomes at year 6. This study brought reassuring data concerning the safety of infant 3TC or LPV/r prophylaxis.

Cancer Among Children With Perinatal Exposure to HIV and Antiretroviral Medications--New Jersey, 1995-2010

BACKGROUND

Concerns remain regarding the cancer risk associated with perinatal antiretroviral (ARV) exposure among infants. No excessive cancer risk has been found in short-term studies.

METHODS

Children born to HIV-infected women (HIV-exposed) in New Jersey from 1995 to 2008 were identified through the Enhanced HIV/AIDS Reporting System and cross-referenced with data from the New Jersey State Cancer Registry to identify new cases of cancer among children who were perinatally exposed to ARV. Matching of individuals in the Enhanced HIV/AIDS Reporting System to the New Jersey State Cancer Registry was conducted based on name, birth date, Social Security number, residential address, and sex using AutoMatch. Age- and sex-standardized incidence ratio (SIR) and exact 95% confidence intervals (CIs) were calculated using New Jersey (1979-2005) and US (1999-2009) cancer rates.

RESULTS

Among 3087 children (29,099 person-years; median follow-up: 9.8 years), 4 were diagnosed with cancer. Cancer incidence among HIV-exposed children who were not exposed to ARV prophylaxis (22.5 per 100,000 person-years) did not differ significantly from the incidence among children who were exposed to any perinatal ARV prophylaxis (14.3 per 100,000 person-years). Furthermore, the number of cases observed among individuals exposed to ARV did not differ significantly from cases expected based on state (SIR = 1.21; 95% CI: 0.25 to 3.54) and national (SIR = 1.27; 95% CI: 0.26 to 3.70) reference rates.

CONCLUSIONS

Our findings are reassuring that current use of ARV for perinatal HIV prophylaxis does not increase cancer risk. We found no evidence to alter the current federal guidelines of 2014 that recommend ARV prophylaxis of HIV-exposed infants.

Prevention of mother-to-child transmission of HIV type 1: the role of neonatal and infant prophylaxis

The prevention of mother-to-child transmission (PMTCT) of HIV is one of the great public health successes of the past 20 years. Much concerted research efforts and dedicated work have led to the achievement of very low rates of PMTCT of HIV in settings that can implement optimal prophylaxis. Though several implementation challenges remain, global elimination of pediatric HIV infection seems now more than ever to be an attainable goal. Often overlooked, the role of prophylaxis of the newborn is nevertheless a very important component of PMTCT. In this paper, we focus on the role of neonatal and infant prophylaxis, discuss mechanisms of protection, and present the clinical trial-generated evidence that led to the current recommendations for preventing infections in breastfed and non-breastfed infants. PMTCT of HIV should not end at birth; a continuum of care extending postpartum and postnatally is required to minimize the risk of new pediatric HIV infections.

Adverse drug reactions associated with antiretroviral therapy during pregnancy

INTRODUCTION

Antiretroviral (ARV) drug use during pregnancy significantly reduces mother-to-child HIV transmission, delays disease progression in the women and reduces the risk of HIV transmission to HIV-serodiscordant partners. Pregnant women are susceptible to the same adverse reactions to ARVs as nonpregnant adults as well as to specific pregnancy-related reactions. In addition, we should consider adverse pregnancy outcomes and adverse reactions in children exposed to ARVs during intrauterine life. However, studies designed to assess the safety of ARV in pregnant women are rare, usually with few participants and short follow-up periods.

AREAS COVERED

In this review, we discuss studies reporting adverse reactions to ARV drugs, including maternal toxicity, adverse pregnancy outcomes and the consequences of exposure to ARV in infants. We included results of observational studies, both prospective and retrospective, as well as randomized clinical trials, systematic reviews and meta-analyses.

EXPERT OPINION

The benefits of ARV use during pregnancy outweigh the risks of adverse reactions identified to date. More studies are needed to assess the adverse effects in the medium- and long term in children exposed to ARVs during pregnancy, as well as pregnant women using lifelong antiretroviral therapy and more recently available drugs.

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.

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?

Premature delivery in HIV-infected women starting protease inhibitor therapy during pregnancy: role of the ritonavir boost?

BACKGROUND

The association between combination antiretroviral (cARV) therapy use by human immunodeficiency virus (HIV)-infected women during pregnancy and risk of prematurity is still controversial. We explored this question, focusing on the initiation of ritonavir-boosted protease inhibitors (PIs) during pregnancy, which is now standard care.

METHODS

Trends in prematurity (<37 gestational weeks) were studied among all singleton pregnancies in the Agence Nationale de Recherche sur le SIDA (ANRS) French Perinatal Cohort from 1990 through 2009 (n = 13 271). In-depth analysis was conducted in a more detailed substudy of the cohort, among women starting PI-based ARV therapy during pregnancy (n = 1253). Multivariable analysis adjusted for immunovirological status and known risk factors for prematurity.

RESULTS

Prematurity increased from 9.2% during 1990-1993 (no therapy) and 9.6% during 1994-1996 (mostly zidovudine monotherapy) to 12.4% during 1997-1999 (dual-nucleoside analog therapy) and 14.3% during 2005-2009 (routine cARV therapy; P < .01). Prematurity was associated with cARV therapy, compared with zidovudine monotherapy, with an adjusted odds ratio of 1.69 (95% confidence interval [CI], 1.38-2.07; P < .01) when accounting for maternal age, intravenous drug use, geographic origin, and CD4 cell count. During 2005-2009, the prematurity rate was higher with boosted than with nonboosted PI therapy started during pregnancy (14.4% vs 9.1% [P = .05]; adjusted hazard ratio, 2.03 [95% CI, 1.06-3.89; P = .03] in multivariate analysis). The difference concerned mainly induced preterm delivery for maternal or fetal indications (5.6% vs 1.6%; P = .02),

CONCLUSIONS

The prematurity rate among HIV-infected pregnant women was twice that in the general population in France; this was not entirely explained by sociodemographic characteristics. Prematurity was independently associated with cARV therapy and, particularly, with the initiation of ritonavir-boosted PI therapy during pregnancy.

Point-of-care capillary blood lactate measurements in human immunodeficiency virus-uninfected children with in utero exposure to human immunodeficiency virus and antiretroviral medications

OBJECTIVES

To estimate the prevalence of elevated point-of-care (POC) capillary blood lactate concentrations in human immunodeficiency virus (HIV)-exposed, uninfected children (HEU) and to determine if POC lactate varies with in utero antiretroviral (ARV) exposure.

METHODS

The Surveillance Monitoring for Antiretroviral Therapy Toxicities protocol of the Pediatric HIV/AIDS Cohort Study enrolled 1934 children between 2007 and 2009, 0 to 12 years of age, born to HIV-infected mothers. POC lactate was measured annually on capillary blood using the Lactate Pro device. Associations of POC lactate with in utero ARV exposure and other characteristics were evaluated using logistic regression models, adjusting for maternal characteristics and other confounders.

RESULTS

Of 1641 children with POC measurements (median age, 3.0 years), 3.4% had POC lactate >3 mmol/L. Median POC lactate level decreased with age (1.9 mmol/L, 1.7 mmol/L, and 1.6 mmol/L for children 0-<6 months [99% ≤6 weeks of life], 6-<24 months, and ≥24 months of age, respectively; P < 0.001). Prevalence of elevated POC lactate did not differ by in utero ARV exposure drug class, but was significantly higher in children exposed in utero to emtricitabine or efavirenz, cocaine or opiates, and those of white race.

CONCLUSIONS

POC lactate testing is a useful rapid laboratory screening assay for HEU children with ARV exposure. ARV use during pregnancy has resulted in a dramatic decrease in mother-to-child transmission of HIV, and the risk of elevated lactate in HEU children is low. However, as new ARVs and more complex regimens are used during pregnancy by HIV-infected women, continued monitoring for infant toxicities is essential.

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.

Metabolic complications associated with antiretroviral therapy in HIV-infected and HIV-exposed uninfected paediatric patients

IMPORTANCE OF THE FIELD

HIV-infection has become a chronic disease in paediatric patients with the potential for long-term survival and exposure to antiretroviral (ARV) therapies for 2 decades longer than HIV-infected adults. On the other hand, the administration of ARV to HIV-infected pregnant women has greatly increased both treatment of HIV infection and prevention of perinatal HIV transmission. Therefore, researches aiming to evaluate the safety of ARV therapies in HIV-infected children as well as in HIV-uninfected infants born to HIV-infected mothers are emerging as a new challenge and urgent priority.

AREAS COVERED IN THIS REVIEW

The purpose of this review is to describe some of the more concerning metabolic complications associated with ARV in paediatric population: hyperlactataemia (HLA) syndromes, body shape abnormalities, disorders of glucose homeostasis and dyslipidaemia in HIV-infected children and adolescents. Frequency, risk factors, clinical findings, prevention and intervention strategies of the previously described abnormalities are discussed in depth.

WHAT THE READER WILL GAIN

This review covers our current understanding of HLA syndromes in ARV-exposed uninfected infants born to HIV-infected mothers.

TAKE HOME MESSAGE

Prevention of these metabolic complications should assume prominence and future researches should address several of the existing treatment gaps.

The clinical care of the HIV-1-infected infant

Despite well-established strategies to decrease the mother-to-child transmission of HIV-1, new perinatal infections continue to occur globally, reflecting marked disparities in access to health care. Once HIV-1 infection has been established in an infant, the combination of early initiation of antiretroviral therapy and prophylaxis against Pneumocystis jiroveci pneumonia is paramount to reducing disease progression. This article reviews the recommendations and evidence for the treatment of HIV-1-infected infants.

[In-utero antiretroviral exposure and mitochondrial toxicity in a cohort of uninfected infants born to HIV-1-infected women]

INTRODUCTION

In this study, we attempt to find out the percentage of uninfected infants born to HIV-infected women and exposed in-utero and perinatally to Antiretroviral Treatment (ART) that show high lactate levels, or any other mitochondrial damage markers (such as hypertransaminasaemia or hyperamylasaemia), during the first three months of age. We shall also establish whether certain drugs used in-utero are associated with higher lactate, transaminase or amylase levels.

METHODS

We analysed the available data from 623 uninfected infants born in the Spanish FIPSE cohort that were born in the period 2000-2005. The normal values for lactate, transaminases and amylase were set according to AIDS Clinical Groups Trials toxicity tables for infants.

RESULTS

The percentages of children with high lactate levels at 0.5; 1.5 and 3 months of age were 48%, 51.4% and 43% among those infants with available data. Respectively, the percentages of children with high AST values were 13.2; 10.4 and 17.2%. The values for high ALT were 3.3%; 3.4% and 5%. The percentages for hyperamylasaemia were 0%; 0.6% and 2.6%. We found no significant difference among the drugs used in utero for the four analysed biochemical markers along the first three months of age.

CONCLUSIONS

We have found a high proportion of hyperlactataemia among infants exposed in-utero to ART, as shown in other cohorts of similar characteristics. No morbidity or mortality was communicated to the cohort analysis group. No ART drug among those used in-utero was statistically associated with a higher proportion of high lactate levels in these infants.

Italian consensus statement on paediatric HIV infection

The objective of this document is to identify and reinforce current recommendations concerning the management of HIV infection in infants and children in the context of good resource availability. All recommendations were graded according to the strength and quality of the evidence and were voted on by the 57 participants attending the first Italian Consensus on Paediatric HIV, held in Siracusa in 2008. Paediatricians and HIV/AIDS care specialists were requested to agree on different statements summarizing key issues in the management of paediatric HIV. The comprehensive approach on preventing mother-to-child transmission (PMTCT) has clearly reduced the number of children acquiring the infection in Italy. Although further reduction of MTCT should be attempted, efforts to personalize intervention to specific cases are now required in order to optimise the treatment and care of HIV-infected children. The prompt initiation of treatment and careful selection of first-line regimen, taking into consideration potency and tolerance, remain central. In addition, opportunistic infection prevention, adherence to treatment, and long-term psychosocial consequences are becoming increasingly relevant in the era of effective antiretroviral combination therapies (ART). The increasing proportion of infected children achieving adulthood highlights the need for multidisciplinary strategies to facilitate transition to adult care and maintain strategies specific to perinatally acquired HIV infection.

Update on antiretroviral therapy in paediatrics

This review provides an update on the most relevant issues concerning the current management of HIV infection in infants and children. Tremendous progress has been made over the last few years to diagnose and treat infants and children with HIV infection, yet much remains to be done. Every day there are nearly 1150 new infections in children under 15 years of age, more than 90% of them occurring in the developing world and most being the result of transmission from mother-to-child (WHO 2008). The comprehensive approach to preventing mother-to-child transmission (MTCT) has clearly reduced the number of children acquiring the infection in Western countries; while a further reduction of mother-to-child transmission should be aimed for personalized setting, specific intervention needs to be put in place and new efforts are now required in order to optimise treatment and care in HIV-infected children. The prompt initiation of treatment and a careful selection of first-line regimen, which considers potency as well as tolerability remain central. In addition, occurrence and prevention of opportunistic infections, adherence as well as long-term psychosocial consequences are becoming more and more relevant in the era of effective antiretroviral therapy. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of Antiretroviral Drug Discovery and Development, vol. 85, issue 1, 2010.

Advances and failures in preventing perinatal human immunodeficiency virus infection

An estimated 2.5 million children are currently living with HIV, the vast majority as a result of mother-to-child transmission. Prevention of perinatal HIV infection has been immensely successful in developed countries. A comprehensive package of services, including maternal and infant antiretroviral therapy, elective cesarean section, and avoidance of breast-feeding, has resulted in transmission rates of less than 2%. However, in developing countries, access to such services is often not available, as demonstrated by the fact that the vast majority of children with HIV live in Africa. Over the past few years, many developing nations have made great strides in improving access to much-needed services. Notably, in eastern and southern Africa, the regions most affected by HIV, mother-to-child-transmission coverage rates for HIV-positive women increased from 11% in 2004 to 31% in 2006. These successes are deserving of recognition, while not losing sight of the fact that much remains to be done; currently, an estimated 75% of pregnant women worldwide have an unmet need for antiretroviral therapy. Further work is needed to determine the optimal strategy for reducing perinatal transmission among women in resource-poor settings, with a particular need for reduction of transmission via breast-feeding.

Evaluation and management of the infant exposed to HIV-1 in the United States

The pediatrician plays a key role in the prevention of mother-to-child transmission of HIV-1 infection. For infants born to women with HIV-1 infection identified during pregnancy, the pediatrician ensures that antiretroviral prophylaxis is provided to the infant to decrease the risk of acquiring HIV-1 infection and promotes avoidance of postnatal HIV-1 transmission by advising HIV-1-infected women not to breastfeed. The pediatrician should perform HIV-1 antibody testing for infants born to women whose HIV-1 infection status was not determined during pregnancy or labor. For HIV-1-exposed infants, the pediatrician monitors the infant for early determination of HIV-1 infection status and for possible short- and long-term toxicity from antiretroviral exposures. Provision of chemoprophylaxis for Pneumocystis jiroveci pneumonia and support of families living with HIV-1 by providing counseling to parents or caregivers are also important components of care.

Antiretroviral drugs for preventing mother-to-child transmission of HIV in sub-Saharan Africa: balancing efficacy and infant toxicity

OBJECTIVE

Antiretroviral drugs can prevent mother-to-child transmission of HIV infection, but in-utero antiretroviral exposure may be associated with neurologic symptoms due to mitochondrial toxicity. We sought to identify the currently recommended regimen to prevent mother-to-child transmission that optimally balances risks of pediatric HIV infection and neurologic mitochondrial toxicity.

DESIGN

Published MTCT and mitochondrial toxicity data were used in a decision analytic model of MTCT among women in sub-Saharan Africa.

METHODS

We investigated the HIV and mitochondrial toxicity risks associated with no antiretroviral prophylaxis and five recommended regimens ranging from single-dose nevirapine to three-drug antiretroviral therapy (ART). Sensitivity analyses varied all parameters, including infant feeding strategy and the disability of mitochondrial toxicity relative to HIV.

RESULTS

Provision of no antiretroviral drugs is the least effective and least toxic strategy, with 18-month HIV risk of 30.4% and mitochondrial toxicity risk of 0.2% (breastfed infants). With increasing drug number and duration, HIV risk decreases markedly (to 4.9% with three-drug ART), but mitochondrial toxicity risk also increases (to 2.2%, also with three-drug ART). Despite increased toxicity, three-drug ART minimizes total adverse pediatric outcomes (HIV plus mitochondrial toxicity), unless the highest published risks are true for both HIV and mitochondrial toxicity, or the disability from mitochondrial toxicity exceeds 6.4 times that of HIV infection.

CONCLUSION

The risk of pediatric mitochondrial toxicity from effective regimens to prevent mother-to-child transmission is at least an order of magnitude lower than the risk of HIV infection associated with less-effective regimens. Concern regarding mitochondrial toxicity should not currently limit the use of three-drug ART to prevent mother-to-child transmission where it is available.

High levels of zidovudine (AZT) and its intracellular phosphate metabolites in AZT- and AZT-lamivudine-treated newborns of human immunodeficiency virus-infected mothers

Newborns from human immunodeficiency virus-infected mothers are given antiretroviral prophylaxis against mother-to-child transmission, including predominantly nucleoside reverse transcriptase inhibitors. Pharmacological monitoring of these drugs in newborns has so far been limited to plasma and cord blood. In this study, samples from newborns (up to 45 days old) treated with zidovudine (AZT) alone (n = 29) or in combination with lamivudine (3TC) (n = 20) were analyzed for both intracellular concentrations of phosphate metabolites in peripheral blood mononuclear cells and levels of parent drugs in plasma. Plasma AZT and intracellular AZT-monophosphate and AZT-triphosphate (TP) concentrations were significantly higher during the first 15 days of life (199 versus 52.7 ng/ml [P < 0.0001], 732 versus 282 fmol/10(6) cells [P < 0.0001], and 170 versus 65.1 fmol/10(6) cells [P < 0.0001], respectively) and then became comparable to those of adults. No difference in intracellular AZT metabolite concentrations was found when AZT- and AZT-3TC-treated groups were compared. Plasma 3TC levels (lower limit of quantification [LLOQ], 1,157 ng/ml; median, 412.5 ng/ml) were not associated with the newborn's age, gender, or weight. Intracellular 3TC-TP concentrations (LLOQ, 40.4 pmol/10(6) cells; median, 18.9 pmol/10(6) cells) determined for newborns receiving the AZT-3TC combination were associated with neither the age nor weight of the newborns. Concentrations in females were significantly higher (1.8-fold [P = 0.0415]) than those in males. Unexpectedly, newborns on AZT monotherapy whose mothers' treatment included 3TC displayed residual plasma 3TC and intracellular 3TC-TP levels up to 1 week after birth.

Increased mtDNA levels without change in mitochondrial enzymes in peripheral blood mononuclear cells of infants born to HIV-infected mothers on antiretroviral therapy

BACKGROUND

The effects of gestational nucleoside reverse transcriptase inhibitors (NRTIs) on mitochondrial DNA (mtDNA) are controversial. The effects of mtDNA depletion on mitochondrial function have not been assessed.

METHOD

In peripheral blood mononuclear cells (PBMCs) from infants born to HIV-infected women and infants born to HIV-1-uninfected women, mtDNA copy numbers were determined by quantitative PCR; nuclear (COXIV)- and mitochondrial (COXII)-encoded polypeptides of the oxidative phosphorylation enzyme cytochrome c-oxidase (COX or complex IV) were quantified by Western blot.

RESULTS

Overall, 86 infants born to HIV-infected women and 50 controls were studied. HIV-infected mothers had a median CD4 count of 506 cells/microL; 59% had HIV RNA 50 copies/mL. No infant had clinical evidence of mitochondrial disease. The birth weight was lower (p = .016) and the body length higher (p = .002) in the HIV-exposed newborns. Eighty-one HIV-infected women had received gestational NRTIs (median duration 162 days). Median mtDNA copies/PBMC in the HIV-exposed infants were 505 (range, 120-1365) vs. 213 (27-426) in controls (p < .001). COX II/IV ratios were similar in both groups. Although mtDNA levels correlated inversely with maternal lactate, mitochondrial indices did not correlate with maternal CD4+ count, HIV RNA, smoking, or alcohol consumption.

CONCLUSION

We found elevated mtDNA copy numbers in PBMC of infants born to HIV-infected women, the majority of whom received NRTI-based therapy, when compared to those born to healthy HIV-negative controls, but there was no difference in mtDNA-encoded respiratory chain protein. The clinical consequence of these findings is unknown and requires further investigations.

In utero nucleoside reverse transcriptase inhibitor exposure and signs of possible mitochondrial dysfunction in HIV-uninfected children

BACKGROUND

There is equivocal evidence of in utero nucleoside reverse transcriptase inhibitor (NRTI) exposure and the occurrence of mitochondrial dysfunction (MD) in HIV-uninfected children born of HIV-infected women.

METHODS

The primary analysis included 1037 HIV-uninfected children born in 1991-2002 and enrolled in Pediatric AIDS Clinical Trials Group protocols 219/219C. Possible cases with unexplained signs of MD according to the Enquête Périnatale Française criteria were identified through retrospective review. Associations between overall in utero NRTI exposure, and trimester of first in utero NRTI exposure and possible MD were estimated with exact logistic regression.

RESULTS

Cases (n = 20) were significantly more likely to be male and to be born in earlier years than non-cases (n = 1017). There was no association between overall in utero NRTI exposure and MD. In unadjusted models there were higher odds of first in utero exposure in the third trimester to lamivudine (3TC) [odds ratio (OR), 3.76 versus 3TC unexposed; 95% confidence interval (CI), 1.09-11.78] and to zidovudine (ZDV) and 3TC in combination (ZDV/3TC) (OR, 3.29 vs. ZDV/3TC unexposed; 95% CI, 0.96-10.25) among cases than noncases. When adjusted for year of birth the odds of first exposure in the third trimester to 3TC (OR, 10.57; 95% CI, 1.93-75.61) and ZDV/3TC (OR, 9.84; 95% CI, 1.77-71.68) were significantly higher among cases than non-cases. Incomplete data precluded control of possible confounding by maternal viral load and psychoactive drug use.

CONCLUSIONS

Our study suggests that first exposure to 3TC or ZDV/3TC in the third trimester may be associated with the occurrence of possible MD. Further studies that rigorously assess MD and better control confounding are needed.

Safety of Agents Used to Prevent Mother-to-Child Transmission of HIV

Antiretroviral drugs have been used routinely to reduce the risk of mother-to-child transmission of HIV infection since 1994, following the AIDS Clinical Trials Group 076 trial, which demonstrated the efficacy of zidovudine in reducing the risk of in utero and intrapartum transmission. The use of antiretroviral drugs in pregnancy varies geographically, with widespread use of highly active antiretroviral therapy (HAART) in resource-rich settings for delaying maternal HIV disease progression as well as the prevention of mother-to-child transmission; however, in low- and middle-income settings, abbreviated prophylactic regimens focus on the perinatal period, with very limited access to HAART to date. The potential risks associated with antiretroviral exposure for pregnant women, fetuses and infants depend on the duration of this exposure as well as the number and type of drugs. As the benefits of HAART regimens in reducing the risk of mother-to-child transmission and in delaying disease progression are so great, their widespread use has been accepted, despite the relative lack of safety data from human pregnancies. Animal studies have suggested an increased risk of malformations associated with exposure to specific antiretroviral drugs, although evidence to support this from human studies is limited. Trials, cohorts and surveillance studies have shown no evidence of an increased risk of congenital malformations associated with in utero exposure to zidovudine, or other commonly used antiretroviral drugs, with an estimated 2-3% prevalence of birth defects (i.e. similar to that seen in the general population). Exposure to prophylactic zidovudine for prevention of mother-to-child transmission is associated with a usually mild and reversible, but rarely severe, anaemia in infants. However, a medium-term impact on haematological parameters of antiretroviral-exposed infants has been reported, with small but persistent reductions in levels of neutrophils, platelets and lymphocytes in children up to 8 years of age; the clinical significance of this remains uncertain. To date, there is no evidence to suggest that exposure to antiretroviral drugs in utero or neonatally is associated with an increased risk of childhood cancer, but the potential for mutagenic and carcinogenic effects at older ages cannot be excluded. Nucleoside analogue-related mitochondrial toxicity is well recognised from studies in non-pregnant individuals, whilst animal studies have provided evidence of mitochondrial toxicity resulting from in utero antiretroviral exposure. Clinically evident mitochondrial disease in children with antiretroviral exposure has only been described in Europe, with an estimated 18-month incidence of 'established' mitochondrial dysfunction of 0.26% among exposed children. Regarding pregnancy-related adverse effects, increased risks of prematurity, pre-eclampsia and gestational diabetes mellitus have been reported by a variety of observational studies with varying strengths of evidence and with conflicting results. Based on current knowledge, the immense benefits of antiretroviral prophylaxis in prevention of mother-to-child transmission far outweigh the potential for adverse effects. However, these potential adverse effects require further and longer term monitoring because they are likely to be rare and to occur later in childhood.