Incidence of cancer in children perinatally exposed to nucleoside reverse transcriptase inhibitors

Cancer risk among HIV-exposed uninfected children in the United States

In utero exposure to didanosine was associated with increased risk of brain cancer in a French study. We used United States health department records to assess cancer risk among 13 617 children exposed to HIV in utero , who remained HIV-uninfected after birth (1990-2017). Risk of brain tumors was borderline elevated among these children (standardized incidence ratio 2.2, 95% confidence interval 0.8-4.8, P  = 0.12, based on six cases). Risk was not significantly increased for leukemia or other cancers.

Maternal Medication Use and Childhood Cancer in Offspring-Systematic Review and Considerations for Researchers

Cancer is an important cause of childhood mortality, yet the etiology is largely unknown. A combination of pre- and postnatal factors is thought to be implicated, including maternal medication use. We aimed to provide: 1) a systematic review of peer-reviewed publications on associations between maternal medication use and childhood cancer, with a focus on study design and methodology; and 2) suggestions for how to increase transparency, limit potential biases, and improve comparability in studies on maternal medication use and childhood cancer. We conducted a systematic search in the PubMed, Embase, Scopus, Cochrane, and Web of Science databases to June 8, 2020. Altogether, 112 studies were identified. The reviewed studies were heterogeneous in study design, exposure, and outcome classification. In 21 studies (19%), the outcome was any childhood cancer. Of the 91 papers that reported on specific types of cancer, 62% did not report the cancer classification system. The most frequently investigated medication groups were sex hormones (46 studies, excluding fertility medications), and antiinfectives (37 studies). Suggestions for strengthening future pharmacoepidemiologic studies on maternal medication use and childhood cancer relate to choice of cancer classification system, exposure windows, and methods for identification of, and control for, potential confounders.

Grounded theory qualitative approach from Foucault's ethical perspective: Deconstruction of patient self-determination in the clinical setting

This paper aims to explain the construction of the autonomous subject from Foucault's ethical perspective for the qualitative analysis of interprofessional relationships, patient-professional relationships, and moral ethics critique. Foucault tried to break loose from the self, which is merely the result of a biopolitical subjectivation and constituted an interpersonal level. From this, different elements involved in the decision-making capacity of patients in a clinical setting were analysed. Firstly, the context in which decision-making occurs has been explained, distinguishing between traditional practices involved in self-care and the more modern conceptions that make certain possible transformations. Secondly, an attempt is made to explain the formation of the medicalisation of society using the transformations of what Foucault called "techniques of the self". Finally, the ethical framework for a subject's "self-creation", insisting more on the exercises of self-subjectivation, reinforcing the ethics of the self by itself, the "care of the self", has been explained. The role of the patient is understood as an autonomous subject to the extent that the clinical institution and the professionals involved comprehend how the patient's autonomy in the clinical environment is constituted. All these elements could generate grounded theory on the qualitative methodology of this phenomenon. The current ethical model based on universal principles is not useful to provide a capacity for patients decision-making, relegating to the background their opinions and beliefs. Consequently, a new ethical perspective emerges that aims to return the patient to the fundamental axis of attention.

HIV-1, HAART and cancer: A complex relationship

HIV infected people are at higher risk of developing cancer, although it is globally diminished in the era of highly active antiretroviral treatment (HAART). Recently, antioncogenic properties of some HAART drugs were discovered. We discuss the role of HAART in the prevention and improvement of treatment outcomes of cancers in HIV-infected people. We describe different trends in HAART-cancer relationships: cancer-predisposing as well as cancer-preventing. We cover the roles of particular drug regimens in cancer prevention. We also describe the causes of cancer treatment with HAART drugs in HIV-negative people, including ongoing clinical studies that may directly point to a possible independent anti-oncogenic activity of HAART drugs. We conclude that despite potent antioncogenic activities of every class of HAART drugs reported in preclinical models, the evidence to date indicates that their independent clinical impact in HIV-infected people is limited. Improved cancer prevention strategies besides HAART are needed to reduce HIV-cancer-related mortality.

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.

Toxicity and genotoxicity induced by abacavir antiretroviral medication alone or in combination with zidovudine and/or lamivudine in Drosophila melanogaster

Abacavir (ABC), zidovudine (AZT), and lamivudine (3TC) are nucleoside analog reverse transcriptase inhibitors (NRTIs) widely used as combination-based antiretroviral therapy against human immunodeficiency virus. Despite effective viral suppression using NRTI combinations, genotoxic potential of NRTIs can be increased when administered in combination. This study investigated the toxic and genotoxic potential of ABC when administered alone or in combination with AZT and/or 3TC using the somatic mutation and recombination test in Drosophila melanogaster. This test simultaneously evaluated two events related to carcinogenic potential: mutation and somatic recombination. The results indicated that ABC was responsible for toxicity when administered alone or in combination with AZT and/or 3TC. In addition, all treatment combinations increased frequencies of mutation and somatic recombination. The combination of AZT/3TC showed the lowest genotoxic activity compared to all combinations with ABC. Therefore, our results indicated that ABC was responsible for a significant portion of genotoxic activity of these combinations. Somatic recombination was the main genetic event observed, ranging from 83.7% to 97.7%.

Assessment of complex genomic alterations induced by AZT, 3TC, and the combination AZT +3TC

Highly active antiretroviral therapy (HAART) regimens are based on the use of nucleoside reverse transcriptase inhibitors (NRTIs), which are the main drugs used by patients infected with the human immunodeficiency virus (HIV). The use of NRTIs combinations has afforded clear clinical benefits to patients undergoing HAART. However, the combination of two NRTIs may increase the risk of genomic instability in comparison with the drugs administered individually. We analyzed the ability of zidovudine (AZT) and lamivudine (3TC), and the combination AZT +3TC to induce complex genomic alterations using the cytokinesis-block micronucleus (CBMN) assay in Chinese hamster ovary (CHO)-K1 cells. The 24-h cell treatment with individual NRTIs showed that AZT increased micronucleus frequencies and nucleoplasmic bridges (NPBs). No significant differences were observed for any parameters investigated after exposure of CHO-K1 cells to 3TC. The combination AZT +3TC significantly increased micronucleus frequencies. Analysis of interaction between these drugs suggested that antagonism occurs in all AZT +3TC concentrations. These results highlight the importance to investigate the genotoxic profile of NRTIs to develop safer intervention strategies in antiretroviral treatment protocols.

HIV-associated malignancies in children

PURPOSE OF REVIEW

HIV-infected children are at an increased risk of developing cancer. Many of the cancers in HIV-infected children are linked to immunosuppression and oncogenic coinfections. Worldwide most HIV-infected children live in sub-Saharan Africa, but cancer data for this population are scarce. In this article, we review the current literature on the epidemiology and prevention of cancer in HIV-infected children.

RECENT FINDINGS

Combined antiretroviral therapy (cART) reduces the risk of developing cancer in HIV-infected children. Cancer risk remains increased in children who start cART at older ages or more advanced immunosuppression as compared with children who start cART at younger age and with mild immunosuppression. Starting cART before severe immunosuppression develops is key to prevent cancer in HIV-infected children but most children in low-income countries start cART at severe immunosuppression levels. Vaccination against high-risk variants of human papillomavirus may protect again human papillomavirus-associated cancer later in life. However, tailoring of human papillomavirus vaccination guidelines for HIV-infected children and young women awaits answers to determine the best vaccination strategies.

SUMMARY

Better data on the short-term and long-term risks of developing cancer and the effects of preventive measures in HIV-infected children from regions with high burden of HIV/AIDS are urgently needed.

Perinatal Antiretroviral Exposure and Prevented Mother-to-child HIV Infections in the Era of Antiretroviral Prophylaxis in the United States, 1994-2010

OBJECTIVES

Using published, nationally-representative estimates, we calculated the total number of perinatally HIV-exposed and HIV-infected infants born during 1978-2010, the number of perinatal HIV cases prevented by interventions designed for the prevention of mother-to-child transmission (PMTCT), and the number of infants exposed to antiretroviral (ARV) drugs during the prenatal and intrapartum periods.

DESIGN

We calculated the number of infants exposed to ARV drugs since 1994, and the number of cases of mother-to-child HIV transmission prevented from 1994 to 2010 using published data. We generated confidence limits for our estimates by performing a simulation study.

METHODS

Data were obtained from published, nationally-representative estimates from the Centers for Disease Control and Prevention. Model parameters included the annual numbers of HIV-infected pregnant women, the annual numbers of perinatally infected infants, the annual proportions of infants exposed to ARV drugs during the prenatal and intrapartum period and the estimated MTCT rate in the absence of preventive interventions. For the simulation study, model parameters were assigned distributions and we performed 1,000,000 repetitions.

RESULTS

Between 1978 and 2010, an estimated 186,157 [95% confidence interval (CI): 185,312-187,003] HIV-exposed infants and approximately 21,003 (95% CI: 20,179-21,288) HIV-infected infants were born in the United States. Between 1994 and 2010, an estimated 124,342 (95% CI: 123,651-125,034) HIV-exposed infants were born in the US, and approximately 6083 (95% CI: 5931-6236) infants were perinatally infected with HIV. During this same period, about 100,207 (95% CI: 99,374-101,028) infants were prenatally exposed to ARV drugs. As a result of PMTCT interventions, an estimated 21,956 (95% CI: 20,191-23,759) MTCT HIV cases have been prevented in the United States since 1994.

CONCLUSION

Although continued vigilance is needed to eliminate mother-to-child HIV transmission, PMTCT interventions have prevented nearly 22,000 cases of perinatal HIV transmission in the United States since 1994.

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.

Strategies for Monitoring Outcomes in HIV-Exposed Uninfected Children in the United Kingdom

Surveillance of pregnancies in women living with HIV is carried out on a national basis in the United Kingdom (UK) through the National Study of HIV in Pregnancy and Childhood. There are currently around 1100-1200 HIV-exposed uninfected (HEU) infants born every year in the UK, where vertical transmission of HIV now occurs in fewer than 5 in every 1000 pregnancies. By the end of 2014, there was a cumulative total of more than 15,000 HEU children with any combination antiretroviral therapy (cART) exposure and more than 5000 with cART exposure from conception in the UK. HEU infants are increasingly being exposed to newer antiretroviral drugs for which less is known regarding both short- and long-term safety. In this commentary, we describe the approaches that have been taken to explore health outcomes in HEU children born in the UK. This includes the Children exposed to AntiRetroviral Therapy (CHART) Study, which was a consented follow-up study carried out in 2002-2005 of HEU children born in 1996-2004. The CHART Study showed that 4% of HEU children enrolled had a major health or development problem in early childhood; this was within expected UK norms, but the study was limited by small numbers and short-term follow-up. However, the problems with recruitment and retention that were encountered within the CHART Study demonstrated that comprehensive, clinic-based follow-up was not a feasible approach for long-term assessment of HEU children in the UK. We describe an alternative approach developed to monitor some aspects of their long-term health, involving the "flagging" of HEU infants for death and cancer registration with the UK Office for National Statistics. Some of the ethical concerns regarding investigation of long-term outcomes of in utero and perinatal exposure to antiretrovirals, including those relating to consent and confidentiality, are also discussed.

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.

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.

Comparing genotoxic signatures in cord blood cells from neonates exposed in utero to zidovudine or tenofovir

OBJECTIVES

Zidovudine and tenofovir are the two main nucleos(t)ide analogs used to prevent mother-to-child transmission of HIV. In vitro, both drugs bind to and integrate into human DNA and inhibit telomerase. The objective of the present study was to assess the genotoxic effects of either zidovudine or tenofovir-based combination therapies on cord blood cells in newborns exposed in utero.

DESIGN

We compared the aneuploid rate and the gene expression profiles in cord blood samples from newborns exposed either to zidovudine or tenofovir-based combination therapies during pregnancy and from unexposed controls (n = 8, 9, and 8, respectively).

METHODS

The aneuploidy rate was measured on the cord blood T-cell karyotype. Gene expression profiles of cord blood T cells and hematopoietic stem and progenitor cells were determined with microarrays, analyzed in a gene set enrichment analysis and confirmed by real-time quantitative PCRs.

RESULTS

Aneuploidy was more frequent in the zidovudine-exposed group (26.3%) than in the tenofovir-exposed group (14.2%) or in controls (13.3%; P < 0.05 for both). The transcription of genes involved in DNA repair, telomere maintenance, nucleotide metabolism, DNA/RNA synthesis, and the cell cycle was deregulated in samples from both the zidovudine and the tenofovir-exposed groups.

CONCLUSION

Although tenofovir has a lower clastogenic impact than zidovudine, gene expression profiling showed that both drugs alter the transcription of DNA repair and telomere maintenance genes.

Strategies for the prevention of mother to child transmission in Western countries: an update

BACKGROUND

During the last decades remarkable scientific advances have been made toward the prevention of HIV mother-to-child transmission, in particular in developed nations. The aim of this review was to analyze the latest findings and available international recommendations on the prevention of HIV mother-to-child transmission in high-income countries.

METHODS

We performed a literature search of the Cochrane Library, MEDLINE by PubMed and EMBASE from database inception through June 2014, using the following terms: HIV, mother-to-child transmission and mother-to-child-transmission prevention. All types of articles in the English language were included. US and available European guidelines were searched and included in the analysis.

RESULTS

One hundred fifty articles were selected for inclusion in this review.

CONCLUSIONS

Global epidemiology of HIV infection is rapidly evolving, in particular in high-resource countries. The interpretation of clinical and epidemiological studies is crucial for the development of evidence-based recommendations to guide the management of HIV mother-to-child transmission. Although significant progress has been made, heterogeneity between countries in specific interventions still exists, which may address future research.

Fetal consequences of maternal antiretroviral nucleoside reverse transcriptase inhibitor use in human and nonhuman primate pregnancy

PURPOSE OF REVIEW

Here we present fetal genotoxicity and mitochondrial toxicity, induced by nucleoside reverse transcriptase inhibitors (NRTIs), in HIV-1-infected pregnant women treated to prevent mother-to-child HIV-1 transmission, and in virus-free pregnant patas monkeys.

RECENT FINDINGS

In the offspring of pregnant patas monkeys given human-equivalent NRTI protocols, aneuploidy was found in cultured bone marrow cells taken at birth, 1, and 3 years of age. In some newborn human infants, the offspring of HIV-1-infected mothers given zidovudine (AZT) therapy, aneuploidy, mitochondrial DNA (mtDNA) depletion, morphologically damaged mitochondria, and reduction in cardiac left ventricular muscle were observed. NRTI-exposed human and patas umbilical cords had similar levels of mtDNA depletion and mitochondrial morphological damage. NRTI-exposed patas offspring showed a compensatory increase in heart mtDNA, and a 50% loss of brain mtDNA at 1 year of age. Mitochondrial morphological damage and mtDNA loss were persistent in blood cells of NRTI-exposed infants up to 2 years of age, and in heart and brain from NRTI-exposed patas up to 3 years of age (human equivalent of 15 years).

SUMMARY

Whereas use of NRTIs in human pregnancy protects many thousands of children worldwide, some HIV-1-uninfected infants born to HIV-1-infected mothers receiving antiretroviral drug therapy sustain toxicities that may have adverse consequences later in life.

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.

[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.

Cardiac Rhabdomyoma in a Neonate With Supraventricular Tachycardia

Cardiac rhabdomyoma (CR) is a rare tumor commonly associated with tuberous sclerosis. They are often detected prenatally or in early infancy. The case of a Nigerian human immunodeficiency virus (HIV)-exposed neonate with CR who presented with supraventricular tachycardia and cardiovascular collapse is presented. The infant was born to a mother on highly active antiretroviral therapy (HAART). The possible role of HIV and HAART in CR etiology and the difficulty in the management of this case are highlighted.

[Tolerance of antiretroviral drugs during pregnancy]

Prevention of transmission from mother to child HIV-1 with antire-trovirals is extraordinarily effective. The risk is now almost zero for a woman properly followed, early in her pregnancy. Rapid expansion of this prophylaxis gives hope of a virtual elimination of pediatric AIDS at a global scale. In 2012, more than 500,000 women around the world have received antiretrovirals during pregnancy making the issue of tolerance crucial. Even if the health of children "exposed-uninfected" is not a concern in the vast majority of cases, a series of biological, clinical and imaging alerts justifies attention. Genotoxic profile of zidovudine, and more generally that of antiretroviral nucleoside analogues for mitochondrial and/or nuclear DNA is certainly the main questions regarding the potential long-term effects to the child.

Perinatal exposure of patas monkeys to antiretroviral nucleoside reverse-transcriptase inhibitors induces genotoxicity persistent for up to 3 years of age

BACKGROUND

Erythrocebus patas (patas) monkeys were used to model antiretroviral (ARV) drug in human immunodeficiency virus type 1-infected pregnant women.

METHODS

Pregnant patas dams were given human-equivalent doses of ARVs daily during 50% of gestation. Mesenchymal cells, cultured from bone marrow of patas offspring obtained at birth and at 1 and 3 years of age, were examined for genotoxicity, including centrosomal amplification, micronuclei, and micronuclei containing whole chromosomes.

RESULTS

Compared with controls, statistically significant increases (P < .05) in centrosomal amplification, micronuclei, and micronuclei containing whole chromosomes were found in mesenchymal cells from most groups of offspring at the 3 time points.

CONCLUSIONS

Transplacental nucleoside reverse-transcriptase inhibitor exposures induced fetal genotoxicity that was persistent for 3 years.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.

Chronic hepatitis B virus infection and pregnancy

Planning of pregnancy and management of chronic hepatitis B virus during pregnancy includes recognition of maternal virological status, assessment of liver disease severity and minimization of risk for mother to infant transmission of infection. Decisions regarding the use of antivirals during pregnancy need to be individualized. Monitoring for infection and immunization in newborns is also important. For mothers on antiviral therapy, breastfeeding is not recommended.

Recent advances in pharmacovigilance of antiretroviral therapy in HIV-infected and exposed children

PURPOSE OF REVIEW

Antiretroviral therapy (ART) has greatly improved the survival of HIV-infected children. However, ART is associated with immediate and long-term adverse events. Pharmacovigilance systems, although imperfect, have been developed in many high-income countries (HICs), but coverage in low- and middle-income countries (LMICs) is poor and uneven. This review covers the recent advances in the understanding of adverse events following perinatal ART exposure, including surveillance from birth cohorts; we also describe the adverse events of antiretroviral drugs among HIV-infected children, focussing particularly on those relevant to LMICs, where more than 90% of HIV-infected children live.

RECENT FINDINGS

ART is largely safe in both HIV-infected and HIV-exposed uninfected children, in whom no significant increase in birth defects has been noted. Among HIV-infected children, toxicity to some drugs may be less frequent than in adults, possibly related to immature immune systems in younger children. As per WHO guidelines, many countries are moving from stavudine-based to zidovudine-based or abacavir-based fixed-dose combination (with nevirapine/lamivudine) paediatric mini-pills. However, reassuring data are emerging about short-term stavudine use in LMICs, as this remains an important first-line regimen for young children, as well as an alternative to zidovudine for anaemic children. Zidovudine appears to be well tolerated in young children living in nonmalarious areas, and, among African children, concerns about abacavir hypersensitivity have not been substantiated.

SUMMARY

Optimization of first-line ART regimens needs to take account of the toxicities in HIV-infected children, in particular as they will take ART much longer than adults and during the period of growth and development. The benefits of ART in pregnancy are clear, but long-term follow-up of ART-exposed infants in LMICs through integrated surveillance systems would be invaluable.

Safety of tenofovir use during pregnancy: early growth outcomes in HIV-exposed uninfected infants

OBJECTIVE

To evaluate the association of tenofovir disoproxil fumarate (TDF) use during pregnancy with early growth parameters in HIV-exposed, uninfected (HEU) infants.

DESIGN

US-based prospective cohort study of HEU children to examine potential adverse effects of prenatal TDF exposure.

METHODS

We evaluated the association of maternal TDF use during pregnancy with small for gestational age (SGA); low birth weight (LBW, <2.5 kg); weight-for-age z-scores (WAZ), length-for-age z-scores (LAZ), and head circumference-for-age (HCAZ) z-scores at newborn visit; and LAZ, HCAZ, and WAZ at age 1 year. Logistic regression models for LBW and SGA were fit, adjusting for maternal and sociodemographic factors. Adjusted linear regression models were used to evaluate LAZ, WAZ, and HCAZ by TDF exposure.

RESULTS

Of 2029 enrolled children with maternal antiretroviral information, TDF was used by 449 (21%) HIV-infected mothers, increasing from 14% in 2003 to 43% in 2010. There was no difference between those exposed to combination regimens with vs. without TDF for SGA, LBW, and newborn LAZ and HCAZ. However, at age 1 year, infants exposed to combination regimens with TDF had significantly lower adjusted mean LAZ and HCAZ than those without TDF (LAZ: -0.17 vs. -0.03, P=0.04; HCAZ: 0.17 vs. 0.42, P=0.02).

CONCLUSION

TDF use during pregnancy was not associated with increased risk for LBW or SGA. The slightly lower mean LAZ and HCAZ observed at age 1 year in TDF-exposed infants are of uncertain significance but underscore the need for additional studies of growth outcomes after TDF use during pregnancy.

[Recommendations issued by the Spanish Society of Pediatric Infectious Diseases for the follow-up of the child exposed to the human immunodeficiency virus and to antiretroviral drugs during pregnancy and the neonatal period]

Human immunodeficiency virus vertical transmission in developed countries has dramatically decreased to less than 2% over the last 15 years due to the consecutive implementation of different prophylactic measures, including the use of antiretrovirals, elective cesarean section and refraining from breastfeeding. The follow-up of these otherwise healthy children is, by far, the most common situation related to HIV infection that general pediatricians currently face in routine clinical care in Spain. These recommendations issued by the Spanish Society of Pediatric Infectious Diseases attempt to summarize the main aspects of this follow-up, including birth management, type of feeding, neonatal antiretroviral prophylaxis, HIV infection diagnosis, common early comorbidities, short- and mid-term toxicities, vaccination and other prophylactic measures and long-term follow-up.

Radiation exposure from CT in early childhood: a French large-scale multicentre study

OBJECTIVES

The increasing use of CT scans in the paediatric population raises the question of a possible health impact of ionising radiation exposure associated with CT scans. The aim of this study was to describe the pattern of CT use in early childhood.

METHODS

In 14 major French paediatric radiology departments, children undergoing at least 1 CT scan before age 5, between 2000 and 2006, were included. For each examination, absorbed organ doses were calculated.

RESULTS

43% of the 27 362 children in the cohort were aged less than 1 year during their first exposure, with 9% being aged less than 1 month. The mean number of examinations per child was 1.6 (range 1-43). The examinations included: head in 63% of the cases, chest in 21%, abdomen and pelvis in 8% and others in 8%. Brain and eye lenses received the highest cumulative doses from head examinations, with mean organ dose values of 22 mGy (maximum 1107 mGy) and 26 mGy (maximum 1392 mGy), respectively. The mean cumulative effective dose was 3.2 mSv (range 0.1-189 mSv).

CONCLUSION

CT scan exposure in childhood is responsible for relatively high doses to radiosensitive organs. The rather large dose range according to the protocols used requires their optimisation. The cohort follow-up will study the risk of long-term radiation-induced cancer.

Antiviral therapy for hepatitis B infection during pregnancy and breastfeeding

It is estimated there are 350-400 million people worldwide chronically infected with HBV. Many of these are women and of reproductive age. As such, they may face therapeutic decisions regarding antiviral therapy and the implication this may have on future or current pregnancies. This article reviews the data of all antivirals licensed for use against hepatitis B infection regarding teratogenicity, carcinogenicity, clinical experience during pregnancy, placental transfer and excretion in breast milk.

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.

Asking the right questions: developing evidence-based strategies for treating HIV in women and children

In July 2010, the World Health Organization (WHO) issued formal revisions of its guidelines on the use of highly active antiretroviral therapy for HIV. The new guidelines greatly expand eligibility for treatment of adults and children, as well as for pregnant women seeking prophylaxis for vertical HIV transmission. WHO's new recommendations bring the guidelines closer to practices in developed countries, and its shift to earlier treatment alone will increase the number of treatment-eligible people by 50% or more.Scaling up access to HIV treatment is revealing important gaps in our understanding of how best to provide for all those in need. This knowledge gap is especially significant in developing countries, where women and children comprise a majority of those living with HIV infection. Given the magnitude and significance of these populations, the International AIDS Society, through its Industry Liaison Forum, prioritized HIV treatment and prophylaxis of women and children. In March 2010, the International AIDS Society and 15 partners launched a Consensus Statement outlining priority areas in which a relative lack of knowledge impedes delivery of optimal prevention of mother to child transmission (PMTCT) and treatment to women and children.The Consensus Statement, "Asking the Right Questions: Advancing an HIV Research Agenda for Women and Children", makes a special appeal for a more gender-sensitive approach to HIV research at all stages, from conception to design and implementation. It particularly emphasizes research to enhance the understanding of sex-based differences and paediatric needs in treatment uptake and response. In addition to clinical issues, the statement focuses on programmatic research that facilitates access and adherence to antiretroviral regimens. Better coordination of HIV management with sexual and reproductive healthcare delivery is one such approach.We discuss here our knowledge gaps concerning effective, safe PMTCT and treatment for women and children in light of the expansion envisioned by WHO's revised guidelines. The guideline's new goals present an opportunity for advancing the women and children's agenda outlined in the Consensus Statement.

The genetic toxicity effects of lamivudine and stavudine antiretroviral agents

IMPORTANCE OF THE FIELD

The nucleoside reverse transcriptase inhibitors (NRTIs) are used in antiretroviral therapy worldwide for the treatment of HIV infections. These drugs act by blocking reverse transcriptase enzyme activity, causing pro-viral DNA chain termination. As a consequence, NRTIs could cause genomic instability and loss of heterozygosity.

AREAS COVERED IN THIS REVIEW

This review highlights the toxic and genotoxic effects of NRTIs, particularly lamivudine (3TC) and stavudine (d4T) analogues. In addition, a battery of short-term in vitro and in vivo systems are described to explain the potential genotoxic effects of these NRTIs as a single drug or a complexity of highly active antiretroviral therapy.

WHAT THE READER WILL GAIN

The readers will gain an understanding of a secondary effect that could be induced by 3TC and d4T treatments.

TAKE HOME MESSAGE

Considering that AIDS has become a chronic disease, more comprehensive toxic genetic studies are needed, with particular attention to the genetic alterations induced by NRTIs. These alterations play a primary role in carcinogenesis and are also involved in secondary and subsequent steps of carcinogenesis.

Progressive mitochondrial compromise in brains and livers of primates exposed in utero to nucleoside reverse transcriptase inhibitors (NRTIs)

Mitochondrial compromise has been documented in infants born to women infected with the human immunodeficiency virus (HIV-1) who received nucleoside reverse transcriptase inhibitor (NRTI) therapy during pregnancy. To model these human exposures, we examined mitochondrial integrity at birth and 1 year in brain cortex and liver from offspring of retroviral-free Erythrocebus patas dams-administered human-equivalent NRTI doses for the last half (10 weeks) of gestation. Additional infants, followed for 1 year, were given the same drugs as their mothers for the first 6 weeks of life. Exposures included: no drug, Zidovudine (AZT), Lamivudine (3TC), AZT/3TC, AZT/Didanosine (ddI), and Stavudine (d4T)/3TC. In brain and liver, oxidative phosphorylation (OXPHOS) enzyme activities (complexes I, II, and IV) showed minimal differences between unexposed and NRTI-exposed offspring at both times. Brain and liver mitochondria from most NRTI-exposed patas, both at birth and 1 year of age, contained significant (p < 0.05) morphological damage observed by electron microscopy (EM), based on scoring of coded photomicrographs. Brain and liver mitochondrial DNA (mtDNA) levels in NRTI-exposed patas were depleted significantly in the 3TC and d4T/3TC groups at birth and were depleted significantly (p < 0.05) at 1 year in all NRTI-exposed groups. In 1-year-old infants exposed in utero to NRTIs, mtDNA depletion was 28.8-51.8% in brain and 37.4-56.5% in liver. These investigations suggest that some NRTI-exposed human infants may sustain similar mitochondrial compromise in brain and liver and should be followed long term for cognitive integrity and liver function.

A review of nucleoside reverse transcriptase inhibitor use to prevent perinatal transmission of HIV

Worldwide, women comprise > 50% of all people living with HIV and the vast majority of these women are of childbearing age. In fact, a significant proportion of these women are identified as HIV-infected during pregnancy. Preventing perinatal transmission has been one of the greatest prevention successes of the HIV epidemic with < 2% of live births resulting in an HIV-infected infant. The strategic use of combination antiretroviral therapy has been a critical component of this reduction. With more antiretroviral agents available for HIV, the appropriate selection of therapy is often based on provider familiarity with the various agents. Although benefits of antiretroviral use in pregnancy tremendously outweigh the risks, concerns regarding short- and long-term toxicity in mothers and their children, in addition to the risk of the development of HIV resistance, remain subjects of discussion. The choice of antiretroviral 'backbone' is supported by extensive data showing efficacy in the prevention of HIV vertical transmission. Co-formulated zidovudine/lamivudine is the most commonly used combination in pregnancy. Long-term consequences of in utero exposure to antiretroviral agents are not fully understood. In this article, we review the data regarding nucleoside reverse transcriptase inhibitors with a focus on tenofovir.