Long-term nonprogression of HIV infection in children: evaluation of the ANRS prospective French Pediatric Cohort

Long-term non-progression and risk factors for disease progression among children living with HIV in Botswana and Uganda: A retrospective cohort study

OBJECTIVES

We utilize a large retrospective study cohort derived from electronic medical records to estimate the prevalence of long-term non-progression (LTNP) and determine the factors associated with progression among children infected with HIV in Botswana and Uganda.

METHODS

Electronic medical records from large tertiary HIV clinical centers in Botswana and Uganda were queried to identify LTNP children 0-18 years enrolled between June 2003 and May 2014 and extract demographic and nutritional parameters. Multivariate subdistribution hazard analyses were used to examine demographic factors and nutritional status in progression in the pre-antiretroviral therapy era.

RESULTS

Between the two countries, 14,246 antiretroviral therapy-naïve children infected with HIV were enrolled into clinical care. The overall proportion of LTNP was 6.3% (9.5% in Botswana vs 5.9% in Uganda). The median progression-free survival for the cohort was 6.3 years, although this was lower in Botswana than in Uganda (6.6 vs 8.8 years; P <0.001). At baseline, the adjusted subdistribution hazard ratio (aHRsd) of progression was increased among underweight children (aHRsd 1.42; 95% confidence interval [CI]: 1.32-1.53), enrolled after 2010 (aHRsd 1.32; 95% CI 1.22-1.42), and those from Botswana (aHRsd 2; 95% CI 1.91-2.10).

CONCLUSIONS

In our study, the prevalence of pediatric LTNP was lower than that observed among adult populations, but progression-free survival was higher than expected. Underweight, year of enrollment into care, and country of origin are independent predictors of progression among children.

Prevalence of undiagnosed HIV among children in South Africa, Côte d'Ivoire and Zimbabwe: a model-based analysis to inform paediatric HIV screening programmes

INTRODUCTION

To improve the diagnosis and survival of children living with HIV (CLWH), the World Health Organization recommends testing approaches beyond traditional infant HIV testing programmes. Information about undiagnosed HIV prevalence among children of varying ages in the general population is needed to guide innovative national/subnational case-finding and testing approaches.

METHODS

We used the Cost-Effectiveness of Preventing AIDS Complications (CEPAC)-Pediatric model to estimate the prevalence of undiagnosed HIV in 2-, 5- and 10-year-old children in South Africa, Côte d'Ivoire and Zimbabwe in 2018. We simulated cohorts of children born in 2008 (10-year-olds), 2013 (5-year-olds) and 2016 (2-year-olds). Country-/year-specific inputs for pregnant/breastfeeding women included: HIV prevalence (4.2-32.3%), HIV incidence (0.03-0.24%/month), knowledge of HIV status (27-89%) and antiretroviral drug coverage (36-95%). Paediatric inputs included early infant testing coverage (6-95%) and breastfeeding duration (0-20 months). We projected the proportion of surviving CLWH in whom HIV remained undiagnosed and the undiagnosed HIV prevalence among surviving children of each age in the general population. For children born in 2016, we projected survival and diagnosis of all CLWH through 2026. We conducted sensitivity analyses on model parameters.

RESULTS

In 2018, the projected proportion of surviving CLWH whose HIV remained undiagnosed in South Africa/Côte d'Ivoire/Zimbabwe was 44.2%/55.8%/52.9% among 2-year-old CLWH; 29.0%/37.8%/33.2% among 5-year-old CLWH; and 18.3%/25.4%/23.1% among 10-year-old CLWH. Projected general population undiagnosed HIV prevalence in South Africa/Côte d'Ivoire/Zimbabwe was 0.44%/0.32%/0.68% among 2-year-olds; 0.25%/0.17%/0.41% among 5-year-olds; and 0.24%/0.14%/0.38% among 10-year-olds. Among all CLWH born in 2016, 50-54% were projected to die without HIV diagnosis (and subsequently without treatment) within 10 years after birth; 80-85% of these deaths occurred in the first 2 years.

CONCLUSIONS

Projected population-level undiagnosed HIV prevalence is low and sharply decreases after age 2, with more CLWH dying than being diagnosed. Despite low undiagnosed prevalence in the general population of older children, we project that a large proportion of CLWH remain undiagnosed, suggesting that innovative strategies targeting untested children of all ages outside of health facility settings should be prioritized. Programmes could consider routine testing of the general population of children below 2 in all settings and children of all ages in high-prevalence settings.

Growth and CD4 patterns of adolescents living with perinatally acquired HIV worldwide, a CIPHER cohort collaboration analysis

INTRODUCTION

Adolescents living with HIV are subject to multiple co-morbidities, including growth retardation and immunodeficiency. We describe growth and CD4 evolution during adolescence using data from the Collaborative Initiative for Paediatric HIV Education and Research (CIPHER) global project.

METHODS

Data were collected between 1994 and 2015 from 11 CIPHER networks worldwide. Adolescents with perinatally acquired HIV infection (APH) who initiated antiretroviral therapy (ART) before age 10 years, with at least one height or CD4 count measurement while aged 10-17 years, were included. Growth was measured using height-for-age Z-scores (HAZ, stunting if <-2 SD, WHO growth charts). Linear mixed-effects models were used to study the evolution of each outcome between ages 10 and 17. For growth, sex-specific models with fractional polynomials were used to model non-linear relationships for age at ART initiation, HAZ at age 10 and time, defined as current age from 10 to 17 years of age.

RESULTS

A total of 20,939 and 19,557 APH were included for the growth and CD4 analyses, respectively. Half were females, two-thirds lived in East and Southern Africa, and median age at ART initiation ranged from <3 years in North America and Europe to >7 years in sub-Saharan African regions. At age 10, stunting ranged from 6% in North America and Europe to 39% in the Asia-Pacific; 19% overall had CD4 counts <500 cells/mm3 . Across adolescence, higher HAZ was observed in females and among those in high-income countries. APH with stunting at age 10 and those with late ART initiation (after age 5) had the largest HAZ gains during adolescence, but these gains were insufficient to catch-up with non-stunted, early ART-treated adolescents. From age 10 to 16 years, mean CD4 counts declined from 768 to 607 cells/mm3 . This decline was observed across all regions, in males and females.

CONCLUSIONS

Growth patterns during adolescence differed substantially by sex and region, while CD4 patterns were similar, with an observed CD4 decline that needs further investigation. Early diagnosis and timely initiation of treatment in early childhood to prevent growth retardation and immunodeficiency are critical to improving APH growth and CD4 outcomes by the time they reach adulthood.

Exome Sequencing Reveals a Putative Role for HLA-C*03:02 in Control of HIV-1 in African Pediatric Populations

Human leucocyte antigen (HLA) class I molecules present endogenously processed antigens to T-cells and have been linked to differences in HIV-1 disease progression. HLA allelotypes show considerable geographical and inter-individual variation, as does the rate of progression of HIV-1 disease, with long-term non-progression (LTNP) of disease having most evidence of an underlying genetic contribution. However, most genetic analyses of LTNP have occurred in adults of European ancestry, limiting the potential transferability of observed associations to diverse populations who carry the burden of disease. This is particularly true of HIV-1 infected children. Here, using exome sequencing (ES) to infer HLA allelotypes, we determine associations with HIV-1 LTNP in two diverse African pediatric populations. We performed a case-control association study of 394 LTNPs and 420 rapid progressors retrospectively identified from electronic medical records of pediatric HIV-1 populations in Uganda and Botswana. We utilized high-depth ES to perform high-resolution HLA allelotyping and assessed evidence of association between HLA class I alleles and LTNP. Sixteen HLA alleles and haplotypes had significantly different frequencies between Uganda and Botswana, with allelic differences being more prominent in HLA-A compared to HLA-B and C allelotypes. Three HLA allelotypes showed association with LTNP, including a novel association in HLA-C (HLA-B∗57:03, aOR 3.21, Pc = 0.0259; B∗58:01, aOR 1.89, Pc = 0.033; C∗03:02, aOR 4.74, Pc = 0.033). Together, these alleles convey an estimated population attributable risk (PAR) of non-progression of 16.5%. We also observed novel haplotype associations with HLA-B∗57:03-C∗07:01 (aOR 5.40, Pc = 0.025) and HLA-B∗58:01-C∗03:02 (aOR 4.88, Pc = 0.011) with a PAR of 9.8%, as well as a previously unreported independent additive effect and heterozygote advantage of HLA-C∗03:02 with B∗58:01 (aOR 4.15, Pc = 0.005) that appears to limit disease progression, despite weak LD (r 2 = 0.18) between these alleles. These associations remained irrespective of gender or country. In one of the largest studies of HIV in Africa, we find evidence of a protective effect of canonical HLA-B alleles and a novel HLA-C association that appears to augment existing HIV-1 control alleles in pediatric populations. Our findings outline the value of using multi-ethnic populations in genetic studies and offer a novel HIV-1 association of relevance to ongoing vaccine studies.

Executive function in HIV-affected children and adolescents: a systematic review and meta-analyses

This review aimed to determine: whether EF is affected in children and adolescents (2-24-years-old) with perinatal HIV infection, perinatal HIV exposure without infection, and behaviourally acquired HIV. A systematic review (PROSPERO number: CRD42017067813) was conducted using 11 electronic databases (01.01.1981-09.07.2019) and 8 conference websites. Primary quantitative studies with EF scores on cognitive tasks and/or behavioural report measures were included. Meta-analyses were performed by EF subtype and subpopulations compared. 1789 records were found. Sixty-one studies were included in the narrative synthesis; 32 (N = 7884 participants) were included in meta-analyses. There was a distinct pattern of reduced EF in those with perinatal HIV infection on antiretroviral therapy compared to controls: pooled effect sizes were largest for verbal and visuospatial working memory, with smaller effects on planning, inhibitory control and set-shifting. Data were limited for other HIV-affected subpopulations. Perinatal HIV infection is associated with reduced EF with varying effect sizes for the different EF subtypes.

Unmapped exome reads implicate a role for Anelloviridae in childhood HIV-1 long-term non-progression

Human immunodeficiency virus (HIV) infection remains a significant public health burden globally. The role of viral co-infection in the rate of progression of HIV infection has been suggested but not empirically tested, particularly among children. We extracted and classified 42 viral species from whole-exome sequencing (WES) data of 813 HIV-infected children in Botswana and Uganda categorised as either long-term non-progressors (LTNPs) or rapid progressors (RPs). The Ugandan participants had a higher viral community diversity index compared to Batswana (p = 4.6 × 10-13), and viral sequences were more frequently detected among LTNPs than RPs (24% vs 16%; p = 0.008; OR, 1.9; 95% CI, 1.6-2.3), with Anelloviridae showing strong association with LTNP status (p = 3 × 10-4; q = 0.004, OR, 3.99; 95% CI, 1.74-10.25). This trend was still evident when stratified by country, sex, and sequencing platform, and after a logistic regression analysis adjusting for age, sex, country, and the sequencing platform (p = 0.02; q = 0.03; OR, 7.3; 95% CI, 1.6-40.5). Torque teno virus (TTV), which made up 95% of the Anelloviridae reads, has been associated with reduced immune activation. We identify an association between viral co-infection and prolonged AIDs-free survival status that may have utility as a biomarker of LTNP and could provide mechanistic insights to HIV progression in children, demonstrating the added value of interrogating off-target WES reads in cohort studies.

Evaluation and Management of the Infant Exposed to HIV in the United States

Pediatricians play a crucial role in optimizing the prevention of perinatal transmission of HIV infection. Pediatricians provide antiretroviral prophylaxis to infants born to women with HIV type 1 (HIV) infection during pregnancy and to those whose mother's status was first identified during labor or delivery. Infants whose mothers have an undetermined HIV status should be tested for HIV infection within the boundaries of state laws and receive presumptive HIV therapy if the results are positive. Pediatricians promote avoidance of postnatal HIV transmission by advising mothers with HIV not to breastfeed. Pediatricians test the infant exposed to HIV for determination of HIV infection and monitor possible short- and long-term toxicity from antiretroviral exposure. Finally, pediatricians support families living with HIV by providing counseling to parents or caregivers as an important component of care.

Cognition, Emotional Health, and Immunological Markers in Children With Long-Term Nonprogressive HIV

BACKGROUND

HIV-infected children with long-term nonprogressive (LTNP) disease eventually convert to a progressive disease type, yet the extent to which these children experience the cognitive and emotional symptoms observed in typical progressive HIV (Progressors) is unknown.

METHODS

Eighty-eight LTNPs, 53 Progressors, and 323 healthy controls completed annual assessments of cognitive and emotional health as part of a prospective study. The 2 HIV-infected groups and the healthy controls were matched on age and sex distribution at enrollment. Plasma HIV RNA, T-cell counts/percentages, activated monocytes, perivascular monocytes, and markers of macrophage activation (sCD163 and sCD14) were compared by progression subtype. Cognitive and emotional outcomes were compared using cross-sectional linear regression analysis and longitudinal sensitivity models.

RESULTS

LTNPs exhibited the same cognitive phenotype and emotional dysregulation as Progressors, with worse outcomes in both groups compared with controls. In addition, cognitive and emotional symptoms were evident before children reached the minimum age for LTNP designation (8 years). Baseline plasma HIV RNA, sCD163, activated monocytes, and perivascular monocytes were lower in LTNPs versus Progressors, with no difference in T-cell counts/percentages or sCD14 levels. Most LTNPs converted to a progressive disease subtype during the study, with similar cognitive and emotion profiles between these subgroups.

CONCLUSIONS

Pediatric LTNPs experience cognitive and emotional difficulties that mirror symptoms of progressive disease. The abnormalities are present at young ages and persist independent of plasma T-cell counts. The findings highlight the neurodevelopmental risk of pediatric HIV, even in those with early innate disease control.

Universal antiretroviral therapy for HIV-infected children: a review of the benefits and risks to consider during implementation

Background: The 2016 World Health Organization (WHO) consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection, recommended to start all HIV-infected children on antiretroviral therapy (ART). Here, we explore the possible benefits and risks of implementing universal ART for all HIV-infected children and adolescents and outline some of the key considerations that led to the 2016 revision of WHO guidelines.

Methods: We conducted a review of the published data from 2000 to 2016, to ascertain the clinical and programmatic benefits, as well as the risks of implementing universal ART for all children.

Results and discussion: Universal ART for all children has the potential to increase treatment coverage, which in 2015 was only 51% globally, as well as providing several biological benefits, by preventing: premature death/loss to follow-up, progressive destruction of the immune system, poor growth and pubertal delay, poor neuro-cognitive outcomes and future burden to the health care system with complications of untreated HIV-infection. However, the strategy could be associated with risks, notably development of HIV drug resistance, antiretroviral drug toxicities and increased costs to an already stretched health system.

Conclusion: Overall, our findings suggest that the benefits could outweigh the risks and support universal ART for all HIV-infected children, but recognize that national programmes will need to put measures in place to minimize the risks if they choose to implement the strategy.

Reticence in disclosure of HIV infection and reasons for bereavement: impact on perinatally infected adolescents' mental health and understanding of HIV treatment and prevention in Johannesburg, South Africa

Survival rates of perinatally infected HIV-positive adolescents (PIA) are increasing in sub-Saharan Africa. There is a gap in understanding how disclosure and bereavement have an impact on PIA beliefs and understanding of their HIV infection and its management. In-depth interviews were conducted with 25 purposively selected adolescents aged 13-19 years from 5 public health clinics in Johannesburg, South Africa. Data were analysed using NVivo 10 using a thematic approach. PIA experience incomplete disclosure both of their HIV status and reasons for their bereavements, which limits their understanding of how they became infected, vertical transmission and prevention options like prevention of mother-to-child transmission (PMTCT). Most participants were orphaned and were experiencing complicated grieving (i.e., engaged in unresolved tasks of grieving) which had a negative impact on their mental health, and ability to accept their HIV status and adhere to treatment. PIA need improved communication regarding vertical transmission and how they became HIV-positive, as well as reasons for death of their loved ones to properly understand their HIV status and engage effectively in management. Honest communication about how relatives died and truthful engagement in the process of disclosure of HIV status is necessary to reduce stigma and complicated grieving, and improve mental health in this population.

Special considerations concerning the use of antiretroviral drugs in children

INTRODUCTION

Antiretroviral therapy is extremely effective in both children and adults infected with HIV. Treatment indications have rapidly expanded; ideally, with rare exceptions, all infected children should now be treated. Areas covered: The use of antiretroviral drugs in children is based largely on extrapolations from experience with adult patients. Pharmacokinetic studies are required in addition to formal studies, which are difficult to conduct in pediatric situations, extending from birth to adolescence. However, despite often inadequate galenic formulation, treatment of children is easier than generally thought. No major or irreversible toxicity has been observed with the latest generation of molecules. Several observations suggest that very early treatment, beginning shortly after birth, provides better long-term immunological control of infection. Expert commentary: All HIV-infected children should be treated with antiretroviral drugs. Manufacturers should propose appropriate dosage forms, including combined forms in particular, and should support pharmacological and tolerance studies in pediatric patients of various ages. Very early treatment maximizes the chances of long-term immunological control.

Viral Evolution and Cytotoxic T Cell Restricted Selection in Acute Infant HIV-1 Infection

Antiretroviral therapy-naive HIV-1 infected infants experience poor viral containment and rapid disease progression compared to adults. Viral factors (e.g. transmitted cytotoxic T- lymphocyte (CTL) escape mutations) or infant factors (e.g. reduced CTL functional capacity) may explain this observation. We assessed CTL functionality by analysing selection in CTL-targeted HIV-1 epitopes following perinatal infection. HIV-1 gag, pol and nef sequences were generated from a historical repository of longitudinal specimens from 19 vertically infected infants. Evolutionary rate and selection were estimated for each gene and in CTL-restricted and non-restricted epitopes. Evolutionary rate was higher in nef and gag vs. pol, and lower in infants with non-severe immunosuppression vs. severe immunosuppression across gag and nef. Selection pressure was stronger in infants with non-severe immunosuppression vs. severe immunosuppression across gag. The analysis also showed that infants with non-severe immunosuppression had stronger selection in CTL-restricted vs. non-restricted epitopes in gag and nef. Evidence of stronger CTL selection was absent in infants with severe immunosuppression. These data indicate that infant CTLs can exert selection pressure on gag and nef epitopes in early infection and that stronger selection across CTL epitopes is associated with favourable clinical outcomes. These results have implications for the development of paediatric HIV-1 vaccines.

IL-8 Alterations in HIV-1 Infected Children With Disease Progression

Disease progression in HIV-1 infected children is faster than in adults. Less than 5% of the infected children maintain stable CD4 counts beyond 7 years of infection and are termed long-term nonprogressors (LTNPs). Delineating the host immune response in antiretroviral naïve (ART) and treated HIV-1 infected children at different disease stages will help in understanding the immunopathogenesis of the disease.A total of 79 asymptomatic, perinatally HIV-1 infected children (50 ART naïve and 29 ART treated) and 8 seronegative donors were recruited in this study. T- and B-cell activation PCR arrays were performed from the cDNA, using total RNA extracted from the peripheral blood mononuclear cells (PBMCs) of 14 HIV-1 infected children at different stages of the disease. The differentially expressed genes were identified. Quantitative RT-PCR was performed for the (interleukin-8) IL-8 gene and its transcriptional mediators, that is, SHP2, GRB2, and IL-8R (IL-8 receptor/CXCR1). Plasma levels of IL-8 were measured by flow cytometry.Gene array data revealed a higher expression of IL-8 in the ART naïve HIV-1 infected progressors and in ART nonresponders than LTNPs and ART responders, respectively. Quantitative RT-PCR analysis demonstrated a significant higher expression of IL-8 (P < 0.001), its receptor CXCR1 (P = 0.03) and the upstream signaling molecule SHP2 (P = 0.04) in the progressors versus LTNPs. Plasma levels of IL-8 were significantly higher in progressors versus LTNPs (P < 0.001), and ART nonresponders versus ART responders (P < 0.001). A significant negative correlation of plasma levels of IL-8 with CD4 counts (cells/μL) was observed in HIV-1 infected ART naïve subjects (r = -0.488; P < 0.001), while the IL-8 levels positively correlated with viral load in the ART treated children (r = 0.5494; P < 0.001). ART naïve progressors on follow up demonstrated a significant reduction in the mRNA expression (P = 0.05) and plasma levels of IL-8 (P = 0.05) post 6 months of ART initiation suggesting the beneficial role of ART therapy in reducing inflammation in infected children.Our data suggest that IL-8 may serve as a potential prognostic marker in adjunct with CD4 counts to monitor disease progression in the HIV-1 infected children and the efficacy of ART.

Interruption of cART in clinical practice is associated with an increase in the long-term risk of subsequent immunosuppression in HIV-1-infected children

BACKGROUND

Antiretroviral treatment interruption (TI) is not recommended in HIV-infected children. We aimed to evaluate the context and consequences of TI in clinical practice.

METHODS

We investigated the probability and risk factors of a first TI in the 483 children treated with combined ART (cART) in the ANRS French national pediatric cohort. Immunologic and virologic outcomes were compared between patients with TI (TI group) and those on continuous treatment (matched control group), from a baseline defined as the age at first interruption for the TI child and the corresponding age for the control child.

RESULTS

At least one TI ≥ 3 months occurred in 42.4% of patients, at a median age of 8.0 years, for a median duration of 12.1 months. After cART initiation, the risk of TI was 7.0% (5.0-9.6) at 1 year and 30.3% (26.1-35.0) at 5 years and was higher for children starting treatment before 2000 and for children starting cART before 6 months of age. AIDS-free survival was similar, but severe immunosuppression occurred earlier in the TI group than in the control group (adjusted HR = 3.1; 1.0-9.1; P = 0.04). Four years after baseline, the proportion of patients with CD4% ≥ 25% was lower in the TI group than in the control group (52.0% vs. 72.0%; P < 0.01), even among children restarting cART at least 6 months earlier (aRR = 0.5; 0.3-0.9; P = 0.03).

CONCLUSIONS

The risk of TI in clinical practice has decreased but remains high. In intent-to-treat analysis, TI was associated with a greater risk of subsequent immunosuppression, even after cART resumption.

[Pediatric HIV infections in developed countries: current situation and future challenges]

In 2013, approximately 1500 HIV-infected children are followed in France. Antiretroviral therapy (ART) has greatly improved the survival of these children, whose long-term clinical outcomes are encouraging in high-resources countries. However, paediatricians continue to face difficulties for these children: missed opportunities for early HIV testing (especially in immigrant children born in Sub-Saharan African countries), high rates of virological failure in ART-experienced children, lack of studies evaluating the long-term toxicity of ART in perinatally-HIV-infected patients. Future challenges will imply to study to what extent very early ART in infants may alter the establishment of HIV infection and improve the long-term immunological and virological outcome of these children.

Terapia antirretroviral em crianças e adolescentes infectados pelo HIV: o que sabemos após 30 anos de epidemia

Este estudo tem como objetivo avaliar o uso da terapia antirretroviral combinada em crianças e adolescentes com AIDS. Foram captados 247 resumos nos portais PubMed e LILACS, publicados entre 1983 e 2013, sendo utilizados 69 artigos para as referências bibliográficas. A atenção atribuída às pesquisas na faixa etária pediátrica durante os trinta anos de epidemia de AIDS se justifica por características imunológicas próprias, sendo a progressão da AIDS mais rápida em crianças que em adultos. Pesquisas recentes abordam estratégias de intervenção medicamentosa de alta potência antes do aparecimento dos sintomas iniciais. A introdução precoce da terapia antirretroviral combinada foi implantada com eficácia e segurança em populações com poucos recursos fixos, com melhora significativa da sobrevida desses pacientes. O desafio atual é lidar com uma doença crônica com intercorrências agudas. Novas pesquisas serão necessárias, atentando para as especificidades populacionais e particularizando as necessidades individuais dos pacientes pediátricos.

[Pediatric aids, 30 years later]

Thirty years after the first descriptions of AIDS in children in May 1983, the risk of viral transmission from mother to child has been reduced to almost zero and the disease in infected children has become an asymptomatic condition, stable in the long-term, thanks to antiretroviral drugs. Unbelievable though it may have seemed until the mid-1990s, children infected during the perinatal period are now growing up to be adults in a chronic, stable, asymptomatic medical condition with often satisfactory personal, family, and social lives. The French perinatal epidemiological cohort, which was set up in 1984 and has included more than 18,000 mother-child pairs to date, traces the steps in this extraordinary revolution in the prevention and treatment of HIV-1 infection in children.

The impact of differential antiviral immunity in children and adults

The course of immune maturation has evolved to favour survival at each stage of development in early life. Fetal and neonatal immune adaptations facilitate intrauterine survival and provide early postnatal protection against extracellular pathogens, but they leave infants susceptible to intracellular pathogens such as viruses that are acquired perinatally. This Review focuses on three such pathogens--HIV, hepatitis B virus and cytomegalovirus--and relates the differential impact of these infections in infants and adults to the antiviral immunity that is generated at different ages. A better understanding of age-specific antiviral immunity may inform the development of integrated prevention, treatment and vaccine strategies to minimize the global disease burden resulting from these infections.

CD4+ lymphocyte-based immunologic outcomes of perinatally HIV-infected children during antiretroviral therapy interruption

OBJECTIVE

To assess the characteristics and outcomes of antiretroviral treatment (ART) interruption (TI) in perinatally HIV-infected children.

DESIGN

The Adolescent Master Protocol (AMP) of the Pediatric HIV/AIDS Cohort Study is a prospective cohort study that enrolled 7- to 16-year-old perinatally HIV-infected children between 2007 and 2009 from 15 sites in the United States and Puerto Rico.

METHODS

TI was defined as ART discontinuation for ≥ 3 months after ≥ 6 months of continuous ART. Subjects with and without TI were compared. Rates of change (slopes) in CD4 T-lymphocyte (CD4) count and percentage (%) per month during TI were calculated. Factors related to CD4 slope in univariable analyses were included in multivariable linear regression.

RESULTS

Of 444 eligible AMP subjects, 101 (23%) had at least one TI. Subjects with TI were born in earlier years but were otherwise similar to those without TI. For 81 TI subjects with complete data, the median (range) CD4% and CD4 count slopes were -0.66% per month (-3.54% to +1.34% per month) and -12.7 cells per cubic millimeter per month (-148 cells/mm to +31 cells/mm per month), respectively. On multivariable linear regression, there was a trend for lower CD4% slope to be associated (P < 0.1) with female sex, higher CD4% at TI, and higher peak viral load before TI. Advanced HIV disease stage and numerous ART regimens were more common in TI subjects in the lowest (fastest declining) CD4% slope quartile.

CONCLUSIONS

TIs in perinatally HIV-infected youth are common. During TIs, CD4 values decline on average but with high intersubject variability. Factors predicting CD4 slope during TI need further study.

Gag-specific CD4+ T-cell responses are associated with virological control of paediatric HIV-1 infection

HIV-specific Elispot responses were investigated in 57 antiretroviral therapy-naive children, of median age 9.9 years. CD8(+) T-cell responses were detected in 96% children; Nef was the immunodominant protein. Responses broadened over time, but there was no association between magnitude, breadth or specificity of response and viraemia. Gag-specific CD4(+) T-cell responses, detectable in 26% children, correlated inversely with viraemia (R = -0.43, P < 0.001), suggesting that preservation of this cell population may be an important goal of therapeutic/vaccine strategies.

Viral genetic determinants of nonprogressive HIV type 1 subtype C infection in antiretroviral drug-naive children

Characterization of HIV-1 from slow progressors is important to facilitate vaccine and antiviral drug development. To identify virus attenuations that may contribute to slower rates of disease progression, the full-length viral genomes from primary isolates of six slow progressing HIV-positive children were sequenced. Proviral DNA was extracted from cocultured peripheral blood mononuclear cells and used to PCR amplify, sequence, and extensively analyze the near full-length genomes and LTR regions. All primary HIV-1 isolates were HIV-1 subtype C throughout their genome, and amino acid (AA) sequence analysis revealed open reading frames for all genes. However, all isolates had at least one unusual gene/protein. For example, isolate LT5 had a 2AA insertion in the Vpr mitochondriotoxic domain. Isolate LT21 contained an additional 5AA in the C-terminus of tat exon 2, while integrase in isolate LT39 had an additional 4AA at the C-terminus. Rev from isolates LT45 and LT46 did not have the characteristic subtype C 16AA truncation, and in addition, had a further 3AA. Furthermore, altered functional domains were noted in several isolates, such as the cAMP-dependent kinase PKA phosphorylation site in Nef (LT5), a Vpr mutation involved in decreased proapoptotic activity (all isolates), and the Nef ExxxLL motif involved in the interaction with AP-1 and AP-2 (LT46). The slower HIV-1 disease progression in these six children may be attributed to altered protein functions. For example, LT46 Nef is unable to bind AP-1 and AP-2 and therefore is inactive on CD4 endocytosis. The biological relevance of these findings requires further investigation.

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.