HIV-1 DNA decay is faster in children who initiate ART shortly after birth than later

Analytical treatment interruption in children living with HIV: position statement from the EPIICAL consortium

Analytical treatment interruption (ATI) is widely acknowledged as an essential component of studies to advance our understanding of HIV cure, but discussion has largely been focused on adults. To address this gap, we reviewed evidence related to the safety and utility of ATI in paediatric populations. Three randomised ATI trials using CD4 T-cell and clinical criteria to guide restart of antiretroviral therapy (ART) have been conducted. These trials found low risks associated with ATI in children, including reassuring findings pertaining to neurocognitive outcomes. Similar to adults treated during acute infection, infants treated early in life have shifts in virological and immunological parameters that increase their likelihood of achieving ART-free viral control. Early ART limits the size and diversity of the viral reservoir and shapes effective innate and HIV-specific humoral and cellular responses. Several cases of durable ART-free viral control in early treated children have been reported. We recommend that, where appropriate for the study question and where adequate monitoring is available, ATI should be integrated into ART-free viral control research in children living with HIV. Paediatric participants have the greatest likelihood of benefiting and potentially the most years to prospectively realise those benefits. Excluding children from ATI trials limits the evidence base and delays access to interventions.

Characterization of HIV-1 Reservoirs in Children and Adolescents: A Systematic Review and Meta-Analysis Toward Pediatric HIV Cure

OBJECTIVE

To conduct a comprehensive, systematic review of the profile of HIV-1 reservoirs in children and adolescents with perinatally acquired HIV infection.

STUDY DESIGN

Randomized and nonrandomized trials, cohort studies, and cross-sectional studies on HIV reservoirs in pediatric populations, published between 2002 and 2022, were included. Archived-drug resistance mutations (ADRMs) and the size of reservoirs were evaluated. Subgroup analyses were performed to characterize further the data, and the meta-analysis was done through random effect models.

RESULTS

Overall, 49 studies from 17 countries worldwide were included, encompassing 2356 perinatally infected participants (48.83% females). There are limited data on the quantitative characterization of viral reservoirs in sub-Saharan Africa, with sensitive methodologies such as droplet digital polymerase chain reaction rarely employed. The overall prevalence of ADRMs was 37.80% (95% CI 13.89-65.17), with 48.79% (95% CI 0-100) in Africa, 42.08% (95% CI 6.68-82.71) in America, 23.88% (95% CI 14.34-34.90) in Asia, and 20.00% (95% CI 10.72-31.17) in Europe, without any difference between infants and adolescents (P = .656). Starting antiretroviral therapy (ART) before 2 months of age limited the levels of HIV-1 DNA (P = .054). Participants with long-suppressed viremia (>5 years) had lower levels of HIV-1 DNA (P = .027). Pre- and post-ART CD4 ≤29% and pre-ART viremia ≥5Log were all found associated with greater levels of HIV-1 DNA (P = .038, P = .047, and P = .041, respectively).

CONCLUSIONS

The pooled prevalence of ADRMs is high in perinatally infected pediatric population, with larger proviral reservoir size driven by delayed ART initiation, a shorter period of viral suppression, and immunovirological failures. Thus, strategies for pediatric HIV functional cure should target children and adolescents with very early ART initiation, immunocompetence, and long-term viral suppression.

Evaluation of HIV-1 DNA levels among adolescents living with perinatally acquired HIV-1 in Yaounde, Cameroon: A contribution to paediatric HIV cure research in Sub-Saharan Africa

Background

With the advent of antiretroviral therapy (ART), most children living with HIV in sub-Saharan Africa (SSA) are growing toward adolescence, with scarcity of evidence on the size of viral reservoirs to enhance paediatric cure research strategies. This study aims to compare HIV-1 proviral DNA levels according to virological response among adolescents living with perinatally acquired HIV-1 (ALPHIV) and identify associated-factors in the Cameroonian context.

Methods

In this observational cohort study, HIV-1 RNA viremia and CD4+ T-cell count were assessed through RT-PCR and flow cytometry respectively at three time-points over 18 months of observation. At the third time-point, 80 randomly-selected participants were classified as with viremia (≥50 HIV-1 copies/mL; n = 40) or without viremia (<50 HIV-1 copies/mL; n = 40); immune-competent (≥500 CD4+ T cells/mm3) or immunocompromised (<500 CD4+ T cells/mm3). Among these participants, total HIV-1 DNA load was quantified through droplet digital PCR using Bio-Rad QX200.

Results

Of the 80 randomly-selected adolescents, median [IQR] age was 15 (13-17) years, 56.2% were female, duration on ART was 9.3 [5.4-12.2] years. Among the 40 viremic ones (median viremia 7312 [283-71482]) HIV-1 copies/ml, 75.0% (30/40) were in virological failure (≥1000 HIV-1 copies/ml), while median of CD4 T cells were 494 [360-793] cell/mm3 with 48.8% (39/80) immunocompromised. No significant variation in HIV-1 RNA viremia and CD4 T cell count was observed between the three time-points, and 13.7% (11/80) adolescents remained aviremic and immune-competent throughout (stable adolescents). A positive and moderate correlation (r = 0.59; p < 0.001) was found between HIV-1 DNA levels and HIV- 1 RNA viremia. Regarding the CD4 T cell count, a negative and weak correlation (r = -0.28; p = 0.014) was found with HIV-1 DNA loads only among adolescents with viremia. Starting ART within the first year of life, ART for over 9 years and aviremia appear as predictors of low HIV-1 DNA loads.

Conclusion

Among ALPHIV, high HIV-1 RNA indicates an elevated viral reservoir size, representing a drawback to cure research. Interestingly, early ART initiation and longer ARTduration lead to sustained viral control and limited HIV-1 reservoir size. As limited size of viral reservoir appears consistent with viral control and immune competence, adolescents with sustained viral control (about 14% of this target population) would be candidates for analytical ART interruptions toward establishing paediatric post-treatment controllers in SSA.

Follow-up for 3 years of a pediatric population diagnosed in 2018 with mother-to-child transmission of HIV in 8 Latin American countries in the PLANTAIDS cohort

INTRODUCTION

The frequency of mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) in Latin America has decreased considerably. However, new infections continue to be recorded, and the pediatric population remains one of the most vulnerable groups in this region. The main objective of the study was to describe the clinical, epidemiological and psychosocial characteristics of new diagnoses of HIV MTCT in 2018 in the PLANTAIDS network (Paediatric Network for Prevention, Early Detection and Treatment of HIV in Children) during the 3 years following diagnosis.

METHODOLOGY

Retrospective, multicenter, descriptive study based on a 3-year follow-up of patients diagnosed with HIV infection due to MTCT in 2018 in 10 hospitals in 8 Latin American countries (Costa Rica, Ecuador, Mexico, Honduras, El Salvador, Panama, Guatemala and Venezuela). The hospitals belonged to the PLANTAIDS network, which is included in CYTED (Ibero-American Programme of Science and Technology for Development).

RESULTS

The study population comprised 72 pediatric patients (38.9% male). The median age at diagnosis was 2.4 years (IQR: 0.8-5.4). There were 35 cases of opportunistic infections corresponding to 25 patients (34.7%), with tuberculosis being the most common. Adequate childhood vaccination coverage was achieved in 80.5%. There were 3 cases of acute SARS-CoV-2 infection, and these were asymptomatic or mildly symptomatic. According to the Centers for Disease Control and Prevention (CDC) classification, the most frequent clinical-immunological stage at all check-ups was C1. Three patients died from opportunistic infections and/or advanced HIV infection.

CONCLUSIONS

It is important to diagnose HIV infection early in pediatrics, since early initiation of ART is associated with a decrease in mortality. Despite this, HIV infection has a poor prognosis in children, necessitating adequate follow-up to ensure adherence to health care and ART, although it can sometimes prove difficult in children.

The clinical effect of point-of-care HIV diagnosis in infants: a systematic review and meta-analysis

BACKGROUND

Timely diagnosis and treatment of HIV is crucial in HIV-exposed infants to prevent the high rates of mortality seen during the first 2 years of life if HIV is untreated. However, challenges with sample transportation, testing, and result delivery to caregivers have led to long delays in treatment initiation. We aimed to compare the clinical effect of point-of-care HIV testing versus laboratory-based testing (standard of care) in HIV-exposed infants.

METHODS

We did a systematic review and meta-analysis and searched PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Embase, Conference Proceedings Citation Index-Science, and WHO Global Index Medicus, from Jan 1, 2014, to Aug 31, 2020. Studies were included if they pertained to the use of point-of-care nucleic acid testing for infant HIV diagnosis, had a laboratory-based nucleic acid test as the comparator or standard of care against the index test (same-day point-of-care testing), evaluated clinical outcomes when point-of-care testing was used, and included HIV-exposed infants aged younger than 2 years. Studies were excluded if they did not use a laboratory-based comparator, a nucleic acid test that had been approved by a stringent regulatory authority, or diagnostic-accuracy or performance evaluations (eg, no clinical outcomes included). Reviews, non-research letters, commentaries, and editorials were also excluded. The risk of bias was evaluated using the ROBINS-I framework. Data were extracted from published reports. Data from all studies were analysed using frequency statistics to describe the overall populations evaluated and their results. Key outcomes were time to result delivery and antiretroviral therapy initiation, and proportion of HIV-positive infants initiated on antiretroviral therapy within 60 days after sample collection.

FINDINGS

164 studies were identified by the search and seven were included in the analysis, comprising 37 377 infants in total across 15 countries, including 25 170 (67%) who had point-of-care HIV testing and 12 207 (33%) who had standard-of-care testing. The certainty of evidence was high. Same-day point-of-care testing led to a significantly shorter time between sample collection and result delivery to caregivers compared with standard-of-care testing (median 0 days [95% CI 0-0] vs 35 days [35-37]). Time from sample collection to antiretroviral therapy initiation in infants found to be HIV-positive was significantly lower with point-of-care testing compared with standard of care (median 0 days [95% CI 0-1] vs 40 days [36-44]). When each study's result was weighted equally, 90·3% (95% CI 76·7-96·5) of HIV-positive infants diagnosed using point-of-care testing had started antiretroviral therapy within 60 days of sample collection, compared with only 51·6% (27·1-75·7) who had standard-of-care testing (odds ratio 8·74 [95% CI 6·6-11·6]; p<0·0001).

INTERPRETATION

Overall, the certainty of the evidence in this analysis was rated as high for the primary outcomes related to result delivery and treatment initiation, with no serious risk of bias, inconsistency, indirectness, or imprecision. In HIV-exposed infants, same-day point-of-care HIV testing was associated with significantly improved time to result delivery, time to antiretroviral therapy initiation, and proportion of HIV-positive infants starting antiretroviral therapy within 60 days compared with standard of care.

FUNDING

The Bill & Melinda Gates Foundation.

Delays in HIV-1 infant polymerase chain reaction testing may leave children without confirmed diagnoses in the Western Cape province, South Africa

Background

Early diagnosis and confirmation of HIV infection in newborns is crucial for expedited initiation of antiretroviral therapy. Confirmatory testing must be done for all children with a reactive HIV PCR result. There is no comprehensive data on confirmatory testing and HIV PCR test request rejections at National Health Laboratory Service laboratories in South Africa.

Objective

This study assessed the metrics of routine infant HIV PCR testing at the Tygerberg Hospital Virology Laboratory, Cape Town, Western Cape, South Africa, including the proportion of rejected test requests, turn-around time (TAT), and rate of confirmatory testing.

Methods

We retrospectively reviewed laboratory-based data on all HIV PCR tests performed on children ≤ 24 months old (n = 43 346) and data on rejected HIV PCR requests (n = 1479) at the Tygerberg virology laboratory over two years (2017–2019). Data from sample collection to release of results were analysed to assess the TAT and follow-up patterns.

Results

The proportion of rejected HIV PCR requests was 3.3%; 83.9% of these were rejected for various pre-analytical reasons. Most of the test results (89.2%) met the required 96-h TAT. Of the reactive initial test results, 53.5% had a follow-up sample tested, of which 93.1% were positive. Of the initial indeterminate results, 74.7% were negative on follow-up testing.

Conclusion

A high proportion of HIV PCR requests were rejected for pre-analytical reasons. The high number of initial reactive tests without evidence of follow-up suggests that a shorter TAT is required to allow confirmatory testing before children are discharged.

Understanding Viral and Immune Interplay During Vertical Transmission of HIV: Implications for Cure

Despite the significant progress that has been made to eliminate vertical HIV infection, more than 150,000 children were infected with HIV in 2019, emphasizing the continued need for sustainable HIV treatment strategies and ideally a cure for children. Mother-to-child-transmission (MTCT) remains the most important route of pediatric HIV acquisition and, in absence of prevention measures, transmission rates range from 15% to 45% via three distinct routes: in utero, intrapartum, and in the postnatal period through breastfeeding. The exact mechanisms and biological basis of these different routes of transmission are not yet fully understood. Some infants escape infection despite significant virus exposure, while others do not, suggesting possible maternal or fetal immune protective factors including the presence of HIV-specific antibodies. Here we summarize the unique aspects of HIV MTCT including the immunopathogenesis of the different routes of transmission, and how transmission in the antenatal or postnatal periods may affect early life immune responses and HIV persistence. A more refined understanding of the complex interaction between viral, maternal, and fetal/infant factors may enhance the pursuit of strategies to achieve an HIV cure for pediatric populations.

Early ART-initiation and longer ART duration reduces HIV-1 proviral DNA levels in children from the CHER trial

Background

Reduction of the reservoir of latent HIV-infected cells might increase the possibility of long-term remission in individuals living with HIV. We investigated factors associated with HIV-1 proviral DNA levels in children receiving different antiretroviral therapy (ART) strategies in the children with HIV early antiretroviral therapy (CHER) trial.

Methods

Infants with HIV  <  12 weeks old with CD4%  ≥  25% were randomized in the CHER trial to early limited ART for 40 or 96 weeks (ART-40 W, ART-96 W), or deferred ART (ART-Def). For ART-Def infants or following ART interruption in ART-40 W/ART-96 W, ART was started/re-started for clinical progression or CD4%  <  25%. In 229 participants, HIV-1 proviral DNA was quantified by PCR from stored peripheral blood mononuclear cells from children who had received  ≥  24 weeks ART and two consecutive undetectable HIV-1 RNA 12–24 weeks apart. HIV-1 proviral DNA was compared between ART-Def and ART-96 W at week 96, and in all arms at week 248. Factors associated with HIV-1 proviral DNA levels were evaluated using linear regression.

Findings

Longer duration of ART was significantly associated with lower HIV-1 proviral DNA at both 96 (p  =  0.0003) and 248 weeks (p  =  0.0011). Higher total CD8 count at ART initiation was associated with lower HIV-1 proviral DNA at both 96 (p  =  0.0225) and 248 weeks (p  =  0.0398). Week 248 HIV-1 proviral DNA was significantly higher in those with positive HIV-1 serology at week 84 than those with negative serology (p  =  0.0042).

Intepretation

Longer ART duration is key to HIV-1 proviral DNA reduction. Further understanding is needed of the effects of “immune-attenuation” through early HIV-1 exposure.

Funding

Wellcome Trust, National Institutes of Health, Medical Research Council.

Continuous Prophylactic Antiretrovirals/Antiretroviral Therapy Since Birth Reduces Seeding and Persistence of the Viral Reservoir in Children Vertically Infected With Human Immunodeficiency Virus

BACKGROUND

Early antiretroviral therapy (ART) restricts the size of the human immunodeficiency virus (HIV) reservoir in infants. However, whether antiretroviral (ARV) prophylaxis given to exposed vertically infected children exerts similar effects remains unknown.

METHODS

We measured total and integrated HIV DNA, as well as the frequency of CD4 T cells producing multiply spliced RNA (msRNA) after stimulation (inducible reservoir) in vertically infected Thai infants. Eighty-five infants were followed longitudinally for up to 3 years. We compared the size of the reservoir in children who received continuous ARV prophylaxis since birth vs those who never received or discontinued prophylaxis before initiating ART. We used samples from a cross-sectional cohort of 37 Thai children who had initiated ART within 6 months of life to validate our findings.

RESULTS

Before ART, levels of HIV DNA and the frequencies of cells producing msRNA were significantly lower in infants who received continuous ARV prophylaxis since birth compared to those in whom ARV prophylaxis was discontinued or never initiated (P < .020 and P < .001, respectively). Upon ART initiation, total and integrated HIV DNA levels decayed significantly in both groups (P < .01 in all cases). Interestingly, the initial differences in the frequencies of infected cells persisted during 3 years on ART. The beneficial effect of prophylaxis on the size of the HIV reservoir was confirmed in the cross-sectional study. Importantly, no differences were observed between children who discontinued prophylactic ARVs before starting ART and those who delayed ART initiation without receiving prior prophylaxis.

CONCLUSIONS

Neonatal ARV prophylaxis with direct transition to ART durably limits the size of the HIV reservoir.

Viral suppression is associated with HIV-antibody level and HIV-1 DNA detectability in early treated children at 2 years of age

OBJECTIVES

Early infant HIV diagnosis and antiretroviral therapy (ART) initiation are now implemented shortly after birth. Maintaining and monitoring ART adherence is difficult and requires frequent visits. We, therefore, investigated whether HIV antibodies and HIV-1 DNA levels are markers of cumulative viremia.

DESIGN

We conducted a cross sectional investigation at 2 years of age of HIV antibodies and HIV-1 DNA levels in a well characterized cohort of 31 children who started ART shortly after birth.

METHODS

HIV antibodies were measured by a combination of the Abbott ARCHITECT HIV Ag/Ab Combo and Geenius HIV 1/2 supplemental assays; and total HIV-1 DNA quantified using a sensitive quantitative PCR (qPCR) assay targeting the HIV-1 integrase gene.

RESULTS

Infant post-exposure prophylaxis consisted of zidovudine (AZT) and nevirapine (NPV) (or NVP only, in one child) within 1 day of birth, transitioning, after positive diagnosis, to three-drug ART, at a median [interquartile range (IQR)] of 7 (4-9.5) days. Twelve of 31 children had well suppressed HIV plasma viral loads (HIVVL) and the remainder periods of viremia (HIVVL > 100 copies/ml after 3 months of ART), classified as non-suppressed. At 24 months of age: 11 of 12 (92%) of well suppressed children had undetectable HIV-1 antibodies versus 3 of 19 (16%) non-suppressed children (P < 0.001) and 7 of 12 (58%) well suppressed children had undetectable HIV-1 DNA versus 3 of 19 (16%) non-suppressed children (P = 0.02).

CONCLUSION

Considering low assay costs and the high proportion of well suppressed children with undetected antibody levels at 2 years, HIV antibody levels may be a valuable marker of cumulative adherence in children who start treatment shortly after birth and could prompt adherence and viral load investigation.

Predictors of cell-associated HIV-1 DNA over one year in very early treated infants

BACKGROUND

Younger age of antiretroviral therapy (ART) initiation is associated with a smaller viral reservoir size in perinatally-acquired HIV-1 infection, but there is wide variability among early-treated infants. Predictors of this variability are not fully described.

METHODS

Sixty-three neonates diagnosed with HIV-1 <48 hours after birth in Johannesburg, South Africa were started on ART as soon as possible. Fifty-nine (94%) infants received daily nevirapine prophylaxis from birth until ART start. Viably-preserved peripheral blood mononuclear cells (PBMC) collected at regular intervals to 48 weeks, and from respective mothers at enrolment, were tested using integrase-targeted, semi-nested, real-time quantitative hydrolysis probe (TaqMan) PCR assays to quantify total HIV-1 subtype C viral DNA (vDNA). Predictors were investigated using Generalized Estimating Equation (GEE) regression models.

RESULTS

Thirty-one (49.2%) infants initiated ART <48 hours, 24 (38.1%) <14 days and 8 (12.7%) >14 days of birth. Three-quarters were infected despite maternal antenatal ART (however, only 9.5% of women had undetectable viral load closest to delivery) and 86% were breastfed. Higher infant CD4+ T-cell percentage and viral load <100,000 copies/ml pre-ART were associated with lower levels of vDNA copies/10 6 PBMC equivalents in the first 48 weeks after ART start. No antenatal maternal ART and breastfeeding were also associated with lower vDNA. Older age at ART initiation had a discernible negative impact when initiated >14 days.

CONCLUSIONS

Among very early treated infants, higher CD4+ T-cell percentage and viral load <100,000 copies/ml pre-ART, infection occurring in the absence of maternal antenatal ART and breastfeeding were associated with lower levels of HIV-1 DNA in the first 48 weeks of treatment.

HIV-1 Persistence in Children during Suppressive ART

There is a growing number of perinatally HIV-1-infected children worldwide who must maintain life-long ART. In early life, HIV-1 infection is established in an immunologically inexperienced environment in which maternal ART and immune dynamics during pregnancy play a role in reservoir establishment. Children that initiated early antiretroviral therapy (ART) and maintained long-term suppression of viremia have smaller and less diverse HIV reservoirs than adults, although their proviral landscape during ART is reported to be similar to that of adults. The ability of these early infected cells to persist long-term through clonal expansion poses a major barrier to finding a cure. Furthermore, the effects of life-long HIV persistence and ART are yet to be understood, but growing evidence suggests that these individuals are at an increased risk for developing non-AIDS-related comorbidities, which underscores the need for an HIV cure.

Clinical validation of a quantitative HIV-1 DNA droplet digital PCR assay: Applications for detecting occult HIV-1 infection and monitoring cell-associated HIV-1 dynamics across different subtypes in HIV-1 prevention and cure trials

BACKGROUND

In HIV-1-exposed infants, nucleic acid testing (NAT) is required to diagnose infection since passively transferred maternal antibodies preclude antibody testing. The sensitivity of clinical NAT assays is lowered with infant antiretroviral prophylaxis and, with empiric very early antiretroviral treatment of high-risk infants, thereby impacting early infant diagnosis. Similarly, adult HIV-1 infections acquired under pre-exposure prophylaxis may occur at low levels, with undetectable plasma viremia and indeterminate antibody tests, for which HIV-1 DNA testing maybe a useful adjunct. Cell-associated HIV-1 DNA concentrations are also used to monitor HIV-1 persistence in viral reservoirs with relevance to HIV-1 cure therapeutics, particularly in perinatal infections.

OBJECTIVES

We clinically validated an HIV-1 DNA quantitative assay using droplet digital PCR (ddPCR), across different HIV-1 subtypes.

STUDY DESIGN

The analytical sensitivity and specificity of an HIV-1 DNA ddPCR assay was determined using serial dilutions of a plasmid containing HIV-1 LTR-gag spiked into peripheral blood mononuclear cells (PBMCs), with MOLT-4 cells or PBMCs infected with different HIV-1 subtypes (A, B and C), and U1 cells spiked into PBMCs. Inter- and intra-run variability were used to determine assay precision.

RESULTS

The HIV-1 LTR-gag ddPCR assay was reliable and reproducible, and exhibited high analytical specificity with sensitivity to near single copy level, across multiple HIV-1 subtypes, and a limit of detection of 4.09 copies/million PBMCs.

CONCLUSIONS

This assay has applications for detecting occult HIV-1-infection in the setting of combination and long-acting regimens used for HIV-1 prevention, across different HIV-1 subtypes, in infants and adults, and in HIV-1 cure interventions.

Early initiation of antiretroviral therapy following in utero HIV infection is associated with low viral reservoirs but other factors determine subsequent plasma viral rebound

Background

Early HIV diagnosis allows combination antiretroviral therapy (cART) initiation in the first days of life following in utero (IU) infection. The impact of early cART initiation on infant viral reservoir size in the setting of high-frequency cART nonadherence is unknown.

Methods

Peripheral blood total HIV DNA from 164 early treated (day 0–21 of life) IU HIV-infected South African infants was measured using droplet digital PCR at birth and following suppressive cART. We evaluated the impact of cART initiation timing on HIV reservoir size and decay, and on the risk of subsequent plasma viremia in cART-suppressed infants.

Results

Baseline HIV DNA (median 2.8 log₁₀ copies/million peripheral blood mononuclear cells, range 0.7–4.8) did not correlate with age at cART initiation (0–21 days) but instead with maternal antenatal cART use. In 98 infants with plasma viral suppression on cART, HIV DNA half-life was 28 days. However, the probability of maintenance of plasma aviremia was low (0.46 at 12 months) and not influenced by HIV DNA load. Unexpectedly, longer time to viral suppression was associated with protection against subsequent viral rebound.

Conclusions

With effective prophylaxis against mother-to-child transmission, cART initiation timing in the first 3 weeks of life is not critical to reservoir size.

Quantifying the Dynamics of HIV Decline in Perinatally Infected Neonates on Antiretroviral Therapy

BACKGROUND

Mathematical modeling has provided important insights into HIV infection dynamics in adults undergoing antiretroviral treatment (ART). However, much less is known about the corresponding dynamics in perinatally infected neonates initiating early ART.

SETTING

From 2014 to 2017, HIV viral load (VL) was monitored in 122 perinatally infected infants identified at birth and initiating ART within a median of 2 days. Pretreatment infant and maternal covariates, including CD4 T cell counts and percentages, were also measured.

METHODS

From the initial cohort, 53 infants demonstrated consistent decline and suppressed VL below the detection threshold (20 copies mL) within 1 year. For 43 of these infants with sufficient VL data, we fit a mathematical model describing the loss of short-lived and long-lived infected cells during ART. We then estimated the lifespans of infected cells and the time to viral suppression, and tested for correlations with pretreatment covariates.

RESULTS

Most parameters governing the kinetics of VL decline were consistent with those obtained previously from adults and other infants. However, our estimates of the lifespan of short-lived infected cells were longer than published values. This difference may reflect sparse sampling during the early stages of VL decline, when the loss of short-lived cells is most apparent. In addition, infants with higher pretreatment CD4 percentage or lower pretreatment VL trended toward more rapid viral suppression.

CONCLUSIONS

HIV dynamics in perinatally infected neonates initiating early ART are broadly similar to those observed in other age groups. Accelerated viral suppression is also associated with higher CD4 percentage and lower VL.

The HIV-1 antibody response: a footprint of the viral reservoir in children vertically infected with HIV

Several assays have been developed to measure and characterise the replication-competent HIV-1 reservoir, which constitutes the barrier to cure. To date, the application of these assays to studies in children and in limited-resource settings has been minimal, primarily because of their expense, the large required blood volumes, and labour-intensive technologies. For children vertically infected with HIV-1 who initiated suppressive antiretroviral therapy (ART) regimens in infancy, HIV-1-specific antibody concentrations are associated with viral persistence and could be used to estimate the size of the residual latent reservoir on ART. This strategy could be particularly useful for screening children on suppressive ART for enrolment into therapeutic vaccine trials and other protocols aimed at achieving HIV-1 remission.

HIV-1 DNA decay is faster in children who initiate ART shortly after birth than later

INTRODUCTION

There is limited data in children on whether persistence of HIV-1 infected cells is affected by age at initiating antiretroviral therapy (ART), its duration or any subsequent ART interruption. We therefore investigated the effects of both age of ART initiation and duration of ART interruption on HIV-1 DNA decay in children.

METHODS

We investigated HIV-1 DNA decay in three groups of children on ART: Group-1 (n = 7) started uninterrupted ART within eight days of life; Group-2 (n = 8) started uninterrupted ART at a median of five months of age; and Group-3 (n = 23) started ART at a median age of 1.8 months for either 40 or 96 weeks, then interrupted ART (median of seven months), and restarted ART based on CD4 count and clinical criteria. Total HIV-1 DNA was assayed using a sensitive HIV-1 subtype C-adapted quantitative PCR for integrase. The duration of ART was square root transformed to fit the observed slowing of HIV-1 DNA decay rate. For each group, point estimates for decay rates were determined after six months of continuous suppressive ART in groups 1 and 2 or six months after restarting ART in Group-3. Groups-2 and 3 were combined using a mixed effect regression model to investigate covariates of HIV-1 DNA decay rate.

RESULTS AND DISCUSSION

At six months of continuous suppressive ART, the HIV-1 DNA t½ (95% CI) was shorter in Group-1 (n = 7): 2.7 months (2.1 to 3.8), than 9.2 months (7.4 to 12.1) in Group-2 (n = 8); and 9.6 months (7.6 to 12.6) in Group-3 (n = 23) (p < 0.01). In multivariable analyses, HIV-1 DNA before treatment (p < 0.001) and the change in HIV-1 DNA during interruption (p < 0.01) were independent predictors of slower HIV-1 DNA decay.

CONCLUSIONS

These data suggest that ART initiation within the first week of life can reduce the persistence of long-lived infected cells. Delaying ART is associated with slower decay of infected cells.