HIV diagnostic challenges in breast-fed infants of mothers on antiretroviral therapy

Growth Trajectories Over the First Year of Life Among Early-Treated Infants with Human Immunodeficiency Virus and Infants Who are Human Immunodeficiency Virus-Exposed Uninfected

OBJECTIVE

To investigate the role of early antiretroviral therapy (ART) on growth trajectories of infants with human immunodeficiency virus (IHIV) in the first year of life.

STUDY DESIGN

As part of a clinical trial of early ART in Johannesburg, South Africa (2015-2018), 116 IHIV diagnosed within 48 hours of birth were started on ART as soon as possible, and 80 uninfected infants born to mothers living with HIV (IHEU) were enrolled. Both groups were followed prospectively from birth through 48 weeks and growth parameters collected. The groups were compared and risk factors for poor growth investigated, in the full cohort and among IHIV separately.

RESULTS

IHIV had lower mean weight-for-age Z-scores (WAZ) than IHEU at 4 and 8 weeks (-1.17 [SE:0.14] vs -0.72 [0.14], P = .035 and -1.23 [0.15] vs -0.67 [0.14], P = .012). Although there was some closing of the gap over time, means remained lower in IHIV through 48 weeks. In length-for-age Z-scores (LAZ), differences widened over time and IHIV had lower Z-scores by 48 weeks (-1.41 [0.15] vs -0.80 [0.18], P = .011). Deficits in WAZ and LAZ in IHIV vs IHEU were most marked among girls. IHIV with pre-ART viral load ≥1000 copies/ml had significantly lower weight-for-length and mid-upper arm circumference Z-scores across all time points through 48 weeks.

CONCLUSIONS

IHIV on early ART had deficits in WAZ over the first 8 weeks of life and lower LAZ at 48 weeks than IHEU. Among IHIV, higher pre-ART viral load was associated with worse anthropometric indicators through 48 weeks.

Can newborn infants with positive HIV soon after birth be diagnosed with intrauterine infection?

BACKGROUND

Mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) can occur intrauterine, intrapartum, and postpartum. Currently, infants with confirmed positive results in virological tests before 48 h of age are defined as having intrauterine infection.

AIM

We herein review the literature that identifies emerging challenges in diagnosing intrauterine HIV infection to rethink the current diagnostic criteria.

FINDINGS

A number of reports have shown that some infants who were diagnosed with intrauterine HIV infection after birth became negative for HIV in the subsequent follow-ups, including negative HIV antibodies at the age of 12-18 months. Such "clearance" of HIV was attributed to various reasons: neonatal antiretroviral treatment (ART), false positivity, strong host immune response, or unknown factors in maternal breast milk.

DISCUSSIONS

Positive HIV tests in newborn infants shortly after birth do not necessarily indicate HIV infection, because maternal HIV can enter fetal circulation intrapartum due to the repetitive, strong uterine contractions. The infants are therefore exposed to, but may not yet be infected with HIV at that time. The current diagnostic criteria cannot differentiate HIV exposure from HIV infection, leading to so-called "challenges in diagnosing intrauterine HIV infection". Those infants diagnosed with intrauterine infection who cleared HIV later were less likely to have been truly infected with HIV, but more likely to have been exposed to HIV. Moreover, we suggest that the determination of HIV antibody titers in infants' serial serum samples can provide valuable information to distinguish intrapartum exposure from intrauterine infection.

What babies need: accelerating access to current and novel antiretroviral drugs in neonates through pharmacokinetic studies

Although 23 antiretroviral drugs are approved for use in adults, only six are approved by regulatory authorities for use in term neonates born to women with HIV, with even fewer options for preterm neonates. A major hurdle for approvals is the delay in the generation of pharmacokinetic and safety data for antiretrovirals in neonates. The median time between the year of approval from the US Food and Drug Administration of an antiretroviral agent for adults and the first publication date for pharmacokinetic data in neonates less than 4 weeks old is 8 years (range 2-23 years). In this Viewpoint, we address pharmacokinetic research gaps and priorities for current and novel antiretroviral use in neonates. We also consider the challenges and provide guidance on neonatal clinical pharmacology research on antiretroviral agents with the goal of stimulating research and expediting the availability of safe medications for the prevention and treatment of HIV in this vulnerable population.

Approach to the management of paediatric HIV spontaneous controllers

Paediatric HIV spontaneous controllers (HSCs) are a unique and understudied population with potential to inform alternative treatment options for patients living with HIV. As HSCs are so rare and often not recognised prior to antiretroviral treatment (ART) initiation, it can be difficult for clinicians to optimally manage this group. We describe the diagnosis, history and management of three paediatric HSCs, two girls and a boy who were followed for 2, 1.25 and 10.4 years, respectively, before starting ART. All had low but detectable viral loads throughout follow-up but mostly marginally low CD4:CD8 ratios. The reason for starting ART in all was a gradual tendency to poorer virological control. This case series should assist in recognising paediatric HSCs. Clinical dilemmas arising in the management of paediatric HSCs include arriving at a correct HIV-positive diagnosis, correct diagnosis as an HSC, as well as whether to initiate ART. Decision-making for initiation of ART in paediatric HSCs should be individualised. Factors supporting ART initiation in these patients included increased frequency of viral load blips, increasing detectable viral load, CD4 percentage and CD4:CD8 ratio. Other factors included Hepatitis C serology and highly sensitive C-reactive protein. All three patients ultimately required ART, which supports universal initiation of ART in paediatric HSCs, but further research is required.

New diagnosis of mother-to-child transmission of HIV in 8 Latin-American countries during 2018

Background

Important prevention efforts have led to a reduction in mother-to-child transmission of HIV (MTCT) globally. However, new cases of paediatric HIV infections still occur. Early diagnosis of new HIV infections is essential to start an appropriate antiretroviral treatment to avoid childhood morbidity and mortality related to infection. The aim of this study was to describe the new cases of MTCT in Latin-American referral hospitals.

Methods

A retrospective, multicentre and descriptive study of the new cases of MTCT diagnosed during 2018 in 13 referral hospitals from 8 Latin-American countries (Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama) belonging to PLANTAIDS (Paediatric Network for Prevention, Early Detection and Treatment of HIV in Children), was conducted. PLANTAIDS is included in CYTED (Ibero-American Programme of Science and Technology for Development).

Results

Eighty-one children (40.7% males) were included, median age at diagnosis of 2.33 years (IQR:0.7–4.7). Less than 3% of women knew their HIV diagnosis before pregnancy. More than 80% of them were diagnosed after delivery, 8.7% during pregnancy, and 2.9% at delivery. Only one patient underwent antiretroviral therapy (ART) prior to pregnancy. At diagnosis, 50.0% of the children presented with an advanced stage of disease (stage C following the current CDC classification for HIV infection), and 34.4% had less than 15% CD4⁺ cells/mm³. The time elapsed between delivery and the maternal diagnosis was correlated with the age of children at diagnosis, ρ = 0.760, p < 0.001. Younger age at diagnosis (p = 0.03), a smaller number of previous hospitalizations (p < 0.01), and better immunovirological status (p < 0.01) were found in children whose mothers knew their HIV status at delivery, compared to mothers who were not aware of it.

Conclusions

Although MTCT in Latin America has declined in recent years, our series shows there are still cases that indicate some failures in prevention, being a critical point to improve an earlier diagnosis of pregnant women. Half of the children were diagnosed in an advanced stage of disease and the delay in maternal diagnosis entailed a worse clinical and immunological child’ prognosis.

Association of Maternal Viral Load and CD4 Count With Perinatal HIV-1 Transmission Risk During Breastfeeding in the PROMISE Postpartum Component

BACKGROUND

Breastfeeding mothers with HIV infection not qualifying for antiretroviral therapy (ART) based on country-specific guidelines at the time of the Promoting Maternal-Infant Survival Everywhere trial and their uninfected neonates were randomized to maternal ART (mART) or infant nevirapine prophylaxis (iNVP) postpartum. HIV transmission proportions were similar (<1%) in the 2 arms. We assessed whether maternal viral load (MVL) and CD4 cell counts were associated with breastfeeding HIV transmission.

METHODS

MVL was collected at entry (7-14 days postpartum) and at weeks 6, 14, 26, and 50 postpartum. CD4 cell counts were collected at entry and weeks 14, 26, 38, and 50 postpartum. Infant HIV-1 nucleic acid test was performed at weeks 1 and 6, every 4 weeks until week 26, and then every 12 weeks. The associations of baseline and time-varying MVL and CD4 cell counts with transmission risk were assessed using time-to-event analyses by randomized treatment arm.

RESULTS

Two thousand four hundred thirty-one mother-infant pairs were enrolled in the study. Baseline MVL (P = 0.11) and CD4 cell counts (P = 0.51) were not significantly associated with infant HIV-1 infection. Time-varying MVL was significantly associated with infant HIV-1 infection {hazard ratio [95% confidence interval (CI)]: 13.96 (3.12 to 62.45)} in the mART arm but not in the iNVP arm [hazard ratio (95% CI): 1.04 (0.20 to 5.39)]. Time-varying CD4 cell counts were also significantly associated with infant HIV-1 infection [hazard ratio (95% CI): 0.18 (0.03 to 0.93)] in the mART arm but not in the iNVP arm [hazard ratio (95% CI): 0.38 (0.08 to 1.77)].

CONCLUSIONS

In women receiving mART, increased MVL and decreased CD4 cell counts during breastfeeding were associated with increased risk of infant HIV-1 infection.

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.

Performance evaluation of the Aptima HIV-1 Quant Dx assay for detection of HIV in infants in Kenya

BACKGROUND

Early infant diagnosis (EID) of HIV-1 exposed infants enables timely initiation of antiretroviral therapy (ART), thereby allowing early diagnosis and treatment to slow disease progression and reduce mortality. Turn-around time to results, partially caused by low to medium throughput technology, remains a hindrance to early treatment. A major solution to this challenge is to incorporate high throughput and accurate technologies in the testing process. The Hologic Aptima Quant Dx Assay (Aptima) is a CE marked Real-Time TMA assay running on the high throughput Panther system.

OBJECTIVES

The objective of this study was to evaluate the performance of Aptima for EID using dried blood spots.

STUDY DESIGN

This was a cross-sectional prospective study of 2,048 infants seeking HIV services from health facilities in Western Kenya, Africa. Capillary Dried Blood Spot samples DBS were collected from infants with the consent of their mothers. The qualitative performance of Aptima was compared with the Roche COBAS Ampliprep/ COBAS Taqman HIV-1 Qualitative Test v2.0 (CAP/CTM), using these DBS. Demographic information of the participants was also collected.

RESULTS

A total of 1,975 successful comparisons between the two platforms were included in the analysis. The overall agreement between the assays was 99.65 %. The sensitivity and specificity of Aptima was 95.24 % (95 % CI 88.40-98.19 %) and 99.84 % (95 % CI 99.49-99.92 %) respectively.

CONCLUSIONS

Aptima assay has performance characteristics that are comparable to those of the Roche CAP/CTM for qualitative testing on DBS taken from infants. The two assays can therefore be used interchangeably for Early Infant Diagnosis of HIV.

Evolving complexities of infant HIV diagnosis within Prevention of Mother-to-Child Transmission programs

Early diagnosis of HIV infection among infants and children is critical as prompt initiation of antiretroviral therapy prevents morbidity and death. Yet despite advances in the accuracy and availability of infant HIV diagnostic testing, there are increasing challenges with making an early definitive diagnosis. These challenges relate primarily to advances in prevention of mother-to-child transmission (PMTCT) of HIV. Although PMTCT programs have proven to be highly effective in reducing infant HIV infection, infants who are HIV-infected may achieve virological suppression and loss of detectability of HIV nucleic acid prior to diagnosis because of antiretroviral drug exposure. Hence, false-negative and indeterminate HIV polymerase chain reaction (PCR) results can occur, especially among high-risk infants given multi-drug prophylactic regimens. However, the infant HIV diagnostic landscape is also complicated by the inevitable decline in the positive predictive value of early infant diagnosis (EID) assays. As PMTCT programs successfully reduce the mother-to-child transmission rate, the proportion of false-positive EID results will increase. Consequently, false-negative and false-positive HIV PCR results are increasingly likely despite highly accurate diagnostic assays. The problem is compounded by the seemingly intractable prevalence of maternal HIV within some settings, resulting in a considerable absolute burden of HIV-infected infants despite a low mother-to-child transmission rate.