When to start, what to start and other treatment controversies in pediatric HIV infection

Optimal timing of antiretroviral treatment initiation in HIV-positive children and adolescents: a multiregional analysis from Southern Africa, West Africa and Europe

Background

There is limited knowledge about the optimal timing of antiretroviral treatment initiation in older children and adolescents.

Methods

A total of 20 576 antiretroviral treatment (ART)-naïve patients, aged 1-16 years at enrolment, from 19 cohorts in Europe, Southern Africa and West Africa, were included. We compared mortality and growth outcomes for different ART initiation criteria, aligned with previous and recent World Health Organization criteria, for 5 years of follow-up, adjusting for all measured baseline and time-dependent confounders using the g-formula.

Results

Median (1st;3rd percentile) CD4 count at baseline was 676 cells/mm 3 (394; 1037) (children aged ≥ 1 and < 5 years), 373 (172; 630) (≥ 5 and < 10 years) and 238 (88; 425) (≥ 10 and < 16 years). There was a general trend towards lower mortality and better growth with earlier treatment initiation. In children < 10 years old at enrolment, by 5 years of follow-up there was lower mortality and a higher mean height-for-age z-score with immediate ART initiation versus delaying until CD4 count < 350 cells/mm 3 (or CD4% < 15% or weight-for-age z-score < -2) with absolute differences in mortality and height-for-age z-score of 0.3% (95% confidence interval: 0.1%; 0.6%) and -0.08 (-0.09; -0.06) (≥ 1 and < 5 years), and 0.3% (0.04%; 0.5%) and -0.07 (-0.08; -0.05) (≥ 5 and < 10 years). In those aged > 10 years at enrolment we did not find any difference in mortality or growth with immediate ART initiation, with estimated differences of -0.1% (-0.2%; 0.6%) and -0.03 (-0.05; 0.00), respectively. Growth differences in children aged < 10 years persisted for treatment thresholds using higher CD4 values. Regular follow-up led to better height and mortality outcomes.

Conclusions

Immediate ART is associated with lower mortality and better growth for up to 5 years in children < 10 years old. Our results on adolescents were inconclusive.

Trends in Diagnoses Among Hospitalizations of HIV-infected Children and Adolescents in the United States: 2003-2012

OBJECTIVE

Using data from 2003-2012, we updated a previous analysis of trends in hospitalizations of HIV-infected children and adolescents in the United States.

METHODS

We used data from the Kids´ Inpatient Database of the Healthcare Cost and Utilization Project to derive nationally representative estimates of the number of hospitalizations and the rates per 1000 hospitalizations of select discharge diagnoses and procedures in 2003, 2006, 2009 and 2012 among HIV-infected and HIV-uninfected children and adolescents ≤18 years, excluding hospitalizations for conditions related to pregnancy/delivery and neonatal diagnoses. We also examined trends in the prevalence of select discharge diagnoses and procedures using multivariable logistic regression models.

RESULTS

During 2003-2012, the number of hospitalizations for HIV-infected children declined 58% versus 17% for uninfected, but the odds of having discharge codes for most of the diagnoses and procedures studied, including death during hospitalization, remained higher among HIV-infected compared with uninfected children. Among HIV-infected children, the prevalence of discharge diagnoses for pneumonia, pneumococcal disease and varicella/herpes zoster infections and odds of death during hospitalization decreased over time, while bacterial infections/sepsis and methicillin-resistant Staphylococcus aureus increased. Among HIV-uninfected children, there was no increase in diagnoses of bacterial infection/sepsis, but otherwise trends were similar.

CONCLUSIONS

The number of hospitalizations for HIV-infected children declined from 2003 to 2012. The decreased prevalence of several discharge diagnoses and lower risk of death during hospitalization likely reflect improvements in HIV therapies and increased uptake of other preventive strategies. However, the increasing prevalence of discharge diagnoses for bacterial infections/sepsis warrants further attention and monitoring.

Higher rates of triple-class virological failure in perinatally HIV-infected teenagers compared with heterosexually infected young adults in Europe

OBJECTIVES

The aim of the study was to determine the time to, and risk factors for, triple-class virological failure (TCVF) across age groups for children and adolescents with perinatally acquired HIV infection and older adolescents and adults with heterosexually acquired HIV infection.

METHODS

We analysed individual patient data from cohorts in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE). A total of 5972 participants starting antiretroviral therapy (ART) from 1998, aged < 20 years at the start of ART for those with perinatal infection and 15-29 years for those with heterosexual infection, with ART containing at least two nucleoside reverse transcriptase inhibitors (NRTIs) and a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a boosted protease inhibitor (bPI), were followed from ART initiation until the most recent viral load (VL) measurement. Virological failure of a drug was defined as VL > 500 HIV-1 RNA copies/mL despite ≥ 4 months of use. TCVF was defined as cumulative failure of two NRTIs, an NNRTI and a bPI.

RESULTS

The median number of weeks between diagnosis and the start of ART was higher in participants with perinatal HIV infection compared with participants with heterosexually acquired HIV infection overall [17 (interquartile range (IQR) 4-111) vs. 8 (IQR 2-38) weeks, respectively], and highest in perinatally infected participants aged 10-14 years [49 (IQR 9-267) weeks]. The cumulative proportion with TCVF 5 years after starting ART was 9.6% [95% confidence interval (CI) 7.0-12.3%] in participants with perinatally acquired infection and 4.7% (95% CI 3.9-5.5%) in participants with heterosexually acquired infection, and highest in perinatally infected participants aged 10-14 years when starting ART (27.7%; 95% CI 13.2-42.1%). Across all participants, significant predictors of TCVF were those with perinatal HIV aged 10-14 years, African origin, pre-ART AIDS, NNRTI-based initial regimens, higher pre-ART viral load and lower pre-ART CD4.

CONCLUSIONS

The results suggest a beneficial effect of starting ART before adolescence, and starting young people on boosted PIs, to maximize treatment response during this transitional stage of development.

Growth and Mortality Outcomes for Different Antiretroviral Therapy Initiation Criteria in Children Ages 1-5 Years: A Causal Modeling Analysis

BACKGROUND

There is limited evidence regarding the optimal timing of initiating antiretroviral therapy (ART) in children. We conducted a causal modeling analysis in children ages 1-5 years from the International Epidemiologic Databases to Evaluate AIDS West/Southern-Africa collaboration to determine growth and mortality differences related to different CD4-based treatment initiation criteria, age groups, and regions.

METHODS

ART-naïve children of ages 12-59 months at enrollment with at least one visit before ART initiation and one follow-up visit were included. We estimated 3-year growth and cumulative mortality from the start of follow-up for different CD4 criteria using g-computation.

RESULTS

About one quarter of the 5,826 included children was from West Africa (24.6%).The median (first; third quartile) CD4% at the first visit was 16% (11%; 23%), the median weight-for-age z-scores and height-for-age z-scores were -1.5 (-2.7; -0.6) and -2.5 (-3.5; -1.5), respectively. Estimated cumulative mortality was higher overall, and growth was slower, when initiating ART at lower CD4 thresholds. After 3 years of follow-up, the estimated mortality difference between starting ART routinely irrespective of CD4 count and starting ART if either CD4 count <750 cells/mm³ or CD4% <25% was 0.2% (95% CI = -0.2%; 0.3%), and the difference in the mean height-for-age z-scores of those who survived was -0.02 (95% CI = -0.04; 0.01). Younger children ages 1-2 and children in West Africa had worse outcomes.

CONCLUSIONS

Our results demonstrate that earlier treatment initiation yields overall better growth and mortality outcomes, although we could not show any differences in outcomes between immediate ART and delaying until CD4 count/% falls below 750/25%.

Differences in virologic and immunologic response to antiretroviral therapy among HIV-1-infected infants and children

BACKGROUND

Virologic and immunologic responses to antiretroviral treatment (ART) in infants may differ from older children due to immunologic, clinical, or epidemiologic characteristics.

METHODS

Longitudinal ART responses were modeled and compared in HIV-infected infants and children enrolled in cohorts in Nairobi, Kenya. Participants were enrolled soon after HIV diagnosis, started on ART, and followed for 2 years. Viral load decline was compared between infant and child cohorts using a nonlinear mixed effects model and CD4% reconstitution using a linear mixed effects model.

RESULTS

Among 121 infants, median age at ART was 3.9 months; among 124 children, median age was 4.8 years. At baseline, viral load was higher among infants than children (6.47 vs. 5.91 log10 copies/ml, P < 0.001). Infants were less likely than children to suppress viral load to less than 250 copies/ml following 6 months of ART (32% infants vs. 73% children, P < 0.0001). CD4% was higher at baseline in infants than children (19 vs. 7.3%, P < 0.001). Older children had more rapid CD4% reconstitution than infants, but failed to catch up to infant CD4%.

CONCLUSION

Despite substantially higher CD4% at ART initiation, viral suppression was significantly slower among infants than older children. New strategies are needed to optimize infant outcomes on ART.

The Need for Pediatric Formulations to Treat Children with HIV

Over 3.2 million children worldwide are infected with HIV, but only 24% of these children receive antiretroviral therapy (ART). ART adherence among children is a crucial part of managing human-immunodeficiency virus (HIV) infection and extending the life and health of infected children. Important causes of poor adherence are formulation- and regimen-specific properties, including poor palatability, large pill burden, short dosing intervals, and the complex storage and transportation of drugs. This review aims to summarize the various regimen- and formulation-based barriers to ART adherence among children to support the need for new and innovative pediatric formulations for antiretroviral therapy (ART). Detailing the arguments both for and against investing in the development of pediatric HIV medications, as well as highlighting recent advances in pediatric ART formulation research, provides a synopsis of the current data related to pediatric ART formulations and adherence.

PRINCE-1: safety and efficacy of atazanavir powder and ritonavir liquid in HIV-1-infected antiretroviral-naïve and -experienced infants and children aged ≥3 months to <6 years

Introduction

PRINCE-1 is an ongoing prospective, international, multicentre, nonrandomized, two-stage clinical trial assessing safety and efficacy of once-daily atazanavir (ATV) powder boosted with ritonavir (RTV) liquid plus optimized dual nucleoside reverse-transcriptase inhibitor (NRTI) background therapy in antiretroviral (ARV)-naïve and -experienced children with HIV-1 infection aged ≥3 months to <6 years.

Methods

Children with HIV-1 infection without prior ATV exposure and with a screening HIV-1 RNA ≥1000 copies/mL were enrolled. The dosing of ATV powder, boosted with 80 mg RTV liquid, was based on three baseline weight bands (5 to <10 kg=150 mg, 10 to <15 kg=200 mg and 15 to <25 kg=250 mg).

Results

Of the 56 treated patients, 46 completed 48 weeks of therapy, 67.9% were from Africa and 60.7% were ART-naïve. Median ages at baseline were 6, 35 and 55 months, and proportions with HIV-1 RNA >100,000 were 85.7, 52.6 and 25% in the three baseline weight bands, respectively. No unexpected safety events occurred and no deaths were reported. Over 48 weeks, upper respiratory tract infections, diarrhoea, vomiting and Grade 3 to 4 hyperbilirubinaemia occurred in 35.7, 35.7, 28.6, and 9.4% of patients, respectively; five patients (8.9%) discontinued due to adverse events (AEs); and 11 patients (19.6%) experienced serious adverse events. At Week 48, using a modified intent-to-treat analysis (two patients were excluded because they switched to ATV capsules before Week 48), 61.1 and 74.1% of patients overall had an HIV-1 RNA level <50 copies/mL and <400 copies/mL, respectively. Virologic suppression rates increased across the lowest to highest baseline weight bands (47.6, 68.4 and 71.4% had HIV-1 RNA <50 copies/mL, and 66.7, 73.7 and 85.7% had HIV-RNA <400 copies/mL, respectively) but did not differ meaningfully between ARV-naïve and -experienced patients. Overall, the median change from baseline in CD4 cell count was +363 cells/mm³, and the median change from baseline in CD4 percent was +7.5%.

Conclusions

ATV powder boosted with RTV liquid once daily plus optimized dual NRTI background therapy was effective and well tolerated in this ART-naïve or -experienced paediatric population aged ≥3 months to <6 years. No unexpected safety findings compared with those from previous ATV paediatric and adult studies were identified.

The effect of tuberculosis treatment on virologic and immunologic response to combination antiretroviral therapy among South African children

BACKGROUND

Many HIV-infected children are diagnosed with tuberculosis (TB), but the effect of TB treatment on virologic and immunologic response to combination antiretroviral therapy (cART) is not well documented.

METHODS

Secondary analysis of a prospective cohort of cART-naive HIV-infected South African children aged 0-8 years initiating cART to assess the effect of TB treatment at the time of cART initiation on virologic suppression (HIV RNA < 50 copies/mL), virologic rebound (HIV RNA > 1000 copies/mL after suppression), and CD4 cell percent (CD4%) increase during the first 24 months of cART.

RESULTS

Of 199 children (median age 2.1 years), 92 (46%) were receiving TB treatment at cART initiation. Children receiving and not receiving TB treatment at cART initiation had similar median baseline HIV RNA (5.4 vs. 5.6 copies/mL), median time to virologic suppression (6.2 months in each group, adjusted hazard ratio, 1.36, 95% confidence interval: 0.94 to 1.96), and rates of virologic rebound by 24 months (23% vs. 24%, adjusted hazard ratio 1.53, 95% confidence interval: 0.71 to 3.30). Children on TB treatment had significantly lower median CD4% at baseline (15.3% vs. 18.8%, P < 0.01) and during the first 12 months of cART but experienced similar median increases in CD4% at 6 months (9.9% vs. 9.6%), 12 months (14.2% vs. 11.9%), and 24 months of cART (14.5% vs. 14.2%). Exploratory analyses suggest that children receiving lopinavir/ritonavir-based cART and TB treatment may have inferior virologic and immunologic response compared with children receiving efavirenz-based cART.

CONCLUSIONS

Receiving TB treatment at the time of cART initiation did not substantially affect virologic or immunologic response to cART in young children.