Long-term effects of protease-inhibitor-based combination therapy on CD4 T-cell recovery in HIV-1-infected children and adolescents

Thirteen-year viral suppression and immunologic recovery of LPV/r-based regimens in pediatric HIV treatment: a multicenter cohort study in resource-constrained settings of China

Background

Antiretroviral Therapy (ART) in children remains challenging due to resource-constrained settings. We conducted a 13-year, prospective, multicenter cohort study on the effectiveness and safety of LPV/r-based regimens in ART-naive and ART-experienced children.

Methods

From January 2008 to May 2021, children living with HIV-1 were recruited with LPV/r-based regimens from 8 clinical research sites in 6 provinces in China. Effectiveness outcomes were virologic failure (defined as at least two consecutive measurements of VL > 200 copies/mL after 6 months of ART) and immune response (defined as CD4% recovered to more than 25% after 12 months of treatment). The safety outcomes were treatment-related grade 2-4 adverse events and abnormal laboratory test results.

Results

A total of 345 ART-naïve children and 113 ART-experienced children were included in this cohort study. The median follow-up time was 7.3 (IQR 5.5-10.5) years. The incidence density of virologic failure was 4.1 (95% CI 3.3-4.9) per 100 person-years in ART-naïve children and 5.0 (95% CI 3.5-6.5) per 100 person-years in ART-experienced children. Kaplan Meyer (KM) curve analysis showed children with ART experience were at a higher risk of virologic failure (p < 0.05). The risk factors of virologic failure in ART-naïve children were clinic setting in rural hospitals (aHR = 2.251, 1.108-4.575), annual missed dose times >5 days of LPV intake (aHR = 1.889, 1.004-3.554); The risk factor of virologic failure in ART-experienced children was missed dose times >5 days (aHR = 2.689, 1.299-5.604) and mother as caregivers for ART administration (aHR = 0.475, 0.238-0.948). However, during long-term treatment, viral suppression rates between ART-naïve and ART-experienced children remained similar. No significant differences were observed in the immune response, treatment-related grade 2-4 events, and abnormal laboratory test results between ART-naïve children and ART-experienced children.

Conclusion

Our research underscores that with consistent, long-term treatment of LPV/r-based regimens, ART-experienced children can achieve therapeutic outcomes comparable to ART-naïve children. It provides crucial insights on LPV/r-based regimens in pediatric HIV treatment, especially in resource-limited settings where high-cost Integrase Strand Transfer Inhibitors (INSTs) are inaccessible. This evidence-based understanding provides an essential addition to the global therapeutic strategies for pediatric HIV treatment.

Infants Receiving Very Early Antiretroviral Therapy Have High CD4 Counts in the First Year of Life

We followed 54 infants with in utero HIV after initiating very early antiretroviral treatment. At weeks 24 and 48, ≥80% had CD4 ≥1500 cells/mm3 and CD4% ≥25%. Routine Pneumocystis jirovecii pneumonia prophylaxis in the first year of life may not be necessary for all very early treated infants.

CLINICAL TRIALS REGISTRATION

NCT02140255.

Prognostic factors of a lower CD4/CD8 ratio in long term viral suppression HIV infected children

BACKGROUND

Combination antiretroviral therapy (cART) is associated with marked immune reconstitution. Although a long term viral suppression is achievable, not all children however, attain complete immunological recovery due to persistent immune activation. We use CD4/CD8 ratio like a marker of immune reconstitution.

METHODS

Perinatal HIV-infected children who underwent a first-line cART, achieved viral suppression in the first year and maintained it for more than 5 years, with no viral rebound were included. Logistic models were applied to estimate the prognostic factors, clinical characteristics at cART start, of a lower CD4/CD8 ratio at the last visit.

RESULTS

146 HIV-infected children were included: 77% Caucasian, 45% male and 28% CDC C. Median age at cART initiation was 2.3 years (IQR: 0.5-6.2). 42 (30%) children received mono-dual therapy previously to cART. Time of undetectable viral load was 9.5 years (IQR: 7.8, 12.5). 33% of the children not achieved CD4/CD8 ratio >1. Univariate analysis showed an association between CD4/CD8 <1 with lower CD4 nadir and baseline CD4; older age at diagnosis and at cART initiation; and a previous exposure to mono-dual therapy. Multivariate analysis also revealed relationship between CD4/CD8 <1 and lower CD4 nadir (OR: 1.002, CI 95% 1.000-1.004) as well as previous exposure to mono-dual therapy (OR: 0.16, CI 95% 0.003-0.720).

CONCLUSIONS

CD4/CD8 >1 was not achieved in 33% of the children. Lower CD4 nadir and previous exposure to suboptimal therapy, before initiating cART, are factors showing independently association with a worse immune recovery (CD4/CD8 < 1).

Clinical, Virologic, Immunologic Outcomes and Emerging HIV Drug Resistance Patterns in Children and Adolescents in Public ART Care in Zimbabwe

OBJECTIVE

To determine immunologic, virologic outcomes and drug resistance among children and adolescents receiving care during routine programmatic implementation in a low-income country.

METHODS

A cross-sectional evaluation with collection of clinical and laboratory data for children (0-<10 years) and adolescents (10-19 years) attending a public ART program in Harare providing care for pediatric patients since 2004, was conducted. Longitudinal data for each participant was obtained from the clinic based medical record.

RESULTS

Data from 599 children and adolescents was evaluated. The participants presented to care with low CD4 cell count and CD4%, median baseline CD4% was lower in adolescents compared with children (11.0% vs. 15.0%, p<0.0001). The median age at ART initiation was 8.0 years (IQR 3.0, 12.0); median time on ART was 2.9 years (IQR 1.7, 4.5). On ART, median CD4% improved for all age groups but remained below 25%. Older age (≥ 5 years) at ART initiation was associated with severe stunting (HAZ <-2: 53.3% vs. 28.4%, p<0.0001). Virologic failure rate was 30.6% and associated with age at ART initiation. In children, nevirapine based ART regimen was associated with a 3-fold increased risk of failure (AOR: 3.5; 95% CI: 1.3, 9.1, p = 0.0180). Children (<10 y) on ART for ≥4 years had higher failure rates than those on ART for <4 years (39.6% vs. 23.9%, p = 0.0239). In those initiating ART as adolescents, each additional year in age above 10 years at the time of ART initiation (AOR 0.4 95%CI: 0.1, 0.9, p = 0.0324), and each additional year on ART (AOR 0.4, 95%CI 0.2, 0.9, p = 0.0379) were associated with decreased risk of virologic failure. Drug resistance was evident in 67.6% of sequenced virus isolates.

CONCLUSIONS

During routine programmatic implementation of HIV care for children and adolescents, delayed age at ART initiation has long-term implications on immunologic recovery, growth and virologic outcomes.

Mutations in the reverse transcriptase and protease genes of human immunodeficiency virus-1 from antiretroviral naïve and treated pediatric patients

The success of highly active antiretroviral therapy (HAART) is challenged by the emergence of resistance-associated mutations in human immunodeficiency virus-1 (HIV-1). In this study, resistance associated mutations in the reverse transcriptase (RT) and protease (PR) genes in antiretroviral therapy (ART) naïve and treated HIV-1 infected pediatric patients from North India were evaluated. Genotyping was successfully performed in 46 patients (30 ART naive and 16 treated) for the RT gene and in 53 patients (27 ART naive and 26 treated) for PR gene and mutations were identified using Stanford HIV Drug Resistance Database. A major drug resistant mutation in RT gene, L74I (NRTI), and two such mutations, K101E and G190A (NNRTI), were observed in two ART naïve patients, while M184V was detected in two ART treated patients. Overall, major resistance associated mutations in RT gene were observed in nine (30%) and seven (36%) of ART naïve and treated children respectively. Minor mutations were identified in PR gene in five children. Few non-clade C viral strains (≈30%) were detected, although subtype C was most predominant. The screening of ART naïve children for mutations in HIV-1 RT and protease genes, before and after initiation of ART is desirable for drug efficacy and good prognosis.

Safety and effectiveness of combination antiretroviral therapy during the first year of treatment in HIV-1 infected Rwandan children: a prospective study

Background

With increased availability of paediatric combination antiretroviral therapy (cART) in resource limited settings, cART outcomes and factors associated with outcomes should be assessed.

Methods

HIV-infected children <15 years of age, initiating cART in Kigali, Rwanda, were followed for 18 months. Prospective clinical and laboratory assessments included weight-for-age (WAZ) and height-for-age (HAZ) z-scores, complete blood cell count, liver transaminases, creatinine and lipid profiles, CD4 T-cell count/percent, and plasma HIV-1 RNA concentration. Clinical success was defined as WAZ and WAZ >−2, immunological success as CD4 cells ≥500/mm³ and ≥25% for respectively children over 5 years and under 5 years, and virological success as a plasma HIV-1 RNA concentration <40 copies/mL.

Results

Between March 2008 and December 2009, 123 HIV-infected children were included. The median (interquartile (IQR) age at cART initiation was 7.4 (3.2, 11.5) years; 40% were <5 years and 54% were female. Mean (95% confidence interval (95%CI)) HAZ and WAZ at baseline were −2.01 (−2.23, −1.80) and −1.73 (−1.95, −1.50) respectively and rose to −1.75 (−1.98, −1.51) and −1.17 (−1.38, −0.96) after 12 months of cART. The median (IQR) CD4 T-cell values for children <5 and ≥5 years of age were 20% (13, 28) and 337 (236, 484) cells/mm³respectively, and increased to 36% (28, 41) and 620 (375, 880) cells/mm³. After 12 months of cART, 24% of children had a detectable viral load, including 16% with virological failure (HIV-RNA>1000 c/mL). Older age at cART initiation, poor adherence, and exposure to antiretrovirals around birth were associated with virological failure. A third (33%) of children had side effects (by self-report or clinical assessment), but only 9% experienced a severe side effect requiring a cART regimen change.

Conclusions

cART in Rwandan HIV-infected children was successful but success might be improved further by initiating cART as early as possible, optimizing adherence and optimizing management of side effects.

Using CD4 percentage and age to optimize pediatric antiretroviral therapy initiation

BACKGROUND

Quantifying pediatric immunologic recovery by highly active antiretroviral therapy (HAART) initiation at different CD4 percentage (CD4%) and age thresholds may inform decisions about timing of treatment initiation.

METHODS

HIV-1-infected, HAART-naive children in Europe and the Americas were followed from 2002 through 2009 in PENPACT-1. Data from 162 vertically infected children, with at least World Health Organization "mild" immunosuppression and CD4% <10th percentile, were analyzed for improvement to a normal CD4% (≥10th percentile) within 4 years after HAART initiation. Data from 209 vertically infected children, regardless of immune status, were analyzed for CD4% outcomes at 4 years and viral failure within 4 years.

RESULTS

Seventy-two percent of baseline immunosuppressed children recovered to normal within 4 years. Compared with "severe" immunosuppression, more children with "mild" immunosuppression (difference 36%, 95% confidence interval [CI]: 22% to 49%) or "advanced" immunosuppression (difference 20.8%, 95% CI: 5.8% to 35.9%) recovered a normal CD4%. For each 5-year increase in baseline age, the proportion of children achieving a normal CD4% declined by 19% (95% CI: 11% to 27%). Combining baseline CD4% and age effects resulted in >90% recovery when initiating HAART with "mild" immunosuppression at any age or "advanced" immunosuppression at age <3 years. Baseline CD4% effects became greater with increasing age (P = .02). At 4 years, most immunologic benefits were still significant but diminished. Viral failure was highest in infancy (56%) and adolescence (63%).

CONCLUSIONS

Initiating HAART at higher CD4% and younger ages maximizes potential for immunologic recovery. Guidelines should weigh immunologic benefits against long-term risks.

Efficacy and safety of darunavir/ritonavir at 48 weeks in treatment-naïve, HIV-1-infected adolescents: results from a phase 2 open-label trial (DIONE)

BACKGROUND

Twice-daily darunavir/ritonavir is indicated in treatment-experienced children (≥3 years). This study assessed once-daily administration in treatment-naïve adolescents.

METHODS

Phase 2, 48-week, open-label, single-arm study evaluating pharmacokinetics, safety and efficacy of once-daily darunavir/ritonavir 800/100 mg in treatment-naïve, HIV-1-infected adolescents (≥12 to <18 years, ≥40 kg) with zidovudine/lamivudine or abacavir/lamivudine.

RESULTS

Twelve patients (67% female; median 14.4 years) were enrolled. After 24 and 48 weeks, respectively, 11 of 12 (92%) and 10 of 12 (83%) patients achieved viral load <50 copies/mL (intent-to-treat time-to-loss of virologic response); all had ≥1 log10 drop in viral load versus baseline. Median CD4 cell count increased by 175 and 221 cells/mm (intent-to-treat-noncompleter = failure) after 24 and 48 weeks, respectively. Eighty-three percent of patients were adherent to darunavir/ritonavir. One patient was never suppressed and 1 patient rebounded. No patients developed darunavir resistance-associated mutations or lost phenotypic susceptibility to any commercially available protease inhibitor or any background nucleoside reverse transcriptase inhibitor. Eleven patients (92%) reported ≥1 adverse event (AE), considered in 2 patients to be at least possibly related to darunavir (gastrointestinal-related events and dizziness). Four patients had ≥1 serious AE. Three patients reported ≥1 grade 3/4 AE; no serious or grade 3/4 AEs were considered darunavir related. No patients discontinued because of AEs.

CONCLUSIONS

Over 48 weeks, once-daily darunavir/ritonavir 800/100 mg plus NRTIs was effective and well-tolerated for treatment of HIV-1-infected, antiretroviral-naïve adolescents (≥12 to <18 years). These findings support use of once-daily darunavir/ritonavir 800/100 mg in this population.

Immediate antiretroviral therapy in young HIV-infected children: benefits and risks

Purpose of review

Recent WHO guidelines recommend immediate initiation of lifelong antiretroviral therapy (ART) in all children below 5 years, irrespective of immune/clinical status, to improve access to paediatric ART. Interim trial results provide strong evidence for immediate ART during infancy because of high short-term risk of mortality and disease progression, but there is wider debate regarding the potential risks and benefits of immediate ART in asymptomatic children aged above 1 year. Concerns include long-term toxicities and treatment failure, particularly in resource-constrained settings with limited paediatric treatment options.

Recent findings

Benefits of immediate ART among infants appear to be maintained in the mid-term to long-term, with low risk of treatment failure, and better neurodevelopmental outcomes. In contrast, a trial reported no benefits of immediate versus deferred ART in asymptomatic children aged above 1 year. However, observational studies suggest that ART initiation at older ages and lower CD4 reduces the probability of immune reconstitution, with unclear implications on risk of clinical events or treatment change. A recent trial on treatment interruption following early intensive ART suggest that this may be a safe alternative approach.

Summary

Although there are clear benefits of immediate ART among infants, there remains conflicting evidence on the benefits for older children.

Clinical, immunological, and virological outcomes of pediatric antiretroviral therapy in central China

Background

Antiretroviral therapy (ART) reduces HIV-related mortality and morbidity substantially in children. The clinical characteristics, immunological and virological outcomes were evaluated in HIV-infected children receiving ART.

Methods

Twenty-six HIV-1-infected children receiving ART in Hubei province, China, were enrolled retrospectively in this study. During the period of ART, plasma viral load, lymphocyte phenotype of CD4 and CD8 cells and clinical events were assessed.

Results

The median duration of ART was 41 months (18–72.3 months). In children showing clinical improvement, high viral suppression rate below log10 (2.7) copies/ml by the third months of ART was observed. The median CD4 cell counts reached to 820.5/μl by 12 months and the median ratio of CD4/CD8 increased to 0.6 by 21 months. The counts of peripheral white blood cells and red blood cells decreased in the first 12 months, while Hb concentration, MCV and MCH increased (P < 0.001).

Conclusions

Despite the limited small sample size, ART is an effective strategy for inhibiting HIV replication and reconstructing the immunological response in children with AIDS.

Immunology of pediatric HIV infection

Most infants born to human immunodeficiency virus (HIV)-infected women escape HIV infection. Infants evade infection despite an immature immune system and, in the case of breastfeeding, prolonged repetitive exposure. If infants become infected, the course of their infection and response to treatment differs dramatically depending upon the timing (in utero, intrapartum, or during breastfeeding) and potentially the route of their infection. Perinatally acquired HIV infection occurs during a critical window of immune development. HIV's perturbation of this dynamic process may account for the striking age-dependent differences in HIV disease progression. HIV infection also profoundly disrupts the maternal immune system upon which infants rely for protection and immune instruction. Therefore, it is not surprising that infants who escape HIV infection still suffer adverse effects. In this review, we highlight the unique aspects of pediatric HIV transmission and pathogenesis with a focus on mechanisms by which HIV infection during immune ontogeny may allow discovery of key elements for protection and control from HIV.

Long-term response to combination antiretroviral therapy in HIV-infected children in the Netherlands registered from 1996 to 2012

OBJECTIVES

To describe demographic and treatment characteristics of the Dutch vertically HIV-infected paediatric population from 1996 to 2012, and to investigate the long-term virological and immunological response to combination antiretroviral therapy (cART), with emphasis on the influence of age at cART initiation and initial CD4 cell counts.

DESIGN

Descriptive cohort study.

METHODS

From 1996 to 2012, all paediatric HIV clinics in the Netherlands provided data on their HIV-infected population. Descriptive statistics, parametric and non-parametric comparative tests, and random-effects linear regression models were performed to investigate the different aspects of this cohort.

RESULTS

A total of 229 vertically HIV-infected children were included. The majority of all mothers (64%) and almost half of the children (43%) originated from sub-Saharan Africa. Ritonavir-boosted lopinavir and efavirenz have replaced indinavir, nelfinavir and nevirapine as preferred first-line cART regimens. Long-term CD4 T-cell reconstitution (with CD4 cell counts corrected for age) was independent of age and CD4 cell count at cART initiation. The decline in HIV viral load after cART introduction occurred faster over the studied time period. The percentage of children with an undetectable viral load rose substantially from 1996 to 2012. Mortality was 0.3 per 100 person-years.

CONCLUSION

A sustained immunological response in the Dutch paediatric HIV-infected population was independent of age as well as CD4 cell count at cART initiation, despite a higher initial HIV viral load in the youngest children. The percentage of children with an undetectable HIV viral load rose substantially over the years and there was a low mortality rate in comparison with reports from other industrialized countries.

Immunologic outcomes of antiretroviral therapy among HIV-infected Nigerian children and its association with early infant feeding and nutritional status at treatment initiation

OBJECTIVES

To evaluate immunologic response to antiretroviral treatment (ART) among HIV-infected Nigerian children (<36 months old) and to assess its association with early infant feeding pattern and nutritional status at treatment initiation.

DESIGN

Mixed prospective and retrospective cohort study.

METHODS

One hundred fifty HIV-infected children were followed for 12 months from initiation of ART. CD4 count/CD4% was assessed at baseline and every 4-6 months. Nutritional status was assessed by height-for-age, weight-for-age and weight-for-height Z scores using the 2006 World Health Organization growth reference. Children were classified into 4 feeding groups--exclusively breast-fed, predominantly breast-fed, mixed fed and exclusively formula fed. Logistic regression was used to model odds of failure to reach CD4% of ≥ 25% at the 12-month follow-up. Linear random effects models were used to model the longitudinal change in CD4%.

RESULTS

There was a significant increase in CD4% for all children from 13.8% at baseline to 28.5% after 12 months (ΔCD4% = 14.7%, 95% confidence interval: 12.1%-17.4%). There was no association of feeding pattern with immunologic outcomes. In adjusted analyses, children who were underweight (weight-for-age < -2.0) or with CD4% <15% at baseline were 4.30 (95% confidence interval: 1.16, 15.87; P < 0.05) times and 3.41 (95% confidence interval: 1.10, 10.52; P < 0.05) times, respectively, more likely not to attain CD4% of ≥ 25% at 12 months.

CONCLUSION

Baseline nutritional status and CD4% were independently associated with failure to reach CD4% ≥ 25% at 12 months among HIV-infected Nigerian children on ART. These results emphasize the importance of early screening and initiation of ART among children in resource-poor settings before malnutrition and severe immunosuppression sets in.

Morbidity after antiretroviral therapy initiation in HIV-1-infected children in West Africa: temporal trends and relation to CD4 count

BACKGROUND

Although 90% of HIV-1-infected children live in sub-Saharan Africa, morbidity data after highly active antiretroviral therapy (HAART) initiation in these settings are limited. The objective of this study was to document the incidence of AIDS-defining events and non-AIDS-defining diseases in African children receiving HAART.

METHODS

Incidences rates (IRs) of AIDS-defining events and 10 other common diseases were estimated overall and by current CD4-strata (<15%, 15 - <25% and ≥25%) from 2 prospective cohorts of African children.

RESULTS

One hundred eighty-eight children contributing to 355 children-years were included. The documented morbidity IRs per 100 children-years were upper respiratory infections, 100 (87-114); infectious diarrhea, 37 (31-44); World Health Organization (WHO) stage 2 events, 22.9 (18.2-28.1); and WHO stage 3/4 events, 12.3 (9.1-16.7). IRs of WHO stage 2 events, severe bacterial infections, infectious diarrhea and pneumonia decreased linearly across all CD4%-strata, whereas WHO stage 3/4 events and viral infections occurred mostly when CD4% <15%. Overall, IRs decreased during the first 2 years on HAART except for upper respiratory infection, mycosis and oral candidiasis.

CONCLUSION

This incidence of AIDS- and non-AIDS-defining diseases declined substantially after HAART in 2 African cohorts, although estimates remained high compared with high-resource settings. Without renewed efforts to increase antiretroviral scale-up, children in developing countries will continue to have a high burden of infections.

Mortality and treatment outcomes of China's National Pediatric antiretroviral therapy program

BACKGROUND

The aim of this study was to describe 3-year mortality rates, associated risk factors, and long-term clinical outcomes of children enrolled in China's national free pediatric antiretroviral therapy (ART) program.

METHODS

Records were abstracted from the national human immunodeficiency virus (HIV)/AIDS case reporting and national pediatric ART databases for all HIV-positive children ≤15 years old who initiated ART prior to December 2010. Mortality risk factors over 3 years of follow-up were examined using Cox proportional hazards regression models. Life tables were used to determine survival rate over time. Longitudinal plots of CD4(+) T-cell percentage (CD4%), hemoglobin level, weight-for-age z (WAZ) score, and height-for-age z (HAZ) score were created using generalized estimating equation models.

RESULTS

Among the 1818 children included in our cohort, 93 deaths were recorded in 4022 child-years (CY) of observed time for an overall mortality rate of 2.31 per 100 CY (95% confidence interval [CI], 1.75-2.78). The strongest factor associated with mortality was baseline WAZ score <-2 (adjusted hazard ratio [HR] = 9.1; 95% CI, 2.5-33.2), followed by World Health Organization stage III or IV disease (adjusted HR = 2.4; 95% CI, 1.1-5.2), and hemoglobin <90 g/L (adjusted HR = 2.2; 95% CI, 1.2-3.9). CD4%, hemoglobin level, WAZ score, and HAZ score increased over time.

CONCLUSIONS

Our finding that 94% of children engaged in this program are still alive and of improved health after 3 years of treatment demonstrates that China's national pediatric ART program is effective. This program needs to be expanded to better meet treatment demands, and efforts to identify HIV-positive children earlier must be prioritized.

Quantification of CD4 responses to combined antiretroviral therapy over 5 years among HIV-infected children in Kinshasa, Democratic Republic of Congo

BACKGROUND

The long-term effects of combined antiretroviral therapy (cART) on CD4 percentage in HIV-infected children are incompletely understood, with evidence from resource-deprived areas particularly scarce even though most children with HIV live in such settings. We sought to describe this relationship.

METHODS

Observational longitudinal data from cART-naive children enrolled between December 2004 and May 2010 into an HIV care and treatment program in Kinshasa, Democratic Republic of Congo were analyzed. To estimate the effect of cART on CD4 percentage while accounting for time-dependent confounders affected by prior exposure to cART, a marginal structural linear mean model was used.

RESULTS

Seven hundred ninety children were active for 2090 person-years and a median of 31 months; 619 (78%) initiated cART. At baseline, 405 children (51%) were in HIV clinical stage 3 or 4; 528 (67%) had advanced or severe immunodeficiency. Compared with no cART, the estimated absolute rise in CD4 percentage was 6.8% [95% confidence interval (CI), 4.7% to 8.9%] after 6 months of cART, 8.6% (95% CI, 7.0% to 10.2%) after 12 months, and 20.5% (95% CI, 16.1% to 24.9%) after 60 months. cART-mediated CD4 percentage gains were slowest but greatest among children with baseline CD4 percentage <15. The cumulative incidence of recovery to "not significant" World Health Organization age-specific immunodeficiency was lower if cART was started when immunodeficiency was severe rather than mild or advanced.

CONCLUSIONS

cART increased CD4 percentages among HIV-infected children in a resource-deprived setting, as previously noted among children in the United States. More gradual and protracted recovery in children with lower baseline CD4 percentages supports earlier initiation of pediatric cART.

Successful clinical outcomes following decentralization of tertiary paediatric HIV care to a community-based paediatric antiretroviral treatment network, Chiangrai, Thailand, 2002 to 2008

INTRODUCTION

Most paediatric antiretroviral treatments (ARTs) in Thailand are limited to tertiary care hospitals. To decentralize paediatric HIV treatment and care, Chiangrai Prachanukroh Hospital (CRH) strengthened a provincial paediatric HIV care network by training community hospital (CH) care teams to receive referrals of children for community follow-up. In this study, we assessed factors associated with death and clinical outcomes of HIV-infected children who received care at CRH and CHs after implementation of a community-based paediatric HIV care network.

METHODS

Clinical records were abstracted for all children who initiated ART at CRH. Paired Wilcoxon signed rank tests were used to assess CD4% and virological change among all children. Cox proportional hazard models were used to assess factors associated with death. Treatment outcomes (CD4%, viral load (VL) and weight-for-age Z-score (WAZ)) were compared between CRH and CH children who met the criteria for analysis.

RESULTS

Between February 2002 and April 2008, 423 HIV-infected children initiated ART and 410 included in the cohort analysis. Median follow-up for the cohort was 28 months (interquartile range (IQR)=12 to 42); 169 (41%) children were referred for follow-up at CH. As of 31 March 2008, 42 (10%) children had died. Baseline WAZ (< -2 (p=0.001)) and baseline CD4% (<5% (p=0.015)) were independently associated with death. At 48 months, 86% of ART-naïve children in follow-up had VL<400 copies/ml. For sub-group analysis, 133 children at CRH and 154 at CHs were included for comparison. Median baseline WAZ was lower in CH children than in CRH children (p=0.001); in both groups, WAZ, CD4% and VL improved after ART with no difference in rate of WAZ and CD4% gain (p=0.421 and 0.207, respectively).

CONCLUSIONS

Children at CHs had more severe immunological suppression and low WAZ at baseline. Community- and tertiary care-based paediatric ART follow-ups result in equally beneficial outcomes with the strengthening of a provincial referral network between tertiary and community care. Nutrition interventions may benefit children in community-based HIV treatment and care.

The unanswered question: when to initiate antiretroviral therapy in children with HIV infection

PURPOSE OF REVIEW

The question of when to initiate antiretroviral treatment for children is perhaps the most critical unanswered question in pediatric HIV therapeutics. With large numbers of children throughout the world acquiring HIV infection and with improved global access to HIV treatment it is particularly timely to consider the optimal time to initiate antiretroviral therapy in infants, children and adolescents.

RECENT FINDINGS

Early treatment can result in suppression of HIV viremia, immune preservation and prevention of disease progression. This must be balanced by the challenges of maintaining adherence to multidrug regimens, the risks of selecting drug-resistant virus, and long and short-term toxicities of medications.

SUMMARY

This review provides a framework within which to consider when to initiate children on antiretroviral treatment. A child's age and developmental status, where they live, and the goals and expectations for treatment provide a context for balancing the risks of disease progression with the risks of drug-related toxicities and viral resistance.

Antiretroviral treatment of US children with perinatally acquired HIV infection: temporal changes in therapy between 1991 and 2009 and predictors of immunologic and virologic outcomes

BACKGROUND

Advances in therapy have allowed children with perinatal HIV infection in the United States to survive into adolescence. We sought to describe the disease status of a large cohort of such children and identify predictors of their current CD4 count and HIV viral load (VL).

METHODS

The Pediatric HIV/AIDS Cohort Study AMP Protocol is an ongoing prospective study conducted at 15 sites in the United States. Between 2007 and 2009, we enrolled a population-based sample of 451 children with perinatal HIV who were 7-16 years of age at entry.

RESULTS

The median age of subjects at entry was 12.2 years, 53% were female, 70% were African-American, and 24% Hispanic. Their median entry CD4% was 33%, and 78% had a CD4% ≥25%; 68% had a suppressed VL. The more recent birth cohorts (1994-2002) had a significantly higher CD4% over time than the earliest birth cohort (1991-1993). The significant independent predictors of a higher CD4% at entry were a suppressed entry VL, a higher nadir CD4%, and starting antiretroviral therapy at a younger age. The mean CD4% at entry for children with a nadir CD4% ≥25% was 9.5% higher than for those with a nadir CD4% <15% (P < 0.001). Independent predictors of a suppressed entry VL were membership in a recent birth cohort, male gender, highly active combination antiretroviral therapy use at entry, and fewer prior antiretroviral therapy regimens.

CONCLUSIONS

Most children with perinatal HIV maintain virologic suppression and good CD4 values. Earlier treatment results in better immune outcome.

Time to and Predictors of CD4+ T-Lymphocytes Recovery in HIV-Infected Children Initiating Highly Active Antiretroviral Therapy in Ghana

Background. CD4+ T-lymphocyte monitoring is not routinely available in most resource-limited settings. We investigated predictors of time to CD4+ T-lymphocyte recovery in HIV-infected children on highly active antiretroviral (HAART) at Korle-Bu Teaching Hospital, Ghana. Methods. Time to CD4+ T-lymphocyte recovery was defined as achieving percent CD4+ T-lymphocytes of 25%. We used Cox proportional hazard models for identifying significant predictor variables. Results. Of the 233 children with complete CD4+ T-lymphocyte data, the mean age at HAART initiation was 5.5 (SD = 3.1) years. The median recovery time was 60 weeks (95% CL: 55–65). Evidence at baseline of severe suppression in CD4+ T-lymphocyte count adjusted for age, age at HAART initiation, gender, and having parents alive were statistically significant in predicting time to CD4+ T-lymphocyte recovery. Conclusions. A targeted approach based on predictors of CD4+ T-lymphocyte recovery can be a viable and cost-effective way of monitoring HAART in HIV-infected children in resource-limited settings.

Post-HAART outcomes in pediatric populations: comparison of resource-limited and developed countries

CONTEXT

No formal comparison has been made between the pediatric post-highly active antiretroviral therapy (HAART) outcomes of resource-limited and developed countries.

OBJECTIVE

To systematically quantify and compare major baseline characteristics and clinical end points after HAART between resource-limited and developed settings.

METHODS

Published articles and abstracts (International AIDS Society 2009, Conference on Retroviruses and Opportunistic Infections 2010) were examined from inception (first available publication for each search engine) to March 2010. Publications that contained data on post-HAART mortality, weight-for-age z score (WAZ), CD4 count, or viral load (VL) changes in pediatric populations were reviewed. Selected studies met the following criteria: (1) patients were younger than 21 years; (2) HAART was given (≥ 3 antiretroviral medications); and (3) there were >20 patients. Data were extracted for baseline age, CD4 count, VL, WAZ, and mortality, CD4 and virologic suppression over time. Studies were categorized as having been performed in a resource-limited country (RLC) or developed country (DC) on the basis of the United Nations designation. Mean percentage of deaths per cohort and deaths per 100 child-years, baseline CD4 count, VL, WAZ, and age were calculated for RLCs and DCs and compared by using independent samples t tests.

RESULTS

Forty RLC and 28 DC publications were selected (N = 17 875 RLCs; N = 1835 DC). Mean percentage of deaths per cohort and mean deaths per 100 child-years after HAART were significantly higher in RLCs than DCs (7.6 vs 1.6, P < .001, and 8.0 vs 0.9, P < .001, respectively). Mean baseline CD4% was 12% in RLCs and 23% in DCs (P = .01). Mean baseline VLs were 5.5 vs 4.7 log(10) copies per mL in RLCs versus DCs (P < .001).

CONCLUSIONS

Baseline CD4% and VL differ markedly between DCs and RLCs, as does mortality after pediatric HAART. Earlier diagnosis and treatment of pediatric HIV in RLCs would be expected to result in better HAART outcomes.

Antiretroviral therapy outcomes of HIV-infected children in the TREAT Asia pediatric HIV observational database

INTRODUCTION

We report responses to combination antiretroviral therapy (cART) in the Therapeutics Research, Education, and AIDS Training in Asia Pediatric HIV Observational Database.

METHODS

Children included were those who had received cART (ie, ≥3 antiretrovirals) at <18 years. The analysis was intention-to-treat by the first cART regimen. Median values are provided with interquartile ranges; hazard ratios (HRs) with 95% confidence intervals.

RESULTS

Of the 1655 children included, 50.4% were male, with a median age at cART of 7.0 (3.9-9.8) years and CD4 of 8% (2.0%-15%); 92.5% were started on an NNRTI; median duration of follow-up was 2.9 (1.4-4.6) years. Loss-to-follow-up and death rates were 4.2 (3.7-4.8) and 2.1 (1.7-2.5) per 100 person-years, respectively. At 36 months, median CD4 was 26% (21%-31%); 81% of those with viral load (n = 302) were <400 copies per milliliter. Children who reached CD4 ≥25% within 5 years were more likely to be females (HR: 1.4; 1.2-1.7), start before 18 months old (HR: 3.8; 2.4-6.2), lack a history of monotherapy/dual therapy (HR: 1.7; 1.4-2.5), and have a higher baseline CD4 (per 10% increase: HR: 2; 1.9-2.2).

CONCLUSIONS

These data underscore the need for early diagnosis and cART initiation to preserve immune function.

Impact of HAART on survival, weight gain and resting energy expenditure in HIV-1-infected children in India

BACKGROUND

In resource-limited countries, use of highly active antiretroviral therapy (HAART) in HIV-infected children is still poorly documented in terms of impact on survival, the immune system and growth. Since the availability of HAART, nutrition of HIV-infected children has been neglected.

AIM

To evaluate the effect of HAART on survival and immune response in HIV-infected children and to investigate the response to nutritional support.

METHODS

In December, 2002 a cohort study was carried out on vertically HIV-1-infected children and was observed longitudinally for CD4(+) T-cell count, antiretroviral treatment and weight until 31 December 2007. Z-scores were calculated for CD4(+) T-cell count to account for age-related differences. Nutritional supplementation was given to all the HIV-infected children and resting energy expenditure (REE) was calculated. Mortality rates were also calculated for the perinatally infected children followed up at the HIV clinic.

RESULTS

A total of 180 children were assessed, 100 (56%) of whom were on HAART. Baseline body mass index was lower in the HAART group (p<0.05). Median duration of survival from date of diagnosis was 15.1 years. Those who received HAART survived significantly longer. The average annual mortality rate was 1.2% during 2005-2006. During HAART, a CD4 Z-score increase of 1 SD was associated with a 0.35 increase in body weight Z-score (p<0.001). The increase in daily energy intake owing to nutritional supplementation was associated with increase in weight Z-score in both the no-HAART and HAART group. REE was independently associated with weight change in the models which tested association of changes in CD4(+) T-cell Z-score and daily REE/kg body weight with changes in body weight Z-score in both the HAART and no-HAART group and then separately in the two groups (p<0.001).

CONCLUSION

Survival rates of children improved which correlated with an increase in CD4(+) T-cell count concurrent with the expanded use of HAART. HAART had a positive effect on growth in HIV-1-infected children. Nutrition supplementation improved the health of children in both the no-HAART and HAART groups.

Adolescent HIV--cause for concern in Southern Africa

Glenda Gray discusses the implications of a new study that found that almost half of all adolescents hospitalized in Zimbabwe were HIV-infected.

Causes of acute hospitalization in adolescence: burden and spectrum of HIV-related morbidity in a country with an early-onset and severe HIV epidemic: a prospective survey

BACKGROUND

Survival to older childhood with untreated, vertically acquired HIV infection, which was previously considered extremely unusual, is increasingly well described. However, the overall impact on adolescent health in settings with high HIV seroprevalence has not previously been investigated.

METHODS AND FINDINGS

Adolescents (aged 10-18 y) systematically recruited from acute admissions to the two public hospitals in Harare, Zimbabwe, answered a questionnaire and underwent standard investigations including HIV testing, with consent. Pre-set case-definitions defined cause of admission and underlying chronic conditions. Participation was 94%. 139 (46%) of 301 participants were HIV-positive (median age of diagnosis 12 y: interquartile range [IQR] 11-14 y), median CD4 count = 151; IQR 57-328 cells/microl), but only four (1.3%) were herpes simplex virus-2 (HSV-2) positive. Age (median 13 y: IQR 11-16 y) and sex (57% male) did not differ by HIV status, but HIV-infected participants were significantly more likely to be stunted (z-score<-2: 52% versus 23%, p<0.001), have pubertal delay (15% versus 2%, p<0.001), and be maternal orphans or have an HIV-infected mother (73% versus 17%, p<0.001). 69% of HIV-positive and 19% of HIV-negative admissions were for infections, most commonly tuberculosis and pneumonia. 84 (28%) participants had underlying heart, lung, or other chronic diseases. Case fatality rates were significantly higher for HIV-related admissions (22% versus 7%, p<0.001), and significantly associated with advanced HIV, pubertal immaturity, and chronic conditions.

CONCLUSION

HIV is the commonest cause of adolescent hospitalisation in Harare, mainly due to adult-spectrum opportunistic infections plus a high burden of chronic complications of paediatric HIV/AIDS. Low HSV-2 prevalence and high maternal orphanhood rates provide further evidence of long-term survival following mother-to-child transmission. Better recognition of this growing phenomenon is needed to promote earlier HIV diagnosis and care.

Pattern and predictors of immunologic recovery in human immunodeficiency virus-infected children receiving non-nucleoside reverse transcriptase inhibitor-based highly active antiretroviral therapy

BACKGROUND

Non-nucleoside reverse transcription inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART) is the recommended first-line regimen for children in Thailand. This study was aimed to assess pattern and predictors of immune recovery in antiretroviral-naive Thai children starting NNRTI-based HAART.

METHODS

Records were extracted from clinical databases of 2 treatment cohorts in Thailand. The inclusion criteria were HIV-infected naive children who initiated NNRTI-based HAART when CD4 <25%. Immune recovery was defined as achieving a target CD4% of 25. The impact of age, gender, baseline clinical category, CD4 and HIV RNA titer, and regimen on immune recovery to weeks 96 was assessed using multiple logistic regression.

RESULTS

There were 274 patients (52% females) with a median baseline age of 7 (Interquartile range [IQR]: 4-9) years and a median CD4% of 5 (IQR: 1-12) who started treatment with nevirapine (66%) or efavirenz (34%) based HAART. Median duration of follow-up was 168 (IQR: 120-192) weeks. The median CD4% increase from baseline was 7% (IQR: 5-11) and 18% (IQR: 12-23) at weeks 24 and 96, respectively. The probability of reaching target CD4% was 51% (95% confidence interval: 45%-57%) by week 96. The predictors of immune recovery at week 96 were younger age, female gender, higher baseline CD4%, and sustained virologic suppression after week 24.

CONCLUSION

In this cohort of children with low baseline CD4, half achieved immune recovery after 96 weeks of HAART. The predictors for immune recovery are younger children, female gender, high baseline CD4%, and long-term virologic suppression.

Short-term and long-term effects of highly active antiretroviral therapy on the incidence of herpes zoster in HIV-infected children

BACKGROUND

Highly active antiretroviral therapy (HAART) has reduced herpes zoster (HZ) incidence in HIV-infected children, yet it remains common.

METHODS

We evaluated perinatally HIV-infected youth with varicella infection enrolled between 1993 and 2006 in a prospective cohort study. Incidence rates (IRs) and 95% confidence intervals of HZ were estimated by calendar year, age group, and HAART use. The effect of initiating HAART was also evaluated by fitting Cox survival models adjusted for potential confounders.

RESULTS

Among 536 perinatally infected children with documented prior varicella (median follow-up = 6.8 years), 116 (22%) developed HZ (IR = 3.2 events/100 person-years, confidence interval: 2.6 to 3.8). IRs increased from 1993 to 1996 and then declined significantly through 2006 (P < 0.001). However, an IR of 1.4-3.1 HZ episodes per 100 person-years persisted from 2001 to 2006. The risk of HZ was higher for those with lower CD4% or in Centers for Disease Control and Prevention clinical class C. The IR of HZ was similar in the 90 days before or after initiation of HAART but declined significantly after more than 90 days of HAART.

CONCLUSIONS

Although HAART has markedly reduced the IR of HZ, it remains a frequent complication in HIV-infected children. The risk of HZ is similar in the 90 days before and after initiating HAART.

Immunological recovery and metabolic disorders in severe immunodeficiency HIV type 1-infected children on highly active antiretroviral therapy

Little is known about immunologic reconstitution in children on highly active antiretroviral treatment (HAART) during very long-term periods. A retrospective study was carried out to assess the effectiveness and development of metabolic disorders after very long-term periods on HAART in HIV-infected children with severe immunodeficiency. We included 55 children who were stratified into three groups according to %CD4(+) pre-HAART and rate of immunologic recovery: (1) S1-Rec: CD4(+) < or =5% at baseline and slow immunologic recovery; (2) S2-Rec: CD4(+) 5-15% at baseline and slow immunologic recovery; (3) R-Rec: CD4(+) < or =15% at baseline and rapid immunologic recovery (reference group). An adequate immune recovery after 8 years on HAART was achieved by only 25% of children. S1-Rec never achieved a mean of CD4(+) > or =25% after 8 years on HAART. All children had a significant increase in plasma cholesterol levels during the first 2 years. Afterward, cholesterol levels reached a plateau and remained stable until year 8 of follow-up. Higher rates of lipodystrophy were found in the R-Rec group [14 (100%)] than in the S1-Rec group [9/19 (47.4%)] or the S2-Rec group [13/20 (65%)] at the end of the study (p = 0.006). Overall, having a low nadir of CD4(+) hindered immune reconstitution; however, children with rapid immunologic recovery showed a higher prevalence of the lipodystrophy syndrome.

Long-term effects of highly active antiretroviral therapy on CD4+ cell evolution among children and adolescents infected with HIV: 5 years and counting

BACKGROUND

Lower percentages of CD4(+) T lymphocytes are associated with adverse clinical outcomes among children and adolescents infected with human immunodeficiency virus (HIV). CD4(+) lymphocyte percentage generally increases with receipt of highly active antiretroviral therapy (HAART), but long-term follow-up is required to assess whether these increases in CD4(+) cell percentage are maintained and whether they lead to normal CD4(+) cell percentages in children with severe immunosuppression.

METHODS

The study population included 1236 children and adolescents perinatally infected with HIV who were enrolled in a US-based multicenter prospective cohort study (Pediatric AIDS Clinical Trials Group 219/219C) and who were not receiving HAART at study initiation. We estimated the effects of HAART, HAART with protease inhibitors, and HAART with nonnucleoside reverse-transcriptase inhibitors on CD4(+) cell percentage, using marginal structural models to account for confounding by severity.

RESULTS

Initiation of any type of HAART increased CD4(+) cell percentage by 2.34% (95% confidence interval, 1.35%-3.33%) in the first year, relative to noninitiation of HAART. The substantial increases in CD4(+) cell percentage observed after the first year of experience with these combination therapies were followed by relatively smaller increases that continued for 5 years after initiation. Although larger increases in CD4(+) cell percentage were observed among children with a greater degree of immunosuppression at baseline, the mean CD4(+) cell percentage after 5 years of HAART did not reach normal levels.

CONCLUSIONS

Our study supports the initiation of HAART in children before severe immunosuppression occurs for long-term maintenance of normal CD4(+) cell percentages. This beneficial result must be weighed against the evidence of potential adverse events associated with the prolonged use of such therapy.

Long-term safety and effectiveness of ritonavir, nelfinavir, and lopinavir/ritonavir in antiretroviral-experienced HIV-infected children

AIM

To evaluate the long-term safety and effectiveness of ritonavir, nelfinavir, and lopinavir/ritonavir in antiretroviral-experienced, initially protease inhibitor (PI)-naive, human immunodeficiency virus (HIV)-1-infected children.

METHODS

HIV-1-infected children enrolled in the Swiss Mother and Child HIV Cohort Study were eligible for this observational cohort study if they received at least 1 PI of interest between March 1996 and October 2003: ritonavir, nelfinavir, or lopinavir/ritonavir. Data regarding demographics, clinical disease and antiretroviral treatment history, HIV-1 RNA copies/mL, CD4 T-cell counts [absolute (cells/microL) and percentages (%)], adverse events, clinical laboratory values, reasons for discontinuation of PIs, and concomitant medications were extracted from the database for PI-naive (first-line) and PI-experienced (second- or higher-line) PI use.

RESULTS

The total duration of ritonavir, nelfinavir, and lopinavir/ritonavir use for 133 HIV-1-infected children was 163.8, 235.0, and 46.1 patient-years, respectively. In an on-treatment analysis, first-line therapy with any of the PIs significantly reduced HIV-1 concentrations and increased CD4 T-cell counts and percentages from baseline throughout the 288-week study (P <or= 0.05) for ritonavir and nelfinavir and throughout 84 weeks of use for lopinavir/ritonavir, which was introduced into treatment more recently. All PIs investigated were most effective in PI-naive children. Thirteen PI-associated toxicities occurred requiring treatment changes or interruptions (neurologic symptoms, n = 2; pancreatitis, n = 1; allergic reactions, n = 4; visual symptoms, n = 3; and hyperlipidemia, n = 3).

CONCLUSIONS

Long-term PI-based therapy seems to be safe and to result in durable virologic and immunologic effectiveness in HIV-1-infected antiretroviral-experienced children.

Sustained immunologic and virologic efficacy after four years of highly active antiretroviral therapy in human immunodeficiency virus infected children in Thailand

We report the long-term efficacy of highly active antiretroviral therapy (HAART) in 107 antiretroviral-naive human immunodeficiency virus (HIV)-infected Thai children. In an intention-to-treat analysis, 70% of the children had undetectable HIV RNA titers after 192 weeks of HAART. The mean CD4 cell percentage increased from 5.3% to 26.6%. HAART is effective for HIV-infected children in this resource-poor setting despite initiation of treatment in the advanced stage of disease.

Early response to highly active antiretroviral therapy in HIV-1-infected Kenyan children

OBJECTIVES

To describe the early response to World Health Organization (WHO)-recommended nonnucleoside reverse transcriptase inhibitor (NNRTI)-based first-line highly active antiretroviral therapy (HAART) in HIV-1-infected Kenyan children unexposed to nevirapine.

DESIGN

Observational prospective cohort.

METHODS

HIV-1 RNA level, CD4 lymphocyte count, weight for age z score, and height for age z score were measured before the initiation of HAART and every 3 to 6 months thereafter. Children received no nutritional supplements.

RESULTS

Sixty-seven HIV-1-infected children were followed for a median of 9 months between August 2004 and November 2005. Forty-seven (70%) used zidovudine, lamivudine (3TC), and an NNRTI (nevirapine or efavirenz), whereas 25% used stavudine (d4T), 3TC, and an NNRTI. Nevirapine was used as the NNRTI by 46 (69%) children, and individual antiretroviral drug formulations were used by 63 (94%), with only 4 (6%) using a fixed-dose combination of d4T, 3TC, and nevirapine (Triomune; Cipla, Mumbai, India). In 52 children, the median height for age z score and weight for age z score rose from -2.54 to -2.17 (P<0.001) and from -2.30 to -1.67 (P=0.001), respectively, after 6 months of HAART. Hospitalization rates were significantly reduced after 6 months of HAART (17% vs. 58%; P<0.001). The median absolute CD4 count increased from 326 to 536 cells/microL (P<0.001), the median CD4 lymphocyte percentage rose from 5.8% before treatment to 15.4% (P<0.001), and the median viral load fell from 5.9 to 2.2 log10 copies/mL after 6 months of HAART (P<0.001). Among 43 infants, 47% and 67% achieved viral suppression to less than 100 copies/mL and 400 copies/mL, respectively, after 6 months of HAART.

CONCLUSION

Good early clinical and virologic response to NNRTI-based HAART was observed in HIV-1-infected Kenyan children with advanced HIV-1 disease.

Treatment Outcomes Stratified by Baseline Immunological Status among Young Children Receiving Nonnucleoside Reverse-Transcriptase Inhibitor-Based Antiretroviral Therapy in Resource-Limited Settings

A study of 568 children aged <5 years who commenced nonnucleoside reverse-transcriptase inhibitor-based antiretroviral therapy in resource-limited settings revealed good early outcomes. After 12 months of antiretroviral therapy, survival probability was 0.89 (95% confidence interval, 0.86-0.92), with no significant difference among children stratified on the basis of baseline immunological levels; 62% attained a CD4 cell percentage >25%, and 7% continued to have a CD4 cell percentage <15%.

Neurodevelopmental functioning in HIV-infected infants and young children before and after the introduction of protease inhibitor-based highly active antiretroviral therapy

OBJECTIVES

The purpose of this work was to examine the effects of HIV infection and the impact of highly active antiretroviral treatment with protease inhibitors on neurodevelopmental functioning during the first 3 years of life.

PATIENTS AND METHODS

Pediatric AIDS Clinical Trials Group 219/219C is a longitudinal cohort study that has enrolled HIV-infected (HIV+) and HIV-exposed but uninfected (HIV-) infants and children since 1993. Longitudinal profiles of neurodevelopmental functioning as measured by the Bayley Scales of Infant Development were compared by HIV-infection status before and after the availability of highly active antiretroviral therapy with a protease inhibitor and within infants with Bayley tests available before and after initiating protease inhibitor therapy.

RESULTS

In the pre-protease inhibitor era, mean mental and motor scores in HIV+ (n = 54) infants <1 year of age were significantly lower than those among HIV- infants (n = 221) and remained lower up to 2 years of age. After protease inhibitors became available, mean mental and motor functioning of HIV+ infants (n = 91) <1 year of age were still significantly lower than those of HIV- infants (n = 838). However, against a background of declining scores among the HIV- infants, there was evidence of limited improvement in the HIV+ infants relative to their uninfected peers. Among infants who had Bayley II evaluations before and after starting a protease inhibitor, there was a trend to improved mental and motor scores after initiation of protease inhibitor therapy.

CONCLUSIONS

The suppression of systemic viral replication and subsequent substantial improvements in survival and immunologic status brought about by highly active antiretroviral therapy have been followed by limited improvements in neurodevelopmental functioning in young children. Additional longitudinal research is needed to better understand the role of antiretroviral therapy as well as the impact of genetic and environmental factors on neurodevelopmental functioning in children affected by HIV.

Quantitative immunoassay to measure plasma and intracellular atazanavir levels: analysis of drug accumulation in cultured T cells

We have developed an enzyme immunoassay to measure atazanavir (ATV) levels in plasma and cells. Anti-ATV polyclonal antibodies were raised in rabbits by using a synthetic ATV derivative coupled to bovine serum albumin as the immunogen, and the enzyme tracer was prepared by chemically coupling the ATV derivative with acetylcholinesterase. These reagents were used to develop a sensitive competitive enzyme immunoassay performed in microtitration plates, and the lowest limit of quantification was 150 pg/ml, which is about 10 times more sensitive than previously published techniques. The plasma assay was performed, after a simple methanol extraction, with a minimum of 30 microl of plasma. This assay showed good precision and efficiency, since the rates of recovery from human plasma and cell extracts spiked with ATV ranged form 93 to 113%, with coefficients of variation of less than 10%. ATV concentrations were measured in peripheral blood mononuclear cells incubated with various ATV concentrations and in CEM cells in the absence or presence of antiretroviral drugs and drug transporter inhibitors. The results indicated a dose-dependent uptake (intracellular concentration/extracellular concentration ratio range, 0.04 to 19). A significant increase in the accumulation of ATV was noticed in the presence of P-glycoprotein and MRP1 inhibitors (dipyridamole, inter alia). Interestingly, efavirenz significantly increased the baseline accumulation of ATV, whereas nevirapine induced a marked reduction. This new enzyme immunoassay for measuring plasma and intracellular ATV levels was fully validated and provides an inexpensive and useful tool for routine therapeutic drug monitoring. Moreover, in vitro results suggested the implication of drug transporters and interactions with other antiviral drugs that should be further explored in human immunodeficiency virus-infected patients.

Partial treatment interruption of protease inhibitor-based highly active antiretroviral therapy regimens in HIV-infected children

Treatment guidelines for HIV-infected children recommend using combinations of reverse transcriptase inhibitors (RTIs) and protease inhibitors (PIs). Successful suppression of HIV replication and adherence to these regimens are often suboptimal because of multiple factors. For patients with detectable viremia and limited treatment options, therapy simplification consisting of RTIs, referred to as partial treatment interruption (PTI), may represent a temporizing option. We describe a cohort of 26 HIV-infected children who underwent treatment simplification by discontinuing the PI and continuing therapy with 2 or more RTIs. The subjects, who were identified retrospectively, were followed for a period of 24 to 96 weeks. Data collected included clinical information, viral load, and CD4T lymphocyte percentage (CD4%) at baseline and 24, 48, and 96 weeks after PTI. Twenty-six, 21, and 11 patients were evaluated at 24, 48, and 96 weeks, respectively. No child had Centers for Disease Control and Prevention-defined disease progression, and there were no significant changes in viral loads (P > 0.5) across all study intervals after interruption of the PIs. Although most children maintained a CD4% > 15%, comparisons of CD4% at 24 and 48 weeks demonstrated a statistically significant decrease compared with baseline. Therapy simplification by PTI may provide a practical option in patients intolerant of or failing PI-based highly active antiretroviral therapy.

Low immunologic response to highly active antiretroviral therapy in naive vertically human immunodeficiency virus type 1-infected children with severe immunodeficiency

We conducted a retrospective study to analyze the CD4 recovery of naive vertically human immunodeficiency virus-infected children with severe immunodeficiency who were followed up during at least 4 years of receiving highly active antiretroviral therapy (HAART). Children with baseline CD4 of <15% did not reach a mean CD4 of > or =25% after the 4th year on HAART. We conclude that starting HAART after severe immunosuppression of naive HIV-infected children may not be effective for recovery of normal %CD4.

Long-Term Effects of Highly Active Antiretroviral Therapy in Pretreated, Vertically HIV Type 1-Infected Children: 6 Years of Follow-Up

BACKGROUND

Several studies of children with human immunodeficiency virus (HIV) type 1 infection have demonstrated sustained increases in CD4+ cell count, even when virological failure has occurred after receipt of highly active antiretroviral therapy (HAART), but these studies were of limited duration. Moreover, the CD4+ cell count threshold at which antiretroviral treatment should be initiated is still unsettled. The aim of this study was to define the long-term impact of HAART on CD4+ cell percentage and viral load according to CD4+ cell percentages before HAART was initiated.

METHODS

We conducted a retrospective study of 113 pretreated HIV-1-infected children stratified by pre-HAART CD4+ cell percentage (<5%, 5%-15%, 15%-25%, and >25%). The inclusion criteria were as follows: initiating HAART with a protease inhibitor, having 6 years of follow-up after starting HAART, having a CD4+ cell count or viral load recorded before initiation of HAART, and having received mono- or dual-nucleoside therapy before starting HAART.

RESULTS

During the first 2 years of HAART, HIV-1-infected children experienced a significant increase in CD4+ cell percentage and a decrease in viral load (P<.05). During their last 4 years of receiving HAART, we found a significant decrease in viral load but not an increase in CD4+ cell percentage, because the CD4+ cell percentage reached a plateau after the second year of HAART. Moreover, children with CD4+ cell percentages of <5% at baseline did not achieve CD4+ cell percentages of >25% after 6 years of HAART. Children with CD4+ cell percentages of 5%-25% at baseline had a strong negative association with achieving CD4+ cell percentages of >30% for at least 6 and 12 months but not with achieving CD4+ cell percentages of >30% for at least 24 months.

CONCLUSIONS

Long-term HAART allowed for restoration of CD4+ cell counts and control of viral loads in HIV-1-infected children. However, initiating HAART after severe immunosuppression has occurred is detrimental for the restoration of the CD4+ cell count.

Long-term experience with combination antiretroviral therapy that contains nelfinavir for up to 7 years in a pediatric cohort

OBJECTIVE

We sought to provide long-term data on the clinical, immunologic, and virologic response to highly active antiretroviral therapy in infants and children who are naive to protease inhibitors.

METHODS

HIV-1-infected children who were naive to protease inhibitors were treated with a combination of nelfinavir and 2 nucleoside reverse transcriptase inhibitors (stavudine and lamivudine) in an observational, prospective, single-center study. Virologic failure-free survival was assessed by Kaplan-Meier analyses. The increase in CD4+ T cells during follow-up was estimated with a generalized linear model incorporating repeated measurements.

RESULTS

Thirty-nine HIV-1-infected children were included and followed for a median period of 227 weeks (interquartile range: 108-275 weeks). The virologic failure-free survival rate was 74%, 66%, 58%, and 54% after 48, 96, 144, and 240 weeks, respectively. Children who experienced virologic failure in 48 weeks (or 96 weeks) were younger at baseline compared with the responders (0.8 vs 5.3 years). Eighteen children remained on the regimen for >5 years. All children, including the nonresponders, showed a sustained immunologic response. Grades 3 to 4 toxicity was observed in 2 patients only. Eleven developed clinically evident lipodystrophy.

CONCLUSION

Combination therapy can be used safely in infants and children over a long period. Young age is strongly associated with virologic failure. Although the virologic response declined, immunologic parameters and clinical improvement were sustained up to 7 years, at the expense of lipodystrophy.

Quality of life for children and adolescents: impact of HIV infection and antiretroviral treatment

BACKGROUND

HIV/AIDS mortality rates in the United States are declining; pediatric HIV has become a chronic disease, with quality of life (QoL) outcomes assuming greater importance.

OBJECTIVES

To compare QoL among HIV-infected and uninfected children and to assess the impact of different antiretroviral regimens on QoL among HIV-infected children.

METHODS

Perinatally exposed, HIV-infected (N = 1847) and uninfected (N = 712) children and adolescents were studied. Among infected children, 1283 were available for the antiretroviral regimen analysis. QoL domain scores were assessed for subjects 6 months to 4 years, 5 to 11 years, and 12 to 21 years of age, and the impact of infection status and alternative treatment regimens on QoL domains was evaluated.

RESULTS

HIV infection was associated with significantly worse mean adjusted scores for functional status among children 6 months to 4 years of age and health perceptions, physical resilience, physical functioning, and social/role functioning among those 5 to 11 years of age. However, uninfected children 5 to 11 years of age reported significantly worse psychological functioning. HIV-infected children (5-11 years of age) and adolescents (12-21 years of age) receiving no antiretroviral treatment had worse health perceptions. Adolescents receiving no antiretroviral agents also had worse symptoms. When antiretroviral regimens were compared, adolescents receiving protease inhibitor plus nonnucleoside reverse transcriptase inhibitor-containing therapy had worse symptoms, compared with those receiving protease inhibitor-containing therapy; otherwise, no significant differences were found.

CONCLUSIONS

Generally parents of HIV-infected children 6 months to 4 years and 5 to 11 years of age generally reported lower mean QoL scores than did parents of uninfected children, although worse psychological functioning was reported for uninfected children. HIV-infected adolescents not receiving antiretroviral treatment had worse health perceptions and symptoms. We found no consistent QoL differences among children receiving different antiretroviral regimens.

Impact of long-term viral suppression in CD4+ recovery of HIV-children on Highly Active Antiretroviral Therapy

BACKGROUND

The effects of HAART may differ between children and adults because children have a developing immune system, and the long-term immunological outcome in HIV-infected children on HAART is not well-known. A major aim of our study was to determine CD4+ evolution associated with long-term VL control during 4 years of observation on HAART.

METHODS

We carried out a retrospective study on a cohort of 160 vertically HIV-infected children. It was carried out from 1996 to 2004 in six large Spanish pediatric referral hospitals. We compared 33 children who had long-term VL suppression (VL < or = 400 copies/ml) in the first 12 months of follow-up and maintained that level throughout follow-up (Responders-group), and 127 children with persistently detectable VL in spite of ART switches (Non-Responders-group).

RESULTS

We observed a quick initial and significant increase in CD4+ counts from the baseline to 12 months on HAART in both groups (p < 0.01). The Non-Responders group sustained CD4+ increases and most of these children maintained high CD4+ level counts (> or = 25%). The Non-Responders group reached a plateau between 26% and 27% CD4+ at the first 12 months of follow-up that remained stable during the following 3 years. However, the Responders group reached a plateau between 30% and 32% CD4+ at 24, 36 and 48 months of follow-up. We found that the Responders group had higher CD4+ count values and higher percentages of children with CD4+ > or = 25% than the Non-Responders group (p < 0.05) after month 12.

CONCLUSION

Long-term VL suppression in turn induces large beneficial effects in immunological responses. However, it is not indispensable to recover CD4+ levels.

HIV-1-infected children on HAART: Immunologic features of three different levels of viral suppression

BACKGROUND

HIV-1-infected children show changes of blood lymphocyte subpopulations. We have, therefore, investigated how highly active anti-retroviral therapy (ART) alter these subsets. Blood samples were taken from 41 HIV-1-infected children on ART who were divided into groups showing good, partial and poor responses to ART on the basis of viral load (VL) measurement in blood. The observations were compared to those seen in 20 uninfected children.

METHODS

The samples were studied using 4-color flow cytometry for "naïve", central memory and effector memory cells as well as for CD38 expression as the sign of activation within both the CD4+ and the CD8+ T cell populations. HIV-1 infected children were also evaluated for the presence and the titers of antibodies induced by vaccination against childhood infections in our patients while on HAART.

RESULTS

Lymphocyte counts were lower in the "poor" viral load responding (VLR) group when compared with partial and good VLRs. Poor VLRs had lower total and naïve CD4+ T cell counts. HIV-1-infected children from all three groups had high CD8+ T cell counts. Central memory CD4+ and CD8+ T cell percentages were particularly low in the poor VLR group while in the poor VLR group the percentages of effector memory CD4+ and CD8+ T cells were higher when compared with the control group. Higher cellular activation of CD8+ T cells was observed in HIV-1-infected children, particularly when analyzed for the intensity of CD38 expression in the poor VLR group. CD5 expression on B cells was higher among all HIV-1-infected children. Antibodies to tetanus, diphtheria, measles, rubella, and hepatitis B were present in a large proportion of children but the titers were similarly low for all three groups of HIV-infected children.

CONCLUSIONS

Children with different levels of viral response to HAART present immune phenotype characteristics that tend to place the children with partial and good virological responses into the same group. These children are still moderately deficient in their immune responses but show better recovery than seen with children in the poor VLR group. These observations indicate that the proportions of central memory cells among the CD4+ T cells and the intensity of the expression of CD38 activation antigen on CD8+ T cells provide more informative parameters for monitoring children on HAART than the absolute numbers of CD4+ and CD8+ T cells alone.

Children with HIV: improved mortality and morbidity with combination antiretroviral therapy

PURPOSE OF REVIEW

Advances in the management of children with vertical HIV-1 infection in the developing and developed worlds are discussed in reference to literature published in 2003/4. Studies in mother-to-child transmission are beyond the scope of this review.

RECENT FINDINGS

Improvements in mortality and morbidity from HIV-1 infection following combination antiretroviral therapy are extremely encouraging. There is an increase in the understanding of the immune response to HIV-1 in infants and children and a possible future role for immunomodulatory therapies. Preliminary data are available on the timing of initiation of antiretroviral therapy, the optimization of drug combinations and the clinical interpretation of genotypic resistance testing and therapeutic drug monitoring. Evidence is emerging that early antiretroviral therapy can protect the central nervous system in infants. In resource-limited settings, mortality and morbidity remain extremely high but low-cost health interventions such as prophylactic co-trimoxazole can reduce mortality prior to the expansion of antiretroviral therapy programmes.

SUMMARY

Further randomized controlled trials assessing antiretroviral therapy combinations with a sustained virological/immunological response with minimal toxicities are required. The roles of therapeutic drug monitoring and resistance testing require further elucidation. The expansion of antiretroviral therapy programmes is essential for children with HIV living in resource-limited settings.

The rate of serious bacterial infections among HIV-infected children with immune reconstitution who have discontinued opportunistic infection prophylaxis

OBJECTIVE

Receipt of highly active antiretroviral therapy is associated with a decrease in the incidence of opportunistic infections (OIs) among HIV-infected adults. The goal of Pediatric AIDS Clinical Trials Group protocol 1008 was to evaluate prospectively the incidence of serious bacterial infections (SBIs) and other OIs after discontinuation of OI and/or Pneumocystis jiroveci pneumonia (PCP) prophylaxis among HIV-infected pediatric subjects who experienced immune reconstitution while receiving stable antiretroviral therapy.

METHODS

HIV-infected children and adolescents, 2 to 21 years of age, who had received OI and/or PCP prophylaxis for > or =6 months were enrolled if they had sustained responses (>16 weeks before study entry) to antiretroviral therapy, with CD4+ cell percentages of > or =20% for patients >6 years of age or > or =25% for patients 2 to 6 years of age. Prophylaxis was discontinued at entry. To identify whether any correlation existed between functional immune reconstitution and protection from OIs, subjects were immunized with the hepatitis A virus vaccine. The association between the humoral immune response and the likelihood of developing an OI was evaluated.

RESULTS

A total of 235 HIV-infected subjects from 43 participating sites had a median follow-up period of 132 weeks, yielding 547 person-years of observation. Twenty SBIs were observed among 19 subjects, resulting in an incidence rate of 3.66 SBIs per 100 person-years (95% confidence interval: 2.24-5.66 SBIs per 100 person-years). Sixteen of the events were presumed bacterial pneumonia, with 4 proven SBIs. One participant experienced 2 separate pneumonia episodes, of presumed bacterial cause. Ten subjects who developed SBIs had baseline CD4+ cell counts of > or =750 cells per mm3, and 15 had CD4+ cell percentages of > or =25% at the time of their SBIs. Two subjects died as a result of non-SBI-related causes. There were no statistically significant differences in changes over time in CD4+ cell counts or CD4+ cell percentages between subjects who experienced primary end points and those who did not. There was no evidence that baseline protease inhibitor use, gender, race/ethnicity, age, or CD4+ cell count or percentage affected the time to development of a SBI.

CONCLUSIONS

OI or PCP prophylaxis can be withdrawn safely for HIV-infected pediatric patients who experience CD4+ cell recovery while receiving stable antiretroviral therapy. More studies are needed to assess the association between antibody responses to neoantigens and the development of SBIs.