Discordance between CD4 cell count and CD4 cell percentage: implications for when to start antiretroviral therapy in HIV-1 infected children

Antiretroviral treatment for HIV infection: Swedish recommendations 2019

The Swedish Reference Group for Antiviral Therapy (RAV) published recommendations for the treatment of HIV infection in this journal most recently in 2017. An expert group under the guidance of RAV here provides updated recommendations. The most important updates in the present guidelines are the following: (a) The risk of HIV transmission through condomless sex from individuals with fully suppressed HIV viral load is effectively zero. (b) Pre-exposure prophylaxis (PrEP) is recommended for groups with a high risk of HIV infection. (c) Since the last update, two new substances have been registered: bictegravir and doravirine. (d) Dual treatment may be an alternative in selected patients, using lamivudine + dolutegravir or lamivudine + boosted darunavir/atazanavir. As with previous publications, recommendations are evidence-graded in accordance with the Oxford Centre for Evidence Based Medicine. This document does not cover treatment of opportunistic infections and tumours.

Temporal Improvements in Long-term Outcome in Care Among HIV-infected Children Enrolled in Public Antiretroviral Treatment Care: An Analysis of Outcomes From 2004 to 2012 in Zimbabwe

BACKGROUND

Increasing numbers of children are requiring long-term HIV care and antiretroviral treatment (ART) in public ART programs in Africa, but temporal trends and long-term outcomes in care remain poorly understood.

METHODS

We analyzed outcomes in a longitudinal cohort of infants (<2 years of age) and children (2-10 years of age) enrolling in a public tertiary ART center in Zimbabwe over an 8-year period (2004-2012).

RESULTS

The clinic enrolled 1644 infants and children; the median age at enrollment was 39 months (interquartile range: 14-79), with a median CD4% of 17.0 (interquartile range: 11-24) in infants and 15.0 (9%-23%) in children (P = 0.0007). Among those linked to care, 33.5% dropped out of care within the first 3 months of enrollment. After implementation of revised guidelines in 2009, decentralization of care and increased access to prevention of mother to child transmission services, we observed an increase in infants (48.9%-68.3%; P < 0.0001) and children (48.9%-68.3%; P < 0.0001) remaining in care for more than 3 months. Children enrolled from 2009 were younger, had lower World Health Organization clinical stage, improved baseline CD4 counts than those who enrolled in 2004-2008. Long-term retention in care also improved with decreasing risk of loss from care at 36 months for infants enrolled from 2009 (aHR: 0.57; 95% confidence interval: 0.34-0.95; P = 0.031). ART eligibility at enrollment was a significant predictor of long-term retention in care, while delayed ART initiation after 5 years of age resulted in failure to fully reconstitute CD4 counts to age-appropriate levels despite prolonged ART.

CONCLUSIONS

Significant improvements have been made in engaging and retaining children in care in public ART programs in Zimbabwe. Guideline and policy changes that increase access and eligibility will likely to continue to support improvement in pediatric HIV outcomes.

Modelling CD4 T Cell Recovery in Hepatitis C and HIV Co-infected Children Receiving Antiretroviral Therapy

BACKGROUND

The effect of hepatitis C virus (HCV) coinfection on CD4 T cell recovery in treated HIV-infected children is poorly understood.

OBJECTIVE

To compare CD4 T cell recovery in HIV/HCV coinfected children with recovery in HIV monoinfected children.

METHOD

We studied 355 HIV monoinfected and 46 HIV/HCV coinfected children receiving antiretroviral therapy (ART) during a median follow-up period of 4.2 years (interquartile range: 2.7-5.3 years). Our dataset came from the Ukraine pediatric HIV Cohort and the HIV/HCV coinfection study within the European Pregnancy and Paediatric HIV Cohort Collaboration. We fitted an asymptotic nonlinear mixed-effects model of CD4 T cell reconstitution to age-standardized CD4 counts in all 401 children and investigated factors predicting the speed and extent of recovery.

RESULTS

We found no significant impact of HCV coinfection on either pre-ART or long-term age-adjusted CD4 counts (z scores). However, the rate of increase in CD4 z score was slower in HIV/HCV coinfected children when compared with their monoinfected counterparts (P < 0.001). Both monoinfected and coinfected children starting ART at younger ages had higher pre-ART (P < 0.001) and long-term (P < 0.001) CD4 z scores than those who started when they were older.

CONCLUSIONS

HIV/HCV coinfected children receiving ART had slower CD4 T cell recovery than HIV monoinfected children. HIV/HCV coinfection had no impact on pre-ART or long-term CD4 z scores. Early treatment of HIV/HCV coinfected children with ART should be encouraged.

Mortality in Children with Human Immunodeficiency Virus Initiating Treatment: A Six-Cohort Study in Latin America

OBJECTIVES

To assess the risks of and factors associated with mortality, loss to follow-up, and changing regimens after children with HIV infected perinatally initiate combination antiretroviral therapy (cART) in Latin America and the Caribbean.

STUDY DESIGN

This 1997-2013 retrospective cohort study included 1174 antiretroviral therapy-naïve, perinatally infected children who started cART age when they were younger than 18 years of age (median 4.7 years; IQR 1.7-8.8) at 1 of 6 cohorts from Argentina, Brazil, Haiti, and Honduras, within the Caribbean, Central and South America Network for HIV Epidemiology. Median follow-up was 5.6 years (IQR 2.3-9.3). Study outcomes were all-cause mortality, loss to follow-up, and major changes in cART. We used Cox proportional hazards models stratified by site to examine the association between predictors and times to death or changing regimens.

RESULTS

Only 52% started cART at younger than 5 years of age; 19% began a protease inhibitor. At cART initiation, median CD4 count was 472 cells/mm³ (IQR 201-902); median CD4% was 16% (IQR 10-23). Probability of death was high in the first year of cART: 0.06 (95% CI 0.04-0.07). Five years after cART initiation, the cumulative mortality incidence was 0.12 (95% CI 0.10-0.14). Cumulative incidences for loss to follow-up and regimen change after 5 years were 0.16 (95% 0.14-0.18) and 0.30 (95% 0.26-0.34), respectively. Younger children had the greatest risk of mortality, whereas older children had the greatest risk of being lost to follow-up or changing regimens.

CONCLUSIONS

Innovative clinical and community approaches are needed for quality improvement in the pediatric care of HIV in the Americas.

Antiretroviral treatment for HIV infection: Swedish recommendations 2016

The Swedish Medical Products Agency and the Swedish Reference Group for Antiviral Therapy (RAV) have jointly published recommendations for the treatment of HIV infection on seven previous occasions (2002, 2003, 2005, 2007, 2009, 2011 and 2014). In February 2016, an expert group under the guidance of RAV once more revised the guidelines. The most important updates in the present guidelines are as follows: Tenofovir alafenamide (TAF) has recently been registered. TAF has several advantages over tenofovir disoproxilfumarate (TDF) and is recommended instead of TDF in most cases. First-line treatment for previously untreated individuals includes dolutegravir, boosted darunavir or efavirenz with either abacavir/lamivudine or tenofovir (TDF/TAF)/emtricitabine. Pre-exposure prophylaxis (PrEP) is recommended for high-risk individuals. As in the case of the previous publication, recommendations are evidence-graded in accordance with the Oxford Centre for Evidence Based Medicine ( http://www.cebm.net/oxford-centre-evidence-based-medicine-levels-evidence-march-2009/ ) ( Table 1 ). This document does not cover treatment of opportunistic infections and tumours. [Table: see text].

Paediatric European Network for Treatment of AIDS (PENTA) guidelines for treatment of paediatric HIV-1 infection 2015: optimizing health in preparation for adult life

The 2015 Paediatric European Network for Treatment of AIDS (PENTA) guidelines provide practical recommendations on the management of HIV‐1 infection in children in Europe and are an update to those published in 2009. Aims of treatment have progressed significantly over the last decade, moving far beyond limitation of short‐term morbidity and mortality to optimizing health status for adult life and minimizing the impact of chronic HIV infection on immune system development and health in general. Additionally, there is a greater need for increased awareness and minimization of long‐term drug toxicity. The main updates to the previous guidelines include: an increase in the number of indications for antiretroviral therapy (ART) at all ages (higher CD4 thresholds for consideration of ART initiation and additional clinical indications), revised guidance on first‐ and second‐line ART recommendations, including more recently available drug classes, expanded guidance on management of coinfections (including tuberculosis, hepatitis B and hepatitis C) and additional emphasis on the needs of adolescents as they approach transition to adult services. There is a new section on the current ART ‘pipeline’ of drug development, a comprehensive summary table of currently recommended ART with dosing recommendations. Differences between PENTA and current US and World Health Organization guidelines are highlighted and explained.

Induction with lopinavir-based treatment followed by switch to nevirapine-based regimen versus non-nucleoside reverse transcriptase inhibitors-based treatment for first line antiretroviral therapy in HIV infected children three years and older

BACKGROUND

The World Health Organization recommends non-nucleoside reverse transcriptase inhibitors (NNRTIs)-based antiretroviral therapy (ART) for children three years and older. In younger children, starting ART with lopinavir boosted with ritonavir (LPVr) results in lower risk of virological failure, but data in children three years and older are scarce, and long-term ART with LPVr is problematic in resource-poor settings.

METHODOLOGY

Retrospective cohort of children three years and older who started triple ART including LPVr or a NNRTI between 2007 and 2013 in a rural setting in India. Children who started LPVr were switched to nevirapine-based ART after virological suppression. We analysed two outcomes, virological suppression (HIV-RNA <400 copies/ml) within one year of ART using logistic regression, and time to virological failure (HIV-RNA >1000 copies/ml) after virological suppression using Cox proportional hazard regression. A sensitivity analysis was performed using inverse probability of treatment weighting (IPTW) based of propensity score methods.

FINDINGS

Of 325 children having a viral load during the first year of ART, 74/83 (89.2%) in the LPVr group achieved virological suppression versus 185/242 (76.5%) in the NNRTI group. In a multivariable analysis, the use of LPVr-based ART was associated with higher probability of virological suppression (adjusted odds ratio 3.19, 95% confidence interval [CI] 1.11-9.13). After IPTW, the estimated risk difference was 12.2% (95% CI, 2.9-21.5). In a multivariable analysis including 292 children who had virological suppression and available viral loads after one year of ART, children switched from LPVr to nevirapine did not have significant higher risk of virological failure (adjusted hazard ratio 1.18, 95% CI 0.36-3.81).

CONCLUSIONS

In a cohort of HIV infected children three years and older in a resource-limited setting, an LPVr induction- nevirapine maintenance strategy resulted in more initial virological suppression and similar incidence of virological failure after initial virological suppression than NNRTI-based regimens.

Association between age at antiretroviral therapy initiation and 24-month immune response in West-African HIV-infected children

OBJECTIVE

We describe the association between age at antiretroviral therapy (ART) initiation and 24-month CD4 cell response in West African HIV-infected children.

METHODS

All HIV-infected children from the IeDEA paediatric West African cohort, initiating ART, with at least two CD4 cell count measurements, including one at ART initiation (baseline) were included. CD4 cell gain on ART was estimated using a multivariable linear mixed model adjusted for baseline variables: age, CD4 cell count, sex, first-line ART regimen. Kaplan-Meier survival curves and a Cox proportional hazards regression model compared immune recovery for age within 24 months post-ART.

RESULTS

Of the 4808 children initiated on ART, 3014 were enrolled at a median age of 5.6 years; 61.2% were immunodeficient. After 12 months, children at least 4 years at baseline had significantly lower CD4 cell gains compared with children less than 2 years, the reference group (P<0.001). However, by 24 months, we observed higher CD4 cell gain in children who initiated ART between 3 and 4 years compared with those less than 2 years (P<0.001). The 24-month CD4 cell gain was also strongest in immunodeficient children at baseline. Among these children, 75% reached immune recovery: 12-month rates were significantly highest in all those aged 2-5 years at ART initiation compared with those less than 2 years. Beyond 12 months on ART, immune recovery was significantly lower in children initiated more than 5 years (adjusted hazard ratio: 0.69, 95% confidence interval: 0.56-0.86).

CONCLUSION

These results suggest that both the initiation of ART at the earliest age less than 5 years and before any severe immunodeficiency is needed for improving 24-month immune recovery on ART.

Mortality and Loss to Follow up Before Initiation of Antiretroviral Therapy Among HIV-Infected Children Eligible for HIV Treatment

Data on attrition due to mortality or loss to follow-up (LTFU) from antiretroviral therapy (ART) eligibility to ART initiation of HIV-infected children are scarce. The aim of this study is to describe attrition before ART initiation of 247 children who were eligible for ART in a cohort study in India. Multivariable analysis was performed using competing risk regression. The cumulative incidence of attrition was 12.6% (95% confidence interval, 8.7-17.3) after five years of follow-up, and the attrition rate was higher during the first months after ART eligibility. Older children (>9 years) had a lower mortality risk before ART initiation than those aged <2 years. Female children had a lower risk of LTFU before ART initiation than males. Children who belonged to scheduled tribes had a higher risk of delayed ART initiation and LTFU. Orphan children had a higher risk of delayed ART initiation and mortality. Children who were >3 months in care before ART eligibility were less likely to be LTFU. The 12-month risk of AIDS, which was calculated using the absolute CD4 cell count and age, was strongly associated with mortality. A substantial proportion of ART-eligible children died or were LTFU before the initiation of ART. These findings can be used in HIV programmes to design actions aimed at reducing the attrition of ART-eligible children in India.

Separating signal from noise: the challenge of identifying useful biomarkers in sepsis

Sepsis diagnosis remains based largely on clinical presentation despite significant advances in the understanding of underlying pathophysiology and host-pathogen interactions. The systematic review article by Zonneveld and colleagues in the previous issue of Critical Care describes another potential avenue of study for using biomarkers for sepsis diagnosis and prognostication. Soluble leukocyte adhesion molecules and their associated sheddase enzymes vary in detectable levels and activity in patients in relation to immunologic status, age, and systemic inflammation, including in the setting of sepsis. Unfortunately, studies of these molecules as diagnostic or prognostic aids (or both) in sepsis have thus far been disappointing. Zonneveld and colleagues propose two potential avenues to enhance the performance characteristics of soluble adhesion molecules and their sheddases in sepsis diagnosis and prognosis: (a) identifying age-adjusted normal values for soluble leukocyte adhesion molecules and their sheddases and (b) investigating simultaneous measurement of both soluble adhesion molecules and sheddases in integrated sepsis evaluation schema. This commentary discusses the proposed solutions of Zonneveld and colleagues in more detail and outlines additional considerations that should be addressed in order to develop robust and valid diagnostic and prognostic tools for clinicians managing patients with sepsis.

Description of the cascade of care and factors associated with attrition before and after initiating antiretroviral therapy of HIV infected children in a cohort study in India

In low- and middle-income countries, the attrition across the continuum of care of HIV infected children is not well known. The aim of this study was to investigate predictors of mortality and loss to follow up (LTFU) in HIV infected children from a cohort study in India and to describe the cascade of care from HIV diagnosis to virological suppression after antiretroviral therapy (ART) initiation. Multivariable analysis was performed using competing risk regression. The cumulative incidence of attrition due to mortality or LTFU after five year of follow-up was 16% from entry into care to ART initiation and 24.9% after ART initiation. Of all children diagnosed with HIV, it was estimated that 91.9% entered into care, 77.2% were retained until ART initiation, 58% stayed in care after ART initiation, and 43.4% achieved virological suppression on ART. Approximately half of the attrition occurred before ART initiation, and the other half after starting ART. Belonging to socially disadvantaged communities and living >90 min from the hospital were associated with a higher risk of attrition. Being >10 years old and having higher 12-month risk of AIDS (calculated using the absolute CD4 lymphocyte count and the age) were associated with an increased risk of mortality. These findings indicate that we should consider placing more emphasis on promoting research and implementing interventions to improve the engagement of HIV infected children in pre-ART care. The results of this study can be used by HIV programmes to design interventions aimed at reducing the attrition across the continuum of care of HIV infected children in India.

Predictors of loss to follow-up after engagement in care of HIV-infected children ineligible for antiretroviral therapy in an HIV cohort study in India

INTRODUCTION

Previous studies performed in low- and middle-income countries have shown that nearly half of HIV-infected adults not eligible for antiretroviral therapy (ART) at the time of enrolment in care are lost to follow-up (LTFU). However, data about the attrition from enrolment in care to ART eligibility of HIV-infected children are scarce, especially outside sub-Saharan Africa.

METHODS

This is a retrospective study about the attrition before ART eligibility of 282 children ineligible for ART at enrolment in care in a cohort study in India. Multivariate analysis was performed using competing risk regression.

RESULTS

During 5695 child-months of follow-up, three children died, 36 were LTFU and 144 became ART eligible. The cumulative incidence of attrition (mortality and LTFU) was 15.6% (95% confidence interval [CI], 11.3-20.5) at five years, and the attrition rate was higher during the first year after enrolment in care. The cumulative incidence of LTFU and mortality was 14.4% (95% CI, 10.2-19.2) and 1.2% (95% CI, 0.3-3.3) at five years, respectively. Children with a 12-month AIDS risk <3% had a higher risk of LTFU (subdistribution hazard ratio [SHR] 10.77, 95% CI 1.93-60.07) than those with a risk >4%. Those children whose father had died had a lower risk of LTFU (SHR 0.26, 95% CI 0.09-0.75) than those whose parents were alive and were living in a rented house. Children aged 10-14 had a lower risk of LTFU (SHR 0.12, 95% CI 0.03-0.55) than those aged 5-9 years.

CONCLUSION

In our setting, a substantial proportion of children ineligible for ART are lost to follow-up before ART eligibility, especially those with younger age, less severe immunosuppression or living with parents in poor socio-economic conditions. These findings can be used by HIV programmes to design interventions aimed at reducing the attrition of pre-ART care of HIV-infected children in India.

Predicting patterns of long-term CD4 reconstitution in HIV-infected children starting antiretroviral therapy in sub-Saharan Africa: a cohort-based modelling study

BACKGROUND

Long-term immune reconstitution on antiretroviral therapy (ART) has important implications for HIV-infected children, who increasingly survive into adulthood. Children's response to ART differs from adults', and better descriptive and predictive models of reconstitution are needed to guide policy and direct research. We present statistical models characterising, qualitatively and quantitatively, patterns of long-term CD4 recovery.

METHODS AND FINDINGS

CD4 counts every 12 wk over a median (interquartile range) of 4.0 (3.7, 4.4) y in 1,206 HIV-infected children, aged 0.4-17.6 y, starting ART in the Antiretroviral Research for Watoto trial (ISRCTN 24791884) were analysed in an exploratory analysis supplementary to the trial's pre-specified outcomes. Most (n = 914; 76%) children's CD4 counts rose quickly on ART to a constant age-corrected level. Using nonlinear mixed-effects models, higher long-term CD4 counts were predicted for children starting ART younger, and with higher CD4 counts (p<0.001). These results suggest that current World Health Organization-recommended CD4 thresholds for starting ART in children ≥5 y will result in lower CD4 counts in older children when they become adults, such that vertically infected children who remain ART-naïve beyond 10 y of age are unlikely ever to normalise CD4 count, regardless of CD4 count at ART initiation. CD4 profiles with four qualitatively distinct reconstitution patterns were seen in the remaining 292 (24%) children. Study limitations included incomplete viral load data, and that the uncertainty in allocating children to distinct reconstitution groups was not modelled.

CONCLUSIONS

Although younger ART-naïve children are at high risk of disease progression, they have good potential for achieving high CD4 counts on ART in later life provided ART is initiated following current World Health Organization (WHO), Paediatric European Network for Treatment of AIDS, or US Centers for Disease Control and Prevention guidelines. In contrast, to maximise CD4 reconstitution in treatment-naïve children >10 y, ART should ideally be considered even if there is a low risk of immediate disease progression. Further exploration of the immunological mechanisms for these CD4 recovery profiles should help guide management of paediatric HIV infection and optimise children's immunological development. Please see later in the article for the Editors' Summary.

Late-stage diagnosis of HIV infection in Brazilian children: evidence from two national cohort studies

This study analyzed data from two consecutive retrospective cohort samples (1983 to 1998 and 1999 to 2002) of Brazilian children with AIDS (N = 1,758) through mother-to-child-transmission. Late-stage diagnosis (CDC category C) was investigated in relation to the following variables: year of birth, year of HIV diagnosis, and time periods related to changes in government treatment guidelines. Late-stage diagnosis occurred in 731 (41.6%) of cases and was more prevalent in infants under 12 months of age. The rate of late-stage diagnosis decreased from 48% to 36% between the two periods studied. We also observed a reduction in the proportion of late-stage diagnoses and the time lapse between HIV diagnosis and ART initiation. A significant association was found between timely diagnosis and having been born in recent years (OR = 0.62; p = 0.009) and year of HIV diagnosis (OR = 0.72; p = 0.002/OR = 0.62; p < 0.001). Infants under the age of 12 months were more likely to be diagnosed at a late stage than older children (OR = 1.70; p = 0.004). Despite advances, there is a need to improve the effectiveness of policies and programs focused on improving early diagnosis and management of HIV/AIDS.

Mortality in the year following antiretroviral therapy initiation in HIV-infected adults and children in Uganda and Zimbabwe

In low-income countries, children ≥4 years and adults with low CD4 count have equally high mortality risk in the 3 months after initiation of antiretroviral therapy, similar to that of untreated individuals. Bacterial infections play a major role; targeted interventions could have important benefits.

Background. Adult mortality in the first 3 months on antiretroviral therapy (ART) is higher in low-income than in high-income countries, with more similar mortality after 6 months. However, the specific patterns of changing risk and causes of death have rarely been investigated in adults, nor compared with children in low-income countries.

Methods. We used flexible parametric hazard models to investigate how mortality risks varied over the first year on ART in human immunodeficiency virus–infected adults (aged 18–73 years) and children (aged 4 months to 15 years) in 2 trials in Zimbabwe and Uganda.

Results. One hundred seventy-nine of 3316 (5.4%) adults and 39 of 1199 (3.3%) children died; half of adult/pediatric deaths occurred in the first 3 months. Mortality variation over year 1 was similar; at all CD4 counts/CD4%, mortality risk was greatest between days 30 and 50, declined rapidly to day 180, then declined more slowly. One-year mortality after initiating ART with 0–49, 50–99 or ≥100 CD4 cells/μL was 9.4%, 4.5%, and 2.9%, respectively, in adults, and 10.1%, 4.4%, and 1.3%, respectively, in children aged 4–15 years. Mortality in children aged 4 months to 3 years initiating ART in equivalent CD4% strata was also similar (0%–4%: 9.1%; 5%–9%: 4.5%; ≥10%: 2.8%). Only 10 of 179 (6%) adult deaths and 1 of 39 (3%) child deaths were probably medication-related. The most common cause of death was septicemia/meningitis in adults (20%, median 76 days) and children (36%, median 79 days); pneumonia also commonly caused child deaths (28%, median 41 days).

Conclusions. Children ≥4 years and adults with low CD4 values have remarkably similar, and high, mortality risks in the first 3 months after ART initiation in low-income countries, similar to cohorts of untreated individuals. Bacterial infections are a major cause of death in both adults and children; targeted interventions could have important benefits.

Early antiretroviral treatment reduces risk of bacille Calmette-Guérin immune reconstitution adenitis

SETTING

Two centres in Soweto and Cape Town, South Africa.

OBJECTIVE

To assess the effects of timing of initiation of antiretroviral treatment (ART) and other factors on the risk of bacille Calmette-Guérin (BCG) related regional adenitis due to immune reconstitution inflammatory syndrome (BCG-IRIS) in human immunodeficiency virus (HIV) infected infants.

DESIGN

HIV-infected infants aged 6-12 weeks with CD4 count ≥25% enrolled in the Children with HIV Early Antiretroviral Therapy (CHER) Trial received early (before 12 weeks) or deferred (after immunological or clinical progression) ART; infants with CD4 count <25% all received early ART. All received BCG vaccination after birth. Reactogenicity to BCG was assessed prospectively during routine study follow-up.

RESULTS

Of 369 infants, 32 (8.7%) developed BCG-IRIS within 6 months of starting ART, 28 (88%) within 2 months after ART initiation. Of the 32 cases, 30 (93.8%) had HIV-1 RNA > 750 000 copies/ml at initiation. Incidence of BCG-IRIS was 10.9 and 54.3 per 100 person-years (py) among infants with CD4 count ≥25% at enrolment receiving early (at median age 7.4 weeks) vs. deferred (23.2 weeks) ART, respectively (HR 0.24, 95%CI 0.11-0.53, P < 0.001). Infants with CD4 count <25% receiving early ART had intermediate incidence (41.7/100 py). Low CD4 counts and high HIV-1 RNA at initiation were the strongest independent risk factors for BCG-IRIS.

CONCLUSIONS

Early ART initiation before immunological and/or clinical progression substantially reduces the risk of BCG-IRIS regional adenitis.

Age and CD4 count at initiation of antiretroviral therapy in HIV-infected children: effects on long-term T-cell reconstitution

BACKGROUND

Effective therapies and reduced AIDS-related morbidity and mortality have shifted the focus in pediatric human immunodeficiency virus (HIV) from minimizing short-term disease progression to maintaining optimal long-term health. We describe the effects of children's age and pre-antiretroviral therapy (ART) CD4 count on long-term CD4 T-cell reconstitution.

METHODS

CD4 counts in perinatally HIV-infected, therapy-naive children in the Paediatric European Network for the Treatment of AIDS 5 trial were monitored following initiation of ART for a median 5.7 years. In a substudy, naive and memory CD4 counts were recorded. Age-standardized measurements were analyzed using monophasic, asymptotic nonlinear mixed-effects models.

RESULTS

One hundred twenty-seven children were studied. Older children had lower age-adjusted CD4 counts in the long term and at treatment initiation (P < .001). At all ages, lower counts before treatment were associated with impaired recovery (P < .001). Age-adjusted naive CD4 counts increased on a timescale comparable to overall CD4 T-cell reconstitution, whereas age-adjusted memory CD4 counts increased less, albeit on a faster timescale.

CONCLUSIONS

It appears the immature immune system can recover well from HIV infection via the naive pool. However, this potential is progressively damaged with age and/or duration of infection. Current guidelines may therefore not optimize long-term immunological health.