Effect of combination therapy including protease inhibitors on mortality among children and adolescents infected with HIV-1

Dyslipidemia among perinatally HIV-infected children enrolled in the PACTS-HOPE cohort, 1999-2004: a longitudinal analysis

BACKGROUND

Protease inhibitor (PI)-containing regimens have led to improved survival among HIV-infected children. However, adverse effects, including dyslipidemia, may put children at risk for cardiovascular disease.

METHODS

Serum cholesterol and triglyceride levels were recorded on perinatally HIV-infected children participating in the PACTS-HOPE cohort (1999-2004). Hypercholesterolemia (HC) was defined as cholesterol > or =200 mg/dL and hypertriglyceridemia (HT) as triglycerides >or =150 mg/dL. HC and HT were modeled over time using generalized estimating equations.

RESULTS

For 178 children, 47% met criteria for HC and 67% for HT at least once during the study period. In generalized estimating equation models, PI use, undetectable viral load, and immunologic category 3 were independent predictors of HC. HT was significantly associated with PI use and body mass index (BMI) > or =90th percentile for age and gender. Among children on PI-containing regimens, HC was significantly associated with multiple PIs and undetectable viral load; HT was predicted by body mass index > or =90th percentile and ritonavir use. The prevalence of clinical lipodystrophy was 5.6% (10/178).

CONCLUSIONS

Children on PI-containing regimens have a higher risk of both HC and HT. Lipid levels should be measured regularly in children on antiretroviral treatment. Interventions such as diet, exercise, or lipid-lowering drug therapy may benefit some children.

HIV treatment-related knowledge and self-efficacy among caregivers of HIV-infected children

OBJECTIVE

Improvements in treatment-related knowledge and self-efficacy may improve clinical outcomes in HIV-infected populations. We examined whether caregivers' knowledge and self-efficacy was associated with better clinical outcomes and anti-retroviral therapy (ART) adherence among HIV-infected children.

METHODS

Caregivers of 77 perinatally HIV-infected children were administered a semi-structured interview which included scales of HIV treatment-related knowledge, adherence self-efficacy and caregiver reports of child medication adherence.

RESULTS

While caregivers correctly answered 74% of the knowledge questions, specific misconceptions were noted. Caregivers rated themselves as having high adherence self-efficacy, but were least confident in their ability to adhere to ART if it caused side effects or might result in social disclosure. Higher caregiver treatment-related knowledge and self-efficacy were associated with better clinical outcomes, as measured by viral load and CD4+ count, but not with caregiver reports of ART adherence.

CONCLUSION/DISCUSSION

While additional factors may be important determinants of adherence to ART in this population, improving the HIV treatment-related knowledge and self-efficacy of caregivers may help to improve the clinical outcomes of HIV-infected children.

PRACTICE IMPLICATIONS

Care providers should address both misconceptions that might serve to undermine adherence as well as factors that limit patients' self-efficacy in adhering to treatment, prior to the initiation of ART and throughout the course of treatment.

Oral lesions in Brazilian HIV-infected children undergoing HAART

INTRODUCTION

The advent of new antiretroviral drugs such as protease inhibitors (PI) has generated sensible changes in oral manifestation patterns in human immunodeficiency virus (HIV) infected adult patients.

OBJECTIVES

The purpose of the present study was to assess whether the use of highly active antiretroviral therapy (HAART) has brought changes to pattern and prevalence of oral lesions related to HIV in the HIV-infected pediatric population.

CASUISTIC AND METHOD

We analyzed medical charts of 471 children aged zero to 12 years and 11 months with HIV infection and followed up by the Ambulatory of AIDS, Clinical Otorhinolaryngology, Hospital das Clinicas, Medical School, Sao Paulo University, from January 1990 to December 2004. Four hundred and fifty-nine children were divided into two groups, according to age range: X (0-5 years and 11 months) and Y (6-12 years and 11 months). These groups were subdivided into four subgroups, according to use of ART (antiretroviral therapy without PI) or HAART. We recorded data related to type of oral lesion presented, as well as serum CD4+ lymphocyte count. The groups were compared concerning prevalence and presentation pattern of oral manifestations.

RESULTS

Out of 459 children, 144 (31.4%) had oral lesions. We observed that in children aged 6-12 years and 11 months who were taking HAART, there was lower prevalence of oral lesions (p=0.005), specially hairy leukoplakia (p<0.02), without any affection to the common presentation pattern of these lesions. The same subgroup also had higher serum CD4+ lymphocyte counts (p<0.001).

CONCLUSION

We concluded that use of HAART could lead to reduction in prevalence of oral lesions in HIV-infected children.

Association of CD4+ T-lymphocyte counts and new thymic emigrants in HIV-infected children during successful highly active antiretroviral therapy

BACKGROUND

In a cohort of children receiving highly active antiretroviral therapy (HAART) with sustained plasma HIV-1 RNA < 50 copies/mL, children who reached undetectable RNA after week 8 (slow responders, median: week 20) had higher HIV-1 intracellular DNA (HIV-1 DNA) and equal or greater CD4+ T-lymphocyte counts compared with children who reached undetectable plasma HIV-1 RNA by week 8 (rapid responders) throughout HAART.

OBJECTIVE

To determine whether levels of T-cell receptor excision circles (TRECs) could explain the apparent inconsistency between the quantity of HIV-1 DNA and CD4+ T-lymphocyte counts in HIV-1-infected children receiving HAART with sustained virologic suppression.

METHODS

T-cell receptor excision circles and HIV-1 DNA and plasma HIV-1 RNA were quantified longitudinally by PCR in 31 children (median age, 5.6 years) with sustained undetectable plasma HIV-1 RNA for >104 weeks of HAART.

RESULTS

There was a positive correlation between TREC and HIV-1 DNA during HAART, notably at weeks 48 and 80 (P < .004). During the early stage of HAART, TREC levels positively correlated with CD4+ T-lymphocyte percentages (P < .02) and naive CD4+ T-lymphocyte counts (P < .001) and percentages (P = .05). Median TREC levels were consistently equal or higher in slow responders compared with rapid responders (P < .001) despite slow responders having consistently greater quantities of HIV-1 DNA.

CONCLUSION

To maintain adequate levels of CD4+ T-lymphocytes, children with high HIV-1 DNA maintain high levels of TREC while receiving HAART. Thus, a thymic control mechanism is required to maintain new CD4+ T lymphocytes in the presence of persistent virus.

CLINICAL IMPLICATIONS

The TREC level is a useful marker of thymic function in HIV-infected children.

Underdosing of antiretrovirals in UK and Irish children with HIV as an example of problems in prescribing medicines to children, 1997-2005: cohort study

OBJECTIVE

To measure the extent of underdosing of antiretroviral drugs in children.

DESIGN

Multicentre cohort study.

SETTING

Clinical centres in hospitals in the United Kingdom and Ireland in the collaborative HIV paediatric study (CHIPS).

PARTICIPANTS

615 HIV infected children aged 2-12 years receiving antiretrovirals.

MAIN OUTCOME MEASURES

Doses relative to weight and height compared with current recommended doses in 2004 European guidelines.

RESULTS

The CHIPS cohort of 934 children comprises 80% of diagnosed HIV infected children in the UK and Ireland between January 1997 and March 2005, of which 66% (615) aged 2-12 years were prescribed antiretrovirals. Actual doses standardised to weight or surface area varied widely across individual drugs, antiretroviral class, and calendar time, with children underdosed (prescribed less than 90% of current recommended doses) from 6-62% child time at risk. Three serious issues in prescribing antiretrovirals, which may also be relevant to paediatric prescribing in general, were identified. Firstly, dosing was inadequate before incorrect recommendations at licensing were later revised when important pharmacokinetic results emerged. Secondly, guidelines stating dosage alternatives (by weight/surface area) for the same drug led to different and inconsistent doses. And, thirdly, ongoing growth was not adjusted for.

CONCLUSIONS

Largely inadvertently, HIV infected children in the United Kingdom and Ireland have been underdosed with antiretrovirals, highlighting problems applicable throughout paediatric prescribing.

Outcomes for human immunodeficiency virus-1-infected infants in the United kingdom and Republic of Ireland in the era of effective antiretroviral therapy

BACKGROUND

There are few data about disease progression and response to antiretroviral therapy (ART) in vertically HIV-infected infants in the era of effective therapy.

DESIGN

Cohort study.

METHODS

We examined progression to acquired immunodeficiency syndrome (AIDS) and death over calendar time for infants reported to the National Study of HIV in Pregnancy and Childhood in the United Kingdom/Ireland. The use of ART and CD4 and HIV-1 RNA responses were assessed in a subset in the Collaborative HIV Pediatric Study.

RESULTS

Among 481 infants, mortality was lower in those born after 1997 (HR 0.30; P < 0.001), with no significant change in progression to AIDS. Of 174 infants born since 1997 in the Collaborative HIV Pediatric Study, 41 (24%) were followed from birth, 77 (44%) presented pre-AIDS and 56 (32%) presented with AIDS. Of 125 (72%) children on 3- or 4-drug ART by the age of 2 years, 59% had HIV-1 RNA <400 at 12 months; median CD4 percentage increased from 24% to 35%. Among 41 infants followed from birth, 12 progressed to AIDS (5 while ART naive) and 3 died; 1 of 10 infants initiating ART before 3 months of age progressed clinically.

CONCLUSION

Mortality in HIV-infected infants is significantly lower in the era of effective ART, but symptomatic disease rates remain high. Infrequent clinic attendance and poor compliance with cotrimoxazole prophylaxis and/or ART in infants born to diagnosed HIV-infected women and late presentation of infants identified after birth appear to be major contributors. Poor virologic response to ART during infancy is of concern because of increased likelihood of early development of resistance.

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.

Differential Restoration of Myeloid and Plasmacytoid Dendritic Cells in HIV-1-Infected Children after Treatment with Highly Active Antiretroviral Therapy

Numerical and functional deficits in myeloid (mDC) and plasmacytoid dendritic cell (pDC) subsets have been found in both adult and pediatric HIV-1 carriers. Whether these impaired DC subsets can be restored after treatment with highly active antiretroviral therapy (HAART) is currently unknown, especially in HIV-1-infected children. In this report, we characterized mDC and pDC subsets in 18 HIV-1-infected children who received HAART treatment and compared them with those in 6 untreated HIV-1-infected children and 27 HIV-1-uninfected healthy children. Among children treated with HAART, 11 were found to suppress HIV-1 replication successfully below the detection limit (HAART-suppressed group) while the remaining 7 failed (HAART-failure group). In HAART-suppressed children, a gradual and complete restoration of the frequency and function of mDCs was observed while the recovery of pDCs was only partial. However, mDC and pDC subsets in HARRT failure children were indistinguishable from the HAART-naive infected children. We also found that mDC frequency and IFN-alpha-releasing capacity of pDC positively correlated with CD4 T cell percentages in all HIV-1-infected children. In HAART-naive children, the mDC frequency correlated the HIV-1-specific CTL frequency. Our findings suggest that HAART has a differential impact on the restoration of mDC and pDC subsets. These findings may help guide the development of HIV-1-specific immune therapy aimed at fully restoring host immune function in chronically HIV-1-infected children.

Multidisciplinary, inpatient directly observed therapy for HIV-1-infected children and adolescents failing HAART: A retrospective study

Children and adolescents with HIV-1 infection and elevated viral loads are at risk for disease progression. When outpatient adherence efforts fail to reduce viral loads, we have chosen to hospitalize patients for directly observed antiretroviral therapy. A retrospective chart review was performed for patients who were admitted for adherence concerns to a rehabilitation facility from December 1, 2000 to December 1, 2003. Differences in CD4 count and viral load at admission, prior to discharge and 6 months after discharge were evaluated using the Wilcoxon signed-ranks test. Nineteen admissions were included in the analysis. Compared to the mean CD4 count at admission (262), the mean CD4 counts at discharge (492) and 6 months after discharge (429) were significantly higher (p < 0.001 and p = 0.01, respectively). Similar results were observed for change in CD4 percentage. Compared to the mean viral load at admission (log 5.7), the mean viral loads at discharge (log 4.7) and 6 months after discharge (log 5) were significantly lower (p < 0.001 and p < 0.004). The majority of admissions (74%) involved a change in highly active antiretroviral therapy (HAART) regimen. In conclusion, hospitalization for directly observed therapy of HIV-1-infected children and adolescents with elevated viral loads and nonadherence resulted in an immediate and sustained (up to 6 months) reduction in viral load and increase in CD4 count.

Thymic volume, T-cell populations, and parameters of thymopoiesis in adolescent and adult survivors of HIV infection acquired in infancy

OBJECTIVES

Antiretroviral therapy has significantly prolonged the lifespan of children who acquire HIV infection in infancy, but the impact of HIV on thymus-mediated maintenance of T lymphocytes has not been studied. To examine the long-term effects of HIV infection in childhood on thymopoiesis, thymic volume and parameters of thymic function from clinically stable adolescents and young adults with HIV infection acquired in infancy were compared with those from uninfected controls.

METHODS

Thymic volume was determined using three-dimensional reconstruction and volumetric analysis of non-contrast enhanced computed tomography images of the upper chest. The degree of fat involution was assessed using a semiquantitive scoring system. CD4 and CD8 T cell populations and T cell receptor recombination excision circles (TREC) concentrations in peripheral blood lymphocytes were measured in all subjects.

RESULTS

Twenty youths (aged 17.6 +/- 2.5 years) with HIV infection acquired perinatally (n = 18) or by neonatal transfusion (n = 2) were enrolled whose HIV plasma viral load had been undetectable for a median of 3.1 years, along with 18 seronegative healthy young adults (aged 20.6 +/- 1.3 years). HIV infected subjects and controls had indistinguishable CD4 T cell counts, thymus volumes (20.5 versus 15.8 cm), thymic index scores, and TREC values. Thymic volume correlated with the number and percentage of CD4 T lymphocytes in the control group and with the number of TREC in CD4 lymphocytes in the HIV infected group.

CONCLUSIONS

Long term survivors of pediatric HIV infection appear to have retained or recovered thymic volume and thymic activity approximating uninfected youths.

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.

HIV-1 encephalopathy among perinatally infected children: Neuropathogenesis and response to highly active antiretroviral therapy

HIV-1 encephalopathy among perinatally infected children in the United States was initially defined by a classic triad of findings that included: (1) developmental delay, (2) secondary or acquired microcephaly, and (3) pyramidal tract neuromotor deficits. The most severe form of this disorder typically occurred among young children who developed rapidly progressive disease in concert with profound immunosuppression, and Pneumocystis jiroveci pneumonitis (PCP). The neuropathogenesis of this disorder appears to involve a cascade of viral products, various cytokines and chemokines, and neurotransmitters which promote ongoing inflammation, excitation, and overstimualtion of the N-methyl-D-aspartate type receptor (NMDAR) system. These subsequently lead to neuronal injury and death secondary to apoptosis or necrosis, astrocytosis, as well as dentritic and synaptic damage. The frequency of the most severe forms of encephalopathy among children has dropped dramatically since the introduction of highly active antiretroviral therapy (HAART). Of concern, however, is the possibility that a more insidious form of this disorder may be occurring presently among older vertically infected children as a result of inadequate penetration of HAART agents into the cerebrospinal fluid (CSF). This paper will review what published data there is as yet that bears on this question.

Neurocognitive outcomes in pediatric HIV

Cognitive impairment has long been associated with the natural history of HIV among vertically infected children. In children, HIV may have a direct or indirect impact on the developing brain, may lead to global or highly specific consequences, and may be responsible for minor cognitive consequences or, conversely, long-term and severe disability. This differential impact is related to multiple factors that influence the individual expression of the virus in any given child. This review provides an overview of the relevant literature on neurocognitive outcomes for infants, children, and youth vertically infected with HIV, with attention to those factors impacting neurocognitive outcome within a developmental framework. Research findings in both the era preceding and following the introduction of combined therapies are reviewed, since many of the issues identified prior to state-of-the-art treatment currently available in the United States and other developed countries still apply in much of the developing world. Intervention issues and directions for future research are also discussed.

Pharmacokinetics of antiretroviral therapy in HIV-1-infected children

The initiation of antiretroviral therapy has resulted in an impressive reduction in the rate of disease progression in AIDS and HIV-1-related deaths in children; however, there are still several major challenges to be faced in order to improve therapy. A major topic that needs to be dealt with is the establishment of the optimal dosage of antiretroviral therapy for children. This review presents the currently available peer-reviewed data on the pharmacokinetics of nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs) and fusion inhibitors (FIs) in children. In addition, the data are discussed in relation to the currently available European and US guidelines and the US FDA-approved drug labels. High intra- and interpatient variability in pharmacokinetics are often observed for all antiretroviral drugs. The number of children included in the pharmacokinetic studies is often small and children are often divided into divergent groups using different dosage levels and/or drug formulations. For a substantial number of antiretroviral drugs, dosage recommendations, especially for young children, are still absent in the European and US guidelines. The recommended drug dosages in the guidelines are often different from that in the officially approved drug product label. In addition, the recommended drug dosages may deviate between the European and US guidelines. Thus, while practioners aim to meet the recommendations in the official guidelines, patients may receive highly divergent dosages of medication. The high intra- and interpatient variability in pharmacokinetics of antiretroviral drugs in children hampers the application of fixed dosages of antiretroviral drugs. For PIs and NNRTIs, plasma drug levels correlate with viral suppression and drug toxicity. NRTIs are prodrugs that are intracellularly converted to their active triphosphate form and, therefore, plasma NRTI levels correlate poorly with viral suppression. Therapeutic drug monitoring of PIs and NNRTIs should be considered to optimise HIV therapy in children.

Tenofovir disoproxil fumarate and an optimized background regimen of antiretroviral agents as salvage therapy for pediatric HIV infection

OBJECTIVES

Highly active antiretroviral therapy has altered the course of HIV infection among children, but new antiretroviral agents are needed for treatment-experienced children with drug-resistant virus. Tenofovir disoproxil fumarate (DF) is a promising agent for use in pediatric salvage therapy, because of its tolerability, efficacy, and resistance profile. We designed this study to provide preliminary pediatric safety and dosing information on tenofovir DF, while also providing potentially efficacious salvage therapy for heavily treatment-experienced, HIV-infected children.

METHODS

Tenofovir DF, alone and in combination with optimized background antiretroviral regimens, was studied among 18 HIV-infected children (age range: 8.3-16.2 years) who had progressive disease with > or = 2 prior antiretroviral regimens, in a single-center, open-label trial. Tenofovir DF monotherapy for 6 days was followed by the addition of individualized antiretroviral regimens. Subjects were monitored with HIV RNA reverse transcription-polymerase chain reaction, flow cytometry, and routine laboratory studies; monitoring for bone toxicity included measurement of lumbar spine bone mineral density (BMD) with dual-energy x-ray absorptiometry. Subjects were monitored through 48 weeks.

RESULTS

Two subjects developed grade 3 elevated hepatic transaminase levels during monotherapy and were removed from the study. The remaining 16 subjects had a median of 4 antiretroviral agents (range: 3-5 agents) added to tenofovir DF. HIV plasma RNA levels decreased from a median pretreatment level of 5.4 log10 copies per mL (range: 4.1-5.9 log10 copies per mL) to 4.21 log10 copies per mL at week 48 (n = 15), with 6 subjects having < 400 copies per mL, including 4 with < 50 copies per mL. The overall median increases in CD4+ T cell counts were 58 cells per mm3 (range: -64 to 589 cells per mm3) at week 24 and 0 cells per mm3 (range: -274 to 768 cells per mm3) at week 48. The CD4+ cell responses among the virologic responders were high and sustained. The major toxicity attributed to tenofovir DF was a >6% decrease in BMD for 5 of 15 subjects evaluated at week 48, necessitating the discontinuation of tenofovir DF therapy for 2; all 5 subjects experienced >2 log10 copies per mL decreases in HIV plasma RNA levels.

CONCLUSIONS

Tenofovir DF-containing, individualized, highly active antiretroviral therapy regimens were well tolerated and effective among heavily treatment-experienced, HIV-infected children. Loss of BMD may limit tenofovir DF use among prepubertal patients.

Partial treatment interruption of protease inhibitors augments HIV-specific immune responses in vertically infected pediatric patients

BACKGROUND

Although highly active antiretroviral therapy has significantly reduced morbidity and mortality in HIV-infected children, it often fails to completely suppress viral replication, thereby allowing the emergence of drug-resistant variants. Protease inhibitor (PI) based therapy has been hypothesized to depress cell-mediated immune responses by reducing antigen presentation.

OBJECTIVES

To determine the effects of partial treatment interruption (PTI) of PI on HIV-specific cellular immune responses in children.

METHODS

We conducted a retrospective longitudinal study of HIV-specific cellular immune responses in 13 children who were vertically infected with HIV. All had detectable plasma viremia and had undergone PTI for a median of 1.0 year (range, 0.41-3.35 years) while continuing nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor therapy.

RESULTS

No significant changes in viral load were observed in the immediate time-point before and during PTI (P = 0.84) as well as in the overall period before and during PTI (P = 0.17). CD4 T-cell levels declined slowly immediately before and during PTI (P = 0.07) as well as during the overall PTI period (P = 0.0002), but the rate of CD4 T-cell decline was not significantly increased during PTI. Immediate to PTI, HIV-specific CD4 and CD8 T-cell responses increased by 70% (P < 0.0001) and 92% (P < 0.0001), respectively, and CD4 and CD8 T-cell activation levels (P = 0.6834 and P = 0.6081, respectively) remained unchanged.

CONCLUSION

HIV-specific cellular immune responses are boosted in children who have interrupted PI-based therapy.

Immunologic function and virologic suppression among children with perinatally acquired HIV Infection on highly active antiretroviral therapy

BACKGROUND

The goal of highly active antiretroviral therapy (HAART) has been to stabilize and reconstitute immune function and suppress viral replication to the greatest degree possible. Suppression of HIV viral replication has been associated with improved long-term and short-term prognosis. Limited data are available on the level of virologic suppression and immune function of pediatric patients followed in clinical settings in the HAART era.

OBJECTIVE

The objective of this study was to assess the level of virologic suppression and immune function in a cohort of children with perinatally acquired HIV infection followed at dedicated HIV specialty care sites.

RESEARCH DESIGN

This study comprised a cohort study of HIV-infected children and adolescents.

SUBJECTS

Study subjects consisted of 263 HIV-positive children (<or=17 years old), on HAART, with at least one outpatient visit and CD4 test recorded in 2001 seen at 4 U.S. HIV primary pediatrics and specialty care sites (2 eastern, 1 southern, and 1 western).

MEASURES

Measures consisted of all plasma HIV-1 RNA levels <or=400 during calendar year 2001.

RESULTS

Two hundred sixty-three patients received HIV-related treatment during 2001, with a mean age of 8.5 years. Sixty-eight percent were black, 54% were females, and the majority (85%) was insured by Medicaid. A total of 28.6% had a class C AIDS diagnosis. A total of 23.5% and 34% of patients maintained viral suppression at <50 copies per milliliter (cpm), or <400 cpm, respectively, for the calendar year; 32.5% and 38.8%, respectively, fulfilled the criteria if one "blip" to <5000 cpm was allowed. Forty-eight percent maintained all viral loads <5000 cpm, and 74.9% overall had HIV-1 RNAs <or=15,000 cpm. Eighty-seven percent of patients had CD4% >25; only 4.2% had CD4 <15%. Overall, 12.5% of patients had either CD4% <15 or severely decreased absolute CD4 counts (adjusted for age). A total of 4.6% of patients had HIV-1 RNAs >100,000 cpm and severe immunosuppression. Patients who were less likely to achieve virologic suppression to <400 cpm included those with CD4 count <200 cells/mm(3) (odds ratio [OR], 0.06; 95% confidence interval [CI], 0.007-0.46), those with AIDS (OR, 0.5; 95% CI, 0.28-0.94), and those with moderate (OR, 0.42; 95% CI, 0.22-0.79), or severe immunologic suppression (OR, 0.14; 95% CI, 0.046-0.43) based on CD4%.

CONCLUSION

In this multisite, pediatric cohort, the rate of near-complete virologic suppression (<50 or <400 cpm) was low. However, the majority of patients have near-normal CD4 counts and viral loads <15,000 cpm. Follow up will be critical to assess the implications of ongoing low-level viral replication with near-normal CD4 values.

Pharmacokinetics and 24-week efficacy/safety of dual boosted saquinavir/lopinavir/ritonavir in nucleoside-pretreated children

OBJECTIVE

To assess the pharmacokinetics and 24-week efficacy and safety of dual boosted saquinavir/lopinavir/ritonavir combination in children.

DESIGN

Twenty reverse transcription inhibitor-pretreated children at 2 centers in Thailand were treated with saquinavir/lopinavir/ritonavir in an open label, single arm, 6-month prospective study. The dosage was 50 mg/kg twice daily (bid) for saquinavir and 230/57.5 mg/m bid for lopinavir/ritonavir. Ten children also received lamivudine.

METHODS

Samples were collected for a 12-hour pharmacokinetic profile in all children. Plasma concentrations of saquinavir, lopinavir and ritonavir were determined using a validated high performance liquid chromatography technique.

RESULTS

At baseline, the median age was 8.5 years, with human immunodeficiency virus (HIV) RNA 4.9 log10 copies/mL, CD4 count 129 cells/microL and CD4%, 6.5%. Median area under the concentration curve at 0-12 hours and Cmin were 39.4 mg/L.h and 1.4 mg/L for saquinavir and 118 mg/L.hr and 5.9 mg/L for lopinavir. After 24 weeks of treatment, HIV RNA was suppressed below 400 copies/mL for 16 of 20 (80%) children (intent-to-treat analysis) and below 50 copies/mL for 12 of 20 children (60%), and CD4% (count) rose by a median of 6% (216 cells/microL). Median changes of triglyceride and total cholesterol were 56 and 36.5 mg/dL, respectively (P = 0.01). Lopinavir Cmin <1 and saquinavir Cmin <0.28 mg/L correlated with HIV RNA >400 copies/mL, and lopinavir Cmax >15 mg/L correlated with rises in cholesterol (P < 0.05).

CONCLUSION

Plasma drug concentrations of saquinavir, lopinavir and ritonavir were at the higher limits of expected ranges for adult treatment at approved dosages (1000/100 mg bid for saquinavir, 400/100 mg bid for lopinavir/ritonavir). The regimen was well-tolerated and had good efficacy at 24 weeks. This dual boosted protease inhibitor combination should be assessed in larger trials of reverse transcription inhibitor-experienced children.

Perinatally Acquired HIV-1 Infection: Prevention and Evaluation of HIV-Exposed Infants

Perinatal transmission of human immunodeficiency virus type 1 (HIV-1) is the primary cause of pediatric HIV infections. In recent years, perinatal HIV-1 transmission rates in the United States have declined markedly because of several factors that include enhanced voluntary counseling and HIV-1 testing (VCT) for pregnant women, widespread use of antiretroviral prophylaxis or combination antiretroviral therapy, avoidance of breastfeeding, and elective cesarean delivery. However, perinatal transmission of HIV-1 still occurs, and 300 to 400 infected infants are born annually, primarily because of missed prevention opportunities. The pediatrician plays a vital role in the prevention of perinatal transmission of HIV-1 by identifying newborns born to infected mothers who were not tested during pregnancy, administering antiretroviral prophylaxis, and ensuring follow-up to confirm or exclude the diagnosis of HIV-1 infection in early infancy. This article reviews recent advances in the prevention of perinatal transmission of HIV-1, discusses evaluation and treatment of infants exposed to HIV-1, and highlights certain unique features of HIV-1 infections in infants, with a focus on early diagnosis, clinical manifestations, treatment, and prognosis.

Safety and antiviral response at 12 months of lopinavir/ritonavir therapy in human immunodeficiency virus-1-infected children experienced with three classes of antiretrovirals

INTRODUCTION

Many human immunodeficiency virus type 1 (HIV-1)-infected children have already failed treatment with 2 or even 3 classes of antiretrovirals. Coformulation of lopinavir with low dose ritonavir exhibits a potent antiretroviral effect. However, the data in heavily pretreated children are still scarce. This study evaluated the safety and effectiveness of combination therapy including lopinavir/ritonavir in children with prior exposure to all classes of oral antiretrovirals.

METHODS

This was an open label multicenter observational study, in which data were reviewed according to a standardized protocol. The study population included all HIV-1-infected children with virologic failure (HIV-1 RNA >5000 copies/mL) followed in 12 Spanish hospitals for >12 months, experienced with the 3 classes of oral antiretrovirals, in whom a lopinavir/ritonavir-containing regimen was started.

RESULTS

By March 2003, 45 patients had been treated with lopinavir/ritonavir for a median of 18 months (range, 3-28). The median age at baseline was 9.7 years (range, 4.3-17.1). The median times of prior treatment were 88 months (range, 31-145) with nucleoside reverse transcription inhibitors and 42 months (range, 19-63) with protease inhibitors. Twenty-five patients were classified as Centers for Disease Control and Prevention clinical category C. Median values for absolute and percentage CD4 at baseline were 501 (range, 6-1512) and 19% (range, 0.5-49), respectively, and plasma HIV-RNA was 5.0 log10 copies/mL (range, 4.1-6.1). During follow-up, 11 (24%) children switched from liquid to solid formulation. At 48 weeks, the median values for absolute and percentage CD4 increased by 199 cells/microL and 3%, respectively, and median plasma viral load declined 1.75 log10 copies/mL. Forty-two percent of children achieved a plasma RNA of <400 copies/mL (intent to treat analysis). Baseline genotypic resistance was available in 40 children. Nonresponders had 7.0 +/- 1.6 protease inhibitor-associated mutations at baseline compared with 4.8 +/- 1.7 in children achieving virologic suppression (P = 0.06). Adverse events were described in 18 children. Three children permanently discontinued and 4 transiently withdrew lopinavir/ritonavir. At 12 months, there were mild but not significant increases in plasma cholesterol and triglycerides.

CONCLUSIONS

Lopinavir/ritonavir when given as part of salvage regimen is well-tolerated, although switching to pills is frequently required. The regimen has a potent and durable antiretroviral activity in most heavily pretreated children, despite the presence of multiple mutations to all classes of oral antiretrovirals.

Evaluation of a peer support group therapy for HIV-infected adolescents

OBJECTIVE

To assess the effects of a peer support group therapy on HIV-infected adolescents.

DESIGN

A prospective study of a cohort of HIV-infected adolescents participating or not participating in a psychodynamic oriented, emotional support group.

METHODS

From a group of 30 perinatally HIV-infected adolescents who attended an outpatient clinic, 10 agreed to participate in the peer support group (group 1), 10 declined (group 2) and 10 others who lived too far from the clinic were not invited to participate (group 3). The three groups were compared at baseline and 2 years later using the outcome measures: perceived illness experience scale, perceived treatment inventory, self-esteem inventory.

RESULTS

At baseline, the three groups had similar characteristics overall. The adolescents' self-esteem was in the normal range. After 2 years, worries about illness had decreased in group 1, whereas the scores had increased or remained the same for the other adolescents (P = 0.026). The adolescents in group 1 had less negative perception of treatment at 2 years than those in groups 2 and 3 (P = 0.030). After intervention, the percentage of adolescents with an undetectable viral load had increased in group 1 from 30 to 80% (P = 0.063) but was unchanged in groups 2 and 3. Considering the three groups altogether, the decrease in the viral load correlated with improvement of the perceived treatment inventory (Spearman R = 0.482 P = 0.015).

CONCLUSIONS

: This pilot study suggests that a peer support group intervention is associated with an improvement in adolescents' emotional well being, and that this can have a positive influence on medical outcomes.

Comparison of once-daily atazanavir with efavirenz, each in combination with fixed-dose zidovudine and lamivudine, as initial therapy for patients infected with HIV

BACKGROUND

Atazanavir, an azapeptide protease inhibitor (PI), has pharmacokinetics that allow once-daily dosing, and it is not associated with significant PI-associated dyslipidemia.

METHODS

A randomized, double-blind, double-dummy, active-controlled, 2-arm study comparing the antiviral efficacy and safety of atazanavir 400 mg administered once daily with efavirenz 600 mg administered once daily in combination with open-label fixed-dose zidovudine plus lamivudine twice daily. The 810 treatment-naive patients were stratified by HIV RNA level. The primary efficacy end point was the proportion of treated patients with HIV RNA levels <400 copies/mL through week 48.

RESULTS

At week 48, HIV RNA levels were <400 copies/mL in 70% of patients receiving atazanavir and 64% of patients receiving efavirenz (intent-to-treat, difference; 95% confidence interval: 5.2%; -1.2%, 11.7%). Median CD4 cell counts increased at comparable magnitudes and rates in the 2 treatment arms (mean change at week 48: 176 cells/mm with atazanavir, 160 cells/mm with efavirenz). Atazanavir-treated patients relative to comparator-treated patients did not demonstrate significant increases in total cholesterol, fasting low-density lipoprotein cholesterol, or fasting triglycerides over 48 weeks of therapy. Atazanavir-linked bilirubin elevations infrequently resulted in treatment discontinuation (<1%). Atazanavir treatment did not increase fasting glucose or insulin levels.

CONCLUSIONS

For initial HIV treatment, a highly active antiretroviral therapy regimen of atazanavir/zidovudine/lamivudine is as efficacious and well tolerated as the combination of efavirenz/zidovudine/lamivudine.

Ritonavir-based highly active antiretroviral therapy in human immunodeficiency virus type 1-infected infants younger than 24 months of age

BACKGROUND

Few data are available regarding clinical outcomes or dosing requirements for the protease inhibitor ritonavir in human immunodeficiency virus (HIV)-infected children younger than under 24 months of age.

METHODS

This prospective, multicenter phase I/II open label treatment trial used ritonavir, zidovudine and lamivudine to treat protease inhibitor-naive, HIV-infected infants between the ages of 4 weeks and 24 months. Two sequential dosing cohorts were treated with 350 or 450 mg/m(2) ritonavir every 12 hours; this report includes results of pharmacokinetics, safety, tolerability and efficacy through 104 weeks of follow-up of all subjects.

RESULTS

Fifty HIV-infected children were treated. By week 16, 36 had achieved HIV-1 RNA <400 copies/mL (72% intent-to-treat, 84% as-treated analysis); by week 104, 18 maintained durable viral suppression (36% intent-to-treat, 46% as-treated). Poor medication adherence by caregiver report contributed to virologic failure. Few subjects experienced treatment-limiting toxicity: emesis or ritonavir refusal in 6 (12%); and severe but reversible anemia or elevated serum hepatic transaminases in 1 (4%) each. Apparent oral clearance was higher and the median predose concentrations were substantially lower than those found in adults. Median z scores for weight and height for age/gender were below normal at baseline but improved by week 104.

CONCLUSIONS

A combination regimen of ritonavir, zidovudine and lamivudine was generally safe and produced sustained viral suppression in more than one-third of infants who initiated therapy before 2 years of age. Improved palatability of liquid preparations of protease inhibitors, supporting infrastructure and behavioral approaches to improve medication adherence with antiretrovirals will likely be necessary to further improve efficacy.

Hospital and Outpatient Health Services Utilization Among HIV-Infected Children in Care 2000–2001

BACKGROUND

The aging of the pediatric HIV cohort and advances in antiretroviral therapy for children may have resulted in recent changes in patterns of healthcare utilization.

OBJECTIVES

The objectives of this study were to examine inpatient and outpatient HIV-related health service utilization in a multistate sample of HIV-infected children, and to assess sociodemographic and clinical correlates of utilization.

DESIGN

Cohort study of pediatric patients with HIV. Demographic, clinical, and resource utilization data were collected from medical records for 2000 and 2001.

SETTING

This study was conducted at 4 U.S. HIV primary pediatric and specialty care sites in different geographic regions.

PATIENTS

Three hundred three HIV-positive children with at least one outpatient visit or CD4 test in either 2000 or 2001 were studied.

MAIN OUTCOME MEASURES

Mean outcome measures were number of hospital admissions, mean length of hospital stay, and number of outpatient clinic/office visits.

RESULTS

Hospitalization rates decreased significantly from 39.2 (95% confidence interval [CI], 28.4-50.1) to 25.3 (95% CI, 16.4-34.3) admissions per 100 patients between 2000 and 2001. Hospitalizations were higher among patients with greater immunosuppression, those 2 years and under, and those with AIDS, but were not significantly related to receipt of highly active antiretroviral therapy. Mean outpatient visits did not change significantly between 2000 and 2001 from 9.09 (95% CI, 8.3-9.9) to 9.06 (95% CI, 8.4-9.7) visits per child per year. Children 2 years and under, those on highly active antiretroviral therapy, those with AIDS, and those with Medicaid had significantly higher outpatient utilization. Those with higher HIV-1 RNA had higher outpatient utilization than those with less advanced disease.

CONCLUSION

Inpatient utilization significantly decreased between 2000 and 2001, but outpatient utilization did not change over time. Compared with prior studies, utilization rates appear to be declining over time. Unlike adults, racial/ethnic or gender disparities in healthcare utilization are less pronounced for HIV-infected children.

Antiretroviral Therapy in HIV-Infected Children: The Metabolic Cost of Improved Survival

Although highly active antiretroviral therapy (HAART) has positively altered the morality rates in HIV-infected children, these drugs have the potential to cause significant morbidity. These drugs cause changes in fat distribution, lipid profiles, glucose, homeostasis, and bone turnover. The direct relationship between duration of drug exposure and increased risk of cardiovascular disease is particularly concerning for HIV-infected infants and children, who likely will have longer cumulative exposure to HAART. It is unclear whether the metabolic effects of decades of exposure would be reversible with cessation of therapy. The benefits of HAART in HIV infection are indisputable, but the impetus to find a cure or design more tolerable therapy is clear. Infarction may replace infection as the major cause of morbidity and mortality from HIV.

In HIV type 1-infected children cytotoxic T lymphocyte responses are associated with greater reduction of viremia under antiretroviral therapy

The evolution of the HIV-specific CD8+ T cell response in patients receiving potent combination therapy has been well documented in adult patients. However, no study reported whether baseline HIV-specific CD8+ T cell response is linked to treatment outcome. The aims of this study were to investigate both the impact of baseline memory cytotoxic T lymphocytes (CTL) on treatment outcome and the effect of potent therapy on memory HIV-specific CTL in HIV-1-infected pediatric patients. The study group comprised 30 children who started a first-line combination treatment including at least three drugs from two different classes and were longitudinally followed during treatment. Their memory HIV-specific responses were measured at baseline and during treatment, as well as their plasma viremia and CD4+ levels. The intensity of memory Gag-specific CTL and the breadth of the CTL response at the beginning of treatment were significantly correlated with lower plasma viral load during treatment, independently of baseline plasma viral load, CD4+ counts, and age. Children with partially controlled viral replication had enhanced Gag-specific CTL compared to their baseline value. This improvement of antiviral responses during treatment was not observed when viral replication was either fully suppressed or uncontrolled. In conclusion, our results show that higher baseline HIV-specific CTL are linked to lower viremia under combination therapy. This result adds further support to the hypothesis that cooperation between the antiviral immune response and antiviral drugs could be helpful for therapeutic management of HIV-infected patients.

Early structural and functional changes of the vasculature in HIV-infected children: impact of disease and antiretroviral therapy

BACKGROUND

Premature cardiovascular disease is increasingly recognized in HIV-infected patients, but the mechanisms involved are unclear. The purpose of this study was to determine the impact of HIV infection and antiretroviral therapy (ART) on markers of early vascular disease in children.

METHODS AND RESULTS

We studied 83 HIV-infected children (56 had taken ART, of whom 31 received a regimen containing protease inhibitors [PIs]; 27 were never treated) and a control group of 59 healthy children. Carotid intima-media thickness (IMT) and brachial artery flow-mediated dilatation (FMD) were measured. IMT was significantly greater in HIV-infected children compared with the control subjects (P<0.001). Among the HIV-infected children, age and treatment were significantly associated with increased IMT. Children exposed to PIs had greater IMT compared with both non-PI-treated children and untreated children (P=0.02). FMD was also significantly reduced in the HIV-infected children compared with control subjects (P=0.02). Pairwise comparisons of different treatment exposure groups revealed that FMD was impaired by a mean of 3.6% (95% CI, 1.8 to 5.3; P<0.001) for children exposed to PIs compared with untreated children and by a mean of 1.8% (95% CI, 0.01 to 3.5; P=0.05) compared with non-PI-treated children. HIV-infected children had lipid abnormalities, but they did not account for the observed differences in either FMD or IMT.

CONCLUSIONS

HIV infection in childhood is associated with adverse structural and functional vascular changes that are most pronounced in children exposed to PI therapy. Longitudinal studies are required to differentiate the relative impact of HIV disease and ART and to assess the potential for prevention.

Sepsis predisposition in children with human immunodeficiency virus

OBJECTIVE

To review predisposition to sepsis in children infected with human immunodeficiency virus (HIV) in the era of highly active antiretroviral therapy (HAART).

DESIGN

Summary of the literature with review by experts in the field.

RESULTS

In industrialized regions, new diagnoses of vertically acquired HIV infection are falling due to perinatal interventions. Provision of HAART has resulted in an enlarging cohort of clinically stable HIV-infected children, with low viral loads and normal CD4 T-lymphocyte counts. Access to HAART in "developed" countries has markedly decreased the rate of progression to acquired immunodeficiency syndrome, the prevalence of organ-specific complications of HIV, the risk of recurrent sepsis, and the high early childhood mortality from HIV infection. There are currently no data on whether initiation of HAART during acute sepsis reduces short-term morbidity or mortality. Undiagnosed, antiretroviral-naive, HIV-infected infants still present sporadically with opportunistic infections such as Pneumocystis jiroveci and cytomegalovirus pneumonia. HIV-infected children have a greater burden of disease due to viral, bacterial, and fungal sepsis, and the case fatality rate for nonopportunistic infections may be greater than in non-HIV-infected children. In "developing" countries, with limited access to HAART, the natural history of HIV infection has altered very little, with the majority of infected children dying from either opportunistic or nonopportunistic disease before 3 yrs of age.

CONCLUSION

Pediatric HIV infection is not a homogeneous condition in the era of HAART. Susceptibility to sepsis, morbidity, and mortality differ according to stage of disease, access to HAART, and virologic and immunologic response to treatment. These issues should be considered if HIV-infected children are to be enrolled and stratified in clinical trials.

Recomendaciones CEVIHP/SEIP/AEP/PNS respecto al tratamiento antirretroviral en niños y adolescentes infectados por el VIH

OBJECTIVE

To update antiretroviral recommendations in antiretroviral therapy (ART) in HIV-infected children and adolescents.

METHODS

Theses guidelines have been formulated by a panel of members of the Plan Nacional sobre el SIDA (PNS) and the Asociacion Espanola de Pediatria (AEP) by reviewing the current available evidence of efficacy, safety, and pharmacokinetics in pediatric studies. Three levels of evidence have been defined according to the source of data: Level A: randomized and controlled studies; Level B: Cohort and case-control studies; Level C: Descriptive studies and experts' opinion.

RESULTS

When to start ART should be made on an individual basis, discussed with the family, considering the risk of progression according to age, CD4 and viral load, the ART-related complications and adherence. The ART goal is to reach a maximum and durable viral suppression. This is not always possible, even with clinical and immunologic improvement. The difficulties of permanent adherence and side-effects are resulting in a more conservative trend to initiate ART, and to less toxic and simpler strategies. Currently, combinations of at least three drugs are of first choice both in acute and chronic infection. They must include 2 NA 1 1 NN or 2 NA 1 1 PI. ART is recommended in all symptomatic patients and, with few exceptions, in all infants in the first year of life. Older asymptomatic children should start ART according to CD4 count, especially CD4 percentage, that vary with age. Despite potent salvage therapies, it is common not to reach viral undetectability. Therapeutical options when ART fails are scarce due to cross-resistance. The cause of failure must be identified. Occasionally, there exists clinical and/or immunological progression, and a change of therapy with at least two new drugs still active for the patient, is warranted with the aim of increasing the CD4 count to a lower level of risk. Toxicity and adherence must be regularly monitored. Some aspects about post exposure prophylaxis and coinfection with HCV or HBV are discussed.

CONCLUSIONS

A higher level of evidence with regard to ART effectiveness and toxicity in pediatrics is currently available, leading to a more conservative and individualized approach. Clinical symptoms and CD4 count are the main determinants to start and change ART.

Increased Dose of Lopinavir/Ritonavir Compensates for Efavirenz-Induced Drug-Drug Interaction in HIV-1-Infected Children

BACKGROUND

Nucleoside reverse transcriptase inhibitor-sparing regimens have not yet been systematically evaluated in children. The nonnucleoside reverse transcriptase inhibitors nevirapine and efavirenz lower plasma levels of protease inhibitors in adults and children. Therefore, coadministration of lopinavir/ritonavir with nevirapine and efavirenz necessitates a 30% increase in the dose of lopinavir/ritonavir in adults. In children, the extent of the pharmacokinetic interaction between efavirenz and lopinavir/ritonavir has not yet been studied.

OBJECTIVE

To investigate the pharmacokinetics of increased-dose (300/75 mg/m2 twice-daily) lopinavir/ritonavir with normal-dose (14 mg/kg once-daily) efavirenz in HIV-1-infected children.

METHODS

Steady-state pharmacokinetics of lopinavir and efavirenz were determined and compared with historical data.

RESULTS

Fifteen children of median age 11.8 (range, 5.7-16.3) years were included. Area under the plasma concentration-time curve (AUC0-12), peak levels (Cmax), and trough levels (Cmin) of lopinavir were similar to historical data in adults and children. Medians (interquartile range) were 92.3 (43.5-138.5) mg/L.h, 12.5 (6.9-16.7) mg/L, and 5.7 (1.3-8.0) mg/L, respectively. Efavirenz pharmacokinetics approximated previous data in adults and children.

CONCLUSION

The increased dose of 300/75 mg/m2 twice-daily lopinavir/ritonavir compensates for the enzyme-inducing effect of efavirenz in HIV-infected children.

Atazanavir plus ritonavir or saquinavir, and lopinavir/ritonavir in patients experiencing multiple virological failures

OBJECTIVE

To evaluate atazanavir/ritonavir (ATV/RTV) (300/100 mg) once daily, atazanavir/saquinavir (ATV/SQV) (400/1200 mg) once daily, and lopinavir/ritonavir (LPV/RTV) (400/100 mg) twice daily, each with tenofovir (300 mg) once daily and a nucleoside reverse transcriptase inhibitor in treatment-experienced HIV-infected patients.

METHODS

Randomized, open-label, 48-week multicenter trial of 358 randomized adult patients who had failed two or more prior HAART regimens with baseline HIV RNA > or = 1000 copies/ml and CD4 cell count > or = 50 x 10(6) cells/l.

RESULTS

The primary efficacy endpoint [plasma HIV RNA reduction assessed by time-averaged difference (TAD)] was similar for ATV/RTV and LPV/RTV [TAD 0.13; 97.5% confidence interval, -0.12 to 0.39] at 48 weeks. Mean reductions from baseline for ATV/RTV and LPV/RTV were comparable at 1.93 and 1.87 log10 copies/ml, respectively. Mean CD4 cell count increases were 110 and 121 x 10(6) cells/l for ATV/RTV, and LPV/RTV, respectively. The efficacy of ATV/SQV was lower than LPV/RTV by both these parameters. Declines in total cholesterol and fasting triglycerides were greater with ATV/RTV and ATV/SQV than with LPV/RTV (P < or = 0.005). Lipids in the LPV/RTV arm at week 48 generally increased from baseline. Lipid-lowering agents were used more frequently in the LPV/RTV arm than in the ATV arms (P < 0.05 versus ATV/RTV), as were antidiarrheal agents (P < or = 0.04 versus both ATV treatments). No new or unique safety findings emerged.

CONCLUSIONS

ATV boosted with RTV is as effective and well tolerated as LPV/RTV in treatment-experienced patients, with a more favorable impact on serum lipids. Pharmacokinetically enhanced ATV provides a suitable choice for therapy of treatment-experienced HIV-infected patients.

Trends in Antiretroviral Therapy Use and Survival Rates for a Large Cohort of HIV-Infected Children and Adolescents in the United States, 1989-2001

BACKGROUND

In the United States, HIV-infected children and adolescents are aging and using antiretroviral (ARV) therapy for extended periods of time.

OBJECTIVE

To assess trends in ARV use and long-term survival in an observational cohort of HIV-infected children and adolescents in the United States.

METHODS

The Pediatric Spectrum of HIV Disease Study (PSD) is a prospective chart review of more than 2000 HIV-infected children and adolescents. Patients were included in the analysis from enrollment until last follow-up.

RESULTS

Triple-ARV therapy use (for 6 months or more) increased from 27% to 66% during 1997 to 2001 (P < 0.0001, chi for trend). The proportion of patients receiving 3 or more sequential triple-therapy regimens also increased from 4% to 17% during 1997 to 2001 (P < 0.0001, chi for trend), however, and the durability of triple-therapy regimens decreased from 13 to 7 months from the first to third regimen. Survival rates for the 1997 to 2001 birth cohorts were significantly better than for the 1989 to 1993 and 1994 to 1996 cohorts (P < 0.0001).

CONCLUSIONS

Survival rates in the PSD cohort have increased in association with triple-ARV therapy use. With continued changes in ARV regimens, effective modifications in ARV therapy and the sustainability of gains in survival need to be determined.

Cost-effectiveness of HIV screening for incarcerated pregnant women

Antiretroviral therapy (ART) initiated on a prenatal basis in HIV-infected pregnant women is a highly effective method for preventing mother-to-child HIV transmission. We developed a decision analytic model to project the clinical and economic outcomes of alternative HIV screening strategies (voluntary prenatal screening [VPS], routine prenatal screening [RPS], and mandatory newborn screening [MNS]) for a high-risk population of incarcerated pregnant women. Data for the decision model came from the HIV voluntary counseling and testing program at Connecticut's sole correctional facility for women and a comprehensive anonymously linked serosurvey of all inmates who entered the facility during the 2-year period beginning in October 1994. Based on serosurvey results, in the absence of any HIV screening program, 2.5 cases of pediatric HIV infection would be expected per 1000 pregnancies. Multiplied by the discounted lifetime cost per case of $247,000, this translates to a cost of $624 per testing-eligible prison entrant. Entrants were considered eligible if they were pregnant and their HIV status was unknown. MNS would save money, cost $364 per eligible entrant, and simultaneously reduce the rate of infections to 1.1 per 1000 pregnancies. Doing both MNS and RPS is most effective in reducing the rate of new infections (down to 0.2 per 1000 pregnancies). It would, however, increase costs to $430 per eligible entrant. This would result in an incremental cost of $73,603 per additional pediatric HIV case averted when compared with MNS alone. If mandatory newborn testing was not considered a feasible option, RPS would dominate VPS and would be cost-saving compared with no screening. RPS compares favorably with alternative uses of HIV prevention and treatment resources. In correctional facilities where voluntary newborn screening is already in place, our findings show that there remains a small marginal benefit to be realized from switching to RPS. In settings where HIV screening policies are not in place, however, the implementation of RPS can be expected to significantly reduce pediatric HIV cases and net health care expenditures.

An MDR1-3435 variant is associated with higher plasma nelfinavir levels and more rapid virologic response in HIV-1 infected children

OBJECTIVE

The multidrug-resistance transporter gene (MDR1) encoding for P-glycoprotein (P-gp) and genes encoding for isoenzymes of cytochrome P450 (CYP) have an important role in transport and metabolism of antiretroviral agents. This research examined the impact of single nucleotide polymorphisms (SNP) of MDR1 and CYP genes on nelfinavir and efavirenz pharmacokinetics and the response to highly active antiretroviral therapy (HAART) in HIV-1 infected children.

METHODS

Seventy-one HIV-1-infected children from PACTG 382 receiving nelfinavir, efavirenz and one or two nucleoside reverse transcriptase inhibitors had genomic DNA from PBMC evaluated for MDR1 and CYP SNP by real-time PCR. Plasma drug concentrations, CD4 lymphocyte counts and HIV-1 RNA were measured during HAART.

RESULTS

The frequencies of C/C, C/T and T/T genotypes in the MDR1-3435-C-->T polymorphisms were 44% (n = 31), 46% (n = 33) and 10% (n = 7), respectively. Ninety-one percent of children with the C/T genotype reached plasma HIV-1 RNA < 400 copies/ml by week 8 compared to 59% of children with the C/C genotype (P = 0.01). Children with the C/T genotypes had higher 8 h postdose concentration (P = 0.02) and lower clearance rate (P = 0.04) for nelfinavir compared to those with the C/C genotype. The seven children with the T/T genotype had nelfinavir pharmacokinetics and virologic response similar to those with the C/C genotype. No compensatory polymorphisms were observed between MDR1 and CYP genotypes.

CONCLUSIONS

HIV-1 infected children with the MDR1-3435-C/T genotype had more rapid virologic responses to HAART at week 8 with higher plasma nelfinavir concentrations compared to those with the C/C genotype. These findings suggest that P-gp may play an important role in the pharmacokinetics and virologic response to HAART containing nelfinavir.

Malignancy in perinatally human immunodeficiency virus-infected children in the United States

OBJECTIVES

To determine the incidence of and factors associated with malignancy in perinatally human immunodeficiency virus (HIV)-infected children in the United States.

METHODS

Included were 2969 children followed in the Pediatric AIDS Clinical Trials Group (PACTG) 219/219C cohort from 1993 through 2003. Cancer incidence by sex, race, age, histology and highly active antiretroviral therapy (HAART) era (pre-HAART, 1993-1997; HAART, 1998-2003) was estimated, and the standardized incidence ratio contrasting infected and uninfected children was determined. Poisson regression was used to further investigate the relation between HAART use (> or =3 drugs of > or =2 classes, 1 of which was a protease inhibitor), CD4% and cancer.

RESULTS

There were 37 cancers (17 prevalent and 20 incident) diagnosed in 2969 children for a prevalence of 0.6% [95% confidence interval (CI), 0.3, 0.9] and an incidence of 1.56/1000 person-years (95% CI 0.95, 2.41). Compared with uninfected children, the standardized incidence ratio was 10.08 (95% CI 5.87, 16.14). Incidence did not significantly differ by sex, race, age or HAART era. Of the cases, 35% were immunocompetent (CD4 > or =25%), 25% were moderately immunosuppressed (15%< or = CD4 < or =24%) and 40% were severely immunosuppressed (CD4 <15%) at diagnosis. In multivariate regression, the cancer rate was 3.09 (95% CI 1.22, 7.85) times higher in children with < or =2 years of HAART use than in children with >2 years of HAART and 3.20 (95% CI 1.32, 7.76) times higher in children with CD4 <15% at cohort enrollment than in children with CD4 > or =15%.

CONCLUSION

Cancer incidence in this U.S. pediatric cohort was lower than that of European cohorts but was markedly higher than that of HIV-uninfected children. Cancer incidence was highest in children who were severely immunosuppressed and in children who received HAART for < or =2 years.

Neuropsychological functioning and viral load in stable antiretroviral therapy-experienced HIV-infected children

OBJECTIVE

Neuropsychological functioning and its correlation with viral load were investigated for previously treated HIV-infected children who underwent a change in treatment regimen.

METHODS

Thirteen age-appropriate measures of cognitive, neurologic, and behavioral functioning were administered to 489 HIV-infected children who were aged 4 months to 17 years and had been treated previously for at least 16 weeks with antiretroviral therapy. These clinically and immunologically stable children were randomized onto 1 of 7 drug treatment combinations, 6 of which included a protease inhibitor (PI), and evaluated prospectively for 48 weeks with respect to changes in neuropsychological performance and viral load.

RESULTS

Neuropsychological functioning was significantly poorer at baseline for the HIV-infected children as compared with established norms for their age. Children with higher viral load had poorer cognitive, both-hands fine-motor, and neurologic signs at baseline, but single-hand fine-motor and behavioral functioning were not correlated with viral load. After 48 weeks of treatment with PI-containing combination therapy, there was significant improvement in only the vocabulary score. Neuropsychological changes did not differ among the 6 PI-containing combination regimens. At week 48, even children with a viral load response below the level of detection (RNA < or =400 copies/mL) still showed poorer neuropsychological functioning compared with established norms.

CONCLUSION

Poor neuropsychological functioning was seen for HIV-infected children and was worse for children with higher viral loads. Only 1 measure of neuropsychological functioning showed improvement after treatment with PI-containing combination therapy, and the extent of that improvement was relatively minor. Treatment strategies for children with HIV disease need to be reevaluated so that they consider restoration of neuropsychological functioning in addition to lowering the viral load.

Protease inhibitor combination therapy, severity of illness, and quality of life among children with perinatally acquired HIV-1 infection

OBJECTIVES

This study examines quality of life (QOL) among school-aged children with perinatally acquired HIV infection and compares QOL outcomes between treatment groups that differ according to the use of protease inhibitor (PI) combination therapy (PI therapy). To gain insights into how PI therapy might influence QOL, associations between severity of illness and QOL were also investigated.

METHODS

Cross-sectional data for 940 children, 5 to 18 years of age, who were enrolled in Pediatric AIDS Clinical Trials Group Late Outcomes Protocol 219 were used to examine domains of caregiver-reported QOL, as assessed with the General Health Assessment for Children, during 1999. The General Health Assessment for Children is an age-specific, modular, QOL assessment that was developed for the study with previously validated measures. QOL differences between treatment groups were estimated with linear and logistic regressions that controlled for sociodemographic characteristics (age, gender, race/ethnicity, maternal/caregiver education, and respondent) and severity-of-illness indicators related to receipt of PI therapy (AIDS status, log(10) CD4+ cell counts, and height-for-age z scores).

RESULTS

The mean age of participants was 9.7 years. Most children were non-Hispanic black (54%) or Hispanic (31%), and 49% of the participants were female. At the 1999 study visit, approximately 14% of children had severe immune suppression (<15% CD4+ cells), whereas 62% of children had > or =25% CD4+ cells, ie, no immune suppression. Participants did exhibit some lag in growth, with mean height and weight z scores of -0.70 and -0.20, respectively. Twenty-eight percent of the children were reported to have met criteria for AIDS at study entry (1993-1999). When treatment groups were compared, children receiving PI therapy (72%) were older, had lower CD4+ cell percentages, and had lower height and weight z scores than did those receiving non-PI therapies. They were also more likely to have met criteria for AIDS at study entry. The most commonly used PIs were ritonavir (46%) and nelfinavir (63%). Health perceptions ratings for most children were at the upper end of the scale, whereas ratings for 25% of the children ranged over the lower 70% of scale scores. Almost one half of the children had at least some limitations in physical functioning, with more frequent limitations in energy-demanding activities (46%) than in basic activities of daily living (32%). The Behavior Problems Index was used to assess psychologic functioning. The mean total Behavior Problems Index score (9.34) and the proportion of children with extreme scores (23%) were consistent with values reported for chronically ill children and those at social and economic risk. One or more limitations in social/school functioning were reported for 58% of children. More than one third of the children (38%) experienced > or =1 physical symptoms that were at least moderately distressing. Health perceptions, physical functioning, psychologic functioning, social/school functioning, and overall HIV symptom scores did not differ between treatment groups. However, receipt of PI therapy was associated with an increased rate of diarrhea (28 vs 13%; adjusted odds ratio: 2.59; 95% confidence interval: 1.74-3.85). Severity of illness was associated with QOL in all domains except psychologic functioning. Higher log(10) CD4+ cell counts, higher height-for-age z scores, and absence of AIDS at study entry were independently associated with fewer social/school limitations and better HIV symptom scores. Health perceptions and physical functioning scores were associated with log(10) CD4+ cell counts and height z scores, respectively.

CONCLUSIONS

QOL among children receiving PI therapy differed little from that among children receiving non-PI therapy, despite clinical indications of more advanced disease. Importantly, the study found no evidence of direct negative effects of PI therapy on QOL outcomes, other than an increased rate of diarrhea. Findings suggest that the effects of PI combination therapies to slow or to prevent disease progression and to increase CD4+ cell counts and height growth have the potential to improve QOL among children with HIV infection. However, many children do experience a constellation of functional impairments indicated by behavioral problems and clinical symptoms, with limitations in activities and in school performance. Comprehensive health services will continue to be required to minimize long-term illness and disability and to maximize children's potential as they move into adolescence and adulthood.

Analysis of HIV- type 1 protease and reverse transcriptase in Brazilian children failing highly active antiretroviral therapy (HAART)

The aim of this study was to evaluate the genotypic resistance profiles of HIV-1 in children failing highly active antiretroviral therapy (HAART). Forty-one children (median age = 67 months) receiving HAART were submitted to genotypic testing when virological failure was detected. cDNA was extracted from PBMCs and amplified by nested PCR for the reverse transcriptase and protease regions of the pol gene. Drug resistance genotypes were determined from DNA sequencing. According to the genotypic analysis, 12/36 (33.3%) and 6/36 (16.6%) children showed resistance and possible resistance, respectively, to ZDV; 5/36 (14%) and 4/36 (11.1%), respectively, showed resistance and possible resistance to ddI; 4/36 (11.1%) showed resistance to 3TC and D4T; and 3/36 (8.3%) showed resistance to Abacavir. A high percentage (54%) of children exhibited mutations conferring resistance to NNRTI class drugs. Respective rates of resistance and possible resistance to PIs were: RTV (12.2%, 7.3%); APV (2.4%, 12.1%); SQV(0%, 12.1%); IDV (14.6%, 4.9%), NFV (22%, 4.9%), LPV/RTV (2.4%, 12.1%). Overall, 37/41 (90%) children exhibited virus with mutations related to drug resistance, while 9% exhibited resistance to all three antiretroviral drug classes.

Relationship between Changes in Thymic Emigrants and Cell-Associated HIV-1 Dna in HIV-1-Infected Children Initiating Antiretroviral Therapy

Objectives and methods

To investigate the relationship between cell-associated HIV-1 dynamics and recent thymic T-cell emigrants, HIV-1 DNA and T-cell receptor rearrangement excision circles (TREC, a marker of recent thymic emigrants) were measured in peripheral blood mononuclear cells in 181 samples from 33 HIV-1-infected children followed for 96 weeks after antiretroviral therapy (ART) initiation.

Results

At baseline, HIV-1 DNA was higher in children with higher TREC ( P=0.02) and was not related to age, CD4 or HIV-1 RNA in multivariate analyses ( P>0.3). Overall, TREC increased and HIV-1 DNA decreased significantly after ART initiation, with faster HIV-1 DNA declines in children with higher baseline TREC ( P=0.009). The greatest decreases in HIV-1 DNA occurred in children with the smallest increases in TREC levels during ART ( P=0.002). However, this inverse relationship between changes in HIV-1 DNA and TREC tended to vary according to the phase of HIV-1 RNA decline ( P=0.13); for the same increase in TREC, HIV-1 DNA decline was much smaller during persistent or transient viraemia compared with stable HIV-1 RNA suppression.

Conclusions

Overall, these findings indicate that TREC levels predict HIV-1 DNA response to ART and suggest that immune repopulation by thymic emigrants adversely affects HIV-1 DNA decline in the absence of persistent viral suppression, possibly by providing a cellular source for viral infection and replication.

Atazanavir: improving the HIV protease inhibitor class

Protease inhibitors are potent agents against HIV but their use is constrained by poor pharmacokinetics, cross-resistance and metabolic toxicities. Atazanavir [Reyataz] is a new protease inhibitors with once-daily dosing and minimal lipid and glycemic effects. Resistance studies of clinical isolates reveal a mutational pattern distinctive from that of other protease inhibitors. Atazanavir selects for the I50L mutation in HIV protease that confers increased susceptibility to other protease inhibitors in vitro. Clinical trials have shown comparable efficacy to nelfinavir (Viracept) and efavirenz (Sustiva) in treatment-naive patients, and in preliminary studies, ritonavir-boosted atazanavir is effective in patients failing previous protease inhibitor-containing regimens. Reversible elevations in bilirubin occur in some patients but are not associated with hepatic injury. Atazanavir improves upon aspects of currently-available protease inhibitors and appears useful for initial and possibly subsequent HIV therapy.

Radiologic approach to the diagnosis of infectious pulmonary diseases in patients infected with the human immunodeficiency virus

Nearly all patients infected with HIV experience respiratory infection at some point in the course of their illness. The spectrum of infections is varied and in order to generate a useful differential diagnosis based on imaging findings it is imperative for the radiologist to be aware of changing trends in disease prevalence and epidemiology, and the possible pathology related to new therapies. The characterization of the radiographic pattern in correlation with clinical findings and laboratory values (in particular the degree of immunosuppression as reflected in the CD4 level) would be helpful in narrowing the differential diagnosis of infectious pulmonary disease in HIV-positive patients. The most common radiologic patterns considered include areas of ground-glass, consolidation, nodules, and lymphadenopathy. We also include airways diseases and cavitary/cystic lesions because their prevalence has increased over recent years, and we also mention the significance of a normal chest radiograph in the suspicion of a lung infection. In most cases, the clinical and radiographic findings are sufficient for confident diagnosis. The radiologic diagnosis of thoracic infections in patients with AIDS has improved with the use of CT. The greatest value of CT is in excluding lung disease when the radiographic findings are equivocal and in confirming the presence of clinically suspected disease when the radiograph is normal.

Early versus deferred antiretroviral multidrug therapy in infants infected with HIV type 1

BACKGROUND

The clinical impact of early antiretroviral multidrug therapy on the risk of early-onset severe human immunodeficiency virus (HIV) disease has not been evaluated on a large scale.

METHODS

We evaluated the risk of early-onset events associated with acquired immunodeficiency syndrome (AIDS), particularly the risk of encephalopathy, among infants in the French Perinatal Cohort, according to whether antiretroviral multidrug therapy was initiated before or after the age of 6 months.

RESULTS

Of 83 HIV-infected infants born in 1996 (when HAART became available) or later, 40 received early treatment on or before the age of 6 months, and 43 received deferred multidrug therapy after the age of 6 months. In the group that received early multidrug therapy, no child developed an opportunistic infection or an encephalopathy during the first 24 months of life. In the deferred multidrug therapy group, 6 infants presented with a total of 7 AIDS-associated events (P=.01), 3 of which were encephalopathies (P=.08). The small number of events prevented the identification of clinical and biological markers that accurately predict progression of early-onset severe HIV disease.

CONCLUSION

In this observational study, infants who received multidrug therapy before 6 months of age did not have the early-onset severe form of childhood HIV disease. Further studies are needed to find accurate early markers of disease progression in this age group.

Two-year clinical and immune outcomes in human immunodeficiency virus-infected children who reconstitute CD4 T cells without control of viral replication after combination antiretroviral therapy

OBJECTIVE

To evaluate 96-week clinical and immune outcomes to protease inhibitor-containing antiretroviral therapy.

METHODS

A prospective study was conducted of 40 human immunodeficiency virus (HIV)-infected children who displayed viral suppression (VS) with successful immune reconstitution (IS), failure to suppress virus (VF) or develop immune reconstitution (IF), or discordant immune and viral responses (VF/IS) at 24 weeks posttherapy. All children enrolled had viral RNA >4.0 log10 copies per mL and were Centers for Disease Control ad Prevention immune stage 2 or 3. Clinical, viral, and immune outcomes were assessed during the subsequent 72 weeks.

RESULTS

VS/IS and VF/IS groups displayed similar sustained increases in CD4 T cells, although viral levels rebounded by 48 and 96 weeks posttherapy to pretherapy levels in the discordant group. The VF/IS outcome group had significant increases in height and weight z scores compared with entry and were similar to the VS/IS group. After treatment, antigen-specific responses after tetanus immunization were similar in the VF/IS and VS/IS groups. Prevalence of HIV-associated illnesses decreased in both VS/IS and VF/IS but not in VF/IF response groups.

CONCLUSIONS

The findings indicate that viral replication under the selective pressure of protease inhibitors fails to exhibit the same deleterious impact on T-cell immunity as pretherapy viruses. CD4 T-cell counts may be a better predictor of disease progression and improvement in growth than viral burden in HIV-infected children who receive a protease inhibitor as part of a highly active antiretroviral therapy regimen.

The role of psychosocial and family factors in adherence to antiretroviral treatment in human immunodeficiency virus-infected children

BACKGROUND

The toxicity and complexity of antiretroviral therapy (ART) regimens are substantial challenges in the context of patients' lives. This study examines child psychosocial and caregiver/family factors influencing adherence to ART in perinatally human immunodeficiency virus (HIV)-infected children.

METHODS

Seventy-five children (ages 3-13 years) prescribed ART, and their primary caregivers were recruited from 2 urban pediatric HIV programs. A battery of psychologic assessments and self-report adherence data were collected from all caregivers and 48 children who were > or =7 years old.

RESULTS

Forty percent of caregivers and 56% of children reported missed doses of medication in the past month. Families in which the caregiver or child reported missed doses (nonadherent) were compared with families who reported no missed doses (adherent). In univariate analyses, nonadherence was significantly associated with older child age (P < 0.05), worse parent-child communication (P < 0.017), higher caregiver stress (P < 0.002), lower caregiver quality of life (P < 0.003) and worse caregiver cognitive functioning (P = 0.033), and of borderline significance in its association with increased (1) child responsibility for medications (P < 0.07), (2) HIV disclosure to the child (P < 0.07) and (3) child stress (P < 0.08) In logistic regressions controlling for age, caregiver/family factors were the most strongly associated with nonadherence, including worse parent-child communication (P < 0.03), higher caregiver stress (P < 0.01), less disclosure to others (P < 0.05) and quality of life (P < 0.01).

CONCLUSIONS

Our data suggest that efforts to improve children's adherence to complex antiretroviral regimens requires addressing developmental, psychosocial and family factors.