Prospective long-term outcomes of a cohort of Ugandan children with laboratory monitoring during antiretroviral therapy

The impact of viraemia on inflammatory biomarkers and CD4+ cell subpopulations in HIV-infected children in sub-Saharan Africa

OBJECTIVE

To determine the impact of virological control on inflammation and cluster of differentiation 4 depletion among HIV-infected children initiating antiretroviral therapy (ART) in sub-Saharan Africa.

DESIGN

Longitudinal cohort study.

METHODS

In a sub-study of the ARROW trial (ISRCTN24791884), we measured longitudinal HIV viral loads, inflammatory biomarkers (C-reactive protein, tumour necrosis factor alpha, interleukin 6 (IL-6), soluble CD14) and (Uganda only) whole blood immunophenotype by flow cytometry in 311 Zimbabwean and Ugandan children followed for median 3.5 years on first-line ART. We classified each viral load measurement as consistent suppression, blip/post-blip, persistent low-level viral load or rebound. We used multi-level models to estimate rates of increase or decrease in laboratory markers, and Poisson regression to estimate the incidence of clinical events.

RESULTS

Overall, 42% children experienced viral blips, but these had no significant impact on immune reconstitution or inflammation. Persistent detectable viraemia occurred in one-third of children and prevented further immune reconstitution, but had little impact on inflammatory biomarkers. Virological rebound to ≥5000 copies/ml was associated with arrested immune reconstitution, rising IL-6 and increased risk of clinical disease progression.

CONCLUSIONS

As viral load testing becomes more available in sub-Saharan Africa, repeat testing algorithms will be required to identify those with virological rebound, who need switching to prevent disease progression, whilst preventing unnecessary second-line regimen initiation in the majority of children with detectable viraemia who remain at low risk of disease progression.

Antiretroviral drug concentrations in hair are associated with virologic outcomes among young people living with HIV in Tanzania

OBJECTIVE

We assessed the relationship of self-reported adherence versus antiretroviral therapy (ART) concentrations in hair with virologic outcomes among young people living with HIV.

DESIGN

This was a cross-sectional study that enrolled young people living with HIV age 11-24 years, who attended a youth HIV clinic in Moshi, Tanzania.

METHODS

ART adherence was assessed by self-report, drug concentration in hair samples, and plasma HIV-1 RNA measurements. Those with virologic failure, defined as plasma HIV-1 RNA more than 400 copies/ml, had genotypic resistance assessed. Receiver operating characteristic curves were used to evaluate ART-concentration threshold cutoffs for virologic suppression, after excluding those with known high-level resistance mutations.

RESULTS

Among 280 young people enrolled, 227 were included in the final analysis. Seventy-two (32%) self-reported inadequate adherence and 91 (40%) had virologic failure. Hair ART-concentration (P < 0.001), but not self-reported adherence (P = 0.53), was associated with virologic outcome. Sixty-seven (74%) of those with virologic failure had resistance testing performed, of whom 60% had high-level resistance. Receiver operating characteristic curves demonstrated moderate or high classification performance for association with virologic suppression with specific hair ART-concentration cutoffs for lopinavir (1.8 ng/mg), efavirenz (1.04 ng/mg), and nevirapine (33.2 ng/mg).

CONCLUSION

Hair ART-concentrations were significantly associated with virologic outcomes among young people living with HIV. ART-concentration thresholds associated with virologic suppression are proposed. Hair analysis may provide a noninvasive, cost-effective adherence assessment tool in settings with limited second and third-line treatment options.

Five-year Outcomes Among Children Receiving Antiretroviral Therapy in a Community-based Accompaniment Program in Rural Rwanda

Of 277 HIV-infected children in rural Rwanda enrolled in a community-based accompaniment program, 95.0% were retained in care 5 years after treatment initiation, with only 9 (3.3%) deaths and 3 (1.1%) defaults. Of 235 (84.8%) children with a documented viral load result, 201 (85.5%) demonstrated viral load suppression (<1000 copies/mL).

Using Exclusion-Based Sample Preparation (ESP) to Reduce Viral Load Assay Cost

Viral load (VL) measurements are critical to the proper management of HIV in developing countries. However, access to VL assays is limited by the high cost and complexity of existing assays. While there is a need for low cost VL assays, performance must not be compromised. Thus, new assays must be validated on metrics of limit of detection (LOD), accuracy, and dynamic range. Patient plasma samples from the Joint Clinical Research Centre in Uganda were de-identified and measured using both an existing VL assay (Abbott RealTime HIV-1) and our assay, which combines low cost reagents with a simplified method of RNA isolation termed Exclusion-Based Sample Preparation (ESP).71 patient samples with VLs ranging from <40 to >3,000,000 copies/mL were used to compare the two methods. We demonstrated equivalent LOD (~50 copies/mL) and high accuracy (average difference between methods of 0.08 log, R2 = 0.97). Using expenditures from this trial, we estimate that the cost of the reagents and consumables for this assay to be approximately $5 USD. As cost is a significant barrier to implementation of VL testing, we anticipate that our assay will enhance access to this critical monitoring test in developing countries.

Nevirapine Resistance in Previously Nevirapine-Unexposed HIV-1-Infected Kenyan Infants Initiating Early Antiretroviral Therapy

Nevirapine (NVP) resistance occurs frequently in infants following NVP use in prevention of mother-to-child transmission (PMTCT) regimens. However, among previously NVP-unexposed infants treated with NVP-antiretroviral therapy (ART), the development and impact of NVP resistance have not been well characterized. In a prospective clinical trial providing early ART to HIV-infected infants <5 months of age in Kenya (OPH03 study), we followed NVP-unexposed infants who initiated NVP-ART for 12 months. Viral loads were assessed and resistance determined using a population-based genotypic resistance assay. Of 99 infants screened, 33 had no prior NVP exposure, 22 of whom were initiated on NVP-ART. Among 19 infants with follow-up, seven (37%) infants developed resistance: one at 3 months and six at 6 months after ART initiation. The cumulative probability of NVP resistance was 5.9% at 3 months and 43.5% at 6 months. Baseline HIV RNA levels (p=0.7) and other characteristics were not associated with developing resistance. Post-ART, higher virus levels at visits preceding the detection of resistance were significantly associated with increased detection of resistance (p=0.004). Virus levels after 6 and 12 months of ART were significantly higher in infants with resistance than those without (p=0.007, p=0.030, respectively). Among infants without previous NVP exposure, development of NVP resistance was frequent and was associated with virologic failure during the first year of ART. Earlier development of NVP resistance in infants than in adults initiating NVP-ART may be due to longer viremia following ART or inadequate NVP levels resulting from NVP lead-in dosing. The development of NVP resistance may, in part, explain the superiority of protease inhibitor-based ART in infants.

Tackling virological failure in HIV-infected children living in Africa

Drug resistance in HIV-infected children is one of the main contributors to antiretroviral treatment (ART) failure, especially in developing countries. Sub-Saharan Africa has the largest burden of pediatric HIV infection in the world. Herein, we systematically review the current status of ART failure in HIV-infected African children. A literature search for publications within 10 years was performed through PubMed to identify relevant articles. Included studies examined the impact of timing of ART initiation, criteria for diagnosing therapeutic failure, predictors of therapeutic failure, management strategies and future directions to minimize failure rates in these pediatric populations. Although there is scale-up of ART programs in Africa, novel therapeutic and management strategies are needed to overcome current challenges.

Risk of first-line antiretroviral therapy failure in HIV-infected Thai children and adolescents

BACKGROUND

Adolescence may affect adherence and response to highly active antiretroviral therapy (HAART). Limited data are available regarding the long-term treatment outcomes of perinatal HIV-infected adolescents.

METHODS

Data from perinatally acquired HIV-infected Thai children who started first-line nonnucleoside analog-based HAART before 18 years of age and treated for ≥24 weeks were analyzed. Children were categorized by age at HAART initiation; age<3 years, 3-9 years, early adolescence (10-13 years) and middle adolescence (14-16 years). CD4 and HIV-RNA were monitored every 6-12 months. Virologic failure (VF) was defined as HIV-RNA≥1000 copies/mL after ≥24 weeks of HAART.

RESULTS

Of 840 children, 68% were in pre-adolescence. Median baseline CD4% was 7.9%. Use of nevirapine versus efavirenz was 77:23%. Median duration of nonnucleoside reverse transcriptase inhibitor-based HAART was 5.6 years. No differences between groups were observed for rate of HIV-RNA<50 copies/mL (68%, P=0.18) and rate of VF (28%, P=0.82), median time to VF (22 months, P=0.13). Incidence of VF per 100 child-year in children age<3 years, 3-9 years, early adolescence and middle adolescence were 7.9, 4.7, 7.4 and 10.8, respectively (P=0.012). Median adherence by pill count was 97.3% (P=0.23). By multivariate analysis, predictors for VF were age at HAART initiation of <3 years (HR: 1.73, 95% CI: 1.18-2.55), age 10-16 years (HR: 1.47, 95% CI: 1.09-1.97), and nevirapine use (HR: 1.63, 95% CI: 1.14-2.32).

CONCLUSIONS

VF rates were observed in one-third of long-term treated Thai children on first-line HAART. Age 3-9 years at HAART initiation was associated with less VF compared with those younger or older, whereas children who used nevirapine had higher VF.

Durability of antiretroviral therapy and predictors of virologic failure among perinatally HIV-infected children in Tanzania: a four-year follow-up

BACKGROUND

In Tanzania, HIV-1 RNA testing is rarely available and not standard of care. Determining virologic failure is challenging and resistance mutations accumulate, thereby compromising second-line therapy. We evaluated durability of antiretroviral therapy (ART) and predictors of virologic failure among a pediatric cohort at four-year follow-up.

METHODS

This was a prospective cross-sectional study with retrospective chart review evaluating a perinatally HIV-infected Tanzanian cohort enrolled in 2008-09 with repeat HIV-1 RNA in 2012-13. Demographic, clinical, and laboratory data were extracted from charts, resistance mutations from 2008-9 were analyzed, and prospective HIV RNA was obtained.

RESULTS

161 (78%) participants of the original cohort consented to repeat HIV RNA. The average age was 12.2 years (55% adolescents ≥12 years). Average time on ART was 6.4 years with 41% receiving second-line (protease inhibitor based) therapy. Among those originally suppressed on a first-line (non-nucleoside reverse transcriptase based regimen) 76% remained suppressed. Of those originally failing first-line, 88% were switched to second-line and 72% have suppressed virus. Increased level of viremia and duration of ART trended with an increased number of thymidine analogue mutations (TAMs). Increased TAMs increased the odds of virologic failure (p = 0.18), as did adolescent age (p < 0.01).

CONCLUSIONS

After viral load testing in 2008-09 many participants switched to second-line therapy. The majority achieved virologic suppression despite multiple resistance mutations. Though virologic testing would likely hasten the switch to second-line among those failing, methods to improve adherence is critical to maximize durability of ART and improve virologic outcomes among youth in resource-limited settings.

Poor clinical outcomes for HIV infected children on antiretroviral therapy in rural Mozambique: need for program quality improvement and community engagement

INTRODUCTION

Residents of Zambézia Province, Mozambique live from rural subsistence farming and fishing. The 2009 provincial HIV prevalence for adults 15-49 years was 12.6%, higher among women (15.3%) than men (8.9%). We reviewed clinical data to assess outcomes for HIV-infected children on combination antiretroviral therapy (cART) in a highly resource-limited setting.

METHODS

We studied rates of 2-year mortality and loss to follow-up (LTFU) for children <15 years of age initiating cART between June 2006-July 2011 in 10 rural districts. National guidelines define LTFU as >60 days following last-scheduled medication pickup. Kaplan-Meier estimates to compute mortality assumed non-informative censoring. Cumulative LTFU incidence calculations treated death as a competing risk.

RESULTS

Of 753 children, 29.0% (95% CI: 24.5, 33.2) were confirmed dead by 2 years and 39.0% (95% CI: 34.8, 42.9) were LTFU with unknown clinical outcomes. The cohort mortality rate was 8.4% (95% CI: 6.3, 10.4) after 90 days on cART and 19.2% (95% CI: 16.0, 22.3) after 365 days. Higher hemoglobin at cART initiation was associated with being alive and on cART at 2 years (alive: 9.3 g/dL vs. dead or LTFU: 8.3-8.4 g/dL, p<0.01). Cotrimoxazole use within 90 days of ART initiation was associated with improved 2-year outcomes Treatment was initiated late (WHO stage III/IV) among 48% of the children with WHO stage recorded in their records. Marked heterogeneity in outcomes by district was noted (p<0.001).

CONCLUSIONS

We found poor clinical and programmatic outcomes among children taking cART in rural Mozambique. Expanded testing, early infant diagnosis, counseling/support services, case finding, and outreach are insufficiently implemented. Our quality improvement efforts seek to better link pregnancy and HIV services, expand coverage and timeliness of infant diagnosis and treatment, and increase follow-up and adherence.

Virologic and immunologic outcomes of HIV-infected Ugandan children randomized to lopinavir/ritonavir or nonnucleoside reverse transcriptase inhibitor therapy

BACKGROUND

In the Prevention of Malaria and HIV disease in Tororo pediatrics trial, HIV-infected Ugandan children randomized to receive lopinavir/ritonavir (LPV/r)-based antiretroviral therapy (ART) experienced a lower incidence of malaria compared with children receiving nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Here we present the results of the noninferiority analysis of virologic efficacy and comparison of immunologic outcomes.

METHODS

ART-naive or -experienced (HIV RNA <400 copies/mL) children aged 2 months to 6 years received either LPV/r or NNRTI-based ART. The proportion of children with virologic suppression (HIV RNA <400 copies/mL) at 48 weeks was compared using a prespecified noninferiority margin of -11% in per-protocol analysis. Time to virologic failure by 96 weeks, change in CD4 counts and percentages, and incidence of adverse event rates were also compared.

RESULTS

Of 185 children enrolled, 91 initiated LPV/r and 92 initiated NNRTI-based ART. At baseline, the median age was 3.1 years (range, 0.4-5.9), and 131 (71%) children were ART-naive. The proportion of children with virologic suppression at 48 weeks was 80% (67/84) in the LPV/r arm vs. 76% (59/78) in the NNRTI arm, a difference of 4% (95% confidence interval: -9% to +17%). Time to virologic failure, CD4 changes, and the incidence of Division of AIDS grade III/IV adverse events were similar between arms.

CONCLUSIONS

LPV/r-based ART was not associated with worse virologic efficacy, immunologic efficacy, or adverse event rates compared with NNRTI-based ART. Considering these results and the reduction in malaria incidence associated with LPV/r previously reported for this trial, wider use of LPV/r to treat HIV-infected African children in similar malaria-endemic settings could be considered.

Decentralised paediatric HIV care in Ethiopia: a comparison between outcomes of patients managed in health centres and in a hospital clinic

BACKGROUND

In order to increase access to antiretroviral therapy (ART) in HIV-infected children, paediatric HIV care has been introduced in health centres in Ethiopia, where patients are managed by health professionals with limited training.

OBJECTIVE

To compare outcomes of paediatric HIV care in hospital and health centre clinics and to determine risk factors for death and loss to follow-up (LTFU).

DESIGN

Retrospective comparison of patient characteristics and outcomes among children managed in a public hospital and all five public health centres in the uptake area.

RESULTS

Among 1,960 patients (health centres 572, hospital clinic 1,388), 34% were lost to follow-up, 2% died, 14% were transferred out, and 46% remained in care. Children initiating ART in the hospital clinic had lower median CD4 cell counts (age <1 year: 575 vs. 1,183 cells/mm³, p=0.024; age 1-5 years: 370 vs. 598 cells/mm³, p<0.001; age >5 years: 186 vs. 259 cells/mm³, p<0.001), and a higher proportion were <1 year of age (22% vs. 15%, p=0.025). ART initiation rates and retention in care were similar between children managed in health centres and in the hospital clinic (36% vs. 37% and 47% vs. 46%, respectively). Among patients starting ART, mortality was associated with age <1 year [hazard ratio (HR) 12.0; 95% confidence interval (CI): 3.5, 41]. LTFU was associated with CD4 cell counts <350 cells/mm³ (HR 1.8; 95% CI: 1.2, 3.0), weight-for-age z-scores below -4 (HR 2.8; 95% CI: 1.4, 5.6), and age <5 years (1-5 years: HR 1.6; 95% CI: 1.0, 2.5; <1 year: HR 3.3; 95% CI: 1.6, 6.6).

CONCLUSIONS

Outcomes of HIV care were similar for Ethiopian children managed in a hospital clinic or in health centres. However, patients treated at the hospital clinic had characteristics of more advanced disease. Rates of LTFU were high in both types of health facility.

Development of antiretroviral resistance in children with HIV in low- and middle-income countries

With antiretroviral therapy (ART) recommended by the World Health Organization (WHO) for children aged <2 years with human immunodeficiency virus (HIV) and continuing global ART roll-out, ART coverage in children is rising. However ART coverage in children lags considerably behind that in adults (28% vs 58%). Long duration of therapy needed for HIV-infected children requires maximal efficacy, minimal toxicity, and prevention of development of drug resistance. This requires consideration of ways to improve sequencing of regimens during childhood to minimize development of resistance and treatment failure. We consider aspects of virological failure and development of resistance in vertically HIV-infected children in resource-limited settings. We review evidence guiding choices of first- and second-line ART, the impact of drugs given to prevent mother-to-child transmission, adherence issues and, availability of appropriate drug formulations. Recommendations made during the Collaborative HIV and Anti-HIV Drug Resistance Network (CHAIN)/WHO meeting (October 2012) are summarized.

Persistence versus reversion of 3TC resistance in HIV-1 determine the rate of emergence of NVP resistance

When HIV-1 is exposed to lamivudine (3TC) at inhibitory concentrations, resistant variants carrying the reverse transcriptase (RT) substitution M184V emerge rapidly. This substitution confers high-level 3TC resistance and increased RT fidelity. We established a novel in vitro system to study the effect of starting nevirapine (NVP) in 3TC-resistant/NNRTI-naïve clinical isolates, and the impact of maintaining versus dropping 3TC pressure in this setting. Because M184V mutant HIV-1 seems hypersusceptible to adefovir (ADV), we also tested the effect of ADV pressure on the same isolates. We draw four conclusions from our experiments simulating combination therapy in vitro. (1) The presence of low-dose (1 μM) 3TC prevented reversal to wild-type from an M184V mutant background. (2) Adding low-dose 3TC in the presence of NVP delayed the selection of NVP-associated mutations. (3) The presence of ADV, in addition to NVP, led to more rapid reversal to wild-type at position 184 than NVP alone. (4) ADV plus NVP selected for greater numbers of mutations than NVP alone. Inference about the "selection of mutation" is based on two statistical models, one at the viral level, more telling, and the other at the level of predominance of mutation within a population. Multidrug pressure experiments lend understanding to mechanisms of HIV resistance as they bear upon new treatment strategies.