Predictors of virologic failure and genotypic resistance mutation patterns in thai children receiving non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy

Lessons Learned from the Impact of HIV Status Disclosure to Children after First-Line Antiretroviral Treatment Failure in Kinshasa, DR Congo

HIV status disclosure to children remains a challenge in sub-Saharan Africa. For sociocultural reasons, parents often delay disclosure with subsequent risks to treatment compliance and the child’s psychological well-being. This article assesses the effects of HIV disclosure on second-line ART compliance after first-line failure. We conducted a retrospective study of 52 HIV-positive children at Kalembelembe Pediatric Hospital in Kinshasa who were unaware of their HIV status and had failed to respond to the first-line ART. Before starting second-line ART, some parents agreed to disclosure. All children were followed before and during the second-line ART. Conventional usual descriptive statistics were used. For analysis, the children were divided into two groups: disclosed to (n = 39) and not disclosed to (n = 13). Before starting the second-line ART, there was no difference in CD4 count between the two groups (p = 0.28). At the end of the first year of second-line ART, the difference was statistically significant between the two groups with regard to CD4% (p < 0.001) and deaths (p = 0.001). The children disclosed to also reported fewer depressive symptoms post-disclosure and had three times fewer clinic visits. HIV status disclosure to children is an important determinant of ART compliance and a child’s psychological well-being.

Etravirine in treatment-experienced HIV-1-infected children 1 year to less than 6 years of age

OBJECTIVE

To describe the pharmacokinetics, safety, and efficacy of etravirine (ETR) in HIV-infected children 1 to less than 6 years of age.

DESIGN

Phase I/II, open-label, multicenter, dose-finding study.

METHODS

Antiretroviral therapy (ART)-experienced children in two age cohorts (I: 2 to <6 years; II: 1 to less than 2 years) received weight-based ETR, swallowed whole or dispersed in liquid, with optimized ART including a ritonavir-boosted protease inhibitor. Intensive pharmacokinetics occurred 7-18 days after starting ETR. Participants with ETR AUC12h less than 2350 ng h/ml had a dose increase and repeat pharmacokinetics.

RESULTS

Twenty-six children enrolled and 21 (15 in cohort I and 6 in cohort II) had evaluable intensive pharmacokinetics sampling at the final weight-based dose. On the final dose, the geometric mean ETR AUC12h was 3823 ng h/ml for cohort I and 3328 ng h/ml for cohort II. Seven children (33.3%) on the final dose, all taking ETR dispersed, had an AUC12  h less than 2350 ng h/ml and underwent a dose increase. ETR AUC12  h was 3.8-fold higher when ETR was swallowed whole vs. dispersed, P less than 0.0001. On the final dose, 75 and 33.3% in cohorts I and II, respectively, had HIV-1 RNA 400 copies/ml or less or at least 2 log reductions from baseline at week 48. Three children (11.5%) experienced a grade at least 3 adverse event related to ETR but only 1 discontinued.

CONCLUSION

ETR was well tolerated. Predefined pharmacokinetics targets were met but overall exposures were low vs. historical data in adults, particularly in young children taking dispersed tablets. A high rate of viral efficacy was observed among those aged 2 to more than 6 years but not in those less than 2 years.

Virologic failure and switch to second-line antiretroviral therapy in children with HIV in Lilongwe, Malawi: an observational cohort study

BACKGROUND

As routine viral load testing among HIV-infected individuals on antiretroviral therapy (ART) expands, virologic failure (VF) among children in developing countries remains poorly understood. We assessed the rate of VF, the proportion failing who were subsequently switched to second-line ART and factors associated with VF among children ≤18 y.

METHODS

An observation cohort study among 1312 children at two public clinics in Lilongwe, Malawi who initiated a first-line ART regimen between January 2014 and December 2017 and remained on treatment for ≥6 mo was conducted. Kaplan-Meier methods estimated the probabilities of VF. Univariable and multivariable Poisson regression models were used to explore predictors of VF.

RESULT

Overall, 16% (208/1312) of children experienced VF with an incidence rate of 10.1 events per 100 person-years. Of the 208, 184 (88%) were switched to second-line ART: 68 (43%) switched the same day VF was confirmed and 106 (66%) switched within 90 d of confirmed VF. Use of a Nevirapine (NVP)-based regimen and initiating ART in 2016-2017 compared with 2014-2015 were independent predictors of VF.

CONCLUSION

VF is common among children receiving ART. The findings suggest that VF can be reduced by phasing out NVP-based regimen and by ensuring optimal adherence to ART.

Prevalence and impact of comorbid chronic pain and cigarette smoking among people living with HIV

Rates of chronic pain and cigarette smoking are each substantially higher among people living with HIV (PLWH) than in the general population. The goal of these analyses was to examine the prevalence and impact of comorbid chronic pain and cigarette smoking among PLWH. Participants included 3289 PLWH (83% male) who were recruited from five HIV clinics. As expected, the prevalence of smoking was higher among PLWH with chronic pain (41.9%), than PLWH without chronic pain (26.6%, p < .0001), and the prevalence of chronic pain was higher among current smokers (32.9%), than among former (23.6%) or never (17%) smokers (ps < .0001). PLWH who endorsed comorbid chronic pain and smoking (vs. nonsmokers without chronic pain) were more likely to report cocaine/crack and cannabis use, be prescribed long-term opioid therapy, and have virologic failure, even after controlling for relevant sociodemographic and substance-related variables (ps < .05). These results contribute to a growing empirical literature indicating that chronic pain and cigarette smoking frequently co-occur, and extend this work to a large sample of PLWH. Indeed, PLWH may benefit from interventions that are tailored to address bidirectional pain-smoking effects in the context of HIV.

Nevirapine and tuberculosis predict first-line treatment failure in HIV patients in Indonesia: Case-control study

Introduction

Indonesia antiretroviral therapy guideline suggests the use of Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI)-based regiments as first line of HIV treatment and Protease Inhibitor to replace NNRTI when treatment failure occurred. This case-control study was aimed to study factors predicting first-line ART treatment failure among HIV positive patients aged >15 years, non-pregnant, and registered in our institution, Indonesia.

Methods

Diagnosis of HIV treatment failure was made according to the standard WHO criteria. Demographic and outcome variables were recorded. The association between variables were analyzed by Chi-square test with odds ratios (OR) and 95% confidence intervals (95% CI), followed by multivariate analysis using logistic regression test.

Results

Twenty-six index cases and 26 age- and sex-matched control cases were included in the study with a mean age of 32.27 ± 8.7 years and 32.88 ± 8.15 years, respectively. Median time for switching to second-line (Lopinavir/ritonavir, LPV/r) was 46.32 ± 30.21 months. Patients presented with tuberculosis and treated by nevirapine as the first-line treatment were 26.6-folds (95% CI: 2.41-293.81, p = 0.007) and 6.7-folds (95% CI: 1.56-28.45, p = 0.011) higher risk for treatment failure, respectively.

Conclusions

The presence of tuberculosis and the use of nevirapine in first-line treatment were strong predictors for first-line ARV treatment failure, suggesting for closer clinical monitoring for patients with those conditions. A further and larger prospective cohort study is needed to confirm the findings in this study.

Virologic response to efavirenz-based first-line antiretroviral therapy in children with previous exposure to antiretrovirals to prevent mother-to-child transmission

Efavirenz-based first-line regimens have been widely used for children ≥3 years of age starting antiretroviral therapy, despite possible resistance with prior exposure to non-nucleoside reverse transcriptase inhibitors for prevention of mother-to-child transmission (PMTCT). We used logistic regression to examine the association between PMTCT exposure and viral failure (VF) defined as two consecutive viral loads (VL)>1000 copies/ml between 6–18 months on ART. Children with previous nevirapine exposure for PMTCT were not at higher risk of VF compared to unexposed children (adjusted Odds Ratio (aOR): 0.79; 95% CI:0.56, 1.11).

Early and Late Virologic Failure After Virologic Suppression in HIV-Infected Asian Children and Adolescents

BACKGROUND

Virologic failure is a major threat to maintaining effective combination antiretroviral therapy, especially for children in need of lifelong treatment. With efforts to expand access to HIV viral load testing, our understanding of pediatric virologic failure is evolving.

SETTING

An Asian cohort in 16 pediatric HIV services across 6 countries.

METHODS

From 2005 to 2014, patients younger than 20 years who achieved virologic suppression and had subsequent viral load testing were included. Early virologic failure was defined as a HIV RNA ≥1000 copies per milliliter within 12 months of virologic suppression, and late virologic as a HIV RNA ≥1000 copies per milliliter after 12 months following virologic suppression. Characteristics at combination antiretroviral therapy initiation and virologic suppression were described, and a competing risk time-to-event analysis was used to determine cumulative incidence of virologic failure and factors at virologic suppression associated with early and late virologic failure.

RESULTS

Of 1105 included in the analysis, 182 (17.9%) experienced virologic failure. The median age at virologic suppression was 6.9 years, and the median time to virologic failure was 24.6 months after virologic suppression. The incidence rate for a first virologic failure event was 3.3 per 100 person-years. Factors at virologic suppression associated with late virologic failure included older age, mostly rural clinic setting, tuberculosis, protease inhibitor-based regimens, and early virologic failure. No risk factors were identified for early virologic failure.

CONCLUSIONS

Around 1 in 5 experienced virologic failure in our cohort after achieving virologic suppression. Targeted interventions to manage complex treatment scenarios, including adolescents, tuberculosis coinfection, and those with poor virologic control are required.

Role of efavirenz plasma concentrations on long-term HIV suppression and immune restoration in HIV-infected children

Background

To access the long term relationship between efavirenz plasma concentrations and evolution of HIV RNA loads and CD4 cell counts in children.

Methods

Retrospective analysis of data from HIV-infected children on first line efavirenz-containing regimen. A population pharmacokinetic-pharmacodynamic (PK-PD) model was developed to describe the evolution of HIV RNA load and CD4 cell count (efficacy outcomes) in relation to efavirenz plasma concentration. Individual CYP2B6 516 G>T genotype data were not available for this analysis. A score (IS_EFV) quantifying the effect of efavirenz concentrations on the long-term HIV replication was calculated from efavirenz concentrations and PD parameters and, a value of IS_EFV below which HIV replication is likely not suppressed was determined. Cox proportional hazards regression models were used to assess the association of the risk of viral replication with IS_EFV, and with efavirenz mid-dose concentration(C₁₂).

Results

At treatment initiation, median (interquartile range, IQR) age was 8 years (5 to 10), body weight 17 kg (14 to 23), HIV RNA load 5.1 log₁₀ copies/mL (4.6 to 5.4), and CD4 cell count 71 cells/mm³. A model of PK-PD viral dynamics assuming that efavirenz decreases the rate of infected host cells adequately described the relationship of interest. After adjusting for age, baseline HIV RNA load and CD4 cell counts an IS_EFV <85% was significantly associated with a higher risk of viral replication (p-value <0.001) while no significant association was observed with C₁₂ <1.0 mg/L.

Conclusion

The IS_EFV score was a good predictor of viral replication in children on efavirenz-based treatment.

Comparing the Diagnostics Accuracy of CD4+ T-Lymphocyte Count and Percent as a Surrogate Markers of Pediatric HIV Disease

The percentage CD4+ T-lymphocytes is used to monitor pediatric HIV disease. However, in resource-limited settings, enumerating the percentage of CD4+ T-lymphocytes is hampered by the lack of laboratory infrastructure and trained technicians. In this paper, we investigated the performances of the percentage and absolute CD4+ T-lymphocytes as markers of pediatric HIV disease progression using data from HIV-infected children enrolled through the Yale Prospective Longitudinal Pediatric Cohort study. A Lehmann family of Receiver Operating Characteristic (ROC) curves were used to estimate and compare the performance of the two biomarkers in monitoring pediatric HIV disease progression. The area under the ROC (AUC) curve and its empirical estimator have previously been used to assess the performance of biomarkers for a cross-sectional data. However, there is a paucity of literature on the AUC for correlated longitudinal biomarkers. Previous works on the estimation and inference of the AUC for longitudinal biomarkers have largely focused on independent biomarkers or failed to consider the effect of covariates. The Lehmann approach allowed us to estimate the AUC of the aforementioned correlated longitudinal biomarkers as functions of explanatory variables. We found that the overall performance of the two biomarkers was comparable. The area under the ROC curves for CD4+ T cell count and percentage were 0.681 [SE = 0.029; 95% CI: 0.624-0.737] and 0.678 [SE = 0.024; 95% CI:0.630-0.725], respectively. Our results suggest that absolute CD4+ T-lymphocyte counts could be used as a proxy for percentage of CD4+ T-lymphocytes in monitoring pediatric HIV in resource-limited settings.

Long-term virological outcome in children receiving first-line antiretroviral therapy

BACKGROUND

Studies relating to long-term virological outcomes among children on first-line antiretroviral therapy (ART) from low and middle-income countries are limited.

METHODS

Perinatally HIV infected, ART-naive children, between 2 and 12 years of age, initiating NNRTI-based ART during 2010-2015, with at least 12 months of follow-up, were included in the analysis. CD4 cell counts and plasma HIV-1 RNA were measured every 24 weeks post-ART initiation. Immunologic failure was defined as a decrease in the CD4 count to pre-therapy levels or below and virologic failure as HIV-RNA of > 1000 copies/ml at 48 weeks after ART initiation. Genotypic resistance testing was performed for children with virologic failure. Logistic regression analysis was done to identify predictors of virologic failure.

RESULTS

Three hundred and ninety-three ART-naïve children living with HIV [mean (SD) age: 7.6 (3) years; mean (SD) CD4%: 16% (8); median (IQR) HIV-RNA: 5.1 (3.5-5.7) log10 copies/ml] were enrolled into the study. At 48 weeks, significant improvement occurred in weight-for-age and height-for-age z-scores from baseline (all p < 0.001). The immunologic response was good; almost 90% of children showing an increase in their absolute CD4+ T cell count to more than 350 cells/mm3. Immunological failure was noted among 11% (28/261) and virologic failure in 29% (94/328) of children. Of the 94 children with virologic failure at 12 months, 36 children showed immunologic failure while the rest had good immunologic improvement. There was no demonstrable correlation between virologic and immunologic failure. 62% had reported > 90% adherence to ART. At the time of virologic failure, multiple NNRTI-associated mutations were observed: 80%-K103N and Y181C being the major NNRTI mutations-observed. Sensitivity (95% CI) of immunologic failure to detect virologic failure was 7% (2-12), specificity 97% (92.4-98.9), PPV 44% (13.7-78.8) and NPV was 72% (65-77.9). There were no statistically significant predictors to detect children who will develop virologic failure on treatment.

CONCLUSIONS

Considerable immunological improvement is seen in children with ART initiation, but may not be an effective tool to monitor treatment response in the long-term. There is a lack of correlation between immunologic and virologic response while on ART, which may lead to a delay in identifying treatment failures. Periodic viral load monitoring is, therefore, a priority.

High Rates of Baseline Drug Resistance and Virologic Failure Among ART-naive HIV-infected Children in Mali

BACKGROUND

Limited data exist on drug resistance and antiretroviral treatment (ART) outcomes in HIV-1-infected children in West Africa. We determined the prevalence of baseline resistance and correlates of virologic failure (VF) in a cohort of ART-naive HIV-1-infected children <10 years of age initiating ART in Mali.

METHODS

Reverse transcriptase and protease genes were sequenced at baseline (before ART) and at 6 months. Resistance was defined according to the Stanford HIV Genotypic Resistance database. VF was defined as viral load ≥1000 copies/mL after 6 months of ART. Logistic regression was used to evaluate factors associated with VF or death >1 month after enrollment. Post hoc, antiretroviral concentrations were assayed on baseline samples of participants with baseline resistance.

RESULTS

One-hundred twenty children with a median age 2.6 years (interquartile range: 1.6-5.0) were included. Eighty-eight percent reported no prevention of mother-to-child transmission exposure. At baseline, 27 (23%), 4 (3%) and none had non-nucleoside reverse transcriptase inhibitor (NNRTI), nucleoside reverse transcriptase inhibitor or protease inhibitor resistance, respectively. Thirty-nine (33%) developed VF and 4 died >1 month post-ART initiation. In multivariable analyses, poor adherence [odds ratio (OR): 6.1, P = 0.001], baseline NNRTI resistance among children receiving NNRTI-based ART (OR: 22.9, P < 0.001) and protease inhibitor-based ART initiation among children without baseline NNRTI resistance (OR: 5.8, P = 0.018) were significantly associated with VF/death. Ten (38%) with baseline resistance had detectable levels of nevirapine or efavirenz at baseline; 7 were currently breastfeeding, but only 2 reported maternal antiretroviral use.

CONCLUSIONS

Baseline NNRTI resistance was common in children without reported NNRTI exposure and was associated with increased risk of treatment failure. Detectable NNRTI concentrations were present despite few reports of maternal/infant antiretroviral use.

Treatment Outcomes of Third-line Antiretroviral Regimens in HIV-infected Thai Adolescents

BACKGROUND

Efficacy and safety data of third-line antiretroviral (ARV) regimens in adolescents are limited.

METHODOLOGY

This study enrolled HIV-infected Thais who were treated with third-line regimens consisting of darunavir/ritonavir (DRV/r), etravirine (ETR), tipranavir/ritonavir or raltegravir.

RESULTS

Fifty-four adolescents 2-17 years of age were enrolled from 8 sites and followed for 48 weeks. Reasons for switch were second-line failure (n = 44) and toxicity to second-line regimens (n = 10). At switching to third-line ARV, the median age (interquartile range) was 14.3 (12.4-15.4) years. Genotypes at time of second-line failure (n = 44) were M184V (77%), ≥4 thymidine analogue mutations (25%), non-nucleoside reverse transcriptase inhibitor-resistant associated mutation (RAM) (80%), ETR-RAM score ≥4 (14%), any lopinavir-RAM (59%) and ≥1 major DRV-RAM (41%). The third-line regimens had a median of 4 (min-max, 4-6) drugs and included ETR/DRV/r (43%), DRV/r (33%), ETR (17%), tipranavir/ritonavir (2%) or raltegravir/DRV/r/ (4%). The median CD4 (interquartile range) increased from 16% (12-21) at third-line switch to 21% (18-25) and 410 (172-682) to 607 (428-742) cells/mm at 48 weeks (P < 0.001). HIV RNA declined from 3.9 (2.9-4.9) to 1.6 (1.6-3.0) log10 copies/mL (P < 0.001) and 33/50 (66%) had levels <50 copies/mL at 48 weeks. Seventeen (31%) had HIV-RNA ≥1000 copies/mL; about half due to poor adherence; genotyping in 13 of these adolescents revealed ETR-RAM score ≥4 in 2 (15%) and ≥1 major DRV-RAM in 7 (54%).

CONCLUSIONS

Third-line ARV therapy was well tolerated and resulted in virologic suppression in 70% of adolescents at 1 year. Poor adherence and limited ARV options are major problems in the long-term management of adolescents with HIV.

Transitioning to Second-line Antiretroviral Therapy Among Adolescents in Copperbelt Province, Zambia: Predictors of Treatment Switching and Adherence to Second-line Regimens

BACKGROUND

Adolescents living with HIV (ALHIV) experience less favorable antiretroviral therapy (ART) outcomes than other age groups. First-line treatment failure complicates ART management as second-line regimens can be costlier and have greater pill burdens. Understanding predictors of switching ART regimens and adherence among adolescents on second-line ART may help to prevent poor treatment outcomes.

METHODS

A quantitative survey was administered to 309 ALHIV attending 3 ART clinics in the Copperbelt Province, Zambia. Medical chart data, including pharmacy refill data, were abstracted. Associations between being on second-line ART and sociodemographic, psychosocial and ART adherence characteristics were tested. Cox proportional hazards models were used to estimate the effect of baseline ART variables on time to switching.

RESULTS

Ten percent of participants were on second-line regimens. Compared with ALHIV on first-line ART, adolescents on second-line regimens were older (P = 0.02), out of school due to completion of secondary studies (P = 0.04) and on ART longer (P = 0.03). Adolescents on second-line regimens were more likely to report missing ≥48 consecutive hours of drugs in the last 3 months (P = 0.01). Multivariable analysis showed that adolescents who initiated ART with efavirenz-based regimens were more likely to switch to second-line than those put on nevirapine-based regimens (hazard ratio = 2.6; 95% confidence interval: 1.1-6.4).

CONCLUSIONS

Greater support is needed for ALHIV who are on second-line regimens. Interventions for older adolescents that bridge the gap between school years and young adulthood would be helpful. More research is needed on why ALHIV who start on efavirenz-based regimens are more likely to switch within this population.

Virologic Response to First-line Efavirenz- or Nevirapine-based Antiretroviral Therapy in HIV-infected African Children

BACKGROUND

Poorer virologic response to nevirapine- versus efavirenz-based antiretroviral therapy (ART) has been reported in adult systematic reviews and pediatric studies.

METHODS

We compared drug discontinuation and viral load (VL) response in ART-naïve Ugandan/Zimbabwean children ≥3 years of age initiating ART with clinician-chosen nevirapine versus efavirenz in the ARROW trial. Predictors of suppression <80, <400 and <1000 copies/mL at 36, 48 and 144 weeks were identified using multivariable logistic regression with backwards elimination (P = 0.1).

RESULTS

A total of 445 (53%) children received efavirenz and 391 (47%) nevirapine. Children receiving efavirenz were older (median age, 8.6 vs. 7.5 years nevirapine, P < 0.001) and had higher CD4% (12% vs. 10%, P = 0.05), but similar pre-ART VL (P = 0.17). The initial non-nucleoside-reverse-transcriptase-inhibitor (NNRTI) was permanently discontinued for adverse events in 7 of 445 (2%) children initiating efavirenz versus 9 of 391 (2%) initiating nevirapine (P = 0.46); at switch to second line in 17 versus 23, for tuberculosis in 0 versus 26, for pregnancy in 6 versus 0 and for other reasons in 15 versus 5. Early (36-48 weeks) virologic suppression <80 copies/mL was superior with efavirenz, particularly in children with higher pre-ART VL (P = 0.0004); longer-term suppression was superior with nevirapine in older children (P = 0.05). Early suppression was poorer in the youngest and oldest children, regardless of NNRTI (P = 0.02); longer-term suppression was poorer in those with higher pre-ART VL regardless of NNRTI (P = 0.05). Results were broadly similar for <400 and <1000 copies/mL.

CONCLUSION

Short-term VL suppression favored efavirenz, but long-term relative performance was age dependent, with better suppression in older children with nevirapine, supporting World Health Organization recommendation that nevirapine remains an alternative NNRTI.

Plasma Efavirenz Exposure, Sex, and Age Predict Virological Response in HIV-Infected African Children

BACKGROUND

Owing to insufficient evidence in children, target plasma concentrations of efavirenz are based on studies in adults. Our analysis aimed to evaluate the pediatric therapeutic thresholds and characterize the determinants of virological suppression in African children.

METHODS

We analyzed data from 128 African children (aged 1.7-13.5 years) treated with efavirenz, lamivudine, and one among abacavir, stavudine, or zidovudine, and followed up to 36 months. Individual pharmacokinetic (PK) measures [plasma concentration 12 hours after dose (C12h), plasma concentration 24 hours after dose (C24h), and area under the curve (AUC0-24)] were estimated using population PK modeling. Cox multiple failure regression and multivariable fractional polynomials were used to investigate the risks of unsuppressed viral load associated with efavirenz exposure and other factors among 106 initially treatment-naive children, and likelihood profiling was used to identify the most predictive PK thresholds.

RESULTS

The risk of viral load >100 copies per milliliter decreased by 42% for every 2-fold increase in efavirenz mid-dose concentration [95% confidence interval (CI): 23% to 57%; P < 0.001]. The most predictive PK thresholds for increased risk of unsuppressed viral load were C12h 1.12 mg/L [hazard ratio (HR): 6.14; 95% CI: 2.64 to 14.27], C24h 0.65 mg/L (HR: 6.57; 95% CI: 2.86 to 15.10), and AUC0-24 28 mg·h/L (HR: 5.77; 95% CI: 2.28 to 14.58). Children older than 8 years had a more than 10-fold increased risk of virological nonsuppression (P = 0.005); among children younger than 8 years, boys had a 5.31 times higher risk than girls (P = 0.007). Central nervous system adverse events were infrequently reported.

CONCLUSIONS

Our analysis suggests that the minimum target C24h and AUC0-24 could be lowered in children. Our findings should be confirmed in a prospective pediatric trial.

Determinants of virological outcome and adverse events in African children treated with paediatric nevirapine fixed-dose-combination tablets

BACKGROUND

Nevirapine is the only nonnucleoside reverse transcriptase inhibitor currently available as a paediatric fixed-dose-combination tablet and is widely used in African children. Nonetheless, the number of investigations into pharmacokinetic determinants of virological suppression in African children is limited, and the predictive power of the current therapeutic range was never evaluated in this population, thereby limiting treatment optimization.

METHODS

We analysed data from 322 African children (aged 0.3-13 years) treated with nevirapine, lamivudine, and either abacavir, stavudine, or zidovudine, and followed up to 144 weeks. Nevirapine trough concentration (Cmin) and other factors were tested for associations with viral load more than 100 copies/ml and transaminase increases more than grade 1 using proportional hazard and logistic models in 219 initially antiretroviral treatment (ART)-naive children.

RESULTS

Pre-ART viral load, adherence, and nevirapine Cmin were associated with viral load nonsuppression [hazard ratio = 2.08 (95% confidence interval (CI): 1.50-2.90, P < 0.001) for 10-fold higher pre-ART viral load, hazard ratio = 0.78 (95% CI: 0.68-0.90, P < 0.001) for 10% improvement in adherence, and hazard ratio = 0.94 (95% CI: 0.90-0.99, P = 0.014) for a 1 mg/l increase in nevirapine Cmin]. There were additional effects of pre-ART CD4 cell percentage and clinical site. The risk of virological nonsuppression decreased with increasing nevirapine Cmin, and there was no clear Cmin threshold predictive of virological nonsuppression. Transient transaminase elevations more than grade 1 were associated with high Cmin (>12.4 mg/l), hazard ratio = 5.18 (95% CI 1.95-13.80, P < 0.001).

CONCLUSION

Treatment initiation at lower pre-ART viral load and higher pre-ART CD4 cell percentage, increased adherence, and maintaining average Cmin higher than current target could improve virological suppression of African children treated with nevirapine without increasing toxicity.

Prevalence and effect of pre-treatment drug resistance on the virological response to antiretroviral treatment initiated in HIV-infected children - a EuroCoord-CHAIN-EPPICC joint project

Background

Few studies have evaluated the impact of pre-treatment drug resistance (PDR) on response to combination antiretroviral treatment (cART) in children. The objective of this joint EuroCoord-CHAIN-EPPICC/PENTA project was to assess the prevalence of PDR mutations and their association with virological outcome in the first year of cART in children.

Methods

HIV-infected children <18 years initiating cART between 1998 and 2008 were included if having at least one genotypic resistance test prior to cART initiation. We used the World Health Organization 2009 resistance mutation list and Stanford algorithm to infer resistance to prescribed drugs. Time to virological failure (VF) was defined as the first of two consecutive HIV-RNA > 500 copies/mL after 6 months cART and was assessed by Cox proportional hazards models. All models were adjusted for baseline demographic, clinical, immunology and virology characteristics and calendar period of cART start and initial cART regimen.

Results

Of 476 children, 88 % were vertically infected. At cART initiation, median (interquartile range) age was 6.6 years (2.1–10.1), CD4 cell count 297 cells/mm³ (98–639), and HIV-RNA 5.2 log₁₀copies/mL (4.7–5.7). Of 37 children (7.8 %, 95 % confidence interval (CI), 5.5–10.6) harboring a virus with ≥1 PDR mutations, 30 children had a virus resistant to ≥1 of the prescribed drugs. Overall, the cumulative Kaplan-Meier estimate for virological failure was 19.8 % (95 %CI, 16.4–23.9). Cumulative risk for VF tended to be higher among children harboring a virus with PDR and resistant to ≥1 drug prescribed than among those receiving fully active cART: 32.1 % (17.2–54.8) versus 19.4 % (15.9–23.6) (P = 0.095). In multivariable analysis, age was associated with a higher risk of VF with a 12 % reduced risk per additional year (HR 0.88; 95 %CI, 0.82–0.95; P < 0.001).

Conclusions

PDR was not significantly associated with a higher risk of VF in children in the first year of cART. The risk of VF decreased by 12 % per additional year at treatment initiation which may be due to fading of PDR mutations over time. Lack of appropriate formulations, in particular for the younger age group, may be an important determinant of virological failure.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1968-2) contains supplementary material, which is available to authorized users.

Outcomes after viral load rebound on first-line antiretroviraltreatment in children with HIV in the UK and Ireland: an observational cohort study

BACKGROUND

About a third of children with HIV have virological failure within 2 years of beginning antiretroviral treatment (ART). We assessed the probability of switch to second-line ART or virological re-suppression without switch in children who had virological rebound on first-line ART in the UK and Ireland.

METHODS

In this study, we used data reported to the Collaborative HIV Paediatric Study (CHIPS), a national multicentre observational cohort. We included children with virological rebound (confirmed viral load>400 copies per mL after suppression<400 copies per mL) on first-line ART. We did a competing-risk analysis to estimate the probability of switch to second-line treatment, confirmed resuppression (two consecutive viral load measurments<400 copies per mL) without switch, and continued viral load above 400 copies per mL without switch. We also assessed factors that predicted a faster time to switch.

FINDINGS

Of the 900 children starting first-line ART who had a viral load below 400 copies per mL within a year of starting treatment, 170 (19%) had virological rebound by a median of 20·6 months (IQR 9·7–40·5). At rebound, median age was 10·6 years (5·6–13·4), median viral load was 3·6 log10 copies per mL (3·1–4·2), and median CD4% was 24% (17–32). 89 patients (52%) switched to second-line ART at a median of 4·9 months (1·7–13·4) after virological rebound, 53 (31%) resuppressed without switch (19 [61%] of 31 patients on a first-line regimen that included a protease inhibitor and 31 [24%] of 127 patients on a first-line regimen that included a non-nucleoside reverse transcriptase inhibitor; NNRTI), and 28 (16%) neither resuppressed nor switched. At 12 months after rebound, the estimated probability of switch was 38% (95% CI 30–45) and of resuppression was 27% (21–34). Faster time to switch was associated with a higher viral load (p<0·0001), later calendar year at virological rebound (p=0·02), and being on an NNRTI-based or triple nucleoside reverse transcriptase inhibitor-based versus protease-inhibitor-based first-line regimen (p=0·001).

INTERPRETATION

A third of children with virological rebound resuppressed without switch. Clinicians should consider the possibility of resuppression with adherence support before switching treatment in children with HIV.

FUNDING

NHS England (London Specialised Commissioning Group).

Viral load monitoring and antiretroviral treatment outcomes in a pediatric HIV cohort in Ghana

Background

HIV-infected children in sub-Saharan Africa may be at a high risk of staying on a failing first-line regimen and developing drug-resistance HIV variants due to lack of routine viral load monitoring. We investigated whether cumulative viral load, measured as viremia copy-years (VCY) could predict morbidity in a setting where viral load is not routinely monitored.

Methods

This was a single-center prospective observational longitudinal study of HIV-infected children initiating antiretroviral therapy (ART) at the Pediatric HIV/AIDS Care program at Korle-Bu Teaching Hospital in Accra, Ghana. The main outcome was morbidity measured as frequency of hospitalizations, opportunistic infections, and outpatient sick visits. The main explanatory variable was viral load measured as VCY.

Results

The study included 140 children who initiated ART between September 2009 and May 2013 and had at least 2 viral load measurements. There were 184 hospitalizations, with pneumonia being the most common cause (22.8 %). A total of 102 opportunistic infections was documented, with tuberculosis being the most common opportunistic infection (68 %). A total of 823 outpatient sick visits was documented, with upper respiratory infections (14.2 %) being the most common cause. Forty-four percent of our study participants had >4 log₁₀ VCY. Children in this sub-cohort had a higher frequency of sick visits compared with those with <4 log₁₀ VCY (p = 0.03). Only 6.5 % of children with >4 log₁₀ VCY had been identified as treatment failure using WHO clinical and immunological treatment failure criteria.

Conclusions

High level of cumulative viral load may translate to virological failure and subsequent increased all-cause morbidity. Our finding of potential utility of VCY in pediatrics warrants further investigations. VCY may be a good alternate to routine viral load measurement as its determination may be less frequent and could be personalized to save cost.

Sequencing paediatric antiretroviral therapy in the context of a public health approach

Introduction

As access to prevention of mother-to-child transmission (PMTCT) efforts has increased, the total number of children being born with HIV has significantly decreased. However, those children who do become infected after PMTCT failure are at particular risk of HIV drug resistance, selected by exposure to maternal or paediatric antiretroviral drugs used before, during or after birth. As a consequence, the response to antiretroviral therapy (ART) in these children may be compromised, particularly when non-nucleoside reverse transcriptase inhibitors (NNRTIs) are used as part of the first-line regimen. We review evidence guiding choices of first- and second-line ART.

Discussion

Children generally respond relatively well to ART. Clinical trials show the superiority of protease inhibitor (PI)- over NNRTI-based treatment in young children, but observational reports of NNRTI-containing regimens are usually favourable as well. This is reassuring as national guidelines often still recommend the use of NNRTI-based treatment for PMTCT-unexposed young children, due to the higher costs of PIs. After failure of NNRTI-based, first-line treatment, the rate of acquired drug resistance is high, but HIV may well be suppressed by PIs in second-line ART. By contrast, there are currently no adequate alternatives in resource-limited settings (RLS) for children failing either first- or second-line, PI-containing regimens.

Conclusions

Affordable salvage treatment options for children in RLS are urgently needed.

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.

Predictors of Treatment Failure in HIV-Positive Children Receiving Combination Antiretroviral Therapy: Cohort Data From Mozambique and Uganda

BACKGROUND

Delays detecting treatment failure and switching to second-line combination antiretroviral therapy (cART) are often observed in human immunodeficiency virus (HIV)-infected children of low-middle-income countries (LMIC).

METHODS

An observational study included HIV-infected children attending the Beira Central Hospital (Mozambique) and the Nsambya Hospital, Home Care Department (Uganda) evaluated clinical and immunological failure according to World Health Organization (WHO) 2006 guidelines. Baseline predictors for cART failure and for drug substitution were explored in unadjusted and adjusted Cox proportional hazard models.

RESULTS

Two hundred eighteen of 740 children with at least 24 weeks follow-up experienced treatment failure (29%; 95% confidence interval [CI] 26-33), with crude incidence of 20.0 events per 100 person-years (95% CI 17.5-22.9). Having tuberculosis co-infection or WHO stage 4, or starting a nontriple cART significantly increased risk of failure. Two hundred two of 769 (26.3%) children receiving cART substituted drug(s), with crude incidence of 15.4 events per 100 person-years (95% CI 13.4-17.7). Drug toxicity (18.3%), drug availability (17.3%), and tuberculosis drugs interaction (52, 25.7%) were main reported reasons, while only 9 (4%) patients switched cART for clinical or immunological failure. Children starting lamivudine-zidovudine-nevirapine or lamivudine-stavudine-efavirenz or lamivudine-zidovudine-efavirenz were more likely to have substitute drugs. Increased substitution was found in children with mild immunosuppression and tuberculosis co-infection at cART initiation as well as poor adherence before drug substitution.

CONCLUSIONS

Considerable delay in switching to second-line cART may occur despite an observed high rate of failure. Factors including WHO clinical stage and tuberculosis co-infection should be evaluated before starting cART. Toxicity and drug adherence should be monitored to minimize drug substitution in LMIC.

Two-year outcome of first-line antiretroviral therapy among HIV-1 vertically-infected children in Hanoi, Vietnam

A retrospective analysis of 86 HIV-1 vertically-infected Vietnamese children with a follow-up period >24 months after initiating antiretroviral therapy (ART) was performed from 2008 to 2012, to assess the outcome of first-line ART in resource-limited settings. Of the 86 children, 68 (79.1%) were treated successfully (plasma HIV-1 viral load [VL] <1000 copies/ml), and 63 (73.3%) had full viral suppression (VL <400 copies/ml) after 24 months of ART. No significant difference between successfully treated patients and failure groups was observed in VL, CD4(+) T-cell count or clinical stage at baseline; age at ART start; or ART regimen. All 14 children with VL >5000 copies/ml, one of four children with VL 1000-5000 copies/ml and none with VL <1000 copies/ml developed reverse transcriptase inhibitor (RTI)-resistance mutations by 24 months of ART. Y181C and M184V/I were the most dominant non-nucleoside and nucleoside RTI-resistance mutations, respectively (13/15, 86.7%). These findings suggest that VL testing after 24 months of ART can be used to efficiently differentiate ART failures among HIV-1 vertically-infected children in resource-limited settings.

Comparison of adherence monitoring tools and correlation to virologic failure in a pediatric HIV clinical trial

There is no consensus on a gold standard for monitoring adherence to antiretroviral therapy (ART). We compared different adherence monitoring tools in predicting virologic failure as part of a clinical trial. HIV-infected Thai and Cambodian children aged 1-12 years (N=207) were randomized to immediate-ART or deferred-ART until CD4% <15%. Virologic failure (VF) was defined as HIV-RNA >1000 copies/mL after ≥6 months of ART. Adherence monitoring tools were: (1) announced pill count, (2) PACTG adherence questionnaire (form completed by caregivers), and (3) child self-report (self-reporting from children or caregivers to direct questioning by investigators during the clinic visit) of any missed doses in the last 3 days and in the period since the last visit. The Kappa statistic was used to describe agreement between each tool. The median age at ART initiation was 7 years with median CD4% 17% and HIV-RNA 5.0 log(10)copies/mL and 92% received zidovudine/lamivudine/nevirapine. Over 144 weeks, 13% had VF. Mean adherence by announced pill count before VF in VF children was 92% compared to 98% in children without VF (p=0.03). Kappa statistics indicated slight to fair agreement between tools. In multivariate analysis adjusting for gender, treatment arm ethnicity and caregiver education, significant predictors of VF were poor adherence by announced pill count (OR 4.56; 95%CI 1.78-11.69), reporting any barrier to adherence in the PACTG adherence questionnaire (OR 7.08; 95%CI 2.42-20.73), and reporting a missed dose in the 24 weeks since the last HIV-RNA assessment (OR 8.64; 95%CI 1.96-38.04). In conclusion, we recommend the child self-report of any missed doses since last visit for use in HIV research and in routine care settings, because it is easy and quick to administer and a strong association with development of VF.

Incidence and risk factors for first line anti retroviral treatment failure among Ugandan children attending an urban HIV clinic

Background

Early recognition of antiretroviral therapy (ART) failure in resource limited settings is a challenge given the limited laboratory facilities and trained personnel. This study aimed at describing the incidence, risk factors and the resistance associated mutations (RAMs) of first line treatment failure among HIV-1-infected children attending the Joint Clinical Research Centre (JCRC), Kampala, Uganda.

Methods

A retrospective cohort of 701 children who had been initiated on ART between January 2004 and September 2009 at the JCRC was studied. Data of children aged 6 months up to 18 years who had been started on ART for at least 6 months was extracted from the clinic charts. The children who failed the first-line ART were taken as cases and those who did not fail as the controls. Data was analysed using STATA version10.

Results

Of 701 children, 240(34%) failed on first line ART (cases) and 461(66%) did not fail (controls). The overall median time (IQR) to first line ART failure was 26.4 (18.9 – 39.1) months. The factors associated with treatment failure were poor adherence [(OR = 10, 95 CI: 6.4 – 16.7) p < 0.001], exposure to single dose nevirapine (sdNVP) [(OR = 4.2, 95% CI:1.8-9.4), p = 0.005] and a NVP containing regimen [(OR = 2.2,95% CI:1.4-3.6), p < 0.001]. Of 109 genotypic resistance profiles analyzed, the commonest non nucleoside reverse transcriptase inhibitor (NNRTI) resistance associated mutations (RAM) were: K103N (59; 54%)), Y181C (36; 27%)) and G190A (26; 24%)) while the commonest nucleoside reverse transcriptase inhibitor (NRTI) RAM was the M184V (89; 81%). Thymidine analogue- mutations (TAMs) were detected in 20% of patients.

Conclusions

One in three children on first-line ART are likely to develop virological treatment failure after the first 24 months of therapy. Poor adherence to ART, a NVP based first-line regimen, prior exposure to sdNVP were associated with treatment failure.

Extensive drug resistance in HIV-infected Cambodian children who are undetected as failing first-line antiretroviral therapy by WHO 2010 guidelines

Antiretroviral therapy in resource-limited settings is monitored clinically and immunologically according to WHO guidelines. Frequent misclassification of virologic failure is reported, mostly in adults, leading to early therapy switch or late failure diagnosis. Pediatric treatment monitoring and resistance data upon first-line failure are limited, particularly when the 2010-WHO pediatric guidelines are used without routine viral load monitoring. We previously reported high treatment failure misclassification rates by pediatric 2010 guidelines in Cambodian children on first-line therapy. Here we determine the extent and patterns of resistance, with yearly viral load and 6-monthly CD4. Drug resistance mutations were determined using the IAS-USA 2011 list. Predicted resistance interpretation was determined with Stanford Database tools. Fifty-one children with available genotypes met inclusion criteria. All but one (subtype B) were CRF01_AE. The most common regimen was stavudine, lamivudine, and nevirapine (96%), taken for a median of 2.2 years. Resistance was seen in 98%; 96% to nucleoside and nonnucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs); 51% with ≥4 mutations. The most common NRTI mutations were 184V/I and 67N and the most common NNRTI mutations were 181C/Y/I/V and 190A/S. A total of 22% had multiresistant mutations and 18% had predicted high-level resistance to subsequent therapy options didanosine, abacavir, etravirine, and tenofovir. In 98% of Cambodian children misclassified as nonfailing first-line therapy by 2010 guidelines, 51% had extensive drug resistance to current and 18% to subsequent antiretroviral therapy. Affordable routine viral load monitoring allowing for early and more accurate treatment failure diagnosis is desperately needed in resource-limited settings.

High rate of antiretroviral drug resistance mutations in HIV type 1-infected Senegalese children in virological failure on first-line treatment according to the World Health Organization guidelines

The rates of virological failure (VF) and HIV-1 drug resistance were evaluated in a cross-sectional study in HIV-1-infected children living in Dakar, and taking antiretroviral treatment (ART) according to WHO recommendations. The plasma HIV-1 RNA load was measured using the Abbott m2000 RealTime HIV-1 assay. The full-length protease gene and partial reverse transcriptase gene were sequenced, and resistance mutations were assessed by reference to the Stanford University HIV drug resistance database. Of 125 included children (median age, 7 years) taking first-line ART for a median duration of 20 months, 82 (66%) showed detectable HIV-1 RNA load, and 70 (56%) met the 2010 revised WHO criteria of VF (defined as plasma HIV-1 RNA load ≥3.7 log(10) copies/ml). Drug resistance results were available for 52 children with plasma HIV-1 RNA load ≥3.0 log(10) copies/ml, and viruses carrying resistance mutations were found in 48 (92%) children. Among these 48, mutations conferring resistance to nucleoside reverse transcriptase inhibitors (NRTIs) or non-NRTIs (NNRTIs) were found in 42 (88%) and 47 (99%) children, respectively. The NRTI-resistant viruses harbored the M184V/I (95%), Q151M (2%), and thymidine-analogue mutations (40%), and the NNRTI-resistant viruses harbored the K103N (34%), Y181C (32%), G190A (23%), and K101E (21%) mutations. A high rate (56%) of VF was demonstrated in Senegalese children after 20 months of first-line ART and therapeutic failure was assessed by the presence of antiretroviral drug resistance mutations in 9 out of 10 children in VF. These findings point out the difficulties of optimizing ART in children living in sub-Saharan Africa, and the crucial need of laboratory monitoring reinforcement.

Effectiveness and safety of protease inhibitor-based regimens in HIV-infected Thai children failing first-line treatment

OBJECTIVES

Virological failure on first-line nonnucleoside reverse transcriptase inhibitor (NNRTI)-based treatment regimens has become a problem in HIV-infected children on long-term antiretroviral therapy (ART). Protease inhibitor (PI)-based regimens are therefore often given to children failing NNRTI-based regimens. The aim of the study was to assess the 48-week effectiveness, safety and predictive factors for viral suppression of PI-based regimens in HIV-infected Thai children who had failed NNRTI-based regimens.

METHODS

This study assessed 41 HIV-infected children who had failed first-line NNRTI-based regimens and were switched to PI-based regimens for at least 48 weeks. We assessed their CD4 cell counts, plasma HIV RNA levels, weight-for-age and height-for-age z-scores, and adverse events.

RESULTS

The children's median age was 9.5 years (range 1.5-15.8 years). At baseline, their median CD4 cell count was 276 cells/μL [interquartile range (IQR) 160-749 cells/μL], and their median plasma HIV RNA level was 4.5 log10 HIV-1 RNA copies/mL (IQR 3.9-4.8 log10 copies/mL). After 48 weeks of PI-based therapy, their CD4 cell counts increased to a median of 572 cells/μL (IQR 343-845 cells/μL) and in 73.2% plasma HIV RNA levels decreased to < 50 copies/mL. Their median weight-for-age and height-for-age z-scores were stable over the period of the study. Diarrhoea occurred in 29.3% of patients. Triglyceride levels were significantly higher at weeks 24 and 48 in comparison to baseline measurements.

CONCLUSIONS

PI-based regimens are safe and effective for HIV-infected Thai children who have failed first-line NNRTI-based regimens. However, long-term follow-up is warranted in order to ascertain the feasibility and sustainability of these new regimens.

Mid-dosing interval efavirenz plasma concentrations in HIV-1-infected children in Rwanda: treatment efficacy, tolerability, adherence, and the influence of CYP2B6 polymorphisms

This study evaluated mid-dosing interval efavirenz plasma concentrations and the influence of CYP2B6 polymorphisms in relation to efficacy, tolerability, and adherence in 97 Rwandan HIV-infected children (3-16 years). Plasma drug concentrations and CYP2B6 polymorphisms were determined. Ten children were excluded for nonadherence. Large intersubject variability in efavirenz plasma concentrations was found. Of the 87 remaining, efavirenz concentrations were therapeutic, supratherapeutic, and subtherapeutic in 67%, 20%, and 14%, respectively. No associations were found between efavirenz concentrations and central nervous system disturbances or virologic failure. Minor allele frequencies were 0.32 (516G>T), 0.33 (785A>G), and 0.09 (983T>C). Polymorphisms in CYP2B6 were strongly associated with high efavirenz levels.

The role of targeted viral load testing in diagnosing virological failure in children on antiretroviral therapy with immunological failure

OBJECTIVES

To determine the improvement in positive predictive value of immunological failure criteria for identifying virological failure in HIV-infected children on antiretroviral therapy (ART) when a single targeted viral load measurement is performed in children identified as having immunological failure.

METHODS

Analysis of data from children (<16 years at ART initiation) at South African ART sites at which CD4 count/per cent and HIV-RNA monitoring are performed 6-monthly. Immunological failure was defined according to both WHO 2010 and United States Department of Health and Human Services (DHHS) 2008 criteria. Confirmed virological failure was defined as HIV-RNA >5000 copies/ml on two consecutive occasions <365 days apart in a child on ART for ≥18 months.

RESULTS

Among 2798 children on ART for ≥18 months [median (IQR) age 50 (21-84) months at ART initiation], the cumulative probability of confirmed virological failure by 42 months on ART was 6.3%. Using targeted viral load after meeting DHHS immunological failure criteria rather than DHHS immunological failure criteria alone increased positive predictive value from 28% to 82%. Targeted viral load improved the positive predictive value of WHO 2010 criteria for identifying confirmed virological failure from 49% to 82%.

CONCLUSION

The addition of a single viral load measurement in children identified as failing immunologically will prevent most switches to second-line treatment in virologically suppressed children.

High virologic response rate after second-line boosted protease inhibitor-based antiretroviral therapy regimens in children from a resource limited setting

Background

Limited data exist for the efficacy of second-line antiretroviral therapy among children in resource limited settings. We assessed the virologic response to protease inhibitor-based ART after failing first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens.

Methods

A retrospective chart review was conducted at 8 Thai sites of children who switched to PI –based regimens due to failure of NNRTI –based regimens. Primary endpoints were HIV RNA < 400 copies/ml and CD4 change over 48 weeks.

Results

Data from 241 children with median baseline values before starting PI-based regimens of 9.1 years for age, 10% for CD4%, and 4.8 log₁₀ copies/ml for HIV RNA were included; 104 (41%) received a single ritonavir-boosted PI (sbPI) with 2 NRTIs and 137 (59%) received double-boosted PI (dbPI) with/without NRTIs based on physician discretion. SbPI children had higher baseline CD4 (17% vs. 6%, p < 0.001), lower HIV RNA (4.5 vs. 4.9 log₁₀ copies/ml, p < 0.001), and less frequent high grade multi-NRTI resistance (12.4% vs 60.5%, p < 0.001) than the dbPI children. At week 48, 81% had HIV RNA < 400 copies/ml (sbPI 83.1% vs. dbPI 79.8%, p = 0.61) with a median CD4 rise of 9% (+7%vs. + 10%, p < 0.005). However, only 63% had HIV RNA < 50 copies/ml, with better viral suppression seen in sbPI (76.6% vs. 51.4%, p 0.002).

Conclusion

Second-line PI therapy was effective for children failing first line NNRTI in a resource-limited setting. DbPI were used in patients with extensive drug resistance due to limited treatment options. Better access to antiretroviral drugs is needed.

Drug resistance profiles among HIV-1-infected children experiencing delayed switch and 12-month efficacy after using second-line antiretroviral therapy: an observational cohort study in rural China

OBJECTIVE

To analyze the genotypic resistance profiles of HIV-infected children from rural China who were experiencing virologic failure to first-line antiretroviral therapy regimens and to evaluate 1-year regimen efficacy after switching to second-line therapy.

METHODS

A prospective cohort study was performed. Seventy-six children from the first rural pilot program with HIV viral load >1000 copies per milliliter on 2 consecutive occasions were studied. We analyzed genotype results and observed second-line therapy efficacy to 12 months.

RESULTS

After 33.1 (23.3, 41.1) months on first-line treatment after enrollment into national program, 98.7% of genotyped patients developed high-level resistance to nevirapine and 81.6% of patients had high-level resistance to efavirenz. High-level resistance to lamivudine was observed in 82.9%, followed by 57.9% for stavudine and 52.6% for zidovudine. In the nonnucleoside reverse transcriptase inhibitor class, the most common mutations were K103N/S at 50% and Y181C/I at 48.7%. M184V/I was the most common nucleoside reverse transcriptase inhibitor resistance mutation at 77.6%, the mutation rate for ≥3 thymidine analogue mutations, Q151M, and K65R were 33%, 12%, and 9%, respectively. After 12 months of boosted protease inhibitor-based second-line therapy, CD4 counts had on average increased 256 cells per cubic millimeter compared with switch baseline and 83.1% of patients had undetectable viral loads (<50 copies/mL).

CONCLUSIONS

HIV-1-infected children who continued their first-line regimen regardless of virologic failure harbored multiple resistance mutations. Although the extent of resistance to nucleoside reverse transcriptase inhibitor class drugs would be expected to limit subsequent treatment options, the current second-line regimen remained effective during a 1-year observational period.

Immunologic and virologic failure after first-line NNRTI-based antiretroviral therapy in Thai HIV-infected children

Background

There are limited data of immunologic and virologic failure in Asian HIV-infected children using non-nucleoside reverse transcriptase inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART). We examined the incidence rate of immunologic failure (IF) and virologic failure (VF) and the accuracy of using IF to predict VF in Thai HIV-infected children using first-line NNRTI-based HAART.

Methods

Antiretroviral (ART)-naïve HIV-infected children from 2 prospective cohorts treated with NNRTI-based HAART during 2001-2008 were included. CD4 counts were performed every 12 weeks and plasma HIV-RNA measured every 24 weeks. Immune recovery was defined as CD4%≥25%. IF was defined as persistent decline of ≥5% in CD4% in children with CD4%<15% at baseline or decrease in CD4 count ≥30% from baseline. VF was defined as HIV-RNA>1,000 copies/ml after at least 24 weeks of HAART. Clinical and laboratory parameter changes were assessed using a paired t-test, and a time to event approach was used to assess predictors of VF. Sensitivity and specificity of IF were calculated against VF.

Results

107 ART-naive HIV-infected children were included, 52% female, % CDC clinical classification N:A:B:C 4:44:30:22%. Baseline data were median (IQR) age 6.2 (4.2-8.9) years, CD4% 7 (3-15), HIV-RNA 5.0 (4.9-5.5) log₁₀copies/ml. Nevirapine (NVP) and efavirenz (EFV)-based HAART were started in 70% and 30%, respectively.

At 96 weeks, none had progressed to a CDC clinical classification of AIDS and one had died from pneumonia. Overall, significant improvement of weight for age z-score (p = 0.014), height for age z-score, hemoglobin, and CD4 were seen (all p < 0.001). The median (IQR) CD4% at 96 weeks was 25 (18-30)%. Eighty-nine percent of children had immune recovery (CD4%≥25%) and 75% of children had HIV-RNA <1.7log₁₀copies/ml.

Thirty five (32.7%) children experienced VF within 96 weeks. Of these, 24 (68.6%) and 31 (88.6%) children had VF in the first 24 and 48 weeks respectively.

Only 1 (0.9%) child experienced IF within 96 weeks and the sensitivity (95%CI) of IF to VF was 4 (0.1-20.4)% and specificity was 100 (93.9-100)%.

Conclusion

Immunologic failure, as defined here, had low sensitivity compared to VF and should not be recommended to detect treatment failure. Plasma HIV-RNA should be performed twice, at weeks 24 and 48, to detect early treatment failure.

Trial Registration

Clinicaltrials.gov identification number NCT00476606

HIV-1-resistance-associated mutations after failure of first-line antiretroviral treatment among children in resource-poor regions: a systematic review

HIV-positive children are at high risk of drug resistance, which is of particular concern in settings where antiretroviral options are limited. In this Review we explore resistance rates and patterns among children in developing countries in whom antiretroviral treatment has failed. We did a systematic search of online databases and conference abstracts and included studies reporting HIV-1 drug resistance after failure of first-line paediatric regimens in children (<18 years) in resource-poor regions (Latin America, Africa, and Asia). We retrieved 1312 citations, of which 30 studies reporting outcomes in 3241 children were eligible. Viruses with resistance-associated mutations were isolated from 90% (95% CI 88-93%) of children. The prevalence of mutations associated with nucleoside reverse transcriptase inhibitors was 80%, with non-nucleoside reverse transcriptase inhibitors was 88%, and with protease inhibitors was 54%. Methods to prevent treatment failure, including adequate paediatric formulations and affordable salvage treatment options are urgently needed.

Accuracy of immunological criteria for identifying virological failure in children on antiretroviral therapy - the IeDEA Southern Africa Collaboration

OBJECTIVES

To determine the diagnostic accuracy of World Health Organization (WHO) 2010 and 2006 as well as United States Department of Health and Human Services (DHHS) 2008 definitions of immunological failure for identifying virological failure (VF) in children on antiretroviral therapy (ART).

METHODS

Analysis of data from children (<16 years at ART initiation) at South African ART sites at which CD4 count/per cent and HIV-RNA monitoring are performed 6-monthly. Incomplete virological suppression (IVS) was defined as failure to achieve ≥1 HIV-RNA ≤400 copies/ml between 6 and 15 months on ART and viral rebound (VR) as confirmed HIV-RNA ≥5000 copies/ml in a child on ART for ≥18 months who had achieved suppression during the first year on treatment.

RESULTS

Among 3115 children [median (interquartile range) age 48 (20-84) months at ART initiation] on treatment for ≥1 year, sensitivity of immunological criteria for IVS was 10%, 6% and 26% for WHO 2006, WHO 2010 and DHHS 2008 criteria, respectively. The corresponding positive predictive values (PPV) were 31%, 20% and 20%. Diagnostic accuracy for VR was determined in 2513 children with ≥18 months of follow-up and virological suppression during the first year on ART with sensitivity of 5% (WHO 2006/2010) and 27% (DHHS 2008). PPV results were 42% (WHO 2010), 43% (WHO 2006) and 20% (DHHS 2008).

CONCLUSION

Current immunological criteria are unable to correctly identify children failing ART virologically. Improved access to viral load testing is needed to reliably identify VF in children.

Economic evaluation of monitoring virologic responses to antiretroviral therapy in HIV-infected children in resource-limited settings

OBJECTIVE

Antiretroviral therapy (ART) management for HIV-infected children is critical in many resource-constrained countries. We investigated the cost-effectiveness and cost-utility of different frequencies of monitoring plasma viral load among HIV-positive children initiating ART in a resource-limited setting.

DESIGN/METHODS

A stochastic agent-based simulation model was built and directly informed by a cohort of 304 HIV-infected children starting ART in Thailand between 2001 and 2009. The model simulated the expected costs and clinical outcomes over time according to different viral load monitoring frequencies and initiation of second-line therapies when appropriate.

RESULTS

The optimal frequency of viral load monitoring was found to be annual, after a single screening at 6 months. Associated costs of viral load monitoring and appropriate ART would approximately triple current treatment costs. Compared with current conditions, a single screening during the first year of ART led to a 58.4% reduction in the total person-years of virological failure with annual monitoring leading to a 76.6% reduction. The incremental cost per quality adjusted life year gained from the optimal monitoring frequency was estimated as US$ 68,084 when including costs of ART and US$ 7224 without ART costs. The estimated cost attributed to preventing 1 year of virological failure was US$ 3393 with ART costs and US$ 359 without ART costs.

CONCLUSION

Even infrequent viral load monitoring is likely to provide substantial clinical benefit to HIV-infected children on ART. Viral load monitoring can be considered cost-effective in many resource-limited settings. However, the costs associated with second-line therapies could be a barrier to its economic feasibility.

Virologic failure and second-line antiretroviral therapy in children in South Africa--the IeDEA Southern Africa collaboration

BACKGROUND

With expanding pediatric antiretroviral therapy (ART) access, children will begin to experience treatment failure and require second-line therapy. We evaluated the probability and determinants of virologic failure and switching in children in South Africa.

METHODS

Pooled analysis of routine individual data from children who initiated ART in 7 South African treatment programs with 6-monthly viral load and CD4 monitoring produced Kaplan-Meier estimates of probability of virologic failure (2 consecutive unsuppressed viral loads with the second being >1000 copies/mL, after ≥24 weeks of therapy) and switch to second-line. Cox-proportional hazards models stratified by program were used to determine predictors of these outcomes.

RESULTS

The 3-year probability of virologic failure among 5485 children was 19.3% (95% confidence interval: 17.6 to 21.1). Use of nevirapine or ritonavir alone in the initial regimen (compared with efavirenz) and exposure to prevention of mother to child transmission regimens were independently associated with failure [adjusted hazard ratios (95% confidence interval): 1.77 (1.11 to 2.83), 2.39 (1.57 to 3.64) and 1.40 (1.02 to 1.92), respectively]. Among 252 children with ≥1 year follow-up after failure, 38% were switched to second-line. Median (interquartile range) months between failure and switch was 5.7 (2.9-11.0).

CONCLUSIONS

Triple ART based on nevirapine or ritonavir as a single protease inhibitor seems to be associated with a higher risk of virologic failure. A low proportion of virologically failing children were switched.

Early virologic failure and the development of antiretroviral drug resistance mutations in HIV-infected Ugandan children

BACKGROUND

Without virologic testing, HIV-infected African children starting antiretroviral (ARV) therapy are at risk for undetected virologic failure and the development of ARV resistance. We sought to determine the prevalence of early virologic failure (EVF), to characterize the evolution of ARV-resistance mutations and to predict the impact on second-line therapy.

METHODS

The prevalence of EVF (HIV RNA >400 copies/mL on sequential visits after 6 months of therapy) was identified among 120 HIV-infected Ugandan children starting ARV therapy. ARV mutations were identified by population sequencing of HIV-1 pol in sequential archived specimens. Composite discrete genotypic susceptibility scores were determined for second-line ARV regimens.

RESULTS

EVF occurred in 16 children (13%) and persisted throughout a median (interquartile ratio) 938 (760-1066) days of follow-up. M184V and nonnucleoside reverse transcriptase inhibitor-associated mutations emerged within 6 months of EVF; thymidine-analog-mutations arose after 12 months. Worse discrete genotypic susceptibility scores correlated with increasing duration of failure (Spearman R = -0.47; P = 0.001). Only 1 child met World Health Organization CD4 criteria for ARV failure at the time of EVF or during the follow-up period.

CONCLUSIONS

A significant portion of HIV-infected African children experience EVF that would be undetected using CD4/clinical monitoring and resulted in the accumulation of ARV mutations that could compromise second-line therapy options.

Drug resistance in human immunodeficiency virus type-1 infected Zambian children using adult fixed dose combination stavudine, lamivudine, and nevirapine

BACKGROUND

There are few medium-term virologic data in children from resource-limited settings taking adult fixed-dose-combination antiretroviral therapy (cART) without viral load monitoring.

METHODS

CHAP2 (Children with HIV Antibiotic Prophylaxis 2) is a prospective cohort of Zambian children using d4T/3TC/NVP adult Triomune30 dosed according to WHO guidelines.

RESULTS

A total of 103 children (19 with previous antiretroviral therapy) had follow-up >6 months. Median age at cART initiation was 8 years (IQR, 6-12) and CD4 8% (4-12). At 24 months, CD4% had increased by a median of 15% (7-25). For 74 children viral load was known/inferred: 51 of 74 (69%) had viral load <50 copies/mL (45 of 63 [71%] with no previous cART, 6 of 11 [55%] with previous cART; difference P = 0.30); 22 of 74 (30%) had viral load >1000 copies/mL. Of 26 children with resistance data, 25 (96%) had NNRTI resistance; 22 (84%) had M184V; 2 (8%) had Q151M; and 1 (4%) each had K65R, L74V, or K70E. Eight (31%) had > or =1 TAM. Those failing virologically with a genotypic sensitivity score of 0 for first-line therapy had a somewhat smaller increase in CD4% from baseline compared with those failing therapy with a genotypic sensitivity score >0 (+3 vs. +8, P = 0.13), and had somewhat lower CD4% at initiation of cART (2 vs. 11, P = 0.09). In 6 children with >1 resistance test, the estimated rate of accumulation of TAMs was 0.59/yr (95% confidence interval: 0.22-1.29).

CONCLUSIONS

Twenty-four month virologic responses to cART were good. However, the rate of TAM accumulation in those with rebound was higher than reported in Western adult cohorts, and there was some indication of a detrimental effect of high level resistance on CD4% change from baseline.

Drug resistance is widespread among children who receive long-term antiretroviral treatment at a rural Tanzanian hospital

Objectives

To assess long-term virological efficacy and the emergence of drug resistance in children who receive antiretroviral treatment (ART) in rural Tanzania.

Patients and methods

Haydom Lutheran Hospital has provided ART to HIV-infected individuals since 2003. From February through May 2009, a cross-sectional virological efficacy survey was conducted among children (<15 years) who had completed ≥6 months of first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Genotypic resistance was determined in those with a viral load of >200 copies/mL.

Results

Virological response was measured in 19 of 23 eligible children; 8 of 19 were girls and median age at ART initiation was 5 years (range 2–14 years). Median duration of ART at the time of the survey was 40 months (range 11–61 months). Only 8 children were virologically suppressed (≤40 copies/mL), whereas 11 children had clinically relevant resistance mutations in the reverse transcriptase gene. The most frequent mutations were M184V (n = 11), conferring resistance to lamivudine and emtricitabine, and Y181C (n = 4), G190A/S (n = 4) and K103N (n = 4), conferring resistance to NNRTIs. Of concern, three children had thymidine analogue mutations, associated with cross-resistance to all nucleoside reverse transcriptase inhibitors. Despite widespread resistance, however, only one child experienced a new WHO stage 4 event and none had a CD4 cell count of <200 cells/mm³.

Conclusions

Among children on long-term ART in rural Tanzania, >50% harboured drug resistance. Results for children were markedly poorer than for adults attending the same programme, underscoring the need for improved treatment strategies for children in resource-limited settings.

Hidden drug resistant HIV to emerge in the era of universal treatment access in Southeast Asia

BACKGROUND

Universal access to first-line antiretroviral therapy (ART) for HIV infection is becoming more of a reality in most low and middle income countries in Asia. However, second-line therapies are relatively scarce.

METHODS AND FINDINGS

We developed a mathematical model of an HIV epidemic in a Southeast Asian setting and used it to forecast the impact of treatment plans, without second-line options, on the potential degree of acquisition and transmission of drug resistant HIV strains. We show that after 10 years of universal treatment access, up to 20% of treatment-naïve individuals with HIV may have drug-resistant strains but it depends on the relative fitness of viral strains.

CONCLUSIONS

If viral load testing of people on ART is carried out on a yearly basis and virological failure leads to effective second-line therapy, then transmitted drug resistance could be reduced by 80%. Greater efforts are required for minimizing first-line failure, to detect virological failure earlier, and to procure access to second-line therapies.