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

Global, regional, and national prevalence of HIV-1 drug resistance in treatment-naive and treatment-experienced children and adolescents: a systematic review and meta-analysis

Background

Despite significant reductions in mother-to-child HIV-1 transmission risks due to the advancements and scale-up of antiretroviral therapy (ART), the global burden of HIV-1 drug resistance (HIVDR) in treatment-naive and treatment-experienced children and adolescents remains poorly understood. In this study, we conducted a systematic review and meta-analysis to estimate the prevalence of HIVDR in these populations globally, regionally, and at the country level.

Methods

We systematically searched PubMed, Embase, and Web of Science for studies reporting HIVDR in treatment-naive and treatment-experienced children and adolescents from inception to June 28, 2024. Eligible studies reported at least ten successfully genotyped cases. We excluded studies where drug resistance was not reported separately for children and adults or for treatment-naive and treatment-experienced populations. The methodological quality of eligible studies was assessed, and random-effect models were used for meta-analysis to determine the pooled overall and regimen-specific prevalence of one or more HIVDR mutations in these populations globally, regionally, or at the country level. This study is registered with PROSPERO under the number CRD42023424483.

Findings

Of 2282 records identified, 136 studies (28,539 HIV-1-infected children from 52 countries) were included for analysis. The overall prevalence of HIVDR is 26.31% (95% CI, 20.76-32.25) among treatment-naive children and 74.16% (95% CI, 67.74-80.13) among treatment-experienced children (p < 0.0001). HIVDR varied widely across subregion with the highest prevalence in Southern Africa (37.80% [95% CI, 26.24-50.08]) and lowest in South America (11.79% [95% CI, 4.91-20.84]) for treatment-naive children while highest in Asia (80.85% [95% CI, 63.76-93.55]) and lowest in Europe (54.39% [95% CI, 28.61-79.03]) for treatment-experienced children. The proportion of viral failure (VF) presented positive correlation with DR prevalence for treatment-experienced children, which increased from 61.23% (95% CI, 47.98-73.72) in proportion of VF <50%-81.17% (95% CI, 71.57-89.28) in proportion of 100%. Meta-regression analysis for both groups showed that only age (naive: p = 0.0005; treated: p < 0.0001) was the sources of heterogeneity. Non-nucleoside reverse transcriptase inhibitor (NNRTI) resistances were the most seen mutations among the treatment-naive group, with the HIVDR prevalence more than 10% in Southern Africa, Western and Central Africa, Eastern Africa, Asia, and North America. Both nucleoside reverse transcriptase inhibitor (NRTI) and NNRTI resistances were commonly seen among the treatment-experienced group, varying from 36.33% (95% CI, 11.96-64.93) in North America to 77.54% (95% CI, 62.70-89.58) in South America for NRTI and from 39.98% (95% CI, 13.47-69.97) in Europe to 68.86 (95% CI, 43.91-89.17) in Asia for NNRTI, respectively.

Interpretation

This study underscores the significant burden of HIVDR among children and adolescents worldwide, particularly pronounced in sub-Saharan Africa and low-income countries. It emphasizes the critical importance of surveillance in all HIV-1-infected children and advocates for the adoption of dolutegravir (DTG) or other optimal formulations as first-line ART in settings where NNRTI resistance exceeds the WHO's 10% threshold. DTG's high resistance barrier, potent antiviral efficacy, and favorable safety profile makes it a superior choice for managing drug-resistant HIV-1, surpassing traditional antiretroviral therapies.

Funding

This work was supported by the Science and Technology Innovation Committee of Shenzhen Municipality (No. JCYJ20220531102202005) and the Natural Science Foundation of Guangdong Province (No. 2024A1515012118).

Emergence of HIV-1 drug resistance mutations among children and adolescents undergoing prolonged antiretroviral therapy in Guangxi

OBJECTIVE

Antiretroviral therapy (ART) has been implemented in Guangxi for a long time, and there are no reports of HIV drug resistance mutation (DRM) among children and adolescents experiencing virologic failure after ART. This study aimed to analyse HIV DRM prevalence, patterns, and influencing factors among children and adolescents experiencing virologic failure after ART in Guangxi.

METHODS

We collected samples from a total of 491 HIV-infected individuals under 18 years old experiencing virologic failure after ART from 14 cities in Guangxi. Sequencing and DRM analysis were performed based on pol region. Multivariate logistic regression was employed to analysis the influencing factors of DRM.

RESULTS

Among these patients, 396 cases were successfully sequenced. Of all, 52.53% exhibited HIV DRM, including NNRTI (48.48%), NRTI (34.85%) and PI (1.01%). NRTI and NNRTI dual-class resistance was prevalent (30.3%). M184V/I and K103N mutations were the common mutations in NRTI and NNRTI, respectively. Male sex (aOR = 2.1, 95% CI: 1.26-3.50), CRF01_AE subtype (OR = 2.50, 95% CI: 1.02-5.88), the primary regimen 3TC+AZT+NVP (OR = 10.00, 95% CI: 5.00-25.00), low pretreatment CD4+ T lymphocytes (<200 cells/mm³) (OR = 1.85, 95% CI: 1.00-3.45), and high viral load (>1000 copies/mL) (OR = 4.90, 95% CI: 1.03-23.39) showed higher risk of DRM.

CONCLUSION

HIV DRM is pervasive among children and adolescents experiencing virologic failure in Guangxi. Timely HIV DRM monitoring is crucial to mitigate major mutation accumulation and inform effective treatment strategies.

Some pharmacogenetic aspects of the <i>ABCB1</i> gene in lopinavir / ritonavir concentration variability in children with HIV infection: A pilot study

   Polymorphic variants of the multidrug resistance gene (ABCB1 or MDR1) are associated with changes in the absorption and transport of drugs in the body. One of the substrates of the ABCB1 transporter is an antiretroviral drug from the class of protease inhibitors, lopinavir.   The aim. To research the effect of polymorphic variants C1236T and C3435T in the ABCB1 gene on the plasma concentration of lopinavir / ritonavir in children and adolescents living with HIV infection.   Methods. The genotypes of polymorphic variants of the ABCB1 gene were identified in 136 HIV infected children and adolescents; median age – 10 [7–12] years. The plasma concentration of lopinavir / ritonavir was measured from blood taken during the next scheduled appointment as part of dispensary observation at the Irkutsk Regional AIDS Centre using high performance liquid chromatography.   Results. The average duration of lopinavir/ritonavir use as part of an antiretroviral therapy was 55 months. Median viral load in patients was 1 [1–2.03] log 10  copies/ mL; the number of CD4 +  T cells – 38.36 %. The frequency of occurrence of the 3435T and 1236T alleles of the ABCB1 gene was ~50 %. In carriers of the 3435TT genotype, the median lopinavir concentrations 2 and 12 hours after drug intake were 5050.8 [3615.8–5847.7] and 2665.5 [216–4896.3] ng/mL, respectively. In carriers of the 1236TT genotype, median lopinavir concentrations 2 and 12 hours after drug intake were 4913.5 [3355.1–5733.7] and 3290.6 [159.1–4972.5] ng/mL, respectively.   Conclusions. The study did not reveal a significant relationship between the carriage of the C3435T and C1236T genotypes of the ABCB1 gene and the concentrations of lopinavir and ritonavir 2 and 12 hours after drug intake.

Drug resistance profiles and influencing factors among HIV-infected children and adolescents receiving long-term ART: a multicentre observational study in China

OBJECTIVES

To analyse the characteristics and determinants of drug resistance mutations (DRMs) in HIV-infected children and adolescents on long-term ART in China.

METHODS

An observational cohort study was conducted in five centres. All participants younger than 15 years at ART initiation were screened, and those identified as having virological failure (VF) with viral load (VL) ≥ 400 copies/mL were included for genotypic resistance testing. Logistic regression analysis was performed and the accumulation of major mutations was analysed in a subgroup of resistant individuals with complete VL results since HIV diagnosis.

RESULTS

Among 562 eligible participants, protease and RT regions were successfully amplified for 93 who failed treatment with a median of 10.0 years ART. Sixty-eight (73.1%) harboured ≥1 major mutations. NRTI, NNRTI and dual-class resistance accounted for 48.4%, 63.4% and 38.7%, respectively. Only 3.2% were resistant to PIs. Age at ART initiation [adjusted OR (aOR) = 0.813, 95% CI 0.690-0.957], subtype B (aOR = 4.378, 95% CI 1.414-13.560) and an initial NNRTI-based regimen (aOR = 3.331, 95% CI 1.180-9.402) were independently associated with DRMs. Among 40 resistant participants with additional VL data, 55.0% had continued VF on a suboptimal regimen and the estimated duration of VF was positively correlated with the total number of major mutations (r = 0.504, P = 0.001).

CONCLUSIONS

The development of DRMs was common in children and adolescents receiving long-term treatment, and continued VF was prevalent in those with resistance. Timely genotypic testing and new child-friendly formulations are therefore urgently required.

Pre-treatment drug resistance and HIV-1 subtypes in infants from Argentina with and without exposure to antiretroviral drugs for prevention of mother-to-child transmission

OBJECTIVES

To assess the prevalence and patterns of pre-treatment HIV drug resistance (PDR) and HIV-1 subtype in infants from Argentina with exposure to different antiretroviral drugs (ARVs) for the prevention of mother-to-child transmission (PMTCT).

PATIENTS AND METHODS

HIV-1 genotyping was performed in 115 infants (median age = 2.3 months) born between 2007 and 2014 to screen for drug resistance mutations (DRMs) before starting first-line ART. HIV-1 subtype was characterized by phylogenetic and recombination analysis.

RESULTS

Overall, DRMs were found in 34 of 115 infants (PDR level 30% to any ARV, 3.5% to PIs, 12% to NRTIs and 22% to NNRTIs). Of the 115 infants, 22 (19.1%) were ARV-unexposed. Another 93 were ARV-exposed: 28 (24.3%) to short-course zidovudine monotherapy ARV prophylaxis; 25 (21.7%) to nevirapine-based ARV prophylaxis; 12 (10.4%) to perinatal infant zidovudine prophylaxis + maternal combination ART with NNRTIs; and 28 (24.3%) to perinatal infant zidovudine prophylaxis+maternal combination ART with PIs. Transmitted drug resistance among ARV-unexposed infants was 32% (5% to PIs, 9% to NRTIs and 18% to NNRTIs). ART-exposed infants showed multi-class ARV resistance. Importantly, vertical transmission of a triple-class-resistant virus was confirmed in one case. Patterns of DRMs predicted high-level resistance to NNRTIs in a similar and high proportion (>50%) of infants with at least one DRM independently of ARV exposure. BF recombinants were found in 74%, subtype B in 20%, subtype C in 3% and novel AG and AB recombinants in 3%.

CONCLUSIONS

PDR in HIV-1-infected children from Argentina is among the highest reported, jeopardizing successful lifelong suppressive ART as well as the efficacy of current PMTCT regimens.

Outcomes of second-line antiretroviral therapy among children living with HIV: a global cohort analysis

INTRODUCTION

Limited data describe outcomes on second-line antiretroviral therapy (ART) among children globally. Our objective was to contribute data on outcomes among children living with HIV after initiation of second-line ART in the context of routine care within a large global cohort collaboration.

METHODS

Patient-level data from 1993 through 2015 from 11 paediatric HIV cohorts were pooled. Characteristics at switch and through two years of follow-up were summarized for children who switched to second-line ART after starting a standard first-line regimen in North America, Latin America, Europe, Asia, Southern Africa (South Africa & Botswana) and the rest of sub-Saharan Africa (SSA). Cumulative incidences of mortality and loss to follow-up (LTFU) were estimated using a competing risks framework.

RESULTS

Of the 85,389 children on first-line ART, 3,555 (4%) switched to second-line after a median of 2.8 years on ART (IQR: 1.6, 4.7); 69% were from Southern Africa or SSA and 86% of second-line regimens were protease inhibitor-based. At switch, median age was 8.4 years and 50% had a prior AIDS diagnosis. Median follow-up after switch to second-line ranged from 1.8 years in SSA to 5.3 years in North America. Median CD4 counts at switch to second-line ranged from 235 cells/mm3 in SSA to 828 cells/mm3 in North America. Improvements in CD4 counts were observed over two years of follow-up, particularly in regions with lower CD4 counts at second-line switch. Improvements in weight-for-age z-scores were not observed during follow-up. Cumulative incidence of LTFU at two years was <5% in all regions except SSA (7.1%) and Southern Africa (7.4%). Risk of mortality was <3% at two years of follow-up in all regions, except Latin America (4.9%) and SSA (5.5%).

CONCLUSIONS

Children switched to second-line ART experience CD4 count increases as well as low to moderate rates of LTFU and mortality within two years after switch. Severe immune deficiency at time of switch in some settings suggests need for improved recognition and management of treatment failure in children.

Drug resistance evolution in patients with human immunodeficiency virus-1 under long-term antiretroviral treatment-failure in Yunnan Province, China

Background

Understanding the prevalence and evolution of HIV-1 drug resistance (DR) and associated mutation patterns is critical to implementing free antiretroviral therapy in Yunnan, the first antiretroviral treatment location in China. Here We provide a basis for understanding the occurrence and development of HIV-1 resistance in Yunnan and a theoretical foundational for strategy to delay HIV-1 drug resistance and achieve successful individualized treatment.

Methods

Plasma samples from different cities/prefectures were collected at Yunnan Provincial Hospital of Infectious Disease from January 2010 to September 2016, and those from drug-resistant individuals were genotyped using in-house assays, 88 patients were selected for the study who had been on treatment for ≥6 months (and for whom drug resistance was then measured), and each patient had at least 3 genotype resistance tests and who were enrolled to analyze mutation and evolution of HIV resistance.

Results

264 Pol sequences of 88 patients were obtained. Drug resistance levels to eight drugs increased to varying degrees with prolonged treatment. Resistance to efavirenz (EFV) and etravirine (ETR) showed the highest change, comparisons of resistant changes to second and first and to third and second agents showed altered level of drug resistance were 25 and 20 cases, 28 and 18 cases, respectively. The smallest change was Lopinavir/Ritonavir (LPV/r) present 2 and 3 cases; Resistance to lamivudine (3TC) and lopinavir/ritonavir (LPV/r) was high among patients detected thrice, whereas other drugs were distributed in all resistance levels. M184 V/I (26.14%), T69S (11.36%), and T215Y/I (10.23%) mutations were the most common in nucleoside reverse transcriptase inhibitors (NRTIs), and K103 N/R/S (21.59%), V179D/E (20.45%) in Non-NRTIs (NNRTIs). Furthermore, L10 V/F/I (6.82%), A71V (4.55%), and I54V (4.55%) mutations were common in protease inhibitors (PIs).

Conclusions

We found dynamic genotypic changes in HIV-1 drug-resistance in Yunnan, with prolonged treatment, and drug resistance was inevitable. However, resistance to different drugs occurred at varying times, and mutation site emergence was the main cause. These findings enhance our understanding of evolution and regulation, and are valuable for developing HIV-1 DR prevention strategies in Yunnan.

HIV Viral Load Suppression in Adults and Children Receiving Antiretroviral Therapy-Results From the IeDEA Collaboration

BACKGROUND

Having 90% of patients on antiretroviral therapy (ART) and achieving an undetectable viral load (VL) is 1 of the 90:90:90 by 2020 targets. In this global analysis, we investigated the proportions of adult and paediatric patients with VL suppression in the first 3 years after ART initiation.

METHODS

Patients from the IeDEA cohorts who initiated ART between 2010 and 2014 were included. Proportions with VL suppression (<1000 copies/mL) were estimated using (1) strict intention to treat (ITT)-loss to follow-up (LTFU) and dead patients counted as having detectable VL; and (2) modified ITT-LTFU and dead patients were excluded. Logistic regression was used to identify predictors of viral suppression at 1 year after ART initiation using modified ITT.

RESULTS

A total of 35,561 adults from 38 sites/16 countries and 2601 children from 18 sites/6 countries were included. When comparing strict with modified ITT methods, the proportion achieving VL suppression at 3 years from ART initiation changed from 45.1% to 90.2% in adults, and 60.6% to 80.4% in children. In adults, older age, higher CD4 count pre-ART, and homosexual/bisexual HIV exposure were associated with VL suppression. In children, older age and higher CD4 percentage pre-ART showed significant associations with VL suppression.

CONCLUSIONS

Large increases in the proportion of VL suppression in adults were observed when we excluded those who were LTFU or had died. The increases were less pronounced in children. Greater emphasis should be made to minimize LTFU and maximize patient retention in HIV-infected patients of all age groups.

Impact of Single Nucleotide Polymorphisms on Plasma Concentrations of Efavirenz and Lopinavir/Ritonavir in Chinese Children Infected with the Human Immunodeficiency Virus

Single nucleotide polymorphisms (SNPs) in the genes that encode the cytochrome P450 (CYP) drug metabolizing enzymes and drug transporters have been reported to influence antiretroviral drug pharmacokinetics. Although primarily metabolized by CYP2B6 and -3A, efavirenz (EFV) and lopinavir/ritonavir (LPV/r) are substrates of P-glycoprotein and the solute carrier organic (SLCO) anion transporter, respectively. We investigated the association between SNPs and efavirenz (EFV) or lopinavir/ritonavir (LPV/r) concentrations in Chinese children infected with the human immunodeficiency virus (HIV). Genotyping was performed on CYP2B6 516G→T, -1459C→T, and -983T→C, ABCB1 3435C→T, and SLCO1B1 521T→C in 229 HIV-infected Chinese pediatric patients (age range 4.0 to 17.5 yrs). Plasma concentrations of EFV and LPV/r were measured using validated high-performance liquid chromatography coupled with the mass spectrum method among 39 and 69 children who received EFV- and LPV/r-containing regimens, respectively. The frequencies of CYP2B6 516G→T in the study participants were 71%, 25%, and 4% for the G/G, G/T, and T/T genotypes, respectively. Among the children under therapeutic drug monitoring, 21% and 39% experienced EFV and LPV concentrations, respectively, above the upper threshold of the therapeutic window. CYP2B6 516G→T was significantly associated with EFV concentrations (p<0.001). Older children (older than 10 yrs) were more likely to have significantly higher EFV concentrations than the younger ones (p=0.0314). CYP2B6 genotyping and EFV concentration monitoring may help optimize antiretroviral therapy in pediatric patients who initiate an EFV-based regimen.

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 suppression in adolescents on antiretroviral treatment: review of the literature and critical appraisal of methodological challenges

Objective

Medication adherence is often suboptimal for adolescents with HIV, and establishing correct weight‐based antiretroviral therapy dosing is difficult, contributing to virological failure. This review aimed to determine the proportion of adolescents achieving virological suppression after initiating ART.

Methods

MEDLINE, EMBASE and Web of Science databases were searched. Studies published between January 2004 and September 2014 including ≥50 adolescents taking ART and reporting on the proportion of virological suppressed participants were included.

Results

From a total of 5316 potentially relevant citations, 20 studies were included. Only eight studies reported the proportion of adolescents that were virologically suppressed at a specified time point. The proportion of adolescents with virological suppression at 12 months ranged from 27 to 89%.

Conclusion

Adolescent achievement of HIV virological suppression was highly variable. Improved reporting of virological outcomes from a wider range of settings is required to support efforts to improve HIV care and treatment for adolescents.

Genetic Diversity and Drug Resistance Among Antiretroviral Treatment-Failed Individuals from 2010 to 2012 in Honghe, China

The most common antiretroviral treatment (ART) received by individuals infected with HIV-1 in China is the combination therapy, comprised of nucleoside reverse transcriptase inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs). To assess the prevalence of HIV-1 drug resistance and subtypes in Honghe of Yunnan, China, patient plasmas from ART-failed individuals were collected from January 2010 to December 2012. Genotyping was conducted using an in-house assay on patient plasmas. A total of 254 pol sequences were obtained. The prevalence of drug resistance was 47.2% in ART-failed individuals. Of these drug-resistant individuals, 51.7% harbored HIV strains dually resistant to NRTIs and NNRTIs or protease inhibitors (PIs) (34.2% for NNRTIs and 14.2% for NRTIs). Mutations such as M184V, A62V, T69Ins, K103N, Y181C, and G190A were common among the ART-failed individuals. The frequencies of M184V, A62V, and K103N were 20.5%, 11.0%, and 23.6%, respectively. The most common subtypes in Honghe were CRF08_BC (68.50%) and CRF07_BC (12.20%). The subtypes were almost consistent in different time points for one individual. When receiving ART for 6-12 months, the frequency of HIV-1 drug-resistant variants ranked first. This study shows that the high prevalence of HIV drug resistance observed among the ART-failed individuals should be of increasing concern (monitoring of resistance mutations) in ART regions and facilitate developing novel strategies for prevention and control of HIV infection in China.

Drug resistance in the HIV-1-infected paediatric population worldwide: a systematic review

BACKGROUND

Drug resistance monitoring of the paediatric HIV-1-infected population is required to optimize treatment success and preserve future treatment options.

OBJECTIVES

To explore the current knowledge of HIV drug resistance (HIVDR) in naive and pretreated HIV-1-infected paediatric populations across diverse settings and sampling time periods.

METHODS

PubMed database screened until May 2013. We selected publications including data on transmitted (TDR) and acquired drug resistance mutation (DRM) rates and/or pol sequences for HIVDR testing in paediatric patients. We recorded the children's country, age, study period, number of children with pol sequences, presence or absence of antiretroviral treatment (ART) at sampling time, viral region sequenced, HIVDR rate to the three main drug classes (single, double or triple), the considered resistance mutation list and performed assay, specimen type, HIV-1 variants and subtyping methodology when available.

RESULTS

Forty-one selected studies showed HIVDR data from 2538 paediatric HIV-1-infected patients (558 naive and 1980 pretreated) from 30 countries in Africa (11), Asia (6), America (10) and Europe (3). Both TDR and DRM prevalence were reported in 9 studies, only TDR in 6 and only DRM in 26. HIVDR prevalence varied across countries and periods. Most studies used in-house resistance assays using plasma or infected cells. HIV-1 non-B variants were prevalent in 18 paediatric cohorts of the 24 countries with reported subtypes. Only five countries (Uganda, Spain, the UK, Brazil and Thailand) presented resistance data in ≥200 patients.

CONCLUSIONS

Systematic and periodic studies among infected children are crucial to design a more suitable first- or second-line therapy.

Incidence and associated factors of pulmonary tuberculosis in HIV-infected children after highly active antiretroviral therapy (HAART) in China: a retrospective study

China is a country with high tuberculosis (TB) incidence but relatively low HIV prevalence. However, due to difficulties in diagnosis and reporting, true burden of HIV-associated TB in children is unknown. The objective of this study was to describe the incidence of pulmonary TB (PTB) after antiretroviral therapy (ART) and to study risk factors. A retrospective study was performed based on routinely collected data from China national pediatric free antiretroviral treatment database. A total of 3365 children under 15 years on ART from July 2005 to October 2012 were included. Multivariable logistic regression was used to detect associated factors. Two thousand nine hundred and ninety (89%) children got infected from HIV-positive mother, with median age of 6.7 (4.1, 10.0) years at highly active antiretroviral therapy (HAART) initiation in this program. Seventy-seven (2.3%) children were diagnosed with PTB after ART during 7.3 years cohort observation. Median time of occurrence was 212 (30-514) days. Overall incidence was 0.83 (0.65-1.01)/100 person-years (py), with the peak of 3.6/100 py in the first 3 months after antiretroviral treatment. WHO stage IV at baseline showed 2 (95% CI 1.0-6.8) times more risk for developing TB. Late clinical stage at ART initiation was shown to relate with TB incidence. PTB coinfection leads to higher mortality. Early diagnosis and treatment of HIV are highly required to reduce HIV-associated morbidity and mortality due to TB.

Prevalence and mutation patterns of HIV drug resistance from 2010 to 2011 among ART-failure individuals in the Yunnan Province, China

BACKGROUND

Assessing the prevalence of HIV-1 drug-resistance and the mutation patterns associated with resistance in the geographical regions implementing free antiretroviral therapy (ART) in China is necessary for preventing the spread of resistant strains and designing the regimens for the subsequent therapies with limited resources.

METHODS

Plasma samples in different cities/prefectures were collected at Yunnan Provincial Hospital of Infectious Disease from January 2010 to December 2011. Genotyping of drug-resistant individuals was conducted using an in-house assay on plasma samples. Viral load, CD4 T cell counts and demographic data were obtained from medical records and an administered questionnaire.

RESULTS

A total of 609 pol sequences (515 ART-failure and 94 therapy-naïve individuals) derived from 664 samples were obtained. The prevalence of drug-resistance was 45.1% in the ART-failure individuals. Of these, 26.8% harbored HIV strains dually resistant to nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors, and 14.8% harbored HIV strains resistant to only one drug category. Mutations such as M184V/I, K103N, V106A, Y181C and G190A were common among the ART-failure individuals, and the frequencies of M184V/I, K103N and V106A were 28.2%, 19.2%, and 22.1%, respectively. The percentages of individuals exhibiting intermediate or high-level resistance to 3TC, FTC, EFV and NVP drugs were 28.4%, 28.2%, 37.3%, and 37.5%, respectively. Factors such as ethnicity, transmission route, CD4 counts, viral load and the duration of ART were significantly correlated with development of drug resistance in the ART-failure individuals.

CONCLUSIONS

The high prevalence of HIV drug-resistance observed among the ART-failure individuals from 2010 to 2011 in Yunnan province should be of increasing concern in regions where the implementation of ART is widespread. Education about the risk factors associated with HIV drug resistance is important for preventing and controlling the spread of HIV drug-resistant strains.

Profile of HIV-infected patients receiving second-line antiretroviral therapy in a resource-limited setting in Nigeria

BACKGROUND

Second-line antiretroviral therapy (ART) accounts for less than 5% of total ART in resource-limited settings. We described the baseline characteristics, reasons for switch and treatment outcomes of Nigerian patients receiving second-line ART.

METHODS

In this retrospective cohort study we recorded the baseline characteristics of HIV-infected adults whose treatment regimen was switched from a non-nucleoside reverse transcriptase inhibitor, a first-line agent, to a protease inhibitor-based second-line regimen. The duration of follow-up was 12 months.

RESULTS

Of 4229 patients who started first-line therapy, 186 (4.4%) were switched to second-line therapy after a mean duration of 16.6 ± 7.6 months. Their mean age was 41.8 ± 9.6 years and 59.1% were women. The median (range) viral load and CD4 cell counts at switch were 4.7 (4.1-6.3) log10 copies/ml and 71 (6-610) cells/µl, respectively. The predominant reason for switch was virological failure (79.0%). Only 55.4% and 36.6% of patients had CD4 cell count and viral load at 12 months. About 82%, 79% and 82% of patients with available data achieved virological suppression at 3 months, 6 months and 12 months respectively (p = 0.81). The proportion of patients who achieved ≥50% rise in CD4 cell count increased from 55.8% at 3 months to 78.6% at 12 months (p = 0.0002).

CONCLUSION

The rate of switch to second-line therapy was low but there were good treatment outcomes among patients with available data. Attrition rate was high. Regular viral load monitoring, improved availability/affordability of second-line regimens and retention in care should become priorities in resource-limited settings.

Antiretroviral treatment, management challenges and outcomes in perinatally HIV-infected adolescents

Three decades into the HIV/AIDS epidemic there is a growing cohort of perinatally HIV-infected adolescents globally. Their survival into adolescence and beyond represent one of the major successes in the battle against the disease that has claimed the lives of millions of children. This population is diverse and there are unique issues related to antiretroviral treatment and management. Drawing from the literature and experience, this paper discusses several broad areas related to antiretroviral management, including: 1) diverse presentation of HIV, (2) use of combination antiretroviral therapy including in the setting of co-morbidities and rapid growth and development, (3) challenges of cART, including nonadherence, resistance, and management of the highly treatment-experienced adolescent patient, (4) additional unique concerns and management issues related to PHIV-infected adolescents, including the consequences of longterm inflammation, risk of transmission, and transitions to adult care. In each section, the experience in both resource-rich and limited settings are discussed with the aim of highlighting the differences and importantly the similarities, to share lessons learnt and provide insight into the multi-faceted approaches that may be needed to address the challenges faced by this unique and resilient population.

Short communication: high rates of thymidine analogue mutations and dual-class resistance among HIV-infected Ugandan children failing first-line antiretroviral therapy

HIV-infected children are at high risk of acquiring drug-resistant viruses, which is of particular concern in settings where antiretroviral drug options are limited. We aimed to assess resistance patterns and predict viral drug susceptibility among children with first-line antiretroviral therapy (ART) failure in Uganda. A cross-sectional analysis of children switching ART regimens due to first-line failure was performed at three clinical sites in Uganda. HIV-RNA determination and genotypic resistance testing on all specimens with HIV-RNA >1,000 copies/ml were performed. Major drug resistance mutations were scored using the 2011 International Antiviral Society-USA list. The Stanford algorithm was used to predict drug susceptibility. At the time of switch, 44 genotypic resistance tests were available for 50 children. All children harbored virus with nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance [95% confidence interval (CI) 92-100%] and NRTI resistance was present in 98% (95% CI 88-100%). Forty-six percent (95% CI 30-61%) of children harbored ≥2 thymidine analog mutations. M184V was identified as the only NRTI mutation in 27% (95% CI 15-43%). HIV susceptibility to NRTIs, with the exception of tenofovir, was reduced in ≥60% of children. Ugandan children experiencing first-line ART failure in our study harbored high rates of dual-class and accumulated HIV drug resistance. Methods to prevent treatment failure, including adequate pediatric formulations and alternative second-line treatment options, are urgently needed.

Antiretroviral drug resistance profiles and response to second-line therapy among HIV type 1-infected Ugandan children

We sought to determine the pattern of resistance-associated mutations (RAMs) among HIV-1-infected children failing first-line antiretroviral therapy (ART) and ascertain their response to second-line regimens in 48 weeks of follow-up. The design involved a cohort study within an HIV care program. We studied records of 142 children on ART with virological failure to first-line ART and switched to second-line ART with prior genotypic resistance testing. The pattern of RAMs was determined in frequency runs and the factors associated with accumulation of≥3 thymidine analogue mutations (TAMs) and K103N were determined using multivariate logistic models. Changes in weight, height, CD4, and viral load at weeks 24 and 48 after switch to second-line therapy were determined using descriptive statistics. The children were mean age 10.9±4.6 years and 55.6% were male. The commonest nucleoside reverse transcriptase inhibitor (NRTI) RAM was M184V in 129/142 (90.8%) children. TAMs,≥3 TAMs, 69 insertion complex, K65R/N, and Q151M were observed in 43.0%, 10.6%, 18.3%, 2.8%, and 2.1% of the children, respectively. The commonest nonnucleoside reverse transcriptase inhibitor (NNRTI) RAM was K103N in 72/142 (50.7%) children. The starting ART regimen was associated with accumulation of both≥3 TAMs (p=0.046) and K103N (p<0.0001), while a history of poor adherence was associated with K103N accumulation (p=0.0388). After 24 weeks and 48 weeks of follow-up on lopinavir-ritonavir based second-line ART, 86/108 (79.6%) and 84.5% (87/103) of the children had viral loads<400 copies/ml, respectively. The mean CD4 absolute count increased by 173 cells/μl and 267cells/μl at weeks 24 and 48, respectively. Increments were also observed in mean weight (1.6 kg and 4.3 kg) and height (1.8 cm and 5.8 cm) at weeks 24 and 48, respectively. Multiple RAMs were observed among HIV-1-infected children with virological failure on first-line ART with M184V and K103N most frequent. The children responded favorably to boosted PI-based second-line ART.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prediction of treatment failure using 2010 World Health Organization Guidelines is associated with high misclassification rates and drug resistance among HIV-infected Cambodian children

BACKGROUND

Antiretroviral therapy (ART) in resource-limited settings (RLSs) is monitored clinically and immunologically, according to World Health Organization (WHO) or national guidelines. Revised WHO pediatric guidelines were published in 2010, but their ability to accurately identify virological failure is unclear.

METHODS

We evaluated performance of WHO 2010 guidelines and compared them with WHO 2006 and Cambodia 2011 guidelines among children on ≥6 months of first-line ART at Angkor Hospital for Children between January 2005 and September 2010. We determined sensitivity, specificity, positive and negative predictive values, and accuracy using bootstrap resampling to account for multiple tests per child. Human immunodeficiency virus (HIV) resistance was compared between those correctly and incorrectly identified by each guideline.

RESULTS

Among 457 children with 1079 viral loads (VLs), 20% had >400 copies/mL. For children with WHO stage 1/2 HIV, misclassification as failure (met CD4 failure criteria, but VL undetectable) was 64% for WHO 2006 guidelines, 33% for WHO 2010 guidelines, and 81% for Cambodia 2011 guidelines; misclassification as success (did not meet CD4 failure, but VL detectable) was 11%, 12%, and 12%, respectively. For children with WHO stage 3/4 HIV, misclassification as failure was 35% for WHO 2006 guidelines, 40% for WHO 2010 guidelines, and 43% for Cambodia 2011 guidelines; misclassification as success was 13%, 24%, and 21%, respectively. Compared with WHO 2006 guidelines, WHO 2010 guidelines significantly increased the risk of misclassification as success in stage 3/4 HIV (P < .05). The WHO 2010 guidelines failed to identify 98% of children with extensive reverse-transcriptase resistance.

CONCLUSIONS

In our cohort, lack of virological monitoring would result in unacceptable treatment failure misclassification, leading to premature ART switch and resistance accumulation. Affordable virological monitoring suitable for use in RLSs is desperately needed.

Treatment outcomes of patients on second-line antiretroviral therapy in resource-limited settings: a systematic review and meta-analysis

BACKGROUND

A growing proportion of patients on antiretroviral therapy in resource-limited settings have switched to second-line regimens. We carried out a systematic review in order to summarize reported rates and reasons for virological failure among people on second-line therapy in resource-limited settings.

METHODS

Two reviewers independently searched four databases and three conference websites. Full text articles were screened and data extracted using a standardized data extraction form.

RESULTS

We retrieved 5812 citations, of which 19 studies reporting second-line failure rates in 2035 patients across low-income and middle-income countries were eligible for inclusion. The cumulative pooled proportion of adult patients failing virologically was 21.8, 23.1, 26.7 and 38.0% at 6, 12, 24 and 36 months, respectively. Most studies did not report adequate information to allow discrimination between drug resistance and poor adherence as reasons for virological failure, but for those that did poor adherence appeared to be the main driver of virological failure. Mortality on second-line was low across all time points.

CONCLUSION

Rates of virological failure on second-line therapy are high in resource-limited settings and associated with duration of exposure to previous drug regimens and poor adherence. The main concern appears to be poor adherence, rather than drug resistance, from the limited number of studies accessing both factors. Access to treatment options beyond second-line remains limited and, therefore, a cause for a concern for those patients in whom drug resistance is the identified cause of virological failure.