Antiretroviral Resistance Patterns in Children with HIV Infection

Molecular Characterization of the pol Gene of Vertically Transmitted HIV-1 Strains in Children with Virological Failure

HIV-1 pol gene sequences were analyzed from 77 HIV-1 positive children infected perinatally and exhibiting virological failure (VF). Viral subtyping, phylogenetic analysis, and genotypic drug resistance analysis were carried out on samples collected before start of anti retroviral treatment (ART) (baseline, BL), and at 12 months post-ART initiation (M12). Subtype C was found to be most predominant, seen in 75 of the 77 (97.4%) children. The level of pretreatment drug resistance (PDR) was 14% among these children. At BL, K103N (5), E138A/G (4), and M184V (3) were the most common mutations. At M12 the prevalence of any resistance-associated mutation (RAM) (acquired drug resistance/ADR) was 81.8% (63/77). Dual class resistance mutations were seen in 64% (49/77) of children. M184V/I, K103N/S, and Y181C were the most commonly occurring mutations, seen in 76%, 51%, and 36% children. RAMs to the second-generation non-nucleoside reverse transcriptase inhibitors (NNRTI), etravirine (ETR) and rilpivirine (RPV), were seen in 40.2% (31/77) and 48.05% (37/77) of the children, respectively. Our findings reveal similar prevalence rates of PDR and ADR in children with VF as reported in other studies. Occurrence of ETR and RPV resistance associated mutations (RAMs) is of concern and highlights the need for timely switch of regimens guided by genotypic resistance testing in perinatally infected children from India.

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.

Mitochondrial changes associated with viral infectious diseases in the paediatric population

Infectious diseases occur worldwide with great frequency in both adults and children, causing 350,000 deaths in 2017, according to the latest World Health Organization reports. Both infections and their treatments trigger mitochondrial interactions at multiple levels: (i) incorporation of damaged or mutated proteins into the complexes of the electron transport chain; (ii) impact on mitochondrial genome (depletion, deletions and point mutations) and mitochondrial dynamics (fusion and fission); (iii) membrane potential impairment; (iv) apoptotic regulation; and (v) generation of reactive oxygen species, among others. Such alterations may result in serious adverse clinical events with considerable impact on the quality of life of the children and could even cause death. Herein, we use a systematic review to explore the association between mitochondrial alterations in paediatric infections including human immunodeficiency virus, cytomegalovirus, herpes viruses, various forms of hepatitis, adenovirus, T-cell lymphotropic virus and influenza. We analyse how these paediatric viral infectious processes may cause mitochondrial deterioration in this especially vulnerable population, with consideration for the principal aspects of research and diagnosis leading to improved disease understanding, management and surveillance.

HIV-1 subtypes and drug resistance in children during antiretroviral therapy in Brazil

We evaluate the genetic characterization of 132 HIV-1 pol sequences from children and adolescents undergoing antiretroviral therapy in Northeast Brazil. Phylogenetic and recombination analyses were performed using the maximum likelihood method using SeaView version 4 and SIMPLOT software. Most individuals harbored HIV-1 B (84.8%) and BF recombinants (9.8%), although other non-B subtypes were detected: HIV-1 C (1.5%), HIV-1 F (2.4%), and BC recombinants (1.5%). Antiretroviral resistance was 47% (95% confidence interval [CI]: 38.7%-55.4%). Non-nucleoside reverse transcriptase inhibitors (NNRTIs) showed higher frequencies of primary mutations, with 40.9% (95% CI: 32.9%-49.4%), followed by nucleoside reverse transcriptase inhibitors (NRTI) and protease inhibitors (PIs) with 34.8% (95% CI: 27.3-43.3) and 6.1% (95% CI: 3.1%-11.5%), respectively. Among NRTIs, higher resistance levels were observed for abacavir, emtricitabine, and lamivudine; for NNRTI, nevirapine and efavirenz. The most common primary mutations found were M184V (29.5%), K103N (25%), M41L (9.8%), T215Y (8.3%), and G190A (8.3%). Our findings highlight the importance of surveillance of resistance mutations, which contributes to the continuous updating and implementation of preventive measures to decrease mother-to-child-transmission and transmitted drug resistance.

Pretreatment HIV drug resistance predicts accumulation of new mutations in ART-naïve Ugandan children

AIM

To assess the prevalence of pretreatment drug resistance (PDR) and its association with virologic outcomes after 24 weeks of antiretroviral therapy (ART), within an urban cohort of Ugandan children.

METHODS

Prospective observational study. Baseline and 24-week assessments of viral load (VL) and genotypic drug resistance to nucleoside reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase inhibitors (NNRTI) were performed.

RESULTS

Ninety-nine ART-naïve children (3-12 years) initiated efavirenz-based ART 2015-2016 and 18/90 (20%) had baseline NRTI/NNRTI associated drug resistance mutations (DRMs). By 24 weeks, 72/93 (77%) children had VL < 40 copies/mL and a total of 23 children had DRMs. Children with PDR accumulated new DRMs with a mean number (SD) of 1.4 (2.35) new mutations compared to 0.26 (0.98) in 67 children with wild-type virus (P = .003). High pretreatment VL and PDR (number of baseline DRMs) predicted viremia (P = .003; P = .023) as well as acquired drug resistance (P = .02; P = .04).

CONCLUSION

Pretreatment drug resistance to NNRTI/NRTI was common among ART-naïve Ugandan children and predicted viremia and new resistance mutations after only 24 weeks of efavirenz-based therapy. PDR may compromise long-term ART outcomes-especially when access to resistance testing and VL monitoring is poor. The long-term importance of PDR for non-NNRTI-based regimens needs further evaluation.

Virological outcome among HIV infected patients transferred from pediatric care to adult units in Madrid, Spain (1997-2017)

The aim of this transversal study was to describe the virological and immunological features of HIV-infected youths transferred from pediatric to adult care units since 1997 vs. the non-transferred patients from the Madrid Cohort of HIV-infected children and adolescents in Spain. We included 106 non-transferred and 184 transferred patients under clinical follow-up in 17 public hospitals in Madrid by the end of December 2017. Virological and immunological outcomes were compared in transferred vs. non-transferred patients. ART drug resistance mutations and HIV-variants were analyzed in all subjects with available resistance pol genotypes and/or genotypic resistance profiles. Among the study cohort, 133 (72.3%) of 184 transferred and 75 (70.7%) of 106 non-transferred patients had available resistance genotypes. Most (88.9%) of transferred had ART experience at sampling. A third (33.3%) had had a triple-class experience. Acquired drug resistance (ADR) prevalence was significantly higher in pretreated transferred than non-transferred patients (71.8% vs. 44%; p = 0.0009), mainly to NRTI (72.8% vs. 31.1%; p < 0.0001) and PI (29.1% vs. 12%; p = 0.0262). HIV-1 non-B variants were less frequent in transferred vs. non-transferred (6.9% vs. 32%; p < 0.0001). In conclusion, the frequent resistant genotypes found in transferred youths justifies the reinforcement of HIV resistance monitoring after the transition to avoid future therapeutic failures.

Performance of Cepheid Xpert HIV-1 viral load plasma assay to accurately detect treatment failure

BACKGROUND

Coverage of viral load testing remains low with only half of the patients in need having adequate access. Alternative technologies to high throughput centralized machines can be used to support viral load scale-up; however, clinical performance data are lacking. We conducted a meta-analysis comparing the Cepheid Xpert HIV-1 viral load plasma assay to traditional laboratory-based technologies.

METHODS

Cepheid Xpert HIV-1 and comparator laboratory technology plasma viral load results were provided from 13 of the 19 eligible studies, which accounted for a total of 3790 paired data points. We used random effects models to determine the accuracy and misclassification at various treatment failure thresholds (detectable, 200, 400, 500, 600, 800 and 1000 copies/ml).

RESULTS

Thirty percent of viral load test results were undetectable, while 45% were between detectable and 10 000 copies/ml and the remaining 25% were above 10 000 copies/ml. The median Xpert viral load was 119 copies/ml and the median comparator viral load was 157 copies/ml, while the log10 bias was 0.04 (0.02-0.07). The sensitivity and specificity to detect treatment failure were above 95% at all treatment failure thresholds, except for detectable, at which the sensitivity was 93.33% (95% confidence interval: 88.2-96.3) and specificity was 80.56% (95% CI: 64.6-90.4).

CONCLUSION

The Cepheid Xpert HIV-1 viral load plasma assay results were highly comparable to laboratory-based technologies with limited bias and high sensitivity and specificity to detect treatment failure. Alternative specimen types and technologies that enable decentralized testing services can be considered to expand access to viral load.