Publications

14

Sep, 2019

Pharmacokinetics of dolutegravir 5mg dispersible tablets in children weighing 6 to <20kg dosed using WHO weight bands

 

Authors: Waalewijn H, Bollen PDJ, Moore C, Kekitiinwa A, et al. The ODYSSEY Trail Team

Published in: Oral Presentation at 10th IAS Conference, July, 21-24th 2019

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14

Sep, 2019

Follow up of Children with Confirmed Perinatal Zika Virus (ZIKV) Exposure: The First 2 years-experience in the Costa Rican Tertiary Pediatric Hospital

 

Authors: Tedder RS, Dicks S, Ijaz S, et al.

Published in: PLoS One. 2019;14(8):e0215708

Abstract The accurate diagnosis and seroprevalence investigations of Zika virus (ZKV) infections remain complex due to cross reactivity with other flaviviruses. Two assay formats, both using labelled Zika virus NS1 antigen as a revealing agent (a double antigen binding assay, DABA, and an immunoglobulin Ig capture assay, G capture) were initially developed and compared with the indirect EuroimmunZ assay for the detection of anti-Zika antibody. Of 147 pre-Zika period serum samples, 39 (27%) were reactive in the EuroimmunZ or the DABA assays, 28 sera concordantly so. Such false reactivity was influenced by the serotype of Dengue virus (DV) to which individuals had been exposed to. Thus, of sera from patients undergoing secondary Dengue virus infection of known serotype, 91%, 45% and 28% of Dengue virus serotype 2, 3 and 4 respectively were reactive in one or more of the three assays. A novel method of quenching false sero-reactivity was therefore developed for the DABA and G capture assays. Initial addition of a single homologous Dengue virus serotype 3 NS1Ag quench significantly ablated false reactivities in the pre-Zika period sera. An equipotent quadrivalent quench comprising homologous Dengue virus serotypes 1 to 4 NS1Ag was shown to be optimum yet retained sensitivity for the detection of specific anti-Zika antibody. Comparing DABA and G capture assays using quenched and unquenched conjugates in comparison with EuroimmunZ early in the course of PCR-confirmed infection indicated that a significant component of the apparent early anti-ZIKA antibody response is likely to be due to a Zika virus-driven anamnestic anti-Dengue virus response. The increased specificity provided by homologous antigen quenching is likely to provide a significant improvement in sero-diagnostics and to be of clinical value.

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9

Sep, 2019

Past and future spread of the arbovirus vectors Aedes aegypti and Aedes albopictus

 

Authors: Kraemer MUG, Reiner RC Jr, Brady OJ, et al.

Published in: Nat Microbiol. 2019;4:900

Abstract The global population at risk from mosquito-borne diseases—including dengue, yellow fever, chikungunya and Zika—is expanding in concert with changes in the distribution of two key vectors: Aedes aegypti and Aedes albopictus. The distribution of these species is largely driven by both human movement and the presence of suitable climate. Using statistical mapping techniques, we show that human movement patterns explain the spread of both species in Europe and the United States following their introduction. We find that the spread of Ae. aegypti is characterized by long distance importations, while Ae. albopictus has expanded more along the fringes of its distribution. We describe these processes and predict the future distributions of both species in response to accelerating urbanization, connectivity and climate change. Global surveillance and control efforts that aim to mitigate the spread of chikungunya, dengue, yellow fever and Zika viruses must consider the so far unabated spread of these mosquitos. Our maps and predictions offer an opportunity to strategically target surveillance and control programmes and thereby augment efforts to reduce arbovirus burden in human populations globally.

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2

Sep, 2019

The CARMA Study: Children on early suppressive ART Total HIV-1 DNA quantitation 12 years post ART initiation

 

Authors: Foster C, Dominguez S, Tagarro A, Nastouli E, Gkouleli R, Heaney J, PalmaP, Rossi P, Giaquinto C, Rojo P

Published: 10th IAS Conference on HIV Science, July 21rd-24th 2019, Mexico City

Background Future strategies aimed at achieving antiretroviral therapy (ART)-free HIV remission are likely to target individuals with a limited size of viral reservoir. We investigated factors associated with a low reservoir measured as total HIV-1 DNA in PBMCs in perinatally infected children (PaHIV) from 5 European centers in the EPIICAL consortium.

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2

Sep, 2019

Comparison of qPCR and dPCR methods to investigate the latent HIV reservoir in a paediatric population with long viral suppression on therapy

 

Authors: Heaney J, Busby E, Gärtner K, Grant P, Spyer MJ, O’Sullivan DM, Gkouleli T, Marcelin AG, Pillay D, Foster C, Rojo P, Palma P, Muñoz Fernández MA, deRossi A, Huggett JF, Nastouli E

Published: International Workshop on HIV Pediatrics, July 19th-20th, 2019. P_102

Background Despite effective antiretroviral therapy(ART), HIV persists as integrated provirus generating latent viral reservoirs even in the absence of detectable plasma viremia.

Latently infected cells, primarily CD4+ T cells, have the potential to release progeny virus and contribute to viral rebound after treatment interruption or HIV-1 remission.

Robust assays are needed to monitor the viral reservoir, and remission, as emerging therapeutic approaches aimed at achieving ART-free HIV remission, or cure, are likely to target individuals with low levels of total HIV-1 DNA. The current gold standard for measuring specific DNA amounts in clinical diagnostics and research is quantitative PCR (qPCR), whereas digital PCR (dPCR) is a more recent technology that has become commercially available since 2011.

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1

Sep, 2019

Understanding the relation between Zika virus infection during pregnancy and adverse fetal, infant and child outcomes: a protocol for a systematic review and individual participant data meta-analysis of longitudinal studies of pregnant women and their infants and children

 

Authors: Wilder-Smith A, Wei Y, Araújo TVB et al;Zika Virus Individual Participant Data Consortium

Published in: BMJ Open. 2019;9(6):e026092. doi: 10.1136/bmjopen-2018-026092.

Introduction Zika virus (ZIKV) infection during pregnancy is a known cause of microcephaly and other congenital and developmental anomalies. In the absence of a ZIKV vaccine or prophylactics, principal investigators (PIs) and international leaders in ZIKV research have formed the ZIKV Individual Participant Data (IPD) Consortium to identify, collect and synthesise IPD from longitudinal studies of pregnant women that measure ZIKV infection during pregnancy and fetal, infant or child outcomes.

Methods and analysis We will identify eligible studies through the ZIKV IPD Consortium membership and a systematic review and invite study PIs to participate in the IPD meta-analysis (IPD-MA). We will use the combined dataset to estimate the relative and absolute risk of congenital Zika syndrome (CZS), including microcephaly and late symptomatic congenital infections; identify and explore sources of heterogeneity in those estimates and develop and validate a risk prediction model to identify the pregnancies at the highest risk of CZS or adverse developmental outcomes. The variable accuracy of diagnostic assays and differences in exposure and outcome definitions means that included studies will have a higher level of systematic variability, a component of measurement error, than an IPD-MA of studies of an established pathogen. We will use expert testimony, existing internal and external diagnostic accuracy validation studies and laboratory external quality assessments to inform the distribution of measurement error in our models. We will apply both Bayesian and frequentist methods to directly account for these and other sources of uncertainty.

Ethics and dissemination The IPD-MA was deemed exempt from ethical review. We will convene a group of patient advocates to evaluate the ethical implications and utility of the risk stratification tool. Findings from these analyses will be shared via national and international conferences and through publication in open access, peer-reviewed journals.

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30

Aug, 2019

Dolutegravir pharmacokinetics during pregnancy and postpartum

 

Authors: Colbers A, Bollen P, Freriksen J, Konopnicki D, Weizsäcker K, Hidalgo Tenorio C, Moltó J, Taylor G, Alejandre I,  van Crevel R, Burger D; on behalf of the PANNA network

Published: 26th Conference on Retroviruses and Opportunistic Infections, March 4th – 7th, 2019– Seattle. P_758.

 

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30

Aug, 2019

Dolutegravir pharmacokinetics during pregnancy and postpartum

 

Authors: Colbers A, Bollen P, Freriksen J, Konopnicki D, Weizsäcker K, Hidalgo Tenorio C, Moltó J, Taylor G, Alejandre I,  van Crevel R, Burger D.

Published: Oral presentation at 9th edition of the International Workshop on HIV & Women, March 2nd-3rd 2019, Seattle

 

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30

Aug, 2019

Efavirenz pharmacokinetics during pregnancy and infant washout

 

Authors: Kreitchmann R, Schalkwijk S, Best B, et al.

Published in: Antivir Ther. 2019;24(2):95-103

Background Limited data exist on efavirenz pharmacokinetics in HIV-positive pregnant women and neonatal washout.

Methods HIV-infected pregnant women receiving 600 mg efavirenz once daily had intensive steady-state 24-h pharmacokinetics profiles during the second trimester (2T), third trimester (3T) and 6-12 weeks postpartum (PP). Maternal and umbilical cord blood samples were drawn at delivery and neonatal washout pharmacokinetics were determined. Therapeutic targets were the estimated 10th percentile efavirenz area under the concentration-time curve (AUC) in non-pregnant historical controls (40.0 μg•h/ml) and a trough concentration (C24 h) of 1 μg/ml. Data were prospectively collected within two trials: IMPAACT P1026s (United States) and PANNA (Europe).

Results Among 42 women studied, 15, 42 and 40 had efavirenz pharmacokinetic data available in 2T, 3T and PP, respectively. Median (range) 3T age 33 (20.7-43.5) years, weight 74 (50-132) kg and gestational age 33.4 (28.4-37.9 weeks). Efavirenz AUC during the 3T (60 μg•h/ml) was similar to that reported in non-pregnant adults (58 μg•h/ml). Exposure in the 2T was lower, but within the 0.80-1.25 range. C24concentrations during pregnancy were lower compared to historical controls on 600 mg efavirenz, however, they were similar to the C24concentrations after equally potent dose of 400 mg efavirenz. Cord blood/maternal plasma concentration ratio (range) was 0.67 (0.36-0.95). Among 23 infants with washout data available, median (interquartile range) elimination half-life was 65.6 h (40.6-129). HIV RNA viral loads at delivery were <400 and <50 copies/ml for 96.7% and 86.7% of women, respectively. In 3T and PP, respectively, 8/41 (19%) and 6/40 (15%) had AUC below target; 7/41 (17%) and 3/39 (8%) had C24 below target.

Conclusions Efavirenz exposure was similar during pregnancy compared with PP, C24 was in line with C24 after 400 mg equipotent efavirenz dosing. Efavirenz readily crossed the placenta and infant elimination half-life was over twice that of maternal participants.

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30

Aug, 2019

Evaluating darunavir/ritonavir dosing regimens for HIV-positive pregnant women using semi-mechanistic pharmacokinetic modelling

 

Authors: Schalkwijk S, Ter Heine R, Colbers A, et al.

Published in: J Antimicrob Chemother. 2019;30 [Epub ahead of print]

Background Darunavir 800 mg once (q24h) or 600 mg twice (q12h) daily combined with low-dose ritonavir is used to treat HIV-positive pregnant women. Decreased total darunavir exposure (17%-50%) has been reported during pregnancy, but limited data on unbound exposure are available.

Objectives To evaluate total and unbound darunavir exposures following standard darunavir/ritonavir dosing and to explore the value of potential optimized darunavir/ritonavir dosing regimens for HIV-positive pregnant women.

Patients and Methods A population pharmacokinetic analysis was conducted based on data from 85 women. The final model was used to simulate total and unbound darunavir AUC0-τ and Ctrough during the third trimester of pregnancy, as well as to assess the probability of therapeutic exposure.

Results Simulations predicted that total darunavir exposure (AUC0-τ) was 24% and 23% lower in pregnancy for standard q24h and q12h dosing, respectively. Unbound darunavir AUC0-τ was 5% and 8% lower compared with post-partum for standard q24h and q12h dosing, respectively. The probability of therapeutic exposure (unbound) during pregnancy was higher for standard q12h dosing (99%) than for q24h dosing (94%).

Conclusion The standard q12h regimen resulted in maximal and higher rates of therapeutic exposure compared with standard q24h dosing. Darunavir/ritonavir 600/100 mg q12h should therefore be the preferred regimen during pregnancy unless (adherence) issues dictate q24h dosing. The value of alternative dosing regimens seems limited.