High deoxynivalenol and ergot alkaloid levels in wheat grain: effects on growth performance, carcass traits, rumen fermentation, and blood parameters of feedlot cattle

This study was designed to assess the impacts of a mixture of deoxynivalenol (DON) and ergot alkaloids (EAs) on growth performance, rumen function, blood parameters, and carcass traits of feedlot cattle. Forty steers (450 ± 6.0 kg) were stratified by weight and randomly allocated to 1 of 4 treatments; control-low (CON-L), control-high (CON-H) which contained low or high wheat screenings that lacked mycotoxins at the same level as the mycotoxin-low (MYC-L; 5.0 mg/kg DON, 2.1 mg/kg EA), and mycotoxin-high (MYC-H: 10 mg/kg DON, 4.2 mg/kg EA) diets that included wheat screening with mycotoxins. Steers were housed in individual pens for a 112-day finishing trial. Intake was 24.8% lower (P < 0.001) for MYC steers compared to CON steers. As a result, average daily gains of MYC steers were 42.1% lower (P < 0.001) than CON steers. Gain to feed ratio was also lower (P < 0.001) for MYC steers compared to CON steers. Platelets, alanine aminotransferase, globulins, and blood urea nitrogen were lower (P ≤ 0.008), and lymphocytes, glutathione peroxidase activity (GPx), and interleukin-10 (IL-10) were elevated (P ≤ 0.002) in MYC steers compared to CON steers. Hot carcass weights and backfat thickness were reduced (P < 0.001) in MYC steers, resulting in leaner (P < 0.001) carcasses and higher (P < 0.007) meat yield compared to CON steers. Results suggest that a mixture of DON and EAs negatively impacted health, performance, and carcass traits of feedlot steers, with the majority of this response likely attributable to EAs. However, more research is needed to distinguish the relative contribution of each mycotoxin to the specific responses observed.

Clinical outcomes in children living with HIV treated for non-severe tuberculosis in the SHINE Trial

BACKGROUND

Children living with HIV(CLWH) are at high risk of tuberculosis(TB) and face poor outcomes, despite antiretroviral treatment(ART). We evaluated outcomes in CLWH and HIV-uninfected children treated for non-severe TB in the SHINE trial.

METHODS

SHINE was a randomized trial that enrolled children aged <16 years with smear-negative, non-severe TB who were randomized to receive 4 vs 6 months of TB treatment and followed for 72 weeks. We assessed TB relapse/recurrence, mortality, hospitalizations, grade ≥3 adverse events by HIV status, and HIV virological suppression in CLWH.

RESULTS

Of 1204 enrolled, 127(11%) were CLWH, of similar age (median(IQR) 3.6(1.2, 10.3) vs. 3.5(1.5, 6.9)years, p= 0.07), but more underweight (WAZ; -2.3(-3.3, -0.8) vs -1.0(-1.8, -0.2), p<0.01) and anemic (hemoglobin 9.5(8.7, 10.9) vs 11.5(10.4, 12.3)g/dl, p<0.01) compared to HIV-uninfected children. 68(54%) CLWH were ART-naïve; baseline median CD4 count 719(241-1134) cells/mm3, CD4% 16(10-26)%). CLWH were more likely to be hospitalized (aOR=2.4(1.3-4.6)) and die (aHR(95%CI) 2.6(1.2,5.8)). HIV status, age <3 years (aHR 6.3(1.5,27.3)), malnutrition (aHR 6.2(2.4,15.9)) and hemoglobin <7g/dl(aHR 3.8(1.3,11.5) independently predicted mortality. Among children with available VL, 45% and 61% CLWH had VL<1000copies/ml at weeks 24 and 48, respectively. There was no difference in the effect of randomized treatment duration (4 vs 6 months) on TB treatment outcomes by HIV status (p for interaction=0.42).

CONCLUSIONS

We found no evidence of a difference in TB outcomes between 4 and 6 months of treatment for CLWH treated for non-severe TB. Irrespective of TB treatment duration, CLWH had higher rates of mortality and hospitalization than HIV-uninfected counterparts.

Voluntariness of consent in paediatric HIV clinical trials: a mixed-methods, cross-sectional study of participants in the CHAPAS-4 and ODYSSEY trials in Uganda

OBJECTIVES

To examine the voluntariness of consent in paediatric HIV clinical trials and the associated factors.

DESIGN

Mixed-methods, cross-sectional study combining a quantitative survey conducted concurrently with indepth interviews.

SETTING AND PARTICIPANTS

From January 2021 to April 2021, we interviewed parents of children on first-line or second-line Anti-retroviral therapy (ART) in two ongoing paediatric HIV clinical trials [CHAPAS-4 (ISRCTN22964075) and ODYSSEY (ISRCTN91737921)] at the Joint Clinical Research Centre Mbarara, Uganda.

OUTCOME MEASURES

The outcome measures were the proportion of parents with voluntary consent, factors affecting voluntariness and the sources of external influence. Parents rated the voluntariness of their consent on a voluntariness ladder. Indepth interviews described participants' lived experiences and were aimed at adding context.

RESULTS

All 151 parents randomly sampled for the survey participated (84% female, median age 40 years). Most (67%) gave a fully voluntary decision, with a score of 10 on the voluntariness ladder, whereas 8% scored 9, 9% scored 8, 6% scored 7, 8% scored 6 and 2.7% scored 4. Trust in medical researchers (adjusted OR 9.90, 95% CI 1.01 to 97.20, p=0.049) and male sex of the parent (adjusted OR 3.66, 95% CI 1.00 to 13.38, p=0.05) were positively associated with voluntariness of consent. Prior research experience (adjusted OR 0.31, 95% CI 0.12 to 0.78, p=0.014) and consulting (adjusted OR 0.25. 95% CI 0.10 to 0.60, p=0.002) were negatively associated with voluntariness. Consultation and advice came from referring health workers (36%), spouses (29%), other family members (27%), friends (15%) and researchers (7%). The indepth interviews (n=14) identified the health condition of the child, advice from referring health workers and the opportunity to access better care as factors affecting the voluntariness of consent.

CONCLUSIONS

This study demonstrated a high voluntariness of consent, which was enhanced among male parents and by parents' trust in medical researchers. Prior research experience of the child and advice from health workers and spouses were negatively associated with the voluntariness of parents' consent. Female parents and parents of children with prior research experience may benefit from additional interventions to support voluntary participation.

"Getting pregnant during COVID-19 was a big risk because getting help from the clinic was not easy": COVID-19 experiences of women and healthcare providers in Harare, Zimbabwe

The COVID-19 pandemic and associated measures may have disrupted delivery of maternal and neonatal health services and reversed the progress made towards dual elimination of mother-to-child transmission of HIV and syphilis in Zimbabwe. This qualitative study explores the impact of the pandemic on the provision and uptake of prevention of mother-to-child transmission (PMTCT) services from the perspectives of women and maternal healthcare providers. Longitudinal in-depth interviews were conducted with 20 pregnant and breastfeeding women aged 20-39 years living with HIV and 20 healthcare workers in two maternity polyclinics in low-income suburbs of Harare, Zimbabwe. Semi-structured interviews were held after the second and third waves of COVID-19 in March and November 2021, respectively. Data were analysed using a modified grounded theory approach. While eight antenatal care contacts are recommended by Zimbabwe's Ministry of Health and Child Care, women reported only being able to access two contacts. Although HIV testing, antiretroviral therapy (ART) refills and syphilis screening services were accessible at first contact, other services such as HIV-viral load monitoring and enhanced adherence counselling were not available for those on ART. Closure of clinics and shortened operating hours during the second COVID-19 wave resulted in more antenatal bookings occurring later during pregnancy and more home deliveries. Six of the 20 (33%) interviewed women reported giving birth at home, assisted by untrained traditional midwives as clinics were closed. Babies delivered at home missed ART prophylaxis and HIV testing at birth despite being HIV-exposed. Although women faced multiple challenges, they continued to attempt to access services after delivery. These findings underline the importance of investing in robust health systems that can respond to emergency situations to ensure continuity of essential HIV prevention, treatment, and care services.

Acceptability of hepatitis C screening and treatment during pregnancy in pregnant women in Egypt, Pakistan, and Ukraine: A cross-sectional survey

Chronic hepatitis C (HCV) in women of childbearing age is a major public health concern with ∼15 million women aged 15-49 years living with HCV globally in 2019. Evidence suggests HCV in pregnancy is associated with adverse pregnancy and infant outcomes. This includes ∼6% risk of infants acquiring HCV vertically, and this is the leading cause of HCV in children globally. However, few countries offer routine universal antenatal HCV screening, and direct-acting antivirals (DAAs) are not approved for pregnant or breastfeeding women although small clinical trials are ongoing. We conducted a survey of pregnant and postpartum women in 3 high HCV burden lower-middle-income countries to assess the acceptability of universal antenatal HCV screening and DAA treatment in the scenario that DAAs are approved for use in pregnancy. Pregnant and postpartum women attending antenatal clinics in Egypt, Pakistan, and Ukraine were invited to complete a survey and provide demographic and clinical data on their HCV status. Among the 630 women included (n=210 per country), 73% were pregnant and 27% postpartum, 27% were ever HCV antibody or PCR positive. Overall, 586 (93%) reported acceptability of universal antenatal HCV screening and 544 (88%) would take DAAs in pregnancy (92%, 98%, and 73% in Egypt, Pakistan, and Ukraine, respectively). Most said they would take DAAs in pregnancy to prevent vertical acquisition and other risks for the baby, and a smaller proportion would take DAAs for maternal cure. Our findings suggest that should DAAs be approved for use in pregnancy, the uptake of both HCV screening and DAA treatment may be high in women living in lower-middle-income countries.

Evaluating pediatric tuberculosis dosing guidelines: A model-based individual data pooled analysis

BACKGROUND

The current World Health Organization (WHO) pediatric tuberculosis dosing guidelines lead to suboptimal drug exposures. Identifying factors altering the exposure of these drugs in children is essential for dose optimization. Pediatric pharmacokinetic studies are usually small, leading to high variability and uncertainty in pharmacokinetic results between studies. We pooled data from large pharmacokinetic studies to identify key covariates influencing drug exposure to optimize tuberculosis dosing in children.

METHODS AND FINDINGS

We used nonlinear mixed-effects modeling to characterize the pharmacokinetics of rifampicin, isoniazid, and pyrazinamide, and investigated the association of human immunodeficiency virus (HIV), antiretroviral therapy (ART), drug formulation, age, and body size with their pharmacokinetics. Data from 387 children from South Africa, Zambia, Malawi, and India were available for analysis; 47% were female and 39% living with HIV (95% on ART). Median (range) age was 2.2 (0.2 to 15.0) years and weight 10.9 (3.2 to 59.3) kg. Body size (allometry) was used to scale clearance and volume of distribution of all 3 drugs. Age affected the bioavailability of rifampicin and isoniazid; at birth, children had 48.9% (95% confidence interval (CI) [36.0%, 61.8%]; p < 0.001) and 64.5% (95% CI [52.1%, 78.9%]; p < 0.001) of adult rifampicin and isoniazid bioavailability, respectively, and reached full adult bioavailability after 2 years of age for both drugs. Age also affected the clearance of all drugs (maturation), children reached 50% adult drug clearing capacity at around 3 months after birth and neared full maturation around 3 years of age. While HIV per se did not affect the pharmacokinetics of first-line tuberculosis drugs, rifampicin clearance was 22% lower (95% CI [13%, 28%]; p < 0.001) and pyrazinamide clearance was 49% higher (95% CI [39%, 57%]; p < 0.001) in children on lopinavir/ritonavir; isoniazid bioavailability was reduced by 39% (95% CI [32%, 45%]; p < 0.001) when simultaneously coadministered with lopinavir/ritonavir and was 37% lower (95% CI [22%, 52%]; p < 0.001) in children on efavirenz. Simulations of 2010 WHO-recommended pediatric tuberculosis doses revealed that, compared to adult values, rifampicin exposures are lower in most children, except those younger than 3 months, who experience relatively higher exposure for all drugs, due to immature clearance. Increasing the rifampicin doses in children older than 3 months by 75 mg for children weighing <25 kg and 150 mg for children weighing >25 kg could improve rifampicin exposures. Our analysis was limited by the differences in availability of covariates among the pooled studies.

CONCLUSIONS

Children older than 3 months have lower rifampicin exposures than adults and increasing their dose by 75 or 150 mg could improve therapy. Altered exposures in children with HIV is most likely caused by concomitant ART and not HIV per se. The importance of the drug-drug interactions with lopinavir/ritonavir and efavirenz should be evaluated further and considered in future dosing guidance.

TRIAL REGISTRATION

ClinicalTrials.gov registration numbers; NCT02348177, NCT01637558, ISRCTN63579542.

Inadequate Lopinavir Concentrations With Modified 8-Hourly Lopinavir/Ritonavir 4:1 Dosing During Rifampicin-based Tuberculosis Treatment in Children Living With HIV

BACKGROUND

Lopinavir/ritonavir plasma concentrations are profoundly reduced when co-administered with rifampicin. Super-boosting of lopinavir/ritonavir is limited by nonavailability of single-entity ritonavir, while double-dosing of co-formulated lopinavir/ritonavir given twice-daily produces suboptimal lopinavir concentrations in young children. We evaluated whether increased daily dosing with modified 8-hourly lopinavir/ritonavir 4:1 would maintain therapeutic plasma concentrations of lopinavir in children living with HIV receiving rifampicin-based antituberculosis treatment.

METHODS

Children with HIV/tuberculosis coinfection weighing 3.0 to 19.9 kg, on rifampicin-based antituberculosis treatment were commenced or switched to 8-hourly liquid lopinavir/ritonavir 4:1 with increased daily dosing using weight-band dosing approach. A standard twice-daily dosing of lopinavir/ritonavir was resumed 2 weeks after completing antituberculosis treatment. Plasma sampling was conducted during and 4 weeks after completing antituberculosis treatment.

RESULTS

Of 20 children enrolled; 15, 1-7 years old, had pharmacokinetics sampling available for analysis. Lopinavir concentrations (median [range]) on 8-hourly lopinavir/ritonavir co-administered with rifampicin (n = 15; area under the curve 0-24 55.32 mg/h/L [0.30-398.7 mg/h/L]; C max 3.04 mg/L [0.03-18.6 mg/L]; C 8hr 0.90 mg/L [0.01-13.7 mg/L]) were lower than on standard dosing without rifampicin (n = 12; area under the curve 24 121.63 mg/h/L [2.56-487.3 mg/h/L]; C max 9.45 mg/L [0.39-26.4 mg/L]; C 12hr 3.03 mg/L [0.01-17.7 mg/L]). During and after rifampicin cotreatment, only 7 of 15 (44.7%) and 8 of 12 (66.7%) children, respectively, achieved targeted pre-dose lopinavir concentrations ≥1mg/L.

CONCLUSIONS

Modified 8-hourly dosing of lopinavir/ritonavir failed to achieve adequate lopinavir concentrations with concurrent antituberculosis treatment. The subtherapeutic lopinavir exposures on standard dosing after antituberculosis treatment are of concern and requires further evaluation.

Modelling the potential effectiveness of hepatitis C screening and treatment strategies during pregnancy in Egypt and Ukraine

BACKGROUND & AIMS

HCV test and treat campaigns currently exclude pregnant women. Pregnancy offers a unique opportunity for HCV screening and to potentially initiate direct-acting antiviral treatment. We explored HCV screening and treatment strategies in two lower middle-income countries with high HCV prevalence, Egypt and Ukraine.

METHODS

Country-specific probabilistic decision models were developed to simulate a cohort of pregnant women. We compared five strategies: S0, targeted risk-based screening and deferred treatment (DT) to after pregnancy/breastfeeding; S1, World Health Organization (WHO) risk-based screening and DT; S2, WHO risk-based screening and targeted treatment (treat women with risk factors for HCV vertical transmission [VT]); S3, universal screening and targeted treatment during pregnancy; S4, universal screening and treatment. Maternal and infant HCV outcomes were projected.

RESULTS

S0 resulted in the highest proportion of women undiagnosed: 59% and 20% in Egypt and Ukraine, respectively, with 0% maternal cure by delivery and VT estimated at 6.5% and 7.9%, respectively. WHO risk-based screening and DT (S1) increased the proportion of women diagnosed with no change in maternal cure or VT. Universal screening and treatment during pregnancy (S4) resulted in the highest proportion of women diagnosed and cured by delivery (65% and 70%, respectively), and lower levels of VT (3.4% and 3.6%, respectively).

CONCLUSIONS

This is one of the first models to explore HCV screening and treatment strategies in pregnancy, which will be critical in informing future care and policy as more safety/efficacy data emerge. Universal screening and treatment in pregnancy could potentially improve both maternal and infant outcomes.

IMPACT AND IMPLICATIONS

In the context of two lower middle-income countries with high HCV burdens (Egypt and Ukraine), we designed a decision analytic model to explore five different HCV testing and treatment strategies for pregnant women, with the assumption that treatment was safe and efficacious for use in pregnancy. Assuming direct-acting antiviral treatment during pregnancy would reduce vertical transmission, our findings indicate that the provision of universal (rather than risk-based targeted) screening and treatment would provide the greatest maternal and infant benefits. While future trials are needed to assess the safety and efficacy of direct-acting antivirals in pregnancy and their impact on vertical transmission, there is increasing recognition that the elimination of HCV cannot leave entire subpopulations of pregnant women and young children behind. Our findings will be critical for policymakers when developing improved screening and treatment recommendations for pregnant women.

The hard part we often forget: providing care to children and adolescents with advanced HIV disease

INTRODUCTION

Many children and adolescents living with HIV still present with severe immunosuppression with morbidity and mortality remaining high in those starting antiretroviral therapy (ART) when hospitalized.

DISCUSSION

The major causes of morbidity and mortality in children living with HIV are pneumonia, tuberculosis, bloodstream infections, diarrhoeal disease and severe acute malnutrition. In contrast to adults, cryptococcal meningitis is rare in children under 5 years of age but increases in adolescence. In 2021, the World Health Organizations (WHO) consolidated guidelines for managing HIV disease and rapid ART included recommendations for children and adolescents. In addition, a WHO technical brief released in 2020 highlighted the various interventions that are specifically related to children and adolescents with advanced HIV disease (AHD). We discuss the common clinical presentations of children and adolescents with AHD with a focus on diagnosis, prevention and treatment, highlight some of the challenges in the implementation of the existing package of care, and emphasize the importance of additional research to address the needs of children and adolescents with AHD.

CONCLUSIONS

There are limited data informing these recommendations and an urgent need for further research on how to implement optimal strategies to ensure tailored approaches to prevent and treat AHD in children and adolescents. Holistic care that goes beyond a simple choice of ART regimen should be provided to all children and adolescents with AHD.

Global estimates and determinants of antituberculosis drug pharmacokinetics in children and adolescents: a systematic review and individual patient data meta-analysis

BACKGROUND

Suboptimal exposure to antituberculosis (anti-TB) drugs has been associated with unfavourable treatment outcomes. We aimed to investigate estimates and determinants of first-line anti-TB drug pharmacokinetics in children and adolescents at a global level.

METHODS

We systematically searched MEDLINE, Embase and Web of Science (1990-2021) for pharmacokinetic studies of first-line anti-TB drugs in children and adolescents. Individual patient data were obtained from authors of eligible studies. Summary estimates of total/extrapolated area under the plasma concentration-time curve from 0 to 24 h post-dose (AUC0-24) and peak plasma concentration (C max) were assessed with random-effects models, normalised with current World Health Organization-recommended paediatric doses. Determinants of AUC0-24 and C max were assessed with linear mixed-effects models.

RESULTS

Of 55 eligible studies, individual patient data were available for 39 (71%), including 1628 participants from 12 countries. Geometric means of steady-state AUC0-24 were summarised for isoniazid (18.7 (95% CI 15.5-22.6) h·mg·L-1), rifampicin (34.4 (95% CI 29.4-40.3) h·mg·L-1), pyrazinamide (375.0 (95% CI 339.9-413.7) h·mg·L-1) and ethambutol (8.0 (95% CI 6.4-10.0) h·mg·L-1). Our multivariate models indicated that younger age (especially <2 years) and HIV-positive status were associated with lower AUC0-24 for all first-line anti-TB drugs, while severe malnutrition was associated with lower AUC0-24 for isoniazid and pyrazinamide. N-acetyltransferase 2 rapid acetylators had lower isoniazid AUC0-24 and slow acetylators had higher isoniazid AUC0-24 than intermediate acetylators. Determinants of C max were generally similar to those for AUC0-24.

CONCLUSIONS

This study provides the most comprehensive estimates of plasma exposures to first-line anti-TB drugs in children and adolescents. Key determinants of drug exposures were identified. These may be relevant for population-specific dose adjustment or individualised therapeutic drug monitoring.

Growth and CD4 patterns of adolescents living with perinatally acquired HIV worldwide, a CIPHER cohort collaboration analysis

INTRODUCTION

Adolescents living with HIV are subject to multiple co-morbidities, including growth retardation and immunodeficiency. We describe growth and CD4 evolution during adolescence using data from the Collaborative Initiative for Paediatric HIV Education and Research (CIPHER) global project.

METHODS

Data were collected between 1994 and 2015 from 11 CIPHER networks worldwide. Adolescents with perinatally acquired HIV infection (APH) who initiated antiretroviral therapy (ART) before age 10 years, with at least one height or CD4 count measurement while aged 10-17 years, were included. Growth was measured using height-for-age Z-scores (HAZ, stunting if <-2 SD, WHO growth charts). Linear mixed-effects models were used to study the evolution of each outcome between ages 10 and 17. For growth, sex-specific models with fractional polynomials were used to model non-linear relationships for age at ART initiation, HAZ at age 10 and time, defined as current age from 10 to 17 years of age.

RESULTS

A total of 20,939 and 19,557 APH were included for the growth and CD4 analyses, respectively. Half were females, two-thirds lived in East and Southern Africa, and median age at ART initiation ranged from <3 years in North America and Europe to >7 years in sub-Saharan African regions. At age 10, stunting ranged from 6% in North America and Europe to 39% in the Asia-Pacific; 19% overall had CD4 counts <500 cells/mm3 . Across adolescence, higher HAZ was observed in females and among those in high-income countries. APH with stunting at age 10 and those with late ART initiation (after age 5) had the largest HAZ gains during adolescence, but these gains were insufficient to catch-up with non-stunted, early ART-treated adolescents. From age 10 to 16 years, mean CD4 counts declined from 768 to 607 cells/mm3 . This decline was observed across all regions, in males and females.

CONCLUSIONS

Growth patterns during adolescence differed substantially by sex and region, while CD4 patterns were similar, with an observed CD4 decline that needs further investigation. Early diagnosis and timely initiation of treatment in early childhood to prevent growth retardation and immunodeficiency are critical to improving APH growth and CD4 outcomes by the time they reach adulthood.

Pharmacokinetics of first-line drugs in children with tuberculosis using WHO-recommended weight band doses and formulations

Background

Dispersible pediatric fixed-dose combination (FDC) tablets delivering higher doses of first-line antituberculosis drugs in World Health Organization–recommended weight bands were introduced in 2015. We report the first pharmacokinetic data for these FDC tablets in Zambian and South African children in the treatment-shortening SHINE trial.

Methods

Children weighing 4.0–7.9, 8.0–11.9, 12.0–15.9, or 16.0–24.9 kg received 1, 2, 3, or 4 tablets daily, respectively (rifampicin/isoniazid/pyrazinamide [75/50/150 mg], with or without 100 mg ethambutol, or rifampicin/isoniazid [75/50 mg]). Children 25.0–36.9 kg received doses recommended for adults <37 kg (300, 150, 800, and 550 mg/d, respectively, for rifampicin, isoniazid, pyrazinamide, and ethambutol). Pharmacokinetics were evaluated after at least 2 weeks of treatment.

Results

In the 77 children evaluated, the median age (interquartile range) was 3.7 (1.4–6.6) years; 40 (52%) were male and 20 (26%) were human immunodeficiency virus positive. The median area under the concentration-time curve from 0 to 24 hours for rifampicin, isoniazid, pyrazinamide, and ethambutol was 32.5 (interquartile range, 20.1–45.1), 16.7 (9.2–25.9), 317 (263–399), and 9.5 (7.5–11.5) mg⋅h/L, respectively, and lower in children than in adults for rifampicin in the 4.0–7.9-, 8–11.9-, and ≥25-kg weight bands, isoniazid in the 4.0–7.9-kg and ≥25-kg weight bands, and ethambutol in all 5 weight bands. Pyrazinamide exposures were similar to those in adults.

Conclusions

Recommended weight band–based FDC doses result in lower drug exposures in children in lower weight bands and in those ≥25 kg (receiving adult doses). Further adjustments to current doses are needed to match current target exposures in adults. The use of ethambutol at the current World Health Organization–recommended doses requires further evaluation.

Plasticity of the Immune System in Children Following Treatment Interruption in HIV-1 Infection

It is intriguing that, unlike adults with HIV-1, children with HIV-1 reach a greater CD4+ T cell recovery following planned treatment cessation. The reasons for the better outcomes in children remain unknown but may be related to increased thymic output and diversity of T cell receptor repertoires. HIV-1 infected children from the PENTA 11 trial tolerated planned treatment interruption without adverse long-term clinical, virological, or immunological consequences, once antiretroviral therapy was re-introduced. This contrasts to treatment interruption trials of HIV-1 infected adults, who had rapid changes in T cells and slow recovery when antiretroviral therapy was restarted. How children can develop such effective immune responses to planned treatment interruption may be critical for future studies. PENTA 11 was a randomized, phase II trial of planned treatment interruptions in HIV-1-infected children (ISRCTN 36694210). In this sub-study, eight patients in long-term follow-up were chosen with CD4+ count>500/ml, viral load <50c/ml at baseline: four patients on treatment interruption and four on continuous treatment. Together with measurements of thymic output, we used high-throughput next generation sequencing and bioinformatics to systematically organize memory CD8+ and naïve CD4+ T cell receptors according to diversity, clonal expansions, sequence sharing, antigen specificity, and T cell receptor similarities following treatment interruption compared to continuous treatment. We observed an increase in thymic output following treatment interruption compared to continuous treatment. This was accompanied by an increase in T cell receptor clonal expansions, increased T cell receptor sharing, and higher sequence similarities between patients, suggesting a more focused T cell receptor repertoire. The low numbers of patients included is a limitation and the data should be interpreted with caution. Nonetheless, the high levels of thymic output and the high diversity of the T cell receptor repertoire in children may be sufficient to reconstitute the T cell immune repertoire and reverse the impact of interruption of antiretroviral therapy. Importantly, the effective T cell receptor repertoires following treatment interruption may inform novel therapeutic strategies in children infected with HIV-1.

Abacavir pharmacokinetics in African children living with HIV: A pooled analysis describing the effects of age, malnutrition and common concomitant medications

Aims

Abacavir is part of WHO‐recommended regimens to treat HIV in children under 15 years of age. In a pooled analysis across four studies, we describe abacavir population pharmacokinetics to investigate the influence of age, concomitant medications, malnutrition and formulation.

Methods

A total of 230 HIV‐infected African children were included, with median (range) age of 2.1 (0.1–12.8) years and weight of 9.8 (2.5–30.0) kg. The population pharmacokinetics of abacavir was described using nonlinear mixed‐effects modelling.

Results

Abacavir pharmacokinetics was best described by a two‐compartment model with first‐order elimination, and absorption described by transit compartments. Clearance was predicted around 54% of its mature value at birth and 90% at 10 months. The estimated typical clearance at steady state was 10.7 L/h in a child weighing 9.8 kg co‐treated with lopinavir/ritonavir, and was 12% higher in children receiving efavirenz. During coadministration of rifampicin‐based antituberculosis treatment and super‐boosted lopinavir in a 1:1 ratio with ritonavir, abacavir exposure decreased by 29.4%. Malnourished children living with HIV had higher abacavir exposure initially, but this effect waned with nutritional rehabilitation. An additional 18.4% reduction in clearance after the first abacavir dose was described, suggesting induction of clearance with time on lopinavir/ritonavir‐based therapy. Finally, absorption of the fixed dose combination tablet was 24% slower than the abacavir liquid formulation.

Conclusion

In this pooled analysis we found that children on lopinavir/ritonavir or efavirenz had similar abacavir exposures, while concomitant TB treatment and super‐boosted lopinavir gave significantly reduced abacavir concentrations.

Long-term clinical, virological and immunological outcomes following planned treatment interruption in HIV-infected children

OBJECTIVES

Planned treatment interruption (PTI) of antiretroviral therapy (ART) in adults is associated with adverse outcomes. The PENTA 11 trial randomized HIV-infected children to continuous ART (CT) vs. CD4-driven PTIs. We report 5 years' follow-up after the end of main trial.

METHODS

Post-trial, all children resumed ART. Clinical, immunological, virological and treatment data were collected annually. A sub-study investigated more detailed immunophenotype. CT and PTI arms were compared using intention-to-treat. Laboratory parameters were compared using linear regression, adjusting for baseline values; mixed models were used to include all data over time.

RESULTS

In all, 101 children (51 CT, 50 PTI) contributed a median of 7.6 years, including 5.1 years of post-trial follow-up. Post-trial, there were no deaths, one pulmonary tuberculosis and no other CDC stage B/C events. At 5 years post-trial, 90% of children in the CT vs. 82% in the PTI arm had HIV RNA < 50 copies/mL (P = 0.26). A persistent increase in CD8 cells was observed in the PTI arm. The sub-study (54 children) suggested that both naïve and memory populations contributed to higher CD8 cells following PTI. Mean CD4/CD8 ratios at 5 years post-trial were 1.22 and 1.08 in CT and PTI arms, respectively [difference (CT - PTI) = -0.15; 95% CI: -0.34-0.05), P = 0.14]. The sub-study also suggested that during the trial and at early timepoints after the end of the trial, reduction in CD4 in the PTI arm was mainly from loss of CD4 memory cells.

CONCLUSIONS

Children tolerated PTI with few long-term clinical, virological or immunological consequences.

Naive B Cell Output in HIV-Infected and HIV-Uninfected Children

In this study, we aimed to quantify KREC (kappa-deleting recombination excision circle) levels and naive B cell output in healthy HIV-uninfected children, compared with HIV-infected South African children, before and after starting ART (antiretroviral therapy). Samples were acquired from a Child Wellness Clinic (n = 288 HIV-uninfected South African children, 2 weeks-12 years) and the Children with HIV Early Antiretroviral Therapy (CHER) trial (n = 153 HIV-infected South African children, 7 weeks-8 years). Naive B cell output was estimated using a mathematical model combining KREC levels to reflect B cell emigration into the circulation, flow cytometry measures of naive unswitched B cells to quantify total body naive B cells, and their rates of proliferation using the intracellular marker Ki67. Naive B cell output increases from birth to 1 year, followed by a decline and plateau into late childhood. HIV-infected children on or off ART had higher naive B cell outputs than their uninfected counterparts (p = .01 and p = .04). This is the first study to present reference ranges for measurements of KRECs and naive B cell output in healthy and HIV-infected children. Comparison between HIV-uninfected healthy children and HIV-infected children suggests that HIV may increase naive B cell output. Further work is required to fully understand the mechanisms involved and clinical value of measuring naive B cell output in children.

Early and Highly Suppressive Antiretroviral Therapy Are Main Factors Associated With Low Viral Reservoir in European Perinatally HIV-Infected Children

BACKGROUND

Future strategies aiming to achieve HIV-1 remission are likely to target individuals with small reservoir size.

SETTING

We retrospectively investigated factors associated with HIV-1 DNA levels in European, perinatally HIV-infected children starting antiretroviral therapy (ART) <6 months of age.

METHODS

Total HIV-1 DNA was measured from 51 long-term suppressed children aged 6.3 years (median) after initial viral suppression. Factors associated with log10 total HIV-1 DNA were analyzed using linear regression.

RESULTS

At ART initiation, children were aged median [IQR] 2.3 [1.2-4.1] months, CD4% 37 [24-45] %, CD8% 28 [18-36] %, log10 plasma viral load (VL) 5.4 [4.4-5.9] copies per milliliter. Time to viral suppression was 7.98 [4.6-19.3] months. After suppression, 13 (25%) children had suboptimal response [≥2 consecutive VL 50-400 followed by VL <50] and/or experienced periods of virological failure [≥2 consecutive VL ≥400 followed by VL <50]. Median total HIV-1 DNA was 43 [6195] copies/10 PBMC. Younger age at therapy initiation was associated with lower total HIV-1 DNA (adjusted coefficient [AC] 0.12 per month older, P = 0.0091), with a month increase in age at ART start being associated with a 13% increase in HIV DNA. Similarly, a higher proportion of time spent virally suppressed (AC 0.10 per 10% higher, P = 0.0022) and the absence of viral failure/suboptimal response (AC 0.34 for those with fail/suboptimal response, P = 0.0483) were associated with lower total HIV-1 DNA.

CONCLUSIONS

Early ART initiation and a higher proportion of time suppressed are linked with lower total HIV-1 DNA. Early ART start and improving adherence in perinatally HIV-1-infected children minimize the size of viral reservoir.

The epidemiology of adolescents living with perinatally acquired HIV: A cross-region global cohort analysis

BACKGROUND

Globally, the population of adolescents living with perinatally acquired HIV (APHs) continues to expand. In this study, we pooled data from observational pediatric HIV cohorts and cohort networks, allowing comparisons of adolescents with perinatally acquired HIV in "real-life" settings across multiple regions. We describe the geographic and temporal characteristics and mortality outcomes of APHs across multiple regions, including South America and the Caribbean, North America, Europe, sub-Saharan Africa, and South and Southeast Asia.

METHODS AND FINDINGS

Through the Collaborative Initiative for Paediatric HIV Education and Research (CIPHER), individual retrospective longitudinal data from 12 cohort networks were pooled. All children infected with HIV who entered care before age 10 years, were not known to have horizontally acquired HIV, and were followed up beyond age 10 years were included in this analysis conducted from May 2016 to January 2017. Our primary analysis describes patient and treatment characteristics of APHs at key time points, including first HIV-associated clinic visit, antiretroviral therapy (ART) start, age 10 years, and last visit, and compares these characteristics by geographic region, country income group (CIG), and birth period. Our secondary analysis describes mortality, transfer out, and lost to follow-up (LTFU) as outcomes at age 15 years, using competing risk analysis. Among the 38,187 APHs included, 51% were female, 79% were from sub-Saharan Africa and 65% lived in low-income countries. APHs from 51 countries were included (Europe: 14 countries and 3,054 APHs; North America: 1 country and 1,032 APHs; South America and the Caribbean: 4 countries and 903 APHs; South and Southeast Asia: 7 countries and 2,902 APHs; sub-Saharan Africa, 25 countries and 30,296 APHs). Observation started as early as 1982 in Europe and 1996 in sub-Saharan Africa, and continued until at least 2014 in all regions. The median (interquartile range [IQR]) duration of adolescent follow-up was 3.1 (1.5-5.2) years for the total cohort and 6.4 (3.6-8.0) years in Europe, 3.7 (2.0-5.4) years in North America, 2.5 (1.2-4.4) years in South and Southeast Asia, 5.0 (2.7-7.5) years in South America and the Caribbean, and 2.1 (0.9-3.8) years in sub-Saharan Africa. Median (IQR) age at first visit differed substantially by region, ranging from 0.7 (0.3-2.1) years in North America to 7.1 (5.3-8.6) years in sub-Saharan Africa. The median age at ART start varied from 0.9 (0.4-2.6) years in North America to 7.9 (6.0-9.3) years in sub-Saharan Africa. The cumulative incidence estimates (95% confidence interval [CI]) at age 15 years for mortality, transfers out, and LTFU for all APHs were 2.6% (2.4%-2.8%), 15.6% (15.1%-16.0%), and 11.3% (10.9%-11.8%), respectively. Mortality was lowest in Europe (0.8% [0.5%-1.1%]) and highest in South America and the Caribbean (4.4% [3.1%-6.1%]). However, LTFU was lowest in South America and the Caribbean (4.8% [3.4%-6.7%]) and highest in sub-Saharan Africa (13.2% [12.6%-13.7%]). Study limitations include the high LTFU rate in sub-Saharan Africa, which could have affected the comparison of mortality across regions; inclusion of data only for APHs receiving ART from some countries; and unavailability of data from high-burden countries such as Nigeria.

CONCLUSION

To our knowledge, our study represents the largest multiregional epidemiological analysis of APHs. Despite probable under-ascertained mortality, mortality in APHs remains substantially higher in sub-Saharan Africa, South and Southeast Asia, and South America and the Caribbean than in Europe. Collaborations such as CIPHER enable us to monitor current global temporal trends in outcomes over time to inform appropriate policy responses.

Economic evaluation of weekends-off antiretroviral therapy for young people in 11 countries

OBJECTIVES

To analyze the cost effectiveness of short-cycle therapy (SCT), where patients take antiretroviral (ARV) drugs 5 consecutive days a week and have 2 days off, as an alternative to continuous ARV therapy for young people infected with human immunodeficiency virus (HIV) and taking efavirenz-based first-line ARV drugs.

METHODS

We conduct a hierarchical cost-effectiveness analysis based on data on clinical outcomes and resource use from the BREATHER trial. BREATHER is a randomized trial investigating the effectiveness of SCT and continuous therapy in 199 participants aged 8 to 24 years and taking efavirenz-based first-line ARV drugs in 11 countries worldwide. Alongside nationally representative unit costs/prices, these data were used to estimate costs and quality adjusted life years (QALYs). An incremental cost-effectiveness comparison was performed using a multilevel bivariate regression approach for total costs and QALYs. Further analyses explored cost-effectiveness in low- and middle-income countries with access to low-cost generic ARV drugs and high-income countries purchasing branded ARV drugs, respectively.

RESULTS

At 48 weeks, SCT offered significant total cost savings over continuous therapy of US dollar (USD) 41 per patient in countries using generic drugs and USD 4346 per patient in countries using branded ARV drugs, while accruing nonsignificant total health benefits of 0.008 and 0.009 QALYs, respectively. Cost-effectiveness estimates were similar across settings with access to generic ARV drugs but showed significant variation among high-income countries where branded ARV drugs are purchased.

CONCLUSION

SCT is a cost-effective treatment alternative to continuous therapy for young people infected with HIV in countries where viral load monitoring is available.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Qualitative study of the BREATHER trial (Short Cycle antiretroviral therapy): is it acceptable to young people living with HIV?

OBJECTIVES

A qualitative study of the BREATHER (PENTA 16) randomised clinical trial, which compared virological control of Short Cycle Therapy (SCT) (5 days on: 2 days off) with continuous efavirenz (EFV)-based antiretroviral therapy (CT) in children and young people (aged 8-24) living with HIV with viral load <50 c/mL to examine adaptation, acceptability and experience of SCT to inform intervention development.

SETTING

Paediatric HIV clinics in the UK (2), Ireland (1), the USA (1) and Uganda (1).

PARTICIPANTS

All BREATHER trial participants who were over the age of 10 and aware of their HIV diagnosis were invited to participate. 49 young people from both arms of the BREATHER trial (31 females and 18 males; 40% of the total trial population in the respective sites; age range 11-24) gave additional consent to participate in the qualitative study.

RESULTS

Young people from both trial arms had initial concerns about the impact of SCT on their health and adherence, but these decreased over the early months in the trial. Young people randomised to SCT reported preference for SCT compared with CT pre-trial. Attitudes to SCT did not vary greatly by gender or country. Once short-term adaptation challenges were overcome, SCT was positively described as reducing impact of side effects, easing the pressure to carry and remember medication and enabling more weekend social activities. Young people on both arms reported frequent medication side effects and occasional missed doses that they had rarely voiced to clinical staff. Participants liked SCT by trial end but were concerned that peers who had most problems adhering could find SCT disruptive and difficult to manage.

CONCLUSIONS

To realise the potential of SCT (and mitigate possible risks of longer interruptions), careful dissemination and communication post-trial is needed. SCT should be provided alongside a package of monitoring, support and education over 3 months to allow adaptation.

TRIAL REGISTRATION NUMBER

NCT 01641016.

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.

Measuring and Valuing Informal Care for Economic Evaluation of HIV/AIDS Interventions: Methods and Application in Malawi

BACKGROUND

Economic evaluation studies often neglect the impact of disease and ill health on the social network of people living with HIV (PLHIV) and the wider community. An important concern relates to informal care requirements which, for some diseases such as HIV/AIDS, can be substantial.

OBJECTIVES

To measure and value informal care provided to PLHIV in Malawi.

METHODS

A modified diary that divided a day into natural calendar changes was used to measure informal care time. The monetary valuation was undertaken by using four approaches: opportunity cost (official minimum wage used to value caregiving time), modified opportunity cost (caregiver's reservation wage), willingness to pay (amount of money caregiver would pay for care), and willingness to accept (amount of money caregiver would accept for providing care to someone else) approaches. Data were collected from 130 caregivers of PLHIV who were accessing antiretroviral therapy from six facilities in Phalombe district in southeast Malawi.

RESULTS

Of the 130 caregivers, 62 (48%) provided informal care in the survey week. On average, caregivers provided care of 8 h/wk. The estimated monetary values of informal care provided per week were US $1.40 (opportunity cost), US $2.41 (modified opportunity cost), US $0.40 (willingness to pay), and US $2.07 (willingness to accept).

CONCLUSIONS

Exclusion of informal care commitments may be a notable limitation of many applied economic evaluations. This work demonstrates that inclusion of informal care in economic evaluations in a low-income context is feasible.

BREATHER (PENTA 16) short-cycle therapy (SCT) (5 days on/2 days off) in young people with chronic human immunodeficiency virus infection: an open, randomised, parallel-group Phase II/III trial

BACKGROUND

For human immunodeficiency virus (HIV)-infected adolescents facing lifelong antiretroviral therapy (ART), short-cycle therapy (SCT) with long-acting agents offers the potential for drug-free weekends, less toxicity, better adherence and cost savings.

OBJECTIVES

To determine whether or not efavirenz (EFV)-based ART in short cycles of 5 days on and 2 days off is as efficacious (in maintaining virological suppression) as continuous EFV-based ART (continuous therapy; CT). Secondary objectives included the occurrence of new clinical HIV events or death, changes in immunological status, emergence of HIV drug resistance, drug toxicity and changes in therapy.

DESIGN

Open, randomised, non-inferiority trial.

SETTING

Europe, Thailand, Uganda, Argentina and the USA.

PARTICIPANTS

Young people (aged 8-24 years) on EFV plus two nucleoside reverse transcriptase inhibitors and with a HIV-1 ribonucleic acid level [viral load (VL)] of < 50 copies/ml for > 12 months.

INTERVENTIONS

Young people were randomised to continue daily ART (CT) or change to SCT (5 days on, 2 days off ART).

MAIN OUTCOME MEASURES

Follow-up was for a minimum of 48 weeks (0, 4 and 12 weeks and then 12-weekly visits). The primary outcome was the difference between arms in the proportion with VL > 50 copies/ml (confirmed) by 48 weeks, estimated using the Kaplan-Meier method (12% non-inferiority margin) adjusted for region and age.

RESULTS

In total, 199 young people (11 countries) were randomised (n = 99 SCT group, n = 100 CT group) and followed for a median of 86 weeks. Overall, 53% were male; the median age was 14 years (21% ≥ 18 years); 13% were from the UK, 56% were black, 19% were Asian and 21% were Caucasian; and the median CD4% and CD4 count were 34% and 735 cells/mm(3), respectively. By week 48, only one participant (CT) was lost to follow-up. The SCT arm had a 27% decreased drug exposure as measured by the adherence questionnaire and a MEMSCap(™) Medication Event Monitoring System (MEMSCap Inc., Durham, NC, USA) substudy (median cap openings per week: SCT group, n = 5; CT group, n = 7). By 48 weeks, six participants in the SCT group and seven in the CT group had a confirmed VL > 50 copies/ml [difference -1.2%, 90% confidence interval (CI) -7.3% to 4.9%] and two in the SCT group and four in the CT group had a confirmed VL > 400 copies/ml (difference -2.1%, 90% CI -6.2% to 1.9%). All six participants in the SCT group with a VL > 50 copies/ml resumed daily ART, of whom five were resuppressed, three were on the same regimen and two with a switch; two others on SCT resumed daily ART for other reasons. Overall, three participants in the SCT group and nine in the CT group (p = 0.1) changed ART regimen, five because of toxicity, four for simplification reasons, two because of compliance issues and one because of VL failure. Seven young people (SCT group, n = 2; CT group, n = 5) had major non-nucleoside reverse transcriptase inhibitor mutations at VL failure, of whom two (n = 1 SCT group, n = 1 CT group) had the M184V mutation. Two young people had new Centers for Disease Control B events (SCT group, n = 1; CT group, n = 1). There were no significant differences between SCT and CT in grade 3/4 adverse events (13 vs. 14) or in serious adverse events (7 vs. 6); there were fewer ART-related adverse events in the SCT arm (2 vs. 14; p = 0.02). At week 48 there was no evidence that SCT led to increased inflammation using an extensive panel of markers. Young people expressed a strong preference for SCT in a qualitative substudy and in pre- and post-trial questionnaires. In total, 98% of the young people are taking part in a 2-year follow-up extension of the trial.

CONCLUSIONS

Non-inferiority of VL suppression in young people on EFV-based first-line ART with a VL of < 50 copies/ml was demonstrated for SCT compared with CT, with similar resistance, safety and inflammatory marker profiles. The SCT group had fewer ART-related adverse events. Further evaluation of the immunological and virological impact of SCT is ongoing. A limitation of the trial is that the results cannot be generalised to settings where VL monitoring is either not available or infrequent, nor to use of low-dose EFV. Two-year extended follow-up of the trial is ongoing to confirm the durability of the SCT strategy. Further trials of SCT in settings with infrequent VL monitoring and with other antiretroviral drugs such as tenofovir alafenamide, which has a long intracellular half-life, and/or dolutegravir, which has a higher barrier to resistance, are planned.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN97755073; EUDRACT 2009-012947-40; and CTA 27505/0005/001-0001.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme (projects 08/53/25 and 11/136/108), the European Commission through EuroCoord (FP7/2007/2015), the Economic and Social Research Council, the PENTA Foundation, the Medical Research Council and INSERM SC10-US19, France, and will be published in full in Health Technology Assessment; Vol. 20, No. 49. See the NIHR Journals Library website for further project information.

When information does not suffice: young people living with HIV and communication about ART adherence in the clinic

Despite mounting evidence recommending disclosure of human immunodeficiency virus (HIV) status to young people with perinatally acquired HIV as a central motivating factor for adherence to antiretroviral therapy, many young people continue to experience disclosure as a partial event, rather than a process. Drawing from two longitudinal, interview-based qualitative studies with young people living with HIV (aged 10-24) in five different countries in low and high income settings, we present data regarding disclosure and information about HIV in the clinic. The article highlights the limits of discussions framing disclosure and patient literacy, and young people's reluctance to voice their adherence difficulties in the context of their relationships with clinical care teams. We suggest that a clinician-initiated, explicit acknowledgment of the social and practical hurdles of daily adherence for young people would aid a more transparent conversation and encourage young people to disclose missed doses and other problems they may be facing with their treatment. This may help to reduce health harms and poor adherence in the longer-term.

HIV-1 Drug Resistance and Second-Line Treatment in Children Randomized to Switch at Low Versus Higher RNA Thresholds

BACKGROUND

The PENPACT-1 trial compared virologic thresholds to determine when to switch to second-line antiretroviral therapy (ART). Using PENPACT-1 data, we aimed to describe HIV-1 drug resistance accumulation on first-line ART by virologic threshold.

METHODS

PENPACT-1 had a 2 × 2 factorial design, randomizing HIV-infected children to start protease inhibitor (PI) versus nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART, and switch at a 1000 copies/mL versus 30,000 copies/mL threshold. Switch criteria were not achieving the threshold by week 24, confirmed rebound above the threshold thereafter, or Center for Disease Control and Prevention stage C event. Resistance tests were performed on samples ≥1000 copies/mL before switch, resuppression, and at 4-years/trial end.

RESULTS

Sixty-seven children started PI-based ART and were randomized to switch at 1000 copies/mL (PI-1000), 64 PIs and 30,000 copies/mL (PI-30,000), 67 NNRTIs and 1000 copies/mL (NNRTI-1000), and 65 NNRTI and 30,000 copies/mL (NNRTI-30,000). Ninety-four (36%) children reached the 1000 copies/mL switch criteria during 5-year follow-up. In 30,000 copies/mL threshold arms, median time from 1000 to 30,000 copies/mL switch criteria was 58 (PI) versus 80 (NNRTI) weeks (P = 0.81). In NNRTI-30,000, more nucleoside reverse transcriptase inhibitor (NRTI) resistance mutations accumulated than other groups. NNRTI mutations were selected before switching at 1000 copies/mL (23% NNRTI-1000, 27% NNRTI-30,000). Sixty-two children started abacavir + lamivudine, 166 lamivudine + zidovudine or stavudine, and 35 other NRTIs. The abacavir + lamivudine group acquired fewest NRTI mutations. Of 60 switched to second-line, 79% PI-1000, 63% PI-30,000, 64% NNRTI-1000, and 100% NNRTI-30,000 were <400 copies/mL 24 weeks later.

CONCLUSIONS

Children on first-line NNRTI-based ART who were randomized to switch at a higher virologic threshold developed the most resistance, yet resuppressed on second-line. An abacavir + lamivudine NRTI combination seemed protective against development of NRTI resistance.

Single Genome Analysis for the Detection of Linked Multiclass Drug Resistance Mutations in HIV-1-Infected Children After Failure of Protease Inhibitor-Based First-Line Therapy

The WHO recommends protease inhibitor (PI)-based antiretroviral therapy (ART) for vertically infected children after failed nevirapine (NVP) prophylaxis. Emergence of PI resistance on the backdrop of preexisting non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance could compromise long-term treatment options in such children. We characterized multiclass drug resistance using single genome sequencing (SGS) in children with viremia while receiving PI-based ART. We applied SGS of HIV-1 protease (PR) and reverse transcriptase to longitudinal samples from a cohort of the Children with HIV Early Antiretroviral Therapy trial with viral loads >1000 copies per milliliter after 40 weeks of early ART. Bulk sequencing revealed NVP-selected resistance in 50% of these children, whereas SGS revealed NVP-selected resistance in 70%. Two children had baseline NRTI and PI mutations, suggesting previous maternal ART. Linked multiclass drug resistance after PI-based ART was detected by SGS in 2 of 10 children. In one child, the majority species contained M184V in reverse transcriptase linked to L10F, M46I/L, I54V, and V82A in PR and a triple-class drug-resistant variant with these mutations linked to the NNRTI mutation V108I. In the second child, the majority species contained M184V and V82A linked within viral genomes. We conclude that when PI-based ART is initiated soon after birth after single dose-NVP prophylaxis, PI and NRTI resistance can occur in the majority species as expected and also be selected on the same genomes as preexisting NNRTI-resistant mutations. These observations highlight a future therapeutic challenge for vertically infected children where antiretroviral drug classes are limited.

Paediatric European Network for Treatment of AIDS (PENTA) guidelines for treatment of paediatric HIV-1 infection 2015: optimizing health in preparation for adult life

The 2015 Paediatric European Network for Treatment of AIDS (PENTA) guidelines provide practical recommendations on the management of HIV‐1 infection in children in Europe and are an update to those published in 2009. Aims of treatment have progressed significantly over the last decade, moving far beyond limitation of short‐term morbidity and mortality to optimizing health status for adult life and minimizing the impact of chronic HIV infection on immune system development and health in general. Additionally, there is a greater need for increased awareness and minimization of long‐term drug toxicity. The main updates to the previous guidelines include: an increase in the number of indications for antiretroviral therapy (ART) at all ages (higher CD4 thresholds for consideration of ART initiation and additional clinical indications), revised guidance on first‐ and second‐line ART recommendations, including more recently available drug classes, expanded guidance on management of coinfections (including tuberculosis, hepatitis B and hepatitis C) and additional emphasis on the needs of adolescents as they approach transition to adult services. There is a new section on the current ART ‘pipeline’ of drug development, a comprehensive summary table of currently recommended ART with dosing recommendations. Differences between PENTA and current US and World Health Organization guidelines are highlighted and explained.

Effect of low-oil corn dried distillers’ grains with solubles on growth performance, carcass traits and beef fatty acid profile of feedlot cattle

He, M. L., Xu, L., Yang, W. Z., Gibb, D. and McAllister, T. A. 2014. Effect of low-oil corn dried distillers’ grains with solubles on growth performance, carcass traits and beef fatty acid profile of feedlot cattle. Can. J. Anim. Sci. 94: 343–347. The objective of this study was to investigate the effects of dietary inclusion of low-oil corn dried distillers’ grains with solubles (LO-DDGS) on growth, carcass traits and beef fatty acids profiles of finishing feedlot cattle. One hundred and eighty British crossbred steers (450±28.5 kg; six pens/treatment) were offered barley grain-barley silage as the control diet with LO-DDGS replacing barley grain at 200 and 300 g kg−1 dry matter basis in treatment diets. Compared with control, LO-DDGS at 200 g kg−1 did not affect growth performance or carcass traits, whereas at 300 g kg−1 it decreased (P<0.05) gain:feed, but increased (P<0.05) levels of desirable fatty acids in beef. LO-DDGS can replace 200 g kg−1 barley grain in finishing feedlot diets without undesirable impacts on growth performance or carcass traits.

Evaluation of a shelf-stable direct-fed microbial for control of Escherichia coli O157 in commercial feedlot cattle

Stanford, K, Gibb, D. and McAllister, T. A. 2013. Evaluation of a shelf-stable direct-fed microbial for control of Escherichia coli O157 in commercial feedlot cattle. Can. J. Anim. Sci. 93: 535–542. A direct-fed microbial (DFM) registered for use in cattle in Canada containing Lactobacillus acidophilus strain BT-1386 and a Saccharomyces cerevisiae yeast autolysate was evaluated for control of E. coli O157. Weaned calves entered the feedlot in October and November and in January were sorted into Control (12 pens with a total of 2170 calves) and DFM treatment groups (10 pens with a total of 2040 calves). Although targeted dosage of L. acidophilus was 9 log10 colony forming units (CFU) head−1 d−1, analyses after storage at ambient temperature showed an average dose of 8.6 Log10 CFU head−1 d−1 and demonstrated stability of DFM over the range of temperatures encountered (−32.6 to 32.9°C) during storage. Calves entering the feedlot had low prevalence (0.8%) of E. coli O157 in feces, which increased to 11.2% in January. A 47°C range in ambient temperature for that month may have stressed cattle and led to increased shedding of E. coli O157 compared with seasonal norms. Comparing hide swabs collected at initiation of DFM feeding with those at shipping for slaughter, prevalence of E. coli O157 declined (P<0.05) in cattle fed DFM, although prevalence of E. coli O157 in hide swabs from Control and DFM-treated cattle did not differ at any time. As well, numbers of E. coli O157 and prevalence of the organism in fecal pats did not differ among treatments. Colonization of calves with E. coli O157 prior to DFM feeding likely reduced efficacy of DFM in the present study. Additional information regarding timing of feeding DFM relative to interactions among organisms within the gastrointestinal tract of cattle are required to ensure consistent efficacy of DFM for pre-harvest control of E. coli O157.

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

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

Effect of high dietary levels of canola meal on growth performance, carcass quality and meat fatty acid profiles of feedlot cattle

He, M. L., Gibb, D., McKinnon, J. J. and McAllister, T. A. 2013. Effect of high dietary levels of canola meal on growth performance, carcass quality and meat fatty acid profiles of feedlot cattle. Can. J. Anim. Sci. 93: 269–280. This study investigated the effect of substituting canola meal (CM) for barley grain on growth performance, carcass quality and meat fatty acid (FA) profiles of feedlot cattle. Cross bred calves (n=140; 285±27 kg) were individually fed diets comprised of a barley grain based concentrate (including 5% supplement) and barley silage at ratios of 45:55 and 92:8 (DM basis) during growing and finishing periods, respectively. Pressed CM from Brassica napus, containing 11.4% residual oil and solvent-extracted CM derived from B. napus or Brassica juncea canola seed were compared. Canola meal was substituted for 0 (control), 15, or 30% barley grain (DM basis) in both growing and finishing diets. Regardless of diet, cattle did not differ (P>0.05) in average daily gain in either the growing or finishing period. For the overall feeding period, inclusion of 30% CM increased (P<0.01) DMI of cattle compared with 15% CM groups, but reduced (P<0.05) gain: feed (G:F) as compared with control and 15% B. juncea and 15% pressed CM. Gain: feed of cattle fed CM was also reduced (P<0.05) during the finishing period as compared with the control diet with this reduction being more notable at the 30% level. Carcass quality and incidence of liver abscesses were not affected (P>0.05) by inclusion of CM. Inclusion of 30% pressed CM resulted in higher (P<0.05)%FAME of total polyunsaturated fatty acid, n-3, alpha-linolenic acid and conjugated linoleic acid (CLA), and a decrease (P<0.05) in n-6/n-3 ratio in the pars costalis diaphragmatis muscle as compared with the control diet. In conclusion, inclusion of CM did not alter the growth performance or G:F of beef cattle during the growing period, but did lower G:F during the finishing period. The inclusion of 15 or 30% solvent-extracted CM did not alter carcass quality, whereas 30% pressed CM increased the levels of desirable fatty acids (i.e., n-3 and CLA) in beef.

Effectiveness of antiretroviral therapy in HIV-infected children under 2 years of age

BACKGROUND

In the absence of antiretroviral therapy (ART), over 50% of HIV-infected infants progress to AIDS and death by 2 years of age. However, there are challenges to initiate ART in early life, including the possibility of drug resistance in the context of prevention of mother-to-child transmission (PMTCT) programs, a paucity of drug choices , uncertain dosing for some medications and long-term toxicities. Key management decisions include when to start ART, what regimen to start, and whether and when to switch or interrupt therapy. This review aims to summarize the currently available evidence on this topic and inform the ART management in HIV-infected children less than 2 years of age.

OBJECTIVES

To evaluate 1) when to start ART in young children; 2) what ART to start with, comparing first-line non-nucleoside reverse transcriptase inhibitor (NNRTI) and PI-based regimens; and 3) whether and when ART should be stopped or switched from a PI-based regimen to an NNRTI-based regimen.

SEARCH METHODS

We searched for published studies in the Cochrane HIV/AIDS Review Group Trials Register, The Cochrane Library, Pubmed, EMBASE and CENTRAL. We screened abstracts from relevant conference proceedings and searched for unpublished and ongoing trials in clinical trial registries (ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform).

SELECTION CRITERIA

We identified RCTs that recruited perinatally HIV-infected children under 2 years of age without restriction of setting. We rejected trials that did not include children less than 2 years of age, or did not evaluate either timing of ART initiation, choice of drug regimen or treatment switch/interruption strategy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied study selection criteria, assessed study quality and extracted data. Effects were assessed using the hazard ratio (HR) for time-to-event outcomes, relative risk for dichotomous outcomes and weighted mean difference for continuous outcomes.

MAIN RESULTS

Of 1921 records retrieved, 5 studies were eligible for inclusion in the review, addressing when to start treatment (n=2), what to start (n=2) and whether to switch regimen (n=1). Three ongoing studies that address the question of treatment interruption were also identified.Early infant treatment was associated with a 75% reduction (HR=0.25; 95%CI 0.12-0.51; p=0.0002) in mortality or disease progression in the one trial with sufficient power to address this question. In a smaller trial,median CD4 cell count was not significantly different between early and deferred treatment groups 12 months after ART.Regardless of previous exposure to nevirapine for PMTCT, the hazard for treatment failure was 2.01 (95%CI 1.47, 2.77) times higher in children starting ART with a NVP-based regimen compared to those starting with a LPV/r-based regimen (p<0.0001) with no clear difference in effect by age group. The hazard for virological failure was overall 2.28 (95%CI 1.55, 3.34) times higher for children starting ART with a NVP-based regimen compared to those starting with a LPV/r-based regimen (p=0.0005) with a larger difference in time to virological failure (or death) between the NVP and LPV/r-based regimens when ART was initiated in the first year of life. By contrast, increases in weight z-score (MD=0.37, 95%CI 0.08, 0.65, p=0.01) and height z-score (MD=0.23, 95%CI 0.04, 0.42, p=0.02) were larger in the NVP arm compared to the LPV/r arm .Infants starting on a LPV/r regimen but who then switched to a NVP-based regimen after a median time of 9 months on LPV/r were less likely to develop virological failure (defined as at least one VL greater than 50 copies/mL) compared with infants who started and stayed on LPV/r (HR=0.62, 95%CI 0.41, 0.92, p=0.02). However the hazard for confirmed failure at a higher viral load (>1000 copies/mL) was higher among children who switched to NVP compared to those who remained on LPV/r (HR=10.19, 95% CI 2.36, 43.94, p=0.002).

AUTHORS' CONCLUSIONS

Immediate ART reduces morbidity and mortality among infants and may improve neurodevelopmental outcome. However It remains unclear whether all children diagnosed with HIV infection between 1-2 years of age should start ART, as has been recommended by the World Health Organization on practical grounds.The available evidence suggests that a LPV/r-based first-line regimen is more potent than NVP, regardless of PMTCT exposure status. However, this finding provides a dilemma to policy-makers because higher cost, poor palatability, inconvenient formulation and cold chain requirements make LPV/r a more costly and challenging first-line regimen. An alternative approach to long-term LPV/r is switching to NVP (maintaining the NRTI backbone) once virological suppression is achieved. This strategy looked promising in the one trial undertaken, but may be difficult to implement in the absence of VL testing. Ongoing trials are exploring the possibility of starting early ART and interrupting treatment beyond the critical period of rapid disease progression and neurological development. Further evidence is urgently required to better inform policy on first-line treatment recommendations in young children and more robust data addressing non-virological outcomes are also needed.

Young HIV-infected children and their adult caregivers prefer tablets to syrup antiretroviral medications in Africa

Background

Provision of anti-retroviral therapy (ART) for HIV-infected children is complicated using syrup formulations, which are costlier than tablets, harder to transport and store and difficult for health-workers to prescribe and caregivers to administer. Dispersible/crushable tablets may be more appropriate. We studied the acceptability of syrups and scored tablets among young children who used both in the AntiRetroviral Research fOr Watoto (ARROW) trial.

Methods

ARROW is an ongoing randomized trial of paediatric ART monitoring and treatment strategies in 1206 children in Uganda and Zimbabwe. 405 children initially received syrups of combination ART including Nevirapine, Zidovudine, Abacavir and Lamivudine before changing, when reaching the 12-<15 kg weightband, to scored adult-dose tablets prescribed according to WHO weightband tables. Caregiver expectations and experiences were collected in questionnaires at their last visit on syrups and after 8 and 24 weeks on tablets.

Results

Questionnaires were completed by caregivers of 267 children (median age 2.9 years (IQR 2.5, 3.4)). At last visit on syrups, 79% caregivers reported problems with syrups, mostly related to number, weight, transportation and conspicuousness of bottles. Difficulties taking tablets were expected by 127(48%) caregivers; however, after 8 and 24 weeks, only 26% and 18% reported their children had problems with tablets and no problems were reported with transportation/conspicuousness. Taste, swallowing or vomiting were reported as problems ‘sometimes/often’ for 14%, 9%, 22% children on syrups and 16%, 9%, 8% on tablets. At last visit on syrups, 74% caregivers expected to prefer tablets but only 27% thought their child would. After 8/24 weeks, 94%/97% caregivers preferred tablets and 57%/59% reported their child did.

Conclusions

Most children at about 3 years can take tablets; caregivers and children themselves generally prefer tablets to liquid formulations of HIV medications above this age. Preferences of caregivers and children should be considered when designing and licensing paediatric drug formulations.

Removal of supplemental vitamin A from barley-based diets improves marbling in feedlot heifers

Gibb, D. J., Van Herk, F. H., Mir, P. S., Loerch, S. and McAllister, T. A. 2011. Removal of supplemental vitamin A from barley-based diets improves marbling in feedlot heifers. Can. J. Anim. Sci. 91: 669–674. The objective of this research was to determine if removing supplemental vitamin A from barley-based feedlot diets affects animal performance, health, or carcass quality. Six pens per treatment (10 heifers per pen) were randomly assigned to receive zero (–VA) or 3640 (+VA) IU kg−1 dry matter of supplemental vitamin A in barley-based feedlot diets. Initial serum retinol was similar between treatments (28 µg dL−1; P=0.34), but –VA reduced levels by 40% (30 vs. 50 µg dL−1; P<0.001) by day 217. Removal of supplemental vitamin A reduced dry matter intake during the 58 d backgrounding period (6.93 vs. 7.07 kg d−1; P=0.007) and over the 218-d trial (9.18 vs. 9.35 kg d−1; P<0.001), but had no effect on average daily gain during backgrounding (1.22 kg d−1; P=0.46) or over all (1.46 kg d−1; P=0.15). Based on camera grading, –VA increased degree of marbling (480.6 vs. 439.3; P=0.02) without affecting backfat thickness (0.74 cm; P=0.62). Ultrasound measurements were highly correlated with camera grading, but did not detect treatment difference in marbling score (P=0.99). Results from this study show that the removal of supplemental vitamin A increased marbling without affecting backfat, gains, or animal health.

Translating evidence into policy in low-income countries: lessons from co-trimoxazole preventive therapy

In the April 2010 issue of this journal, Date et al. expressed concern over the slow scale-up in low-income settings of two therapies for the prevention of opportunistic infections in people living with the human immunodeficiency virus: co-trimoxazole prophylaxis and isoniazid preventive therapy. This short paper discusses the important ways in which policy analysis can be of use in understanding and explaining how and why certain evidence makes its way into policy and practice and what local factors influence this process. Key lessons about policy development are drawn from the research evidence on co-trimoxazole prophylaxis, as such lessons may prove helpful to those who seek to influence the development of national policy on isoniazid preventive therapy and other treatments. Researchers are encouraged to disseminate their findings in a manner that is clear, but they must also pay attention to how structural, institutional and political factors shape policy development and implementation. Doing so will help them to understand and address the concerns raised by Date et al. and other experts. Mainstreaming policy analysis approaches that explain how local factors shape the uptake of research evidence can provide an additional tool for researchers who feel frustrated because their research findings have not made their way into policy and practice.

Survey of children accessing HIV services in a high prevalence setting: time for adolescents to count?

OBJECTIVE

To establish the proportion of adolescents among children infected with human immunodeficiency virus (HIV) in Zimbabwe who receive HIV care and support, and what clinic staff perceives to be the main problems faced by HIV-infected children and adolescents.

METHODS

In July 2008, we sent a questionnaire to all 131 facilities providing HIV care in Zimbabwe. In it we requested an age breakdown of the children (aged 0-19 years) registered for care and asked what were the two major problems faced by younger children (0-5 years) and adolescents (10-19 years).

FINDINGS

Nationally, 115 (88%) facilities responded. In 98 (75%) that provided complete data, 196 032 patients were registered and 24 958 (13%) of them were children. Of children under HIV care, 33% were aged 0-4 years; 25%, 5-9 years; 25%, 10-14 years; and 17%, 15-19 years. Staff highlighted differences in the problems most commonly faced by younger children and adolescents. For younger children, such problems were malnutrition and lack of appropriate drugs (cited by 46% and 40% of clinics, respectively); for adolescents they concerned psychosocial issues and poor drug adherence (cited by 56% and 36%, respectively).

CONCLUSION

Interventions for the large cohort of adolescents who are receiving HIV care in Zimbabwe need to target the psychosocial concerns and poor drug adherence reported by staff as being the main concerns in this age group.

Effect of concurrent zidovudine use on the resistance pathway selected by abacavir-containing regimens

OBJECTIVES

Abacavir (ABC) selects for four mutations (K65R, L74V, Y115F and M184V) in HIV-1 reverse transcriptase (RT), both in vitro and during monotherapy in vivo. The aim of this analysis was to compare the selection of these and other nucleoside reverse transcriptase inhibitor (NRTI)-associated mutations by ABC-containing therapies in the presence and absence of concurrent lamivudine (3TC) and/or zidovudine (ZDV) and to assess the effect of these mutations on phenotypic susceptibility to the NRTIs.

DESIGN

This study was a retrospective analysis of the patterns of NRTI-associated mutations selected following virological failure in six multicentre trials conducted during the development of ABC.

METHODS

Virological failure was defined as confirmed vRNA above 400 HIV-1 RNA copies/mL. RT genotype and phenotype were determined using standard methods.

RESULTS

K65R was selected infrequently by ABC-containing regimens in the absence of ZDV (13 of 127 patients), while L74V/I was selected more frequently (51 of 127 patients). Selection of both K65R and L74V/I was significantly reduced by co-administration of ZDV with ABC (one of 86 and two of 86 patients, respectively). Y115F was uncommon in the absence (seven of 127 patients) or presence (four of 86 patients) of ZDV. M184V was the most frequently selected mutation by ABC alone (24 of 70 patients) and by ABC plus 3TC (48 of 70 patients). Thymidine analogue mutations were associated with ZDV use. The K65R mutation conferred the broadest phenotypic cross-resistance of the mutations studied.

CONCLUSIONS

The resistance pathway selected upon virological failure of ABC-containing regimens is significantly altered by concurrent ZDV use, but not by concurrent 3TC use. These data may have important implications for the efficacy of subsequent lines of NRTI therapies.

Maintaining the nelfinavir trough concentration above 0.8 mg/L improves virologic response in HIV-1-infected children

Differences in virologic response were compared in 32 HIV-infected children with a nelfinavir trough concentration either below (n=7) or above (n=25) 0.8 mg/L. Virologic response at week 48 was observed in 29% of children with subtherapeutic nelfinavir troughs versus 80% in children with therapeutic nelfinavir troughs (P=.02).

Elective cerclage vs. ultrasound-indicated cerclage in high-risk pregnancies

OBJECTIVE

To compare pregnancy outcome after elective vs. ultrasound-indicated cervical cerclage in women at high risk of spontaneous mid-trimester loss or early preterm birth.

METHODS

This was a retrospective study comparing two management strategies in women with singleton pregnancies who had at least one previous spontaneous delivery at 16-33 weeks of gestation. One group was managed by the placement of an elective cerclage at 12-16 weeks and the other group had transvaginal ultrasound examinations of the cervix at 12-15+6, 16-19+6, and 20-23+6 weeks and cervical cerclage was carried out if the cervical length was 25 mm or less.

RESULTS

A total of 90 patients were examined, including 47 that were managed expectantly and 43 treated by elective cerclage. In the expectantly managed group, 59.6% (28/47) required a cervical cerclage. We excluded from further analysis three patients who were lost to follow-up and three because of fetal death or iatrogenic preterm delivery. Miscarriage or spontaneous delivery before 34 weeks' gestation occurred in 14.6% (6/41) of the elective cerclage group, compared with 20.9% (9/43) in the expectantly managed group (chi2 = 0.219, P = 0.640).

CONCLUSION

In women at increased risk of spontaneous mid-trimester or early preterm delivery, a policy of sonographic surveillance followed by cervical cerclage in those with a short cervix reduces the need for surgical intervention without significantly increasing adverse pregnancy outcome.