733. Letermovir treatment for refractory or resistant cytomegalovirus infection or disease with concurrent organ dysfunction: an interim analysis of a Phase 2 open label study

Background

Cytomegalovirus (CMV) disease is associated with increased morbidity and mortality following solid organ and hematopoietic cell transplantation. Currently, standard of care CMV treatments often have significant myelosuppressive or renal toxicities. Given letermovir’s favorable safety profile when used prophylactically, it may be a safe and efficacious alternative agent for CMV treatment.

Methods

A proof-of-concept, open-label trial was conducted in patients who lacked effective therapeutic options or presented with baseline organ dysfunction. Participants were eligible for enrollment if they were ≥12 years old and had documented CMV infection refractory to treatment defined as failure to achieve >1 log reduction in CMV viral load (VL) (when VL > 500 IU/mL) or lack of clinical improvement for CMV end-organ disease after ≥14 days of standard CMV treatment. Alternatively, patients with severe myelosuppression and renal dysfunction at baseline or genotypic antiviral resistance were also eligible. Participants were excluded if their current CMV infection developed while receiving letermovir for CMV prophylaxis. Letermovir was administered daily (480 mg PO/IV) for up to 12 weeks, with optional additional 12 weeks of treatment for secondary prophylaxis if clinically indicated.

Results

Ten patients met eligibility criteria and were enrolled. Reasons for enrollment included ganciclovir resistance (1/10), refractory CMV infection (6/10), renal dysfunction (7/10), and myelosuppression (7/10). The median baseline CMV VL was 1272 IU/ml [interquartile range (IQR); 925, 2546]. Six patients completed the study, three died due to complications of primary disease, and one discontinued due to diarrhea. Five patients (50%) had documented CMV viremia clearance, with a median time to first unquantifiable/undetectable CMV VL of 13 days [IQR; 9,18] and a median treatment duration of 53 days [IQR; 15,84]. Infections and GI disorders were the most common adverse events (AE), none considered related to study drug. No unexpected AE were observed during letermovir treatment.

Conclusion

Letermovir may be a safe and tolerable alternative for patients with treatment refractory CMV infection or for patients with severe baseline myelosuppression and renal dysfunction.

Disclosures

Matthew Cheng, MD, AstraZeneca: Honoraria|Cidara Therapeutics: Grant/Research Support|Scynexis Inc.: Grant/Research Support Sandra Burchett, MD, MSc, merck: Grant/Research Support Sarah P. Hammond, MD, F2G: Advisor/Consultant|F2G: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|pfizer: Advisor/Consultant|Scynexis: Grant/Research Support Nicolas C. Issa, MD, AiCuris: Grant/Research Support|Merck: Grant/Research Support Francisco M. Marty, MD, SM, AlloVir: Advisor/Consultant|Amplyx: Advisor/Consultant|Amplyx: Grant/Research Support|Ansun: Grant/Research Support|Avir: Advisor/Consultant|Chimerix: Grant/Research Support|Cidara: Grant/Research Support|F2G: Advisor/Consultant|F2G: Grant/Research Support|Gilead: Grant/Research Support|Janssen: Advisor/Consultant|Kyorin: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Regeneron: Advisor/Consultant|Regeneron: Grant/Research Support|ReViral: Advisor/Consultant|Scynexis: Grant/Research Support|Symbio: Advisor/Consultant|Takeda: Grant/Research Support|United Medical: Advisor/Consultant|WHISCO: Grant/Research Support.

Pharmacokinetics of darunavir and cobicistat in pregnant and postpartum women with HIV

OBJECTIVE

To evaluate darunavir and cobicistat pharmacokinetics during pregnancy compared with postpartum and in infant washout samples after delivery.

DESIGN

Nonrandomized, open-label, parallel-group, multicenter phase-IV prospective study of darunavir and cobicistat pharmacokinetics in pregnant women with HIV and their children in the United States.

METHODS

Intensive steady-state 24-h pharmacokinetic profiles were performed after administration of 800 mg of darunavir and 150 mg of cobicistat orally in fixed dose combination once-daily during the second trimester, third trimester, and postpartum. Infant washout samples were collected after birth. Darunavir and cobicistat were measured in plasma by validated HPLC-UV and liquid chromatography with tandem mass spectrometry detection (LC-MS)/MS assays, respectively. A two-tailed Wilcoxon signed-rank test (α = 0.10) was employed for paired within-participant comparisons.

RESULTS

A total of 29 pregnant women receiving darunavir and cobicistat once-daily enrolled in the study. Compared with paired postpartum data, darunavir AUC0--24 was 53% lower in the second trimester [n = 12, P = 0.0024, geometric mean of ratio (GMR)=0.47, 90% confidence interval (CI) 0.33 - 0.68] and 56% lower in the third trimester (n = 18, P < 0.0001, GMR = 0.44, 90% CI 0.36 - 0.54), whereas cobicistat AUC0--24 was 50% lower in the second trimester (n = 12, P = 0.0024, GMR = 0.50, 90% CI 0.36-0.69) and 56% lower in the third trimester (n = 18, P < 0.0001, GMR = 0.44, 90% CI 0.35-0.55). Placental transfer of darunavir and cobicistat was limited.

CONCLUSION

Standard darunavir/cobicistat dosing during pregnancy results in significantly lower exposure during pregnancy, which may increase the risk of virologic failure and perinatal transmission.

Immunologic and Virologic Factors Associated with Hospitalization in HIV-Exposed, Uninfected Infants in the United States

BACKGROUND

HIV-exposed, uninfected (HEU) infants experience higher rates of morbidity and mortality than HIV-unexposed uninfected (HUU) infants. Few studies have examined whether particular infections and/or immune responses are associated with hospitalization among HEU infants born in the United States.

METHODS

We evaluated a subset of HEU infants enrolled in the International Maternal Pediatric Adolescent AIDS Clinical Trials Group P1025 and/or Pediatric HIV/AIDS Cohort Study Surveillance Monitoring for ART Toxicities studies. We determined seroconversion to 6 respiratory viruses and measured antibody concentrations to 9 vaccine antigens using quantitative ELISA or electrochemiluminesence. Multivariable modified Poisson regression models were fit to evaluate the associations of seroconversion to each respiratory virus/family and antibody concentrations to vaccine antigens with the risk of hospitalization in the first year of life. Antibody concentrations to vaccine antigens were compared between HEU infants and HUU infants from a single site using multivariable linear regression models.

RESULTS

Among 556 HEU infants, seroconversion to respiratory syncytial virus (RSV) and parainfluenza were associated with hospitalization [adjusted risk ratio: 1.95 (95% CI 1.21-3.15); 2.30 (1.42-3.73), respectively]. Antibody concentrations to tetanus toxoid, pertussis, and pneumococcal vaccine antigens were higher among 525 HEU compared with 100 HUU infants. No associations were observed between antibody concentrations to any vaccine and hospitalization among HEU infants.

CONCLUSIONS

RSV and parainfluenza contribute to hospitalization among HEU infants in the first year of life. HEU infants demonstrate robust antibody responses to vaccine antigens; therefore, humoral immune defects likely do not explain the increased susceptibility to infection observed in this population.

POS1493-HPR IMPACT OF THE EULAR HCP CORE COMPETENCIES ON RHEUMATOLOGY PHYSIOTHERAPISTS IN THE UK: SURVEY RESULTS

Background:

A European Alliance of Associations for Rheumatology (EULAR) initiative in 2019 saw the first-ever publication of Core Competencies for Health Care Professionals (HCPs) working in Rheumatology (Edelaar et al 2019). This document sets the tone for how HCPs in Rheumatology should be working. One of the listed research agenda items created as a part of this project was to define discipline-specific competencies related to each of the HCPs unique roles in the multidisciplinary team.

Objectives:

In response to this call for discipline-specific application, a recent national survey of physiotherapists working in rheumatology in the UK included a section looking at the comfort these clinicians feel in the day-to-day application of these Core Competencies.

Methods:

In late 2019, an internet-based survey was emailed, and shared via other digital platforms, aiming to target all UK-based rheumatology physiotherapists. Other areas were covered and have been published (Gregory, Burchett and McCrum 2021), but there are unpublished data from Question 8 on this survey which involved listing the EULAR HCP Core Competencies and asking responders to rate on a 5-point Likert scale their comfort with these statements in relation to their day-to-day practice.

Results:

Ninety-seven UK-based physiotherapists working at least some of their job in rheumatology completed the survey. Overall the EULAR HACP core competency statements with the highest scores were statements 2 and 5; those statements with the lowest comfort response were statements 4 and 6.

Statement 2 relates to assessment and statement 5 to non-pharmacological management; it is in line with the traditional physiotherapy job role that these are the two areas identified by survey responders as their strongest areas.

Statement 4 relates to pharmacological management, and as this is not a formal part of expected specialist rheumatology physiotherapist job role at banding levels below band 8, this result was lower level of comfort probably to be expected. Statement 6 relates to patient education and whilst this is clearly a big part of the physiotherapist role, we expect the lower score here represents respondents awareness that broader disease education may sit better with other members of the rheumatology multi-disciplinary team.

Conclusion:

Written for all HCPs, the competency statements do show less comfort on this survey of physiotherapists with regards to less profession-specific statements, namely medication management and disease education. Team working means these areas will be picked up by other rheumatology HCPs.

Generally there is a good amount of familiarity with and comfort in application of these new core competencies. An alternative conclusion is that the EULAR working group creating the competencies achieved a strong understanding of the HCP roles and the competencies are hence seen to fit well in this survey. As per the concluding statements of the 2019 EULAR core competencies document, there does remain a requirement to work on profession specific competencies in rheumatology.

References:

[1]Edelaar L, Nikiphorou E, Fragoulis GE, et al. 2019 EULAR recommendations for the generic core competences of health professionals in rheumatology. Annals of the Rheumatic Diseases 2020;79:53-60.

[2]Gregory, W.J., Burchett, S. and McCrum, C. (2021), National survey of the current clinical practices of the UK rheumatology physiotherapists: A short report. Musculoskeletal Care. https://doi.org/10.1002/msc.1516

Disclosure of Interests:

William J. Gregory Speakers bureau: Speaker fees from Novartis and Abbvie., Consultant of: Advisory boards for Pfizer and Novartis., Sharon Burchett: None declared, Carol McCrum Speakers bureau: Speaker fees from Novartis

Rates of Hospitalization and Infection-Related Hospitalization Among Human Immunodeficiency Virus (HIV)-Exposed Uninfected Children Compared to HIV-Unexposed Uninfected Children in the United States, 2007-2016

BACKGROUND

Studies from multiple countries have suggested impaired immunity in perinatally human immunodeficiency virus (HIV)-exposed uninfected children (HEU), with elevated rates of all-cause hospitalization and infections. We estimated and compared the incidence of all-cause hospitalization and infection-related hospitalization in the first 2 years of life among HEU and HIV-unexposed uninfected children (HUU) in the United States. Among HEU, we evaluated associations of maternal HIV disease-related factors during pregnancy with risk of child hospitalization.

METHODS

HEU data from subjects enrolled in the Surveillance Monitoring for Antiretroviral Therapy Toxicities Study (SMARTT) cohort who were born during 2006-2017 were analyzed. HUU comparison data were obtained from the Medicaid Analytic Extract database, restricted to states participating in SMARTT. We compared rates of first hospitalization, total hospitalizations, first infection-related hospitalization, total infection-related hospitalizations, and mortality between HEU and HUU using Poisson regression. Among HEU, multivariable Poisson regression models were fitted to evaluate associations of maternal HIV factors with risk of hospitalization.

RESULTS

A total of 2404 HEU and 3 605 864 HUU were included in the analysis. HEU children had approximately 2 times greater rates of first hospitalization, total hospitalizations, first infection-related hospitalization, and total infection-related hospitalizations compared with HUUs. There was no significant difference in mortality. Maternal HIV disease factors were not associated with the risk of child infection or hospitalization.

CONCLUSIONS

Compared with HUU, HEU children in the United States have higher rates of hospitalization and infection-related hospitalization in the first 2 years of life, consistent with studies in other countries. Closer monitoring of HEU infants for infection and further elucidation of immune mechanisms is needed.

Birth Prevalence of Congenital Cytomegalovirus Infection in HIV-Exposed Uninfected Children in the Era of Combination Antiretroviral Therapy

OBJECTIVES

To estimate birth prevalence of congenital cytomegalovirus (cCMV) in HIV-exposed uninfected children born in the current era of combination antiretroviral therapy and describe cCMV-related neurodevelopmental and hearing outcomes.

STUDY DESIGN

The Surveillance Monitoring for ART Toxicities cohort study follows HIV-exposed uninfected children at 22 sites in the US and Puerto Rico. Birth cCMV prevalence was estimated in a subset of participants who had blood pellets collected within three weeks of birth and underwent ≥1 of 6 assessments evaluating cognitive and language development including an audiologic examination between 1 and 5 years of age. Detection of CMV DNA by polymerase chain reaction testing of peripheral blood mononuclear cells was used to diagnose cCMV. Proportions of suboptimal assessment scores were compared by cCMV status using Fisher exact test.

RESULTS

Mothers of 895 eligible HIV-exposed uninfected children delivered between 2007 and 2015. Most (90%) were on combination antiretroviral therapy, 88% had an HIV viral load of ≤400 copies/mL, and 93% had CD4 cell counts of ≥200 cells/μL. Eight infants were diagnosed with cCMV, yielding an estimated prevalence of 0.89% (95% CI, 0.39%-1.75%). After adjusting for a sensitivity of 70%-75% for the testing method, projected prevalence was 1.2%-1.3%. No differences were observed in cognitive, language and hearing assessments by cCMV status.

CONCLUSIONS

Although birth cCMV prevalence in HIV-exposed uninfected children born to women with well-controlled HIV is trending down compared with earlier combination antiretroviral therapy-era estimates, it is above the 0.4% reported for the general US population. HIV-exposed uninfected children remain at increased risk for cCMV.

Immunologic reconstitution following hematopoietic stem cell transplantation despite lymph node paucity in NF-κB-inducing kinase deficiency

This case demonstrates successful immune reconstitution following hematopoietic stem cell transplantation in NIK deficiency.

114. Birth Prevalence of Congenital Cytomegalovirus Infection and Language, Hearing, and Developmental Outcomes in a Cohort of HIV-Exposed, Uninfected Preschool Children

Background

The prevalence of congenital cytomegalovirus infection (cCMV) at birth is 0.5%–1% in the United States. Most cCMV newborns are asymptomatic at birth with 10%–15% subsequently developing sequelae, such as hearing loss. Higher cCMV prevalence (2.5%–11.4%) is reported in infants born to HIV-infected women, associated with maternal immune suppression and lack of antiretroviral therapy (ART), with few studies addressing neurodevelopmental (ND) outcomes in their offspring. We report birth prevalence of cCMV in a cohort of HIV-exposed, uninfected infants (HEU) born to women on combination ART with well-controlled HIV and describe ND outcomes through age 5 years.

Methods

The Surveillance Monitoring for ART Toxicities (SMARTT) study is an ongoing NICHD-funded observational multi-centered cohort study (United States and Puerto Rico) of growth and development of HEU children that commenced in 2007. As of August 1, 2017, participants with stored blood pellets collected ≤3 weeks after birth and at least 1 ND assessment ≥1 year of age had pellets tested by DNA PCR to establish cCMV. Comparisons of ND outcomes (defined in figure) at ages 1, 2, and 5 by cCMV status were made using Wilcoxon and Fisher’s Exact tests.

Results

Of 895 children meeting study criteria (55% black; 32% white; 40% Latino), 8 had cCMV, yielding a birth prevalence of 0.89% (95% CI 0.39–1.75%). All were asymptomatic and similar to CMV-uninfected infants in gestational age and anthropometric measurements at birth. The last HIV viral load prior to delivery was undetectable in 88% of women. The last available CD4% was <20% in 3/8 mothers of cCMV newborns compared with 112/873 in those without (38% vs. 13%, P < 0.07). The mean duration of follow-up (± standard deviation) of children with cCMV was 7.2 years (1.6) and those without 5.9 (2.3) years (P < 0.11). ND assessments for language development (CDI at 1, A&S at 2, TOLD-P:3 at 5), cognition (Bayleys-III at 1), intelligence (WPPSI-III at 5), and hearing (PTA at 5) did not differ by cCMV status (figure).

Conclusion

Birth prevalence of cCMV in HEU children born within the last decade approaches national US prevalence. Preschool HEU children with asymptomatic cCMV at birth did not show poorer language, hearing, and developmental outcomes compared with CMV-uninfected HEU children.

Disclosures

All authors: No reported disclosures.

1564. Lower Rates of Epstein–Barr Virus (EBV) Viremia in Pediatric Solid Organ Transplant (SOT) Recipients Who Received Valganciclovir Prophylaxis

Background

Antiviral prophylaxis to prevent PTLD remains controversial, but some data suggest that valganciclovir or ganciclovir ([val]ganciclovir) use in EBV high-risk pediatric renal transplants reduces EBV viremia. We evaluated the impact of [val]ganciclovir on EBV viremia and post-transplant lymphoproliferative disease (PTLD) in pediatric nonrenal SOT recipients.

Methods

Retrospective study of 100 patients who underwent a first heart, liver, lung, intestine, or multivisceral SOT between November 2013 and November 2016 at Boston Children’s Hospital who survived without re-transplantation for at least 30 days. Data collected included EBV donor/recipient serostatus, donor’s age >2 years-old (to avoid misclassification of EBV risk due to maternal antibody), antiviral use ([val]ganciclovir or acyclovir), time to EBV viremia (>1,000 copies/mL by whole blood PCR), and time to development of PTLD. EBV high-risk patients were those with donor EBV positive [D+]/recipient EBV negative [R–] serologies; intermediate-risk were EBV R+; low risk were EBV D–/R–. Time-to-event analysis using the Kaplan–Meier method was performed and significance (P = 0.05) was evaluated using the log-rank test.

Results

High (n = 45) or intermediate (n = 27) EBV risk was associated with increased EBV viremia (P = 0.007, table). EBV viremia was significantly decreased in the subgroup of high-risk patients with donors >2 years old who received [val]ganciclovir vs. those who received no antiviral (n = 23, n = 4, P = 0.03, Figure 1). Most PTLD cases (8/9) occurred in the high-risk group (P = 0.03, Figure 2). Overall, patients who received [val]ganciclovir had less PTLD than those who did not (P = 0.03), but this was not significant in the high-risk subgroup (P = 0.14, Figure 3).

Conclusion

Lower rates of EBV viremia occurred in high EBV risk transplant recipients who received [val]ganciclovir, possibly by preventing primary EBV infection. Recipients with high EBV risk have the highest rate of PTLD.

Disclosures

F. M. Marty, Merck: Consultant and Investigator, Consulting fee, Research support and Speaker honorarium; Astellas: Consultant and Investigator, Consulting fee and Research support; Chimerix: Consultant and Investigator, Consulting fee and Research support; Fate Therapeutics: Consultant, Consulting fee; GlaxoSmithKline: Consultant, Consulting fee; LFB: Consultant, Consulting fee; Roche Molecular Diagnostics: Consultant, Consulting fee; Shire: Consultant and Investigator, Consulting fee and Research support.

2571. Higher Rates of Hospitalization and Infection-Related Hospitalization Among HIV-Exposed Uninfected Infants Compared with HIV Unexposed Uninfected Infants in the United States

Background

Studies from multiple countries have suggested impaired immunity in perinatally HIV-exposed uninfected (HEU) children, with elevated rates of all-cause hospitalization and infections. We estimated the incidence of all-cause hospitalization and infection-related hospitalization in the first 2 years of life among HEU children and compared this with HIV-unexposed uninfected (HUU) children in the US Among HEU children, we evaluated associations of maternal HIV disease-related factors during pregnancy with risk of infant hospitalization.

Methods

We evaluated HEU children enrolled in the Surveillance Monitoring for ART Toxicities (SMARTT) Study dynamic cohort of the Pediatric HIV/AIDS Cohort Study (PHACS) network who were born 2006–2017 and followed from birth. Data on HUU children were obtained from the Medicaid Analytic Extract database, restricted to states participating in SMARTT. We compared rates of first hospitalization, total hospitalizations, first infection-related hospitalization, total infection-related hospitalizations, and mortality between HEU and HUU children using Poisson regression. Among HEU children, multivariable Poisson regression models were fit to evaluate associations of maternal HIV factors with risk of hospitalization.

Results

Our analysis included 2,404 HEU and 3,605,864 HUU children. HEU children had approximately 2 times greater rates of first hospitalization, total hospitalizations, first infection-related hospitalization, and total infection-related hospitalizations compared with HUU children (figure). There was no significant difference in mortality. Among HEU children, maternal HIV disease factors, including viral load, CD4 count, antiretroviral regimen, and mode of HIV acquisition, were not associated with hospitalization rates.

Conclusion

Compared with HUU, HEU children in the United States have nearly twice the rate of hospitalization and infection-related hospitalization in the first 2 years of life, consistent with studies in other countries. Closer monitoring of HEU infants for infection and further elucidation of immune mechanisms is needed.

Disclosures

E. G. Chadwick, Abbott Labs: Shareholder, stock dividends. AbbVie: Shareholder, stock dividends. R. Van Dyke, Giliad Sciences: Grant Investigator, Research grant.

Elvitegravir/cobicistat pharmacokinetics in pregnant and postpartum women with HIV

OBJECTIVE

To evaluate elvitegravir and cobicistat pharmacokinetics during pregnancy compared with postpartum and in infant washout samples after delivery.

DESIGN

Nonrandomized, open-label, parallel-group, multicenter phase-IV prospective study of antiretroviral pharmacokinetics in HIV-infected pregnant women and their children in the United States.

METHODS

Intensive steady-state 24-h pharmacokinetic profiles after 150 mg of elvitegravir and 150 mg of cobicistat given orally in fixed dose combination once-daily were performed during the second trimester, third trimester, and postpartum. Infant washout samples were collected after birth. Elvitegravir and cobicistat were measured in plasma by a validated liquid chromatography with tandem mass spectrometry assay with a lower quantitation limit of 10 ng/ml. A two-tailed Wilcoxon signed-rank test (α = 0.10) was employed for paired within-participant comparisons.

RESULTS

Thirty pregnant women taking elvitegravir and cobicistat once-daily enrolled in the study. Compared with paired postpartum data, elvitegravir AUC0-24 was 24% lower in the second trimester [n = 14, P = 0.058, geometric mean ratios (GMR) = 0.76, 90% confidence interval (CI) 0.57-1.0] and 44% lower in the third trimester (n = 24, P = 0.0001, GMR = 0.56, 90% CI 0.42-0.73), while cobicistat AUC0-24 was 44% lower in the second trimester (n = 14, P = 0.0085, GMR = 0.56, 90% CI 0.37-0.85) and 59% lower in the third trimester (n = 24, P < 0.0001, GMR = 0.41, 90% CI 0.30-0.57). Median cord blood elvitegravir concentration was 540.6 ng/ml and the median ratio of cord blood to maternal plasma elvitegravir concentrations was 0.91.

CONCLUSION

Standard elvitegravir and cobicistat dosing during pregnancy results in significantly lower exposure which may increase the risk of virologic failure and mother-to-child transmission. Additional studies are needed to optimize elvitegravir and cobicistat dosing regimens in pregnant women.

Dolutegravir pharmacokinetics in pregnant and postpartum women living with HIV

OBJECTIVE

To evaluate dolutegravir pharmacokinetics during pregnancy compared with postpartum and in infant washout samples after delivery.

DESIGN

Ongoing, nonrandomized, open-label, parallel-group, multicenter phase-IV prospective study of antiretroviral pharmacokinetics in HIV-infected pregnant women and infants.

METHODS

Intensive steady-state 24 h pharmacokinetic profiles after dolutegravir 50 mg once-daily were performed during the second trimester (2T), third trimester (3T) and postpartum. Maternal delivery and postnatal infant samples were collected after birth. Dolutegravir was measured by validated LC-MS/MS; quantitation limit was 0.005 μg/ml. A two-tailed Wilcoxon signed-rank test (α = 0.10) was employed for paired within-subject comparisons.

RESULTS

Twenty-nine enrolled participants had a median age of 32 years (range 21-42). Pharmacokinetic data were available for 15 (2T), 28 (3T) and 23 (postpartum) women. Median dolutegravir AUC0-24,Cmax and C24 were 25-51% lower in the 2T and 3T compared with postpartum. The median cord blood/maternal plasma concentration ratio was 1.25 (n = 18). In 21 infants, median elimination half-life was 32.8 h after in utero exposure. Viral load at delivery was less than 50 copies/ml for 27/29 women (93%). Twenty-nine infants were HIV-negative. Renal abnormalities noted on ultrasound in two infants were deemed possibly related to dolutegravir.

CONCLUSION

Dolutegravir exposure is lower in pregnancy compared with postpartum in the same women on once-daily dosing. Median AUC0-24 during pregnancy was similar to, whereas trough concentrations were lower than, those seen in nonpregnant adults. Trough concentrations in pregnancy were well above dolutegravir EC90 (0.064 μg/ml). Dolutegravir readily crosses the placenta. Infant elimination is prolonged, with half-life over twice that of historical adult controls.

Septic Episodes in a Premature Infant After In Utero Exposure to Rituximab

Rituximab is an increasingly used immunotherapeutic agent for women of reproductive age for treatment of autoimmune diseases, leukemias, and lymphomas. Rituximab is a chimeric monoclonal antibody that targets B-cell surface antigen CD20 and can cross the placenta. Current evidence of the impact of this medication on the developing fetus is limited, but there is little to suggest that fetal exposure to this medication places an infant at increased risk of immunosuppression and subsequent infection. Here we report a case of in utero rituximab exposure that was associated with 2 severe septic episodes with Enterococcus faecalis, in a premature infant of 29 weeks' gestational age with a birth weight of 820 g. The patient had a critically depressed B-lymphocyte subset of 10% and undetectable immunoglobulin (Ig)G, IgM, and IgA levels at 37 weeks' postmenstrual age. Interestingly, both episodes of sepsis coincided with transition from donor human milk to formula feeds. She was treated with intravenous immunoglobulin, antibiotics, and donor human milk. We postulate that placental transfer of rituximab, prematurity, and the low levels of protective maternal antibodies increased the susceptibility of this patient to sepsis by E faecalis, a resident of the normal gut flora, whereas the secretory IgA in donor human milk may have played a protective role.

Antiretroviral Drug Resistance Among Children and Youth in the United States With Perinatal HIV

Among 234 US youths with perinatal human immunodeficiency virus, 75% had antiretroviral resistance, substantially higher than that of the reference laboratory overall (36%-44%). Resistance to newer antiretrovirals and to all antiretrovirals in a class was uncommon. The only factor independently associated with future resistance was a higher peak viral load.

Risk of congenital cytomegalovirus infection among HIV-exposed uninfected infants is not decreased by maternal nelfinavir use during pregnancy

BACKGROUND

Congenital cytomegalovirus (cCMV) infection is common among infants born to HIV-infected women. Nelfinavir (NFV), an antiretroviral drug that is safe during pregnancy, inhibits CMV replication in vitro at concentrations that standard doses achieve in plasma. We hypothesized that infants born to women receiving NFV for prevention of mother-to-child transmission of HIV (PMTCT) would have a reduced prevalence of cCMV infection.

METHODS

The prevalence of cCMV infection was compared among HIV-uninfected infants whose HIV-infected mothers either received NFV for >4 weeks during pregnancy (NFV-exposed) or did not receive any NFV in pregnancy (NFV-unexposed). CMV PCR was performed on infant blood samples collected at <3 weeks from birth.

RESULTS

Of the 1,255 women included, 314 received NFV for >4 weeks during pregnancy and 941 did not receive any NFV during pregnancy. The overall prevalence of cCMV infection in the infants was 2.2%, which did not differ by maternal NFV use. Maternal CD4 T cell counts were inversely correlated with risk of cCMV infection, independent of the time NFV was initiated during gestation. Infants with cCMV infection were born 0.7 weeks earlier (P = 0.010) and weighed 170 g less (P = 0.009) than uninfected infants.

CONCLUSION

Among HIV-exposed uninfected infants, cCMV infection was associated with adverse perinatal outcomes. NFV use in pregnancy was not associated with protection against cCMV. Safe and effective strategies to prevent cCMV infection are needed.

Prevalence and Persistence of Varicella Antibodies in Previously Immunized Children and Youth With Perinatal HIV-1 Infection

BACKGROUND

Two doses of live-attenuated varicella-zoster vaccine are recommended for human immunodeficiency virus 1 (HIV-1)-infected children with CD4% ≥ 15%. We determined the prevalence and persistence of antibody in immunized children with perinatal HIV (PHIV) and their association with number of vaccinations, combination antiretroviral therapy (cART), and HIV status.

METHODS

The Adolescent Master Protocol is an observational study of children with PHIV and perinatally HIV-exposed but uninfected (PHEU) children conducted at 15 US sites. In a cross-sectional analysis, we tested participants' most recent stored sera for varicella antibody using whole-cell and glycoprotein enzyme-linked immunosorbent assay. Seropositivity predictors were identified using multivariable logistic regression models and C statistics.

RESULTS

Samples were available for 432 children with PHIV and 221 PHEU children; 82% of children with PHIV and 97% of PHEU children were seropositive (P < .001). Seropositivity after 1 vaccine dose among children with PHIV and PHEU children was 100% at <3 years (both), 73% and 100% at 3-<7 years (P < .05), and 77% and 97% at ≥ 7 years (P < .01), respectively. Seropositivity among recipients of 2 vaccine doses was >94% at all intervals. Independent predictors of seropositivity among children with PHIV were receipt of 2 vaccine doses, receipt of 1 dose while on ≥ 3 months of cART, compared with none (adjusted odds ratio [aOR]: 14.0 and 2.8, respectively; P < .001 for overall dose effect), and in those vaccinated ≥ 3 years previously, duration of cART (aOR: 1.29 per year increase, P = .02).

CONCLUSIONS

Humoral immune responses to varicella vaccine are best achieved when children with PHIV receive their first dose ≥ 3 months after cART initiation and maintained by completion of the 2-dose series and long-term cART use.

Maraviroc Pharmacokinetics in HIV-1-Infected Pregnant Women

OBJECTIVE

To describe the pharmacokinetics of maraviroc in human immunodeficiency virus (HIV)-infected women during pregnancy and post partum.

METHODS

HIV-infected pregnant women receiving maraviroc as part of clinical care had intensive steady-state 12-hour pharmacokinetic profiles performed during the third trimester and ≥2 weeks after delivery. Cord blood samples and matching maternal blood samples were taken at delivery. The data were collected in 2 studies: P1026 (United States) and PANNA (Europe). Pharmacokinetic parameters were calculated.

RESULTS

Eighteen women were included in the analysis. Most women (12; 67%) received 150 mg of maraviroc twice daily with a protease inhibitor, 2 (11%) received 300 mg twice daily without a protease inhibitor, and 4 (22%) had an alternative regimen. The geometric mean ratios for third-trimester versus postpartum maraviroc were 0.72 (90% confidence interval, .60-.88) for the area under the curve over a dosing interval (AUCtau) and 0.70 (0.58-0.85) for the maximum maraviroc concentration. Only 1 patient showed a trough concentration (Ctrough) below the suggested target of 50 ng/mL, both during pregnancy and post partum. The median ratio of maraviroc cord blood to maternal blood was 0.33 (range, 0.03-0.56). The viral load close to delivery was <50 copies/mL in 13 women (76%). All children were HIV negative at testing.

CONCLUSIONS

Overall maraviroc exposure during pregnancy was decreased, with a reduction in AUCtau and maximum concentration of about 30%. Ctrough was reduced by 15% but exceeded the minimum Ctrough target concentration. Therefore, the standard adult dose seems sufficient in pregnancy.

CLINICAL TRIALS REGISTRATION

NCT00825929 and NCT000422890.

Pharmacokinetics of tenofovir during pregnancy and postpartum

OBJECTIVES

Tenofovir disoproxil fumarate (TDF) is increasingly used in the highly active antiretroviral therapy (HAART) regimens of pregnant women, but limited data exist on the pregnancy pharmacokinetics of chronically dosed TDF. This study described tenofovir pharmacokinetics during pregnancy and postpartum.

METHODS

International Maternal Pediatric and Adolescent AIDS Clinical Trials (IMPAACT) P1026s is a prospective, nonblinded pharmacokinetic study of HIV-infected pregnant women that included a cohort receiving 300 mg TDF once daily. Steady-state 24-hour pharmacokinetic profiles were measured at the second and third trimesters, postpartum, and in maternal and umbilical cord samples collected at delivery. Tenofovir was measured by liquid chromatography-mass spectrometry (LC-MS). The target area under the concentration versus time curve from time 0 to 24 h post dose (AUC) was ≥ 1.99 μg h/mL (nonpregnant historical control 10th percentile).

RESULTS

The median tenofovir AUC was decreased during the second (1.9 μg h/mL) and third (2.4 μg h/mL; P = 0.005) trimesters versus postpartum (3.0 μg h/mL). Tenofovir AUC exceeded the target for two of four women (50%) in the second trimester, 27 of 37 women [73%; 95% confidence interval (CI) 56%, 86%] in the third trimester, and 27 of 32 women (84%; 95% CI 67%, 95%) postpartum (P > 0.05). Median second/third-trimester troughs were lower (39/54 ng/mL) than postpartum (61 ng/mL). Median third-trimester weight was greater for subjects below the target AUC versus those above the target (97.9 versus 74.2 kg, respectively; P = 0.006). The median ratio of cord blood to maternal concentrations was 0.88. No infants were HIV infected.

CONCLUSIONS

This study found lower tenofovir AUC and troughs during pregnancy. Transplacental passage with chronic TDF use during pregnancy was high. Standard TDF doses appear to be appropriate for most HIV-infected pregnant women but therapeutic drug monitoring with dose adjustment should be considered in pregnant women with high weight (> 90 kg) or inadequate HIV RNA response.

Influence of age at virologic control on peripheral blood human immunodeficiency virus reservoir size and serostatus in perinatally infected adolescents

IMPORTANCE

Combination antiretroviral therapy initiated within several weeks of human immunodeficiency virus (HIV) infection in adults limits proviral reservoirs that preclude HIV cure. Biomarkers of restricted proviral reservoirs may aid in the monitoring of HIV remission or cure.

OBJECTIVES

To quantify peripheral blood proviral reservoir size in perinatally HIV-infected (PHIV+) adolescents and to identify correlates of limited proviral reservoirs.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study including 144 PHIV+ youths (median age, 14.3 years) enrolled in the United States-based Pediatric HIV/AIDS Cohort Study and receiving durable (median duration, 10.2 years) combination antiretroviral therapy, stratified by age at virologic control.

MAIN OUTCOMES AND MEASURES

The primary end point was peripheral blood mononuclear cell (PBMC) proviral load after virologic control at different ages. Correlations between proviral load and markers of active HIV production (ie, HIV-specific antibodies, 2-long terminal repeat circles) and markers of immune activation and inflammation were also assessed.

RESULTS

Proviral reservoir size was markedly reduced in the PHIV+ youth who achieved virologic control before 1 year of age (4.2 [interquartile range, 2.6-8.6] copies per 1 million PBMCs) compared with those who achieved virologic control at 1 to 5 years of age (19.4 [interquartile range, 5.5-99.8] copies per 1 million PBMCs) or after 5 years of age (70.7 [interquartile range, 23.2-209.4] copies per 1 million PBMCs; P < .001). A proviral burden of less than 10 copies per 1 million PBMCs in PHIV+ youth was measured in 11 (79%), 20 (40%), and 13 (18%) participants with virologic control before 1 year, at 1 to 5 years, and after 5 years of age, respectively (P < .001). Lower proviral load was associated with undetectable 2-long terminal repeat circles (P < .001) and HIV-negative or indeterminate serostatus (P < .001) but not with concentrations of soluble immune activation markers CD14 and CD163.

CONCLUSIONS AND RELEVANCE

Early effective combination antiretroviral therapy with prolonged virologic suppression after perinatal HIV infection leads to negligible peripheral blood proviral reservoirs in adolescence and is associated with negative or indeterminate HIV serostatus. These findings highlight the long-term effect of early effective control of HIV replication on biomarkers of HIV persistence in perinatal infection and the utility of HIV serostatus as a biomarker for small proviral reservoir size, although not necessarily for cure.

Safety and immunogenicity of 2009 pandemic H1N1 influenza vaccination in perinatally HIV-1-infected children, adolescents, and young adults

BACKGROUND

The safety and immunogenicity of high-dose pandemic H1N1 (pH1N1) vaccination in perinatally human immunodeficiency virus type 1 (HIV-1)-infected children, adolescents, and young adults are unknown.

METHODS

Two 30-μg doses of 2009 Novartis pH1N1 monovalent vaccine (Fluvirin) were administered 21-28 days apart to perinatally HIV-1-infected children, adolescents, and young adults. Antibodies were measured by hemagglutination inhibition (HAI) assay at baseline, 21-28 days after first vaccination, 7-13 days after the second vaccination, and 7 months after the first vaccination.

RESULTS

Among the 155 participants, 54 were aged 4-8 years, 51 were aged 9-17 years, and 50 were aged 18-24 years. After 2 doses of Fluvirin, seroresponse (≥ 4-fold rise in HAI titers) was demonstrated in 79.6%, 84.8%, and 83% of participants in the aforementioned age groups, respectively, and seroprotection (HAI titers ≥ 40) was shown in 79.6%, 82.6%, and 85.1%, respectively. Of those lacking seroresponse (n = 43) or seroprotection (n = 37) after the first vaccination, 46.5% and 40.5% achieved seroresponse or seroprotection, respectively, after the second vaccination. Among participants who lacked seroprotection at entry, a "complete response" (both seroresponse and seroprotection) after first vaccination was associated with higher baseline log(10) HAI titer and non-Hispanic ethnicity. No serious vaccine-related events occurred.

CONCLUSION

Two doses of double-strength pH1N1 vaccine are safe and immunogenic and may provide improved protection against influenza in perinatally HIV-1-infected children and youth.

CLINICAL TRIALS REGISTRATION

NCT00992836.

Effect of pregnancy on emtricitabine pharmacokinetics

OBJECTIVES

The aim of the study was to describe emtricitabine pharmacokinetics during pregnancy and postpartum.

METHODS

The International Maternal Pediatric and Adolescent AIDS Clinical Trials (IMPAACT), formerly Pediatric AIDS Clinical Trials Group (PACTG), study P1026s is a prospective pharmacokinetic study of HIV-infected pregnant women taking antiretrovirals for clinical indications, including a cohort taking emtricitabine 200 mg once daily. Intensive steady-state 24-hour emtricitabine pharmacokinetic profiles were performed during the third trimester and 6-12 weeks postpartum, and on maternal and umbilical cord blood samples collected at delivery. Emtricitabine was measured by liquid chromatography-mass spectrometry with a quantification limit of 0.0118 mg/L. The target emtricitabine area under the concentration versus time curve, from time 0 to 24 hours post dose (AUC(0-24) ), was ≥7 mg h/L (≤30% reduction from the typical AUC of 10 mg h/L in nonpregnant historical controls). Third-trimester and postpartum pharmacokinetics were compared within subjects.

RESULTS

Twenty-six women had pharmacokinetics assessed during the third trimester (median 35 weeks of gestation) and 22 postpartum (median 8 weeks postpartum). Mean [90% confidence interval (CI)] emtricitabine pharmacokinetic parameters during the third trimester vs. postpartum were, respectively: AUC: 8.0 (7.1-8.9) vs. 9.7 (8.6-10.9) mg h/L (P = 0.072); apparent clearance (CL/F): 25.0 (22.6-28.3) vs. 20.6 (18.4-23.2) L/h (P = 0.025); 24 hour post dose concentration (C(24) ): 0.058 (0.037-0.063) vs. 0.085 (0.070-0.010) mg/L (P = 0.006). The mean cord:maternal ratio was 1.2 (90% CI 1.0-1.5). The viral load was <400 HIV-1 RNA copies/mL in 24 of 26 women in the third trimester, in 24 of 26 at delivery, and in 15 of 19 postpartum. Within-subject comparisons demonstrated significantly higher CL/F and significantly lower C(24) during pregnancy; however, the C(24) was well above the inhibitory concentration 50%, or drug concentration that suppresses viral replication by half (IC(50) ) in all subjects.

CONCLUSIONS

While we found higher emtricitabine CL/F and lower C(24) and AUC during pregnancy compared with postpartum, these changes were not sufficiently large to warrant dose adjustment during pregnancy. Umbilical cord blood concentrations were similar to maternal concentrations.

Metabolic abnormalities and viral replication are associated with biomarkers of vascular dysfunction in HIV-infected children

OBJECTIVES

HIV-infected children may be at risk for premature cardiovascular disease. We compared levels of biomarkers of vascular dysfunction in HIV-infected children (with and without hyperlipidaemia) with those in HIV-exposed, uninfected (HEU) children enrolled in the Pediatric HIV/AIDS Cohort Study (PHACS), and determined factors associated with these biomarkers.

METHODS

A prospective cohort study was carried out. Biomarkers of inflammation [C-reactive protein (CRP), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP1)], coagulant dysfunction (fibrinogen and P-selectin), endothelial dysfunction [soluble intracellular cell adhesion molecule-1 (sICAM), soluble vascular cell adhesion molecule-1 (sVCAM) and E-selectin], and metabolic dysfunction (adiponectin) were measured in 226 HIV-infected and 140 HEU children. Anthropometry, body composition, lipids, glucose, insulin, HIV disease severity, and antiretroviral therapy were recorded.

RESULTS

The median ages of the children were 12.3 years in the HIV-infected group and 10.1 years in the HEU group. Body mass index (BMI) z-scores, waist and hip circumferences, and percentage body fat were lower in the HIV-infected children. Total and non-high-density lipoprotein (HDL) cholesterol and triglycerides were higher in HIV-infected children. HIV-infected children also had higher MCP-1, fibrinogen, sICAM and sVCAM levels. In multivariable analyses in the HIV-infected children alone, BMI z-score was associated with higher CRP and fibrinogen, but lower MCP-1 and sVCAM. Unfavourable lipid profiles were positively associated with IL-6, MCP-1, fibrinogen, and P- and E-selectin, whereas increased HIV viral load was associated with markers of inflammation (MCP-1 and CRP) and endothelial dysfunction (sICAM and sVCAM).

CONCLUSIONS

HIV-infected children have higher levels of biomarkers of vascular dysfunction than do HEU children. Risk factors associated with higher biomarkers include unfavourable lipid levels and active HIV replication.

International perspectives, progress, and future challenges of paediatric HIV infection

Paediatric HIV infection is a growing health challenge worldwide, with an estimated 1500 new infections every day. In developed countries, well established prevention programmes keep mother-to-child transmission rates at less than 2%. However, in developing countries, where transmission rates are 25-40%, interventions are available to only 5-10% of women. Children with untreated natural infection progress rapidly to disease, especially in resource-poor settings where mortality is greater than 50% by 2 years of age. As in adult infection, antiretroviral therapy has the potential to rewrite the natural history of HIV, but is accessible only to a small number of children needing therapy. We focus on the clinical and immunological features of HIV that are specific to paediatric infection, and the formidable challenges ahead to ensure that all children worldwide have access to interventions that have proved successful in developed countries.

The effect of cold acclimation on the water relations and freezing tolerance of Hordeum vulgare L

During a 5 degree C and a 5/-1 degree C cold acclimation (CA) regime there was a significant decline in the water potential of winter barley, and a concurrent decline in tissue water content of the 5/-1 degree C CA plants. Results of carbohydrate analysis illustrated a significant (P < 0.001) accumulation of sucrose, fructose and glucose in the 5/-1 degree C CA plants, which was inversely correlated to water potential. Using an infrared imaging radiometer during a convection frost test the water release time (WRT) of 5/-1 degree C CA was demonstrated to be significantly (P < 0.001) longer than that observed in non-cold acclimated plants. This observation is consistent with visual analysis of exotherm curves where the rate of cellular water release to extracellular ice is reduced in the 5/-1 degree C CA plants, compared to the non-cold acclimated plants. These biochemical and physiological changes were correlated to increased plant health following a non-lethal freezing test to -5 degree C, where non-cold acclimated plants produced 2.3 +/- 0.3 tillers and 5 degree C and 5/-1 degree C CA plants produced 2.4 +/- 0.3 and 4.7 +/- 0.7 tillers, respectively. Results from this study imply that cold acclimation leads to changes in the physical state of water that result in a less osmotically responsive cellular environment and subsequently significantly less damage to meristematic tissue.

HIV-1 viral escape in infancy followed by emergence of a variant-specific CTL response

Mutational escape from the CTL response represents a major driving force for viral diversification in HIV-1-infected adults, but escape during infancy has not been described previously. We studied the immune response of perinatally infected children to an epitope (B57-TW10) that is targeted early during acute HIV-1 infection in adults expressing HLA-B57 and rapidly mutates under this selection pressure. Viral sequencing revealed the universal presence of escape mutations within TW10 among B57- and B5801-positive children. Mutations in TW10 and other B57-restricted epitopes arose early following perinatal infection of B57-positive children born to B57-negative mothers. Surprisingly, the majority of B57/5801-positive children exhibited a robust response to the TW10 escape variant while recognizing the wild-type epitope weakly or not at all. These data demonstrate that children, even during the first years of life, are able to mount functional immune responses of sufficient potency to drive immune escape. Moreover, our data suggest that the consequences of immune escape may differ during infancy because most children mount a strong variant-specific immune response following escape, which is rarely seen in adults. Taken together, these findings indicate that the developing immune system of children may exhibit greater plasticity in responding to a continually evolving chronic viral infection.

Effect of turning regime and seasonal weather conditions on nitrogen and phosphorus losses during aerobic composting of cattle manure

Cattle manure from stock bedded on straw was aerobically composted under ambient conditions, turning with either a tractor-mounted front-end loader or a rear discharge manure spreader. Three composting experiments, each of approximately four months duration, were conducted to investigate the effect of turning regime and seasonal weather conditions on nitrogen and phosphorus losses during aerobic composting of cattle manure. Manure stacks of 12-15 m(3) initial volume were constructed in separate 5 x 5 m concrete compartments. Experiment 1 (January-April 1999) compared manure heaps turned once (T1) or three times (T3) using a front-end loader with an unturned static (S) control manure stack. Experiment 2 (June-September 1999) compared the same treatments as Experiment 1. Experiment 3 (September-December 1999) compared T1 and T3 turning regimes using a front end loader with turning by a rear-discharge spreader (TR1 and TR1T2) for more effective aeration of the manure. Turning took place at 6 weeks for the one turn treatments, and after 2, 6 and 10 weeks for the three turn treatments. Leachate losses were dominated by NH(4)-N during the first three weeks of composting, after which time NH4-N and NO3-N concentrations in leachates were approximately the same, in the range 0-20 mg N l(-1). The concentrations of both NH4-N and NO3-N in leachate were higher after turning. Molybdate-reactive P concentrations in leachate tended not to be significantly influenced by turning regime. Gaseous losses of NH3 and N2O rose quickly during the initial phases of composting, peaking at 152 g N t(-1) d(-1) for the T3 treatment. Mean NH3 emission rate (25-252 g N t(-1) d(-1)) for the first two weeks of Experiment 2 conducted during the period June-September were an order of magnitude greater (1-10 g N t(-1) d(-1)) than Experiment 3, conducted during the colder, wetter autumn period (September-December). Nitrous oxide emission rates ranged between 1-14 g N t(-1) d(-1) and showed little influence of turning regime. Total N and P concentrations in turned (T) and static (S) manure were elevated at the end of all experiments, due to loss of dry matter. Mean total N losses were 30.4% (T1) and 36.8% (T3) and total P losses 28.2% (T1) and 27.4% (T3).

Human immunodeficiency virus type 1 (HIV-1) gp120-specific antibodies in neonates receiving an HIV-1 recombinant gp120 vaccine

Infants born to human immunodeficiency virus type 1 (HIV-1)-infected mothers were immunized at birth and at ages 4, 12, and 20 weeks with low-, medium-, or high-dose recombinant gp120 vaccine with MF59 adjuvant (HIV-1(SF-2); n=52) or with MF59 alone as a placebo (n=9). An accelerated schedule (birth and ages 2, 8, and 20 weeks) was used for an additional 10 infants receiving the defined optimal dose and for 3 infants receiving placebo. At 24 weeks, anti-gp120 ELISA titers were greater for vaccine-immunized than for placebo-immunized infants on both schedules, and 87% of vaccinees had a vaccine-induced antibody response. At 12 weeks, antibody titers of infants on the accelerated vaccine schedule exceeded those of infants receiving placebo (4949 vs. 551; P=.01), and 63% of the vaccinees met the response criteria. Thus, an accelerated schedule of gp120 vaccinations generated an antibody response to HIV-1 envelope distinct from transplacental maternal antibody by age 12 weeks. These results provide support for further studies of vaccine strategies to prevent mother-to-infant HIV-1 transmission.

Paediatric HIV infection: correlates of protective immunity and global perspectives in prevention and management

The impact of the HIV epidemic on child health globally is beginning to be appreciated. With the burden of new infections falling on young women, there is a skyrocketing number of AIDS orphans, and a rapidly increasing number of children infected via mother-to-child-transmission (MTCT). An estimated 600,000 new paediatric infections occur each year, of which some 1500/day (> 90%) occur in sub-Saharan Africa. But whereas children account for only 4% of those currently living with HIV infection, 20% of AIDS deaths have been in children. This reflects the rapid progression to disease in paediatric HIV infection. Whereas a dramatic reduction in viraemia follows acute adult infection, corresponding to the appearance of a vigorous anti-HIV cytotoxic T lymphocyte response, virtually no impact of the immune response is observed in acute paediatric infection following MTCT. Two specific challenges for the paediatric immune response are: (i) infection occurs before the immune system itself is fully developed; and (ii) the viruses transmitted by MTCT have already evaded an immune system sharing close genetic relatedness to that of the child. Accumulating evidence indicates that the immune system is potentially capable of effective control of HIV infection, and that events occurring in acute infection critically determine the ultimate outcome. Technological advances that have transformed the study of T-cell immunity now enable the developing immune system in childhood to be better understood. Via novel immunotherapeutic approaches described, it may be possible to modulate the infant's immune response to reach effective and durable suppression of HIV, as can be achieved by the rare long-term non-progressors of HIV infection. The feasibility of adopting these approaches globally are as yet untested. Finally, the striking disparity between the burden of paediatric HIV infection and access to the necessary infrastructure and therapeutic options required for its optimal management is addressed in a comparison between three sites of paediatric HIV care: Durban, South Africa; London, UK; and Boston, USA.

A woman with leg cramps and rash

A 68-year-old woman presented with generalized weakness and a rash on her lower extremities. The weakness began one week earlier, shortly after treatment for leg cramps and two days before the rash appeared. She had also had blood-streaked sputum a few days before admission. There was no history of bleeding diathesis, nose bleeding, hematuria, vasculitis, muscle or joint aches, cinchonism, or exposure to tuberculosis. She denied fever, chills, night sweats, leg pain or swelling, chest pain, or abdominal pain.

Single-dose pharmacokinetics and safety of the oral antiviral compound adefovir dipivoxil in children infected with human immunodeficiency virus type 1. The Pediatrics AIDS Clinical Trials Group

The acyclic phosphonate analog adefovir is a potent inhibitor of retroviruses, including human immunodeficiency virus (HIV) type 1, and, unlike some antiviral nucleosides, does not require the initial phosphorylation step for its activity. Two oral dosages of the adefovir prodrug adefovir dipivoxil were evaluated in a phase I study with children with HIV infection. A total of 14 patients were stratified into age groups ranging from 6 months to 18 years of age. Eight patients received 1.5 mg of adefovir dipivoxil per kg of body weight, and six patients received 3.0 mg of adefovir dipivoxil per kg. Serum samples were obtained at intervals during the 8 h postdosing and were analyzed for adefovir concentrations. Patients were monitored for adverse effects. All samples collected resulted in quantifiable levels of adefovir (lower limit of quantitation, 25 ng/ml) from each patient. The areas under the concentration-versus-time curves (AUCs) were similar (P = 0.85) for the 1.5- and 3.0-mg/kg doses, while the apparent oral clearance (CL/F) was significantly higher (P = 0.05) for the 3-mg/kg dose. Pharmacokinetic parameters differed by patient age. In comparing those children older and younger than the median age of 5.1 years, AUC (P = 0.03), maximum concentration of drug in serum (P = 0.004), and the concentration at 8 h postdosing (P = 0.02) were significantly lower for the younger children. There were no significant differences for apparent volume of distribution and CL/F normalized to body surface area, but there was a suggestive difference in half-life (P = 0.07) among the subjects in the older and younger age groups. No significant adverse events were encountered. These data provide the basis for a multidose phase II study of adefovir dipivoxil in HIV-infected infants and children.

Lymphoproliferative responses to recombinant HIV-1 envelope antigens in neonates and infants receiving gp120 vaccines. AIDS Clinical Trial Group 230 Collaborators

Children of mothers infected with human immunodeficiency virus type 1 (HIV-1) were immunized at birth and at 1, 3, and 5 months with 1 of 3 doses of recombinant gp120 vaccines prepared from SF-2 or MN strains of HIV-1. A total of 126 children were not infected; 21 received adjuvant only. Vaccine recipients developed lymphoproliferative responses on >/=2 occasions, responding more often to homologous HIV-1 antigens than did adjuvant recipients (56% vs. 14%; P<.001). Responses were appreciated after 2 immunizations and were maintained for >84 weeks after the last immunization. An accelerated immunization schedule (birth, 2 weeks, 2 months, and 5 months) with the lowest dose of the SF-2 vaccine produced responses in all 11 vaccinees by 4 weeks. Responses to heterologous envelope antigens were also detected. Immune responses to vaccination are achievable at an age when some infection (perinatal or breast milk exposure related) may be prevented.

Use of human immunodeficiency virus (HIV) human hyperimmune immunoglobulin in HIV type 1-infected children (Pediatric AIDS clinical trials group protocol 273)

The clinical, immunologic, and virologic effects and the pharmacokinetics of human immunodeficiency virus (HIV) human hyperimmune immunoglobulin (HIVIG) were assessed in 30 HIV-infected children aged 2-11 years. All had moderately advanced disease with an immune complex-dissociated (ICD) p24 antigen >70 pg/mL and were on stable antiviral therapy. Three groups of 10 children received 6 monthly infusions of 200, 400, or 800 mg/kg of HIVIG, and serial immunologic and virologic assays were performed. HIVIG doses as high as 800 mg/kg were safe and well tolerated. The half-life of HIVIG, determined by serial p24 antibody titers, was 13-16 days, the volume of distribution was 102-113 mL/kg, and clearance was 5.6-6.0 mL/kg/day. Plasma ICD p24 decreased during the infusions, but CD4 cell levels, plasma RNA copy number, cellular virus, immunoglobulin levels, and neutralizing antibody titers were minimally affected by the infusions. Clinical status did not change during the 6-month infusion and 3-month follow-up periods.

Pharmacokinetics of azithromycin administered alone and with atovaquone in human immunodeficiency virus-infected children. The ACTG 254 Team

To evaluate if atovaquone (ATQ) interacts pharmacokinetically with azithromycin (AZ) in human immunodeficiency virus-infected children, 10 subjects (ages, 4 to 13 years) were randomized in a crossover study to receive AZ (5 mg/kg/day) alone (ALONE) or AZ (5 mg/kg/day) and ATQ (30 mg/kg/day) simultaneously (SIM) prior to receiving AZ and ATQ staggered by 12 h. Despite a lack of significant difference in the mean AZ pharmacokinetic parameters, the steady-state values of AZ's area under the concentration-time curve from 0 to 24 h and maximum concentration in serum were consistently lower (n = 7 of 7) for the SIM regimen than they were for the ALONE regimen. A larger study will be required to determine if ATQ affects AZ pharmacokinetics and efficacy in a clinically significant manner.

Dynamics of human immunodeficiency virus type 1 replication in vertically infected infants

Plasma human immunodeficiency virus type 1 (HIV-1) turnover and kinetics were studied in children aged 15 days to 2 years following the initiation of a triple antiretroviral drug regimen consisting of zidovudine, lamivudine, and nevirapine. HIV-1 turnover was at least as rapid as that previously described in adults; turnover rates were more rapid in infants and children aged 3 months to 2 years than in infants less than 3 months of age. These data confirm the central role of HIV-1 replication in the pathogenesis of vertical HIV-1 infection and reinforce the importance of early, potent combination therapies for the long-term control of HIV-1 replication.

Phospholipase A2 secretion during intestinal graft ischemia

The time-dependent appearance of phospholipase A2 (PLA2) activity in the preservation media of ischemic rat intestinal grafts is described. In controls, Ca2+-dependent, secretory PLA2 activity accumulated rapidly during the first 6 hr of ischemia, followed by a linear increase for up to 48 hr. LDH levels, by contrast, increased linearly throughout the 48 hr of ischemia. Addition of inhibitors of PLA2, cyclooxygenase, and lipooxygenase blocked accumulation of PLA2, but not LDH. PX-13, a novel PLA2 inhibitor, was most effective: 40 microM inhibited release by 86%, while 25 microM indomethacin (cyclooxygenase blocker) or nordihydroguiaretic acid (lipooxygenase blocker) inhibited 41 and 36%, respectively. That appearance of PLA2 activity, but not LDH, is attenuated by inhibitors of the eicosanoid cascade suggests a secretory event rather than leakage from dying cells. The secreted PLA2 is most likely the proinflammatory sPLA2 that has been implicated as a stress-induced protein and priming agent in ischemia-reperfusion injury.

Analysis of the maternal components of the AIDS clinical trial group 076 zidovudine regimen in the prevention of mother-to-infant transmission of human immunodeficiency virus type 1

To gain insight into the protective effects of the three components of the zidovudine regimen used in AIDS Clinical Trial Group (ACTG) 076 on mother-to-infant transmission of human immunodeficiency virus (HIV) type 1, 188 zidovudine-treated women and their untreated infants from five HIV-1 obstetric centers were retrospectively studied. The overall rate of mother-to-infant transmission was 12.3% (95% confidence interval [CI], 7.9%-18.0%). When the 38 women with <200 CD4 cells/microL were excluded, the mother-to-infant transmission rate was 8.8% (95% CI, 4.6%-14.8%). This rate compares favorably with the 8.3% transmission in the zidovudine arm of the ACTG 076 study. Apart from low (<200/microL) maternal CD4 cells (P = .016), no factors, including the duration of zidovudine therapy during gestation and intravenous administration of zidovudine during labor, affected the rate of mother-to-infant transmission. These findings suggest that antenatal oral zidovudine may be as effective as antenatal oral plus intravenous zidovudine during labor and the three-component ACTG 076 regimen in decreasing mother-to-infant HIV-1 transmission.

Lack of detection of human immunodeficiency virus type 1 in the saliva of infected children and adolescents

OBJECTIVE

To determine the prevalence of human immunodeficiency virus type 1 (HIV-1) in the saliva of infected children and adolescents.

METHODS

Saliva and blood samples were collected from 13 patients (age range, 1-15 years) with HIV-1 infection. Eleven were taking antiretroviral agents. The presence of HIV-1 was determined by polymerase chain reaction analysis of RNA and DNA as well as by viral culture of the saliva samples and by culture of peripheral blood mononuclear cells.

RESULTS

Although HIV-1 was cultured from peripheral blood mononuclear cells of 12 patients, it was not cultured from their saliva. Only 1 of 13 saliva samples yielded positive test results for HIV-1 RNA, and none did so for HIV-1 DNA. The specimen containing HIV-1 RNA was from an untreated 10-year-old asymptomatic boy with a CD4+ lymphocyte count of 0.91 x 10(9)/L (913 cells/microL) and no infectious virus detected in plasma.

CONCLUSION

The prevalence of HIV-1 in the saliva of HIV-1-infected children and adolescents is low and may not be infectious.

Secretory phospholipase A2 levels in rat small bowel

Preliminary studies on ischemia/reperfusion injury in transplanted small bowel grafts showed that secretory phospholipase A2 (sPLA2) may play a substantial role by breaking down membrane phospholipids. This study sought to determine the normal values of sPLA2 in the rat small bowel as a function of site and length as a baseline for future studies. The entire small bowel of male Lewis rats (200 g) was flushed with normal saline to eliminate solid contents. In group 1, the entire small bowel was divided into 5-cm segments (numbered 1-9), which were snap frozen and processed the same day for sPLA2. In group 2, a 25-cm segment of bowel (corresponding to segments 2-6 in group 1) was harvested from each animal, snap frozen, and immediately processed for sPLA2. To assess the effect of bowel storage on enzyme content, group 3 and group 4 grafts were stored for 7 and 14 days, respectively, at -85 degrees C prior to processing. All samples were homogenized in buffer, extracted with H2SO4 and assayed for sPLA2 activity using [1-14C]oleate-labeled autoclaved Escherichia coli as substrate. Results were analyzed statistically by ANOVA. sPLA2 activity rose from 85.46 +/- 14.46% hydrolysis/min fraction-1 in segment 1, to 476.38 +/- 176.75% hydrolysis/min fraction-1 in segment 9. The increase was linear and statistically significant (p < .0001). There was no significant difference in enzymatic activity between groups 2, 3, and 4. Group 2 activity was 263.02 +/- 43.74% hydrolysis/min fraction-1. This value was not statistically different from the mathematically calculated mean of segments 2-6 in group 1 (237.75). The results show that (1) sPLA2 activity increases predictably with distance from the ligament of Treitz (2) storage at -85 degrees C does not affect sPLA2, activity, and (3) 25-cm grafts may be evaluated in toto with reproducible baseline enzyme activity. Given the variability of enzyme activity along the course of the rat small bowel, it is imperative that exact location be identified in any studies evaluating sPLA2 activity.

Administration of oral acyclovir suppressive therapy after neonatal herpes simplex virus disease limited to the skin, eyes and mouth: results of a phase I/II trial

BACKGROUND

Neonatal herpes simplex virus (HSV) infections limited to the skin, eyes and mouth (SEM) can result in neurologic impairment. A direct correlation exists between the development of neurologic deficits and the frequency of cutaneous HSV recurrences. Thus, the National Institutes of Allergy and Infectious Diseases Collaborative Antiviral Study Group conducted a Phase I/II trial of oral acyclovir therapy for the suppression of cutaneous recurrences after SEM disease in 26 neonates.

METHODS

Infants < or = 1 month of age with virologically confirmed HSV-2 SEM disease were eligible for enrollment. Suppressive oral acyclovir therapy (300 mg/m2/dose given either twice daily or three times per day) was administered for 6 months.

RESULTS

Twelve (46%) of the 26 infants developed neutropenia (< 1000 cells/mm3) while receiving acyclovir. Thirteen (81%) of the 16 infants who received drug 3 times per day experienced no recurrences of skin lesions while receiving therapy. In comparison, a previous Collaborative Antiviral Study Group study found that only 54% of infants have no cutaneous recurrences in the 6 months after resolution of neonatal HSV disease if oral acyclovir suppressive therapy is not initiated. In one infant, HSV DNA was detected in the cerebrospinal fluid during a cutaneous recurrence, and an acyclovir-resistant HSV mutant was isolated from another patient during the course of the study.

CONCLUSIONS

Administration of oral acyclovir can prevent cutaneous recurrences of HSV after neonatal SEM disease. The effect of such therapy on neurologic outcome must be assessed in a larger, Phase III study. As such, additional investigation is necessary before routine use of suppressive therapy in this population can be recommended.

Herpes simplex virus-2 (HSV-2) type-specific antibody correlates of protection in infants exposed to HSV-2 at birth

Western blot analysis was used to compare the herpes simplex virus (HSV)-2 antibody profiles of 40 infants less than 2 wk of age who had been exposed to maternal genital HSV-2 at birth. 4 mothers were HSV seronegative at delivery and seroconverted to HSV-2 ("primary infection"), 9 had HSV-1 antibodies and seroconverted to HSV-2 ("nonprimary first episode infection"), and 27 were HSV-2 seropositive ("recurrent infection"). Neonatal herpes infections developed in 1 of 4 infants of women with primary infection, in 3 of 9 infants of women with nonprimary first episode infection, and in none of the 27 infants of women with recurrent HSV-2. Antibodies to HSV-2 proteins gG-2, VP5, and ICP35 were detected in 83, 89, and 72% of the 36 uninfected infants, respectively. None of the four infected infants had detectable antibodies to gG-2 and only one (25%) had antibodies to VP5 or ICP35. The more limited profiles of the 13 infants born to mothers with first episodes of HSV-2 were then analyzed separately; these profiles were similar among infected and uninfected infants except for gG-2, which elicits antibodies that are type specific for HSV-2. None of the infected infants versus seven of nine (78%) uninfected infants were gG-2 seropositive. These comparisons suggest that maternal type-specific antibodies may play a role in preventing neonatal infection after exposure to HSV-2.

Neonatal herpes simplex virus infection in relation to asymptomatic maternal infection at the time of labor

BACKGROUND AND METHODS

To define the risk factors associated with neonatal acquisition of herpes simplex virus (HSV) infection, we prospectively obtained HSV cultures from the cervix and external genitalia of 15,923 pregnant women in early labor who were without symptoms or signs of genital HSV infection. Follow-up of the women with positive cultures for HSV and their HSV-exposed infants included serologic tests and serial cultures for HSV.

RESULTS

HSV was isolated from 56 of the women (0.35 percent), 18 of whom (35 percent) had serologic evidence of a recently acquired, subclinical first episode of genital HSV infection, and 34 of whom (65 percent) had reactivation of HSV. Neonatal HSV developed in 6 of 18 infants (33 percent) born to the women with a first episode of genital HSV, and in 1 of 34 infants (3 percent) born to the women with reactivation of HSV (P less than 0.01); neonatal HSV also occurred in three of the infants born to the 15,867 women with negative cultures. Neonatal HSV-2 occurred in 1 of 4 infants born to mothers seronegative at delivery for both HSV-1 and HSV-2, in 4 of 12 infants exposed to HSV-2 whose mothers had only HSV-1 antibodies at delivery, and in none of the infants born to 31 women who were HSV-2-seropositive. An increased risk of neonatal HSV was associated with exposure to viral shedding from the cervix and the use of fetal-scalp electrodes.

CONCLUSIONS

Of the asymptomatic women who shed HSV in early labor, about a third have recently acquired genital HSV, and their infants are 10 times more likely to have neonatal HSV than those of women with asymptomatic reactivation of HSV. The presence of maternal antibodies specific to HSV-2 but not HSV-1 appears to reduce the neonatal transmission of HSV-2. Further studies are necessary to determine whether screening and prophylactic treatment are warranted for infants of HSV-2-seronegative mothers who shed HSV-1 or HSV-2 in early labor.