Douglas C. Watson

Efficacy of and adherence to highly active antiretroviral therapy in children infected with human immunodeficiency virus type 1.

BACKGROUND Clinical trials in adults have demonstrated the efficacy of highly active antiretroviral therapy (HAART) to suppress replication of HIV-1 to nondetectable levels, but lower success rates have been observed in practice. We sought to determine the efficacy of HAART in our population of HIV-1-infected children and to identify determinants of efficacy, especially the role of adherence to prescribed antiretrovirals. METHODS The viral load and CD4+ T cell responses of 72 children with perinatally acquired HIV-1 treated with HAART including a protease inhibitor for at least 90 days were examined retrospectively in relation to adherence, as measured by pharmacy records for the first 180 days of HAART. RESULTS Patients were defined as adherent if > or =75% of protease inhibitors and > or =75% of all antiretroviral prescriptions were filled. Of the 42 patients (58%) who were adherent, nondetectable viral loads were achieved and maintained in 22 (52%). A Kaplan-Meier plot showed a drop-off in patients maintaining a nondetectable viral load after 200 days. Higher initial viral load was the only pretreatment factor that identified adherent patients at risk for treatment failure. Only 3 (10%) nonadherent patients maintained a viral load of <400 copies/ml. The adherent group had a prompt and sustained increase in CD4+ T cell counts. CONCLUSIONS HAART can achieve control of viral replication in HIV-1-infected children who adhere to therapy. However, treatment failure is likely unless there is a high level of adherence. Nonadherence to therapy is common and might be the major impediment to successful treatment of children infected with HIV-1.

Continued Production of Drug-Sensitive Human Immunodeficiency Virus Type 1 in Children on Combination Antiretroviral Therapy Who Have Undetectable Viral Loads

ABSTRACT Highly active antiretroviral therapy (HAART) can suppress plasma human immunodeficiency virus type 1 (HIV-1) levels to below the detection limit of ultrasensitive clinical assays. However, HIV-1 persists in cellular reservoirs, and in adults, persistent low-level viremia is detected with more sensitive assays. The nature of this viremia is poorly understood, and it is unclear whether viremia persists in children on HAART, particularly those who start therapy shortly after birth. We therefore developed a reverse transcriptase PCR (RT-PCR) assay that allows genotyping of HIV-1 protease even when viremia is present at levels as low as 5 copies of HIV-1 RNA/ml. We demonstrated that viremia persists in children with plasma virus levels below the limit of detection of clinical assays. Viremia was detected even in children who began HAART in early infancy and maintained such strong suppression of viremia that HIV-1-specific antibody responses were absent or minimal. The low-level plasma virus lacked protease inhibitor resistance mutations despite the frequent use of nelfinavir, which has a low mutational barrier to resistance. Protease sequences resembled those of viruses in the latent reservoir in resting CD4+ T cells. Thus, in most children on HAART with clinically undetectable viremia, there is continued virus production without evolution of resistance in the protease gene.

Cardiac Effects of in utero Exposure to Antiretroviral Therapy in HIV-Uninfected Children Born to HIV-Infected Mothers

Objectives:We evaluated the potential cardiac effects of in-utero exposures to antiretroviral drugs in HIV-exposed but uninfected (HEU) children. Design and methods:We compared echocardiographic parameters of left ventricular function (ejection fraction, fractional shortening, and stress–velocity index) and structure (left ventricular dimension, posterior wall/septal thickness, mass, thickness-to-dimension ratio, and wall stress) (expressed as Z-scores to account for age and body surface area) between HEU and HIV-unexposed cohorts from the Pediatric HIV/AIDS Cohort Studys Surveillance Monitoring for ART Toxicities study. Within the HEU group, we investigated the associations between the echocardiographic Z-scores and in-utero exposures to maternal antiretroviral drugs. Results:There were no significant differences in echocardiographic Z-scores between 417 HEU and 98 HIV-unexposed children aged 2–7 years. Restricting the analysis to HEU children, first-trimester exposures to combination antiretroviral therapy (a regimen including at least three antiretroviral drugs) and to certain specific antiretroviral drugs were associated with significantly lower stress–velocity Z-scores (mean decreases of 0.22–0.40 SDs). Exposure to combination antiretroviral therapy was also associated with lower left ventricular dimension Z-scores (mean decrease of 0.44 SD). First-trimester exposure to combination antiretroviral therapy was associated with higher mean left ventricular posterior wall thickness and lower mean left ventricular wall stress Z-scores. Conclusion:There was no evidence of significant cardiac toxicity of perinatal combination antiretroviral therapy exposure in HEU children. Subclinical differences in left ventricular structure and function with specific in-utero antiretroviral exposures indicate the need for a longitudinal cardiac study in HEU children to assess long-term cardiac risk and cardiac monitoring recommendations.

Effectiveness of efavirenz-based regimens in young HIV-infected children treated for tuberculosis: a treatment option for resource-limited settings.

Background Antiretroviral treatment (ART) options for young children co-infected with HIV and tuberculosis are limited in resource-poor settings due to limited data on the use of efavirenz (EFV). Using available pharmacokinetic data, an EFV dosing schedule was developed for young co-infected children and implemented as the standard of care at Macha Hospital in Southern Province, Zambia. Treatment outcomes inchildren younger than 3 years of age or weighing less than 10 kg receiving either EFV-based ART plus anti-tuberculous treatment or nevirapine-based (NVP) ART were compared. Methods Treatment outcomes were measured in a cohort of HIV-infected children seeking care at Macha Hospital in rural Zambia from 2007 to 2010. Informationon the diagnosis and treatment of tuberculosis was abstracted from medical records. Results Forty-five children treated for tuberculosis initiated an EFV-based regimen and 69 children initiated a NVP-based regimen, 7 of whom also were treated for tuberculosis. Children receiving both regimens were comparable in age, but children receiving EFV started ART with a lower CD4+ T-cell percentage and weight-for-age z-score. Children receiving EFV experienced increases in both CD4+ T-cell percentage and weight-for-age z-score during follow-up, such that levels were comparable to children receiving NVP after two years of ART. Cumulative survival after 12 months of ART did not differ between groups (NVP:87%;EFV:80%;p = 0.25). Eleven children experienced virologic failure during follow-up.The adjusted hazard ratio of virologic failure comparing EFV to NVP was 0.25 (95% CI:0.05,1.24) and 0.13 (95% CI:0.03,0.62) using thresholds of 5000 and 400 copies/mL, respectively.Five children receiving EFV were reported to have had convulsions after ART initiation compared to only one child receiving NVP (p = 0.04). Conclusions Despite poorer health at ART initiation, children treated for tuberculosis and receiving EFV-based regimens showed significant improvements comparable to children receiving NVP-based regimens. EFV-based regimens should be considered for young HIV-infected children co-infected with tuberculosis in resource-limited settings.

STEADY-STATE PHARMACOKINETICS OF LOPINAVIR/RITONAVIR IN COMBINATION WITH EFAVIRENZ IN HUMAN IMMUNODEFICIENCY VIRUS-INFECTED PEDIATRIC PATIENTS

The pharmacokinetics of lopinavir/ritonavir (LPV/RTV) 300 mg/m2 twice daily and efavirenz (EFV) 350 mg/m2 once daily were evaluated in HIV-infected children. The minimum concentrations for LPV contained values above the target range, and the estimated minimum concentrations for EFV contained values below the range. Our data support the current LPV/RTV dose, but EFV 350 mg/m2 may not be sufficient.

Production of the HIV-suppressive chemokines CCL3/MIP-1α and CCL22/MDC is associated with more effective antiretroviral therapy in HIV-infected children

Background: Certain CC chemokines including ligands for the HIV-1 coreceptor CCR5 are associated with suppression of HIV-1 infection. Whether the release of these chemokines from lymphocytes influences treatment outcome in children receiving antiretroviral therapy is not known. Methods: A study of 175 HIV-infected children in Rio de Janeiro, Brazil was conducted to compare clinical measures and HIV-suppressive chemokine release. Clinical measures including %CD4+ T cells, viral loads, and antiretroviral drug-resistant mutations were obtained. Chemokine release was measured in cultures of peripheral blood mononuclear cells collected from 135 children before or after receiving therapy. Chemokine levels were compared between subject groups stratified according to clinical measures and treatment regimen (1–2, 3–4, or no antiretrovirals) extant at the time of cell sample collection. Results: Mean viral loads did not vary significantly between treatment groups although there were significant differences in %CD4+ T cells. Virus from children taking 3–4 antiretrovirals had significantly more drug-resistant mutations than did virus from those receiving 1–2 drugs. Among antiretroviral-treated children, there was a significant direct relationship between %CD4+ T cells and MIP-1α/CCL3 and macrophage-derived chemokine/CCL22 production. In addition, there was a significant inverse relationship between viral load and MIP-1α production in patients receiving 3–4 antiretrovirals. Greater recovery of %CD4+ T cells after therapy was associated with higher MIP-1α and macrophage-derived chemokine production at baseline. Conclusions: The production of HIV-suppressive chemokines is associated with better outcome in children receiving antiretroviral regimens in settings where drug-resistant mutations are prevalent. Such information may provide insights for the design of treatment strategies for pediatric HIV infection under similar circumstances.

Placental Cryptococcus neoformans infection without neonatal disease: case report and review of the literature.

We report placental cryptococcosis in a woman with multi-drug resistant human immunodeficiency virus (HIV) infection. She received antifungal therapy for cryptococcal meningitis prior to delivery. Cesarean section was performed with delivery of a single full-term male infant. There was no evidence of HIV or cryptococcal infection in the infant. The placenta grossly showed multiple white nodules. Microscopically, numerous encapsulated budding yeasts, morphologically consistent with cryptococci, were identified in the intervillous space and, to a lesser extent, in the chorionic villi. Cryptococcal infections are not uncommon, but only 2 cases of placental cryptococcosis have been reported. Our case is the 1st account documenting cryptococcal organisms within the chorionic villi, and yet there was no evidence of infection in the infant. Mother-to-fetal transmission of cryptococcal infection is not well defined. We review the literature and discuss its possible mechanisms.

Paucity of Intact Non-Induced Provirus with Early, Long-Term Antiretroviral Therapy of Perinatal HIV Infection

The latent reservoir is a major barrier to HIV eradication. Reservoir size is emerging as an important biomarker to assess the likelihood of HIV remission in the absence of antiretroviral therapy (ART) and may be reduced by earlier initiation of ART that restricts HIV spread into CD4+ T cells. Reservoir size is traditionally measured with a quantitative viral outgrowth assay (QVOA) that induces replication-competent HIV production through in vitro stimulation of resting CD4+ T cells. However, the recent identification of replication-intact, non-induced proviral genomes (NIPG) suggests the QVOA significantly underestimates (by 62-fold) latent reservoir size in chronically-infected adults. Whether formation and persistence of Intact, NIPG is thwarted by early ART initiation and long-term virologic suppression in perinatal infection is unclear. Here, we show that the latent reservoir in 11 early treated, long-term suppressed perinatally infected children and adolescents was not inducible by QVOA and dominated by defective, NIPG. Single genome analysis of 164 NIPG from 232 million cultured resting CD4+ T cells revealed no replication-intact, near-full length sequences. Forty-three (26%) NIPG contained APOBEC3G-mediated hypermutation, 115 (70%) NIPG contained large internal deletions, one NIPG contained nonsense mutations and indels, and 5 (3%) NIPG were assigned as “Not Evaluable” due to multiple failed sequencing attempts that precluded further classification. The lack of replication competent inducible provirus and intact NIPG in this cohort indicate early, long-term ART of perinatal infection leads to marked diminution of replication-competent HIV-1 reservoirs, creating a favorable state towards interventions aimed at virologic remission.

The Arc of Human Immunodeficiency Virus Capacity Development: Insights from a Decade of Partnership for Medical Education in Zambia

AbstractZambia and other sub-Saharan nations suffer from a critical shortage of trained health-care professionals to combat the human immunodeficiency virus/acquired immunodeficiency syndrome crisis. The University of Maryland and the Zambian Ministry of Health have partnered over the past decade to develop health-care capacity among physicians, nurses, and community health workers. We describe novel interventions to train health-care workers at all levels and argue that our collaboration represents a successful model for such partnerships between western medical institutions and African governmental health agencies.