[Show abstract][Hide abstract] ABSTRACT: The International Maternal, Pediatric, and Adolescent Clinical Trial P1060 trial demonstrated superior outcomes for HIV-infected children less than 3 years old initiating antiretroviral therapy (ART) with lopinavir/ritonavir compared to nevirapine, but lopinavir/ritonavir was four-fold costlier.
We used the Cost-Effectiveness of Preventing AIDS Complications-Pediatric model, with published and P1060 data, to project outcomes under three strategies: no ART; first-line nevirapine (with second-line lopinavir/ritonavir); and first-line lopinavir/ritonavir (second-line nevirapine). The base-case examined South African children initiating ART at age 12 months; sensitivity analyses varied all key model parameters. Outcomes included life expectancy, lifetime costs, and incremental cost-effectiveness ratios [ICERs; dollars/year of life saved ($/YLS)]. We considered interventions with ICERs less than 1× per-capita gross domestic product (South Africa: $7500)/YLS as 'very cost-effective,' interventions with ICERs below 3× gross domestic product/YLS as 'cost-effective,' and interventions leading to longer life expectancy and lower lifetime costs as 'cost-saving'.
Projected life expectancy was 2.8 years with no ART. Both ART regimens markedly improved life expectancy and were very cost-effective, compared to no ART. First-line lopinavir/ritonavir led to longer life expectancy (28.8 years) and lower lifetime costs ($41 350/person, from lower second-line costs) than first-line nevirapine (27.6 years, $44 030). First-line lopinavir/ritonavir remained cost-saving or very cost-effective compared to first-line nevirapine unless: liquid lopinavir/ritonavir led to 2-fold higher virologic failure rates or 15-fold greater costs than in the base-case, or second-line ART following first-line lopinavir/ritonavir was very ineffective.
On the basis of P1060 data, first-line lopinavir/ritonavir leads to longer life expectancy and be cost-saving or very cost-effective compared to first-line nevirapine. This supports the WHO guidelines, but increasing access to pediatric ART is critical regardless of the regimen used.
Preview · Article · Apr 2015 · AIDS (London, England)
[Show abstract][Hide abstract] ABSTRACT: Background:
In a randomized trial comparing nevirapine (NVP)-based versus lopinavir/ritonavir (LPV/r)-based antiretroviral therapy (ART) in HIV-infected children [primary endpoint discontinuation of study treatment for any reason or virologic failure by week 24] aged 2 months to 3 years, we assessed whether clinical, virologic, immunologic and safety outcomes varied by prior single-dose NVP exposure (PrNVP) for prevention of mother-to-child HIV transmission and other covariates.
Efficacy was assessed by time to ART discontinuation or virologic failure, virologic failure/death and death; safety by time to ART discontinuation because of a protocol-defined toxicity and first ≥ grade 3 adverse event; immunology and growth by changes in CD4%, weight/height World Health Organization z-scores from entry to week 48. Cox proportional hazards and linear regression models were used to test whether treatment differences depended on PrNVP exposure and other covariates.
Over a median follow up of 48 (PrNVP) and 72 (no PrNVP) weeks, there was no evidence of differential treatment effects by PrNVP exposure or any other covariates. LPV/r-based ART was superior to NVP-based ART for efficacy and safety outcomes; however, those on NVP had larger improvements in CD4%, weight and height z-scores. Lower pretreatment CD4% and higher HIV-1 RNA levels were associated with reduced efficacy, lower pretreatment CD4% with shorter time to ART discontinuation because of a protocol-defined toxicity, and no PrNVP with shorter time to first grade ≥ 3 adverse event.
Differences between LPV/r and NVP ART in efficacy, safety, immunologic and growth outcomes did not depend on PrNVP exposure, prior breast-feeding, sex, HIV-1 subtype, age, pretreatment CD4%, HIV-1 RNA or World Health Organization disease stage. This finding should be considered when selecting an ART regimen for young children.
Full-text · Article · Aug 2014 · The Pediatric Infectious Disease Journal
[Show abstract][Hide abstract] ABSTRACT: In HIV-infected children, viral diversity tends to increase with age in the absence of antiretroviral treatment (ART). We measured HIV diversity in African children (ages 6-36 months) enrolled in a randomized clinical trial comparing two ART regimens (Cohort I of the P1060 trial). Children in this cohort were exposed to single dose nevirapine (sdNVP) at birth.
HIV diversity was measured retrospectively using a high resolution melting (HRM) diversity assay. Samples were obtained from 139 children at the enrollment visit prior to ART initiation. Six regions of the HIV genome were analyzed: two in gag, one in pol, and three in env. A single numeric HRM score that reflects HIV diversity was generated for each region; composite HRM scores were also calculated (mean and median for all six regions).
In multivariable median regression models using backwards selection that started with demographic and clinical variables, older age was associated with higher HRM scores (higher HIV diversity) in pol (P = 0.005) and with higher mean (P = 0.014) and median (P<0.001) HRM scores. In multivariable models adjusted for age, pre-treatment HIV viral load, pre-treatment CD4%, and randomized treatment regimen, higher HRM scores in pol were associated with shorter time to virologic suppression (P = 0.016) and longer time to study endpoints (virologic failure [VF], VF/death, and VF/off study treatment; P<0.001 for all measures).
In this cohort of sdNVP-exposed, ART-naïve African children, higher levels of HIV diversity in the HIV pol region prior to ART initiation were associated with better treatment outcomes.
[Show abstract][Hide abstract] ABSTRACT: HIV-1 blocks apoptosis, programmed cell death, an innate defense of cells against viral invasion. However, apoptosis can be selectively reactivated in HIV-infected cells by chemical agents that interfere with HIV-1 gene expression. We studied two globally used medicines, the topical antifungal ciclopirox and the iron chelator deferiprone, for their effect on apoptosis in HIV-infected H9 cells and in peripheral blood mononuclear cells infected with clinical HIV-1 isolates. Both medicines activated apoptosis preferentially in HIV-infected cells, suggesting that the drugs mediate escape from the viral suppression of defensive apoptosis. In infected H9 cells, ciclopirox and deferiprone enhanced mitochondrial membrane depolarization, initiating the intrinsic pathway of apoptosis to execution, as evidenced by caspase-3 activation, poly(ADP-ribose) polymerase proteolysis, DNA degradation, and apoptotic cell morphology. In isolate-infected peripheral blood mononuclear cells, ciclopirox collapsed HIV-1 production to the limit of viral protein and RNA detection. Despite prolonged monotherapy, ciclopirox did not elicit breakthrough. No viral re-emergence was observed even 12 weeks after drug cessation, suggesting elimination of the proviral reservoir. Tests in mice predictive for cytotoxicity to human epithelia did not detect tissue damage or activation of apoptosis at a ciclopirox concentration that exceeded by orders of magnitude the concentration causing death of infected cells. We infer that ciclopirox and deferiprone act via therapeutic reclamation of apoptotic proficiency (TRAP) in HIV-infected cells and trigger their preferential elimination. Perturbations in viral protein expression suggest that the antiretroviral activity of both drugs stems from their ability to inhibit hydroxylation of cellular proteins essential for apoptosis and for viral infection, exemplified by eIF5A. Our findings identify ciclopirox and deferiprone as prototypes of selectively cytocidal antivirals that eliminate viral infection by destroying infected cells. A drug-based drug discovery program, based on these compounds, is warranted to determine the potential of such agents in clinical trials of HIV-infected patients.
[Show abstract][Hide abstract] ABSTRACT: Nevirapine-based antiretroviral therapy is the predominant (and often the only) regimen available for children in resource-limited settings. Nevirapine resistance after exposure to the drug for prevention of maternal-to-child human immunodeficiency virus (HIV) transmission is common, a problem that has led to the recommendation of ritonavir-boosted lopinavir in such settings. Regardless of whether there has been prior exposure to nevirapine, the performance of nevirapine versus ritonavir-boosted lopinavir in young children has not been rigorously established.
In a randomized trial conducted in six African countries and India, we compared the initiation of HIV treatment with zidovudine, lamivudine, and either nevirapine or ritonavir-boosted lopinavir in HIV-infected children 2 to 36 months of age who had no prior exposure to nevirapine. The primary end point was virologic failure or discontinuation of treatment by study week 24.
A total of 288 children were enrolled; the median percentage of CD4+ T cells was 15%, and the median plasma HIV type 1 (HIV-1) RNA level was 5.7 log(10) copies per milliliter. The percentage of children who reached the primary end point was significantly higher in the nevirapine group than in the ritonavir-boosted lopinavir group (40.8% vs. 19.3%; P<0.001). Among the nevirapine-treated children with virologic failure for whom data on resistance were available, more than half (19 of 32) had resistance at the time of virologic failure. In addition, the time to a protocol-defined toxicity end point was shorter in the nevirapine group (P=0.04), as was the time to death (P=0.06).
Outcomes were superior with ritonavir-boosted lopinavir among young children with no prior exposure to nevirapine. Factors that may have contributed to the suboptimal results with nevirapine include elevated viral load at baseline, selection for nevirapine resistance, background regimen of nucleoside reverse-transcriptase inhibitors, and the standard ramp-up dosing strategy. The results of this trial present policymakers with difficult choices. (Funded by the National Institute of Allergy and Infectious Diseases and others; P1060 ClinicalTrials.gov number, NCT00307151.).
Full-text · Article · Jun 2012 · New England Journal of Medicine
[Show abstract][Hide abstract] ABSTRACT: Neonatal sepsis due to intestinal bacterial translocation is a major cause of morbidity and mortality. Understanding microbial colonisation of the gut in prematurity may predict risk of sepsis to guide future strategies to manipulate the microbiome.
Prospective longitudinal study of premature infants. Stool samples were obtained weekly. DNA was extracted and the V6 hypervariable region of 16S rRNA was amplified followed by high throughput pyrosequencing, comparing subjects with and without sepsis.
Six neonates were 24-27 weeks gestation at birth and had 18 samples analysed. Two subjects had no sepsis during the study period, two developed late-onset culture-positive sepsis and two had culture-negative systemic inflammation. 324 350 sequences were obtained. The meconium was not sterile and had predominance of Lactobacillus, Staphylococcus and Enterobacteriales. Overall, infants who developed sepsis began life with low microbial diversity, and acquired a predominance of Staphylococcus, while healthy infants had more diversity and predominance of Clostridium, Klebsiella and Veillonella.
In very low birth weight infants, the authors found that meconium is not sterile and is less diverse from birth in infants who will develop late-onset sepsis. Empiric, prolonged antibiotics profoundly decrease microbial diversity and promote a microbiota that is associated not only with neonatal sepsis, but the predominant pathogen previously identified in the microbiome. Our data suggest that there may be a 'healthy microbiome' present in extremely premature neonates that may ameliorate risk of sepsis. More research is needed to determine whether altered antibiotics, probiotics or other novel therapies can re-establish a healthy microbiome in neonates.
Full-text · Article · May 2012 · Archives of Disease in Childhood - Fetal and Neonatal Edition
[Show abstract][Hide abstract] ABSTRACT: Identification of HIV infection in exposed infants facilitates early therapy, which may limit viral reservoirs that maintain HIV infection under HAART.
The dynamics of the resting CD4 T-cell latent HIV reservoir was determined over the first 2 years of life in 17 HIV-infected infants initiating lopinavir/ritonavir-based HAART at a median age of 8.1 weeks and achieving adequate suppression of plasma viral load by 24 weeks.
The resting CD4 T-cell latent HIV reservoir was detected in 12 of 14 (86%) infants tested at 24 weeks of HAART [median frequency 1.88 infectious units per million (IUPM); range <0.22 to 81.7), and remained measurable (median IUPM = 0.32; range <0.22 to 3.25) in six of 10 (60%) children retested at 96 weeks. The reservoir declined, from 24 to 96 weeks of HAART, at an estimated mean rate of 0.028 log10 IUPM/month, corresponding to a half-life of 11 months (95% confidence interval 6-30 months]. A strong relationship was found between the frequency of latently infected CD4 T cells at 96 weeks of HAART and time to first undetectable plasma viral load (Spearman r = 0.91, P < 0.001).
Although the resting CD4 T-cell latent reservoir remains detectable over the first 2 years of HAART in a substantial proportion of infants, its size is associated with time to first undetectable viral load. To minimize HIV reservoirs in infants, rapid curtailment of viremia may limit HIV reservoirs and should be a therapeutic goal of early HAART in infants.
No preview · Article · May 2012 · AIDS (London, England)
[Show abstract][Hide abstract] ABSTRACT: Confirming the diagnosis of childhood tuberculosis is a major challenge. However, research on childhood tuberculosis as it relates to better diagnostics is often neglected because of technical difficulties, such as the slow growth in culture, the difficulty of obtaining specimens, and the diverse and relatively nonspecific clinical presentation of tuberculosis in this age group. Researchers often use individually designed criteria for enrollment, diagnostic classifications, and reference standards, thereby hindering the interpretation and comparability of their findings. The development of standardized research approaches and definitions is therefore needed to strengthen the evaluation of new diagnostics for detection and confirmation of tuberculosis in children. In this article we present consensus statements on methodological issues for conducting research of Tuberculosis diagnostics among children, with a focus on intrathoracic tuberculosis. The statements are complementary to a clinical research case definition presented in an accompanying publication and suggest a phased approach to diagnostics evaluation; entry criteria for enrollment; methods for classification of disease certainty, including the rational use of culture within the case definition; age categories and comorbidities for reporting results; and the need to use standard operating procedures. Special consideration is given to the performance of microbiological culture in children and we also recommend for alternative methodological approaches to report findings in a standardized manner to overcome these limitations are made. This consensus statement is an important step toward ensuring greater rigor and comparability of pediatric tuberculosis diagnostic research, with the aim of realizing the full potential of better tests for children.
Full-text · Article · Apr 2012 · The Journal of Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: HIV is a retrovirus whose genetic material is comprised of RNA. It is a decidedly adaptable virus with properties of high replication rates in association with an RNA copying enzyme-reverse transcriptase-which possesses a relatively high copying error rate, in the order of 1 error or mutation for every 10,000 nucleotides copied. This translates to a single mutation for every viral replication event on average in the setting of a billion viral copies produced daily in an infected individual. As such, the viral quasispecies (the pool of viral variants present at a given time) can and does adapt rapidly to environmental pressures such as the immune response or antiretroviral agents. It should not be surprising, therefore, that as antiretroviral agents have been developed and deployed, mutations in HIV genes associated with ARV resistance have rapidly been detected, underscoring the strategy of multiple agent and multiple class ARV therapy known as highly active antiretroviral therapy (HAART).
No preview · Article · Jan 2012 · Advances in Experimental Medicine and Biology
[Show abstract][Hide abstract] ABSTRACT: Improved antiretroviral therapies are needed for the treatment of HIV-infected infants, given the rapid progression of the disease and drug resistance resulting from perinatal exposure to antiretrovirals. We examined longitudinal pharmacokinetics (PK) data from a clinical trial of lopinavir/ritonavir (LPV/r) in HIV-infected infants in whom therapy was initiated at less than 6 months of age. A population PK analysis was performed using NONMEM to characterize changes in lopinavir (LPV) PK relating to maturational changes in infants, and to assess dosing requirements in this population. We also investigated the relationship between LPV PK and viral dynamic response. Age and ritonavir concentrations were the only covariates found to be significant. Population PK of LPV was characterized by high apparent clearance (CL/F) in young infants, which decreased with increasing age. Although younger infants had lower LPV concentrations, the viral dynamics did not correlate with initial LPV exposure. Monte Carlo simulations demonstrated that WHO weight band-based dosing recommendations predicted therapeutic LPV concentrations and provided drug exposure levels comparable to those resulting from US Food and Drug Administration (FDA)-suggested dosing regimens.
[Show abstract][Hide abstract] ABSTRACT: Highly active antiretroviral therapy (HAART) has improved human immunodeficiency virus (HIV)-associated morbidity and mortality. The bimodal mortality distribution in HIV-infected children makes it important to evaluate temporal effects of HAART among a birth cohort with long-term, prospective follow-up.
Perinatal AIDS Collaborative Transmission Study (PACTS)/PACTS-HIV Follow-up of Perinatally Exposed Children (HOPE) study was a Centers for Disease Control and Prevention-sponsored multicenter, prospective birth cohort study of HIV-exposed uninfected and infected infants from 1985 until 2004. Mortality was evaluated for the no/monotherapy, mono-/dual-therapy, and HAART eras, that is, 1 January 1986 through 31 December 1990, from 1 January 1991 through 31 December 1996, and 1 January 1997 through 31 December 2004.
Among 364 HIV-infected children, 56% were female and 69% black non-Hispanic. Of 98 deaths, 79 (81%) and 61 (62%) occurred in children ≤3 and ≤2 years old, respectively. The median age at death increased significantly across the eras (P < .0001). The average annual mortality rates were 18 (95% confidence interval [CI], 11.6-26.8), 6.9 (95% CI, 5.4-8.8), and 0.8 (95% CI, 0.4-1.5) events per 100 person-years for the no/monotherapy, mono-/dual-therapy and HAART eras, respectively. The corresponding 6-year survival rates for children born in these eras were 57%, 76%, and 91%, respectively (P < .0001). Among children who received HAART in the first 6 months of age, the probability of 6-year survival was 94%. Ten-year survival rates for HAART and non-HAART recipients were 94% and 45% (P < .05). HAART-associated reductions in mortality remained significant after adjustment for confounders (hazard ratio, 0.3; 95% CI, .08-.76). Opportunistic infections (OIs) caused 31.8%, 16.9%, and 9.1% of deaths across the respective eras (P = .051).
A significant decrease in annual mortality and a prolongation in survival were seen in this US perinatal cohort of HIV-infected children. Temporal decreases in OI-associated mortality resulted in relative proportional increases of non-OI-associated deaths.
Full-text · Article · Nov 2011 · Clinical Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Monitoring HIV drug resistance is an important component of the World Health Organization's global HIV program. HIV drug resistance testing is optimal with commercially available clinically validated test kits using plasma; however, that type of testing may not be feasible or affordable in resource-constrained settings. HIV genotyping from dried blood spots (DBS) with noncommercial (in-house) assays may facilitate the capture of HIV drug resistance outcomes in resource-constrained settings but has had varying rates of success. With in-house assays for HIV reverse transcriptase, we evaluated the yield of genotyping DBS samples collected from HIV-infected children who were enrolled in two clinical trials conducted in sub-Saharan Africa (median HIV viral load, 5.88 log(10) HIV RNA copies/ml; range, 4.04 to 6.99). Overall, HIV genotypes were obtained for 94 (89.5%) of 105 samples tested (95% and 84% from clinical trials #1 and #2, respectively); however, successful analysis of 15 (16.1%) of the 94 samples required repeat testing using a different set of primers on previously synthesized cDNA. The yield of genotyping was lower on the DBS that were stored suboptimally from clinical trial #2 (56% versus 88% for optimally stored). Concordance with plasma genotypes derived using a clinically validated, commercial kit-based assay (ViroSeq HIV-1 genotyping system) was also assessed in a subset of children with paired testing. For 34 samples with paired DBS and plasma genotypes, there was 100% concordance for major drug resistance mutations. DBS genotyping using in-house assays provides an alternative for antiretroviral drug resistance testing in children in resource-constrained regions but may require region-specific optimization before widespread use.
[Show abstract][Hide abstract] ABSTRACT: To investigate the longitudinal pharmacokinetics, safety and efficacy of lopinavir/ritonavir (LPV/r) in HIV-infected infants initiating combination antiretroviral therapy (cART) between 2 weeks and 6 months of age.
A prospective, open-label, multicenter Phase I/II study of LPV/r-based cART at a dose of 300/75 mg/m(2)/dose LPV/r twice daily. Intensive pharmacokinetic sampling at 12 months of age and quarterly predose LPV concentrations were collected and safety, virologic and immunologic responses were monitored every 4-12 weeks up to 252 weeks.
Thirty-one HIV-infected infants enrolled into two age cohorts, 14 days to <6 weeks and 6 weeks to <6 months; 29 completed ≥48 weeks of follow-up (median = 123 weeks, range 4-252). At 12 months of age, median LPV area under the curve was comparable for both age cohorts and similar to older children and adults. At week 48, 22 of 31 patients (71%) had HIV-1 RNA <400 copies/ml and 11 of 15 (73%) had <50 copies/ml; 29 of 31 achieved HIV-1 RNA <400 copies/ml on study treatment and 19 (66%) remained durably suppressed until the end of study; viral suppression correlated with a higher percentage of predose time points exceeding the LPV target of 1 μg/ml (92 vs. 71%, P = 0.002).
LPV/r at 300/75 mg/m(2)/dose as part of a cART regimen resulted in viral suppression through 96 weeks of treatment in >65% of young infants. Due to initially low LPV exposure in infants <6 weeks of age, frequent dose adjustment for weight gain is advisable and consideration should be given to studying a higher dose for very young infants.
Full-text · Article · Feb 2011 · AIDS (London, England)
[Show abstract][Hide abstract] ABSTRACT: Diagnosis and management of perinatally acquired human immunodeficiency virus infection poses many challenges in the areas of diagnosis, clinical and psychosocial intervention, and public health policy. Diagnostic tests have evolved over the years and many are currently used in the perinatal setting. Considerable progress has been realized in each of these areas through cooperative efforts of laboratory scientists, clinical teams, and stakeholders. However, there remain multiple challenges to address in the future.
No preview · Article · Dec 2010 · Clinics in perinatology
[Show abstract][Hide abstract] ABSTRACT: Single-dose nevirapine is the cornerstone of the regimen for prevention of mother-to-child transmission of human immunodeficiency virus (HIV) in resource-limited settings, but nevirapine frequently selects for resistant virus in mothers and children who become infected despite prophylaxis. The optimal antiretroviral treatment strategy for children who have had prior exposure to single-dose nevirapine is unknown.
We conducted a randomized trial of initial therapy with zidovudine and lamivudine plus either nevirapine or ritonavir-boosted lopinavir in HIV-infected children 6 to 36 months of age, in six African countries, who qualified for treatment according to World Health Organization (WHO) criteria. Results are reported for the cohort that included children exposed to single-dose nevirapine prophylaxis. The primary end point was virologic failure or discontinuation of treatment by study week 24. Enrollment in this cohort was terminated early on the recommendation of the data and safety monitoring board.
A total of 164 children were enrolled. The median percentage of CD4+ lymphocytes was 19%; a total of 56% of the children had WHO stage 3 or 4 disease. More children in the nevirapine group than in the ritonavir-boosted lopinavir group reached a primary end point (39.6% vs. 21.7%; weighted difference, 18.6 percentage-points; 95% confidence interval, 3.7 to 33.6; nominal P=0.02). Baseline resistance to nevirapine was detected in 18 of 148 children (12%) and was predictive of treatment failure. No significant between-group differences were seen in the rate of adverse events.
Among children with prior exposure to single-dose nevirapine for perinatal prevention of HIV transmission, antiretroviral treatment consisting of zidovudine and lamivudine plus ritonavir-boosted lopinavir resulted in better outcomes than did treatment with zidovudine and lamivudine plus nevirapine. Since nevirapine is used for both treatment and perinatal prevention of HIV infection in resource-limited settings, alternative strategies for the prevention of HIV transmission from mother to child, as well as for the treatment of HIV infection, are urgently required. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00307151.).
Full-text · Article · Oct 2010 · New England Journal of Medicine
[Show abstract][Hide abstract] ABSTRACT: Medication adherence is critical for children's HIV treatment success, but obtaining accurate assessments is challenging when complex measurement technologies are not feasible. Our goal was to evaluate a multidimensional adherence interview designed to improve on existing adherence measures. Data from caregivers (N = 126) of perinatally infected children were analyzed to determine the ability of the revised interview guide to detect potential treatment nonadherence. Questions related to viral load (VL) on a bivariate level included proportion of doses taken in the previous 3 days and 6 months, caregivers' knowledge of prescribed dosing frequencies, and caregivers' reports of problems associated with medication administration. VL was not associated with 3-day recall of missed doses. In multivariate analyses, only caregiver knowledge of prescribed dosing frequencies was uniquely associated with VL. Our modified interview appears to successfully identify family struggles with adherence and to have the capacity to help clinicians address medication adherence challenges.
Full-text · Article · May 2010 · The Journal of the Association of Nurses in AIDS Care: JANAC
[Show abstract][Hide abstract] ABSTRACT: Eukaryotic translation initiation factor eIF5A has been implicated in HIV-1 replication. This protein contains the apparently unique amino acid hypusine that is formed by the post-translational modification of a lysine residue catalyzed by deoxyhypusine synthase and deoxyhypusine hydroxylase (DOHH). DOHH activity is inhibited by two clinically used drugs, the topical fungicide ciclopirox and the systemic medicinal iron chelator deferiprone. Deferiprone has been reported to inhibit HIV-1 replication in tissue culture.
Ciclopirox and deferiprone blocked HIV-1 replication in PBMCs. To examine the underlying mechanisms, we investigated the action of the drugs on eIF5A modification and HIV-1 gene expression in model systems. At early times after drug exposure, both drugs inhibited substrate binding to DOHH and prevented the formation of mature eIF5A. Viral gene expression from HIV-1 molecular clones was suppressed at the RNA level independently of all viral genes. The inhibition was specific for the viral promoter and occurred at the level of HIV-1 transcription initiation. Partial knockdown of eIF5A-1 by siRNA led to inhibition of HIV-1 gene expression that was non-additive with drug action. These data support the importance of eIF5A and hypusine formation in HIV-1 gene expression.
At clinically relevant concentrations, two widely used drugs blocked HIV-1 replication ex vivo. They specifically inhibited expression from the HIV-1 promoter at the level of transcription initiation. Both drugs interfered with the hydroxylation step in the hypusine modification of eIF5A. These results have profound implications for the potential therapeutic use of these drugs as antiretrovirals and for the development of optimized analogs.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: With increasing recognition of the benefits of early antiretroviral therapy initiation in perinatally HIV-infected infants, data are needed regarding the pharmacokinetics (PK), safety, and efficacy of recommended first-line protease inhibitors such as lopinavir/ritonavir (LPV/r).
METHODS: A prospective, phase I/II, open-label, dose-finding trial evaluated LPV/r at a dose of 300/75 mg/m twice daily plus 2 nucleoside analogs in HIV-1-infected infants > or =14 days to /r therapy, and doses were modified to maintain LPV predose concentrations >1 microg/mL and area under the curve (AUC) /mL.
RESULTS: Ten infants enrolled [median age 5.7 (range, 3.6-5.9) weeks] with median HIV-1 RNA of 6.0 (range, 4.7-7.2) log10 copies/mL; all completed 24 weeks of follow-up. Nine completed the intensive PK evaluation at a median LPV dose of 267 (range, 246-305) mg/m q12 hours; median measures were AUC = 36.6 (range, 27.9-62.6) microg hr/mL; predose concentration = 2.2 (range, 0.99-4.9) microg/mL; maximum concentration = 4.76 (range, 2.84-7.28) microg/mL and apparent clearance (L/h/m) = 6.75 (range, 2.79-12.83). Adverse events were limited to transient grade 3 neutropenia in 3 subjects. By week 24, 2 of 10 subjects had experienced a protocol-defined virologic failure.
CONCLUSIONS: Although the LPV AUC in this population was significantly lower than that observed in infants ages 6 weeks to 6 months, LPV/r-based antiretroviral therapy in doses of 300/75 mg/m BID was well tolerated and resulted in virologic control in 8 of 10 infants by 24 weeks. Additional investigation is needed to understand the long-term implications of the lower LPV exposure in this age group.