PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (25)
 

Clipboard (0)
None

Select a Filter Below

Authors
more »
Year of Publication
more »
1.  Cotrimoxazole Prophylaxis and Risk of Severe Anemia or Severe Neutropenia in HAART-Exposed, HIV-Uninfected Infants 
PLoS ONE  2013;8(9):e74171.
Background
Prophylactic cotrimoxazole is recommended for infants born to HIV-infected mothers. However, cotrimoxazole may increase the risk of severe anemia or neutropenia.
Methods
We compared the proportion of HIV-exposed uninfected (HIV-EU) infants experiencing incident severe anemia (and separately, severe neutropenia) between a prospective cohort receiving prophylactic cotrimoxazole from 1 to 6 months vs. infants from two prior trials who did not receive cotrimoxazole. Infants were from rural and urban communities in southern Botswana.
Results
A total of 1705 HIV-EU infants were included. Among these 645 (37.8%) were fed with iron-supplemented formula from birth. Severe anemia developed in 87 (5.1%) infants, and severe neutropenia in 164 (9.6%) infants. In an analysis stratified by infant feeding method, there were no significant differences in the risk of severe anemia by prophylactic cotrimoxazole exposure–risk difference, −0.69% (95% confidence interval [CI] −2.1 to 0.76%). Findings were similar in multivariable analysis, adjusted odds ratio (aOR) 0.35 (95% CI 0.07 to 1.65). There were also no significant differences observed for severe neutropenia by cotrimoxazole exposure, risk difference 2.0% (95% CI −1.3 to 5.2%) and aOR 0.80 (95% CI 0.33 to 1.93).
Conclusions
Severe anemia and severe neutropenia were infrequent among HIV-exposed uninfected infants receiving cotrimoxazole from 1–6 months of age. Concerns regarding hematologic toxicity should not limit the use of prophylactic cotrimoxazole in HIV-exposed uninfected infants.
ClinicalTrials.gov Registration Numbers
NCT01086878 (http://clinicaltrials.gov/show/NCT01086878), NCT00197587 (http://clinicaltrials.gov/show/NCT00197587), and NCT00270296 (http://clinicaltrials.gov/show/NCT00270296).
doi:10.1371/journal.pone.0074171
PMCID: PMC3781096  PMID: 24086319
2.  Switching HIV Treatment in Adults Based on CD4 Count Versus Viral Load Monitoring: A Randomized, Non-Inferiority Trial in Thailand 
PLoS Medicine  2013;10(8):e1001494.
Using a randomized controlled trial, Marc Lallemant and colleagues ask if a CD4-based monitoring and treatment switching strategy provides a similar clinical outcome compared to the standard viral load-based strategy for adults with HIV in Thailand.
Please see later in the article for the Editors' Summary
Background
Viral load (VL) is recommended for monitoring the response to highly active antiretroviral therapy (HAART) but is not routinely available in most low- and middle-income countries. The purpose of the study was to determine whether a CD4-based monitoring and switching strategy would provide a similar clinical outcome compared to the standard VL-based strategy in Thailand.
Methods and Findings
The Programs for HIV Prevention and Treatment (PHPT-3) non-inferiority randomized clinical trial compared a treatment switching strategy based on CD4-only (CD4) monitoring versus viral-load (VL). Consenting participants were antiretroviral-naïve HIV-infected adults (CD4 count 50–250/mm3) initiating non-nucleotide reverse transcriptase inhibitor (NNRTI)-based therapy. Randomization, stratified by site (21 public hospitals), was performed centrally after enrollment. Clinicians were unaware of the VL values of patients randomized to the CD4 arm. Participants switched to second-line combination with confirmed CD4 decline >30% from peak (within 200 cells from baseline) in the CD4 arm, or confirmed VL >400 copies/ml in the VL arm. Primary endpoint was clinical failure at 3 years, defined as death, new AIDS-defining event, or CD4 <50 cells/mm3. The 3-year Kaplan-Meier cumulative risks of clinical failure were compared for non-inferiority with a margin of 7.4%. In the intent to treat analysis, data were censored at the date of death or at last visit. The secondary endpoints were difference in future-drug-option (FDO) score, a measure of resistance profiles, virologic and immunologic responses, and the safety and tolerance of HAART. 716 participants were randomized, 356 to VL monitoring and 360 to CD4 monitoring. At 3 years, 319 participants (90%) in VL and 326 (91%) in CD4 were alive and on follow-up. The cumulative risk of clinical failure was 8.0% (95% CI 5.6–11.4) in VL versus 7.4% (5.1–10.7) in CD4, and the upper-limit of the one-sided 95% CI of the difference was 3.4%, meeting the pre-determined non-inferiority criterion. Probability of switch for study criteria was 5.2% (3.2–8.4) in VL versus 7.5% (5.0–11.1) in CD4 (p = 0.097). Median time from treatment initiation to switch was 11.7 months (7.7–19.4) in VL and 24.7 months (15.9–35.0) in CD4 (p = 0.001). The median duration of viremia >400 copies/ml at switch was 7.2 months (5.8–8.0) in VL versus 15.8 months (8.5–20.4) in CD4 (p = 0.002). FDO scores were not significantly different at time of switch. No adverse events related to the monitoring strategy were reported.
Conclusions
The 3-year rates of clinical failure and loss of treatment options did not differ between strategies although the longer-term consequences of CD4 monitoring would need to be investigated. These results provide reassurance to treatment programs currently based on CD4 monitoring as VL measurement becomes more affordable and feasible in resource-limited settings.
Trial registration
ClinicalTrials.gov NCT00162682
Please see later in the article for the Editors' Summary
Editors' Summary
Background
About 34 million people (most of them living in low-and middle-income countries) are currently infected with HIV, the virus that causes AIDS. HIV infection leads to the destruction of immune system cells (including CD4 cells, a type of white blood cell), leaving infected individuals susceptible to other infections. Early in the AIDS epidemic, most HIV-infected individuals died within 10 years of infection. Then, in 1996, highly active antiretroviral therapy (HAART)—combined drugs regimens that suppress viral replication and allow restoration of the immune system—became available. For people living in affluent countries, HIV/AIDS became a chronic condition but, because HAART was expensive, HIV/AIDS remained a fatal illness for people living in resource-limited countries. In 2003, the international community declared HIV/AIDS a global health emergency and, in 2006, it set the target of achieving universal global access to HAART by 2010. By the end of 2011, 8 million of the estimated 14.8 million people in need of HAART in low- and middle-income countries were receiving treatment.
Why Was This Study Done?
At the time this trial was conceived, national and international recommendations were that HIV-positive individuals should start HAART when their CD4 count fell below 200 cells/mm3 and should have their CD4 count regularly monitored to optimize HAART. In 2013, the World Health Organization (WHO) recommendations were updated to promote expanded eligibility for HAART with a CD4 of 500 cells/mm3 or less for adults, adolescents, and older children although priority is given to individuals with CD4 count of 350 cells/mm3 or less. Because HIV often becomes resistant to first-line antiretroviral drugs, WHO also recommends that viral load—the amount of virus in the blood—should be monitored so that suspected treatment failures can be confirmed and patients switched to second-line drugs in a timely manner. This monitoring and switching strategy is widely used in resource-rich settings, but is still very difficult to implement for low- and middle-income countries where resources for monitoring are limited and access to costly second-line drugs is restricted. In this randomized non-inferiority trial, the researchers compare the performance of a CD4-based treatment monitoring and switching strategy with the standard viral load-based strategy among HIV-positive adults in Thailand. In a randomized trial, individuals are assigned different interventions by the play of chance and followed up to compare the effects of these interventions; a non-inferiority trial investigates whether one treatment is not worse than another.
What Did the Researchers Do and Find?
The researchers assigned about 700 HIV-positive adults who were beginning HAART for the first time to have their CD4 count (CD4 arm) or their CD4 count and viral load (VL arm) determined every 3 months. Participants were switched to a second-line therapy if their CD4 count declined by more than 30% from their peak CD4 count (CD4 arm) or if a viral load of more than 400 copies/ml was recorded (VL arm). The 3-year cumulative risk of clinical failure (defined as death, a new AIDS-defining event, or a CD4 count of less than 50 cells/mm3) was 8% in the VL arm and 7.4% in the CD4 arm. This difference in clinical failure risk met the researchers' predefined criterion for non-inferiority. The probability of a treatment switch was similar in the two arms, but the average time from treatment initiation to treatment switch and the average duration of a high viral load after treatment switch were both longer in the CD4 arm than in the VL arm. Finally, the future-drug-option score, a measure of viral drug resistance profiles, was similar in the two arms at the time of treatment switch.
What Do These Findings Mean?
These findings suggest that, in Thailand, a CD4 switching strategy is non-inferior in terms of clinical outcomes among HIV-positive adults 3 years after beginning HAART when compared to the recommended viral load-based switching strategy and that there is no difference between the strategies in terms of viral suppression and immune restoration after 3-years follow-up. Importantly, however, even though patients in the CD4 arm spent longer with a high viral load than patients in the VL arm, the emergence of HIV mutants resistant to antiretroviral drugs was similar in the two arms. Although these findings provide no information about the long-term outcomes of the two monitoring strategies and may not be generalizable to routine care settings, they nevertheless provide reassurance that using CD4 counts alone to monitor HAART in HIV treatment programs in resource-limited settings is an appropriate strategy to use as viral load measurement becomes more affordable and feasible in these settings.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001494.
The World Health Organization provides information on all aspects of HIV/AIDS (in several languages); its 2010 recommendations for antiretroviral therapy for HIV infection in adults and adolescents are available as well as the June 2013 Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection: recommendations for a public health approach
The 2012 UNAIDS World AIDS Day Report provides up-to-date information about the AIDS epidemic and efforts to halt it
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
NAM/aidsmap provides basic information about HIV/AIDS and summaries of recent research findings on HIV care and treatment
Information is available from Avert, an international AIDS charity on many aspects of HIV/AIDS, including information on the global HIV/AIDS epidemic, on HIV and AIDS in Thailand, on universal access to AIDS treatment, and on starting, monitoring and switching HIV treatment (in English and Spanish)
The UK National Health Service Choices website provides information (including personal stories) about HIV and AIDS
More information about this trial (the PHPT-3 trial) is available
Patient stories about living with HIV/AIDS are available through Avert; the nonprofit website Healthtalkonline also provides personal stories about living with HIV, including stories about HIV treatment
doi:10.1371/journal.pmed.1001494
PMCID: PMC3735458  PMID: 23940461
3.  Pharmacokinetics and safety of a new paediatric fixed-dose combination of zidovudine/lamivudine/nevirapine in HIV-infected children 
Antiviral Therapy  2011;16(8):1287-1295.
Background
Alternatives to the available stavudine-containing paediatric fixed-dose combination (FDC) tablets are rapidly needed due to concerns regarding the cumulative toxicity of long-term stavudine exposure. We report the bioavailability and short-term safety of a novel paediatric FDC tablet of zidovudine (ZDV)/lamivudine (3TC)/nevirapine (NVP; 30/15/28 mg) in HIV-infected children.
Methods
In this Phase I/II open-label pharmacokinetic study, 42 children weighing 6–30 kg treated with NVP-based HAART for ≥4 weeks were randomized to receive the FDC tablets (GPO-VIR Z30) or the liquid formulations. Dosing was weight-based. Intensive 12-h blood sampling was performed after 2 weeks; subjects then crossed-over to the alternate formulation at equal doses and sampling repeated 2 weeks later. Pharmacokinetic parameters were determined by non-compartmental analysis. Buccal-swab samples were collected for cytochrome P450 (CYP)2B6 polymorphism analysis.
Results
With the FDC tablet, the geometric mean (90% CI) area under the curve (AUC) for ZDV, 3TC and NVP was 1.58 (1.49–1.68), 7.78 (7.38–8.19) and 68.88 (62.13–76.36) μg•h/ml, respectively. Rules for NVP therapeutic inadequacy were defined a priori, and despite lower NVP exposure with the tablet (P<0.001), the levels remained therapeutically adequate. ZDV AUC was similar between formulations. 3TC exposure was significantly higher with the tablet but comparable to historical data in adults and children taking branded tablets. While receiving the tablet, NVP AUC in children with CYP2B 516 GG (45%), GT (45%) and TT (10%) genotypes were 67.0, 74.5 and 106.4 μg•h/ml, respectively (P=0.04).
Conclusions
Disparities in drug exposure between formulations were observed; however, the FDC tablet delivered therapeutically adequate exposures of each drug and could well play an important role in simplifying antiretroviral treatment for children.
doi:10.3851/IMP1931
PMCID: PMC3348490  PMID: 22155910
4.  INCREASED INCIDENCE OF ASTHMA IN HIV-INFECTED CHILDREN TREATED WITH HAART IN THE NIH WOMEN AND INFANTS TRANSMISSION STUDY 
BACKGROUND
Immunoreconstitution of HIV-infected (HIV+) patients after treatment with highly antiretroviral therapy (HAART) appears to provoke inflammatory diseases.
OBJECTIVE
Determine whether HIV+ children on HAART (HIV+ HAART+) have a higher incidence of asthma than HIV+ children not on HAART (HIV+ HAART−).
METHODS
To investigate this possibility, 2,664 children (193 HIV+, 2,471 HIV−) born to HIV+ women were evaluated for the incidence and prevalence of asthma (i.e., asthma medication use), and change of CD4+ T cell percentage with time.
RESULTS
The HIV+ HAART+ children had higher CD4+ T cell percentages, lower CD8+ T cell percentages, and lower viral burdens than the HIV+ HAART− children (P≤0.05 to P≤0.01). The cumulative incidence of asthma medication use in HIV+ HAART+ children at 13.5 year rose to 33.5% vs. 11.5% in HIV+ HAART− children (hazard ratio=3.34, P=0.01) and was equal to that in the HIV− children. In children born prior to the HAART era, the prevalence of asthma medication use for HIV+ HAART+ children at 11 years of age was 10.4% vs. 3.8% for HIV+ HAART− children (odds ratio=3.38, P=0.02) and was equal to that of the HIV− children. The rate of change of CD4+ T cells (percent/year) around the time of first asthma medication for HIV+ HAART+ vs. HIV+ HAART− children was 0.81 vs. −1.43 (P=0.01).
CONCLUSION
The increased incidence of asthma in HIV+ HAART+ children may be driven by immunoreconstitution of CD4+ T cells.
CLINICAL IMPLICATIONS
This HIV model of pediatric asthma may yield clues to help explain the epidemic of asthma in the general pediatric population.
doi:10.1016/j.jaci.2008.04.043
PMCID: PMC3246282  PMID: 18547627
pediatric HIV infection; CD4+ T cell mediated induction of asthma; HAART-produced immunoreconstitution
5.  The interrelated transmission of human immunodeficiency virus type 1 and cytomegalovirus during gestation and delivery in the offspring of HIV-infected mothers 
Our objective was to analyze, in formula-fed infants, correlates of HIV mother-to-child transmission, including cytomegalovirus (CMV) infection.
HIV-infected infants were matched with HIV-uninfected by maternal HIV RNA in a case-control design. Infant CMV infection was determined by CMV-IgG at 18 months and timed by earlier CMV-IgM or -DNA. Correlations were assessed using logistic regression.
In utero HIV infection was independently associated with congenital CMV infection (P=0.01), intrapartum HIV infection with congenital-plus-intrapartum/neonatal CMV infection (P=0.01), and overall HIV with overall CMV infection (P=0.001), as well as prematurity (P=0.004).
Congenital and acquired CMV infections are strong independent correlates of mother-to-child HIV transmission.
doi:10.1097/QAI.0b013e31822d0433
PMCID: PMC3237680  PMID: 21792064
6.  Resistance Patterns Selected by Nevirapine vs. Efavirenz in HIV-Infected Patients Failing First-Line Antiretroviral Treatment: A Bayesian Analysis 
PLoS ONE  2011;6(11):e27427.
Background
WHO recommends starting therapy with a non-nucleoside reverse transcriptase inhibitor (NNRTI) and two nucleoside reverse transcriptase inhibitors (NRTIs), i.e. nevirapine or efavirenz, with lamivudine or emtricitabine, plus zidovudine or tenofovir. Few studies have compared resistance patterns induced by efavirenz and nevirapine in patients infected with the CRF01_AE Southeast Asian HIV-subtype. We compared patterns of NNRTI- and NRTI-associated mutations in Thai adults failing first-line nevirapine- and efavirenz -based combinations, using Bayesian statistics to optimize use of data.
Methods and Findings
In a treatment cohort of HIV-infected adults on NNRTI-based regimens, 119 experienced virologic failure (>500 copies/mL), with resistance mutations detected by consensus sequencing. Mutations were analyzed in relation to demographic, clinical, and laboratory variables at time of genotyping. The Geno2Pheno system was used to evaluate second-line drug options. Eighty-nine subjects were on nevirapine and 30 on efavirenz. The NRTI backbone consisted of lamivudine or emtricitabine plus either zidovudine (37), stavudine (65), or tenofovir (19). The K103N mutation was detected in 83% of patients on efavirenz vs. 28% on nevirapine, whereas Y181C was detected in 56% on nevirapine vs. 20% efavirenz. M184V was more common with nevirapine (87%) than efavirenz (63%). Nevirapine favored TAM-2 resistance pathways whereas efavirenz selected both TAM-2 and TAM-1 pathways. Emergence of TAM-2 mutations increased with the duration of virologic replication (OR 1.25–1.87 per month increment). In zidovudine-containing regimens, the overall risk of resistance across all drugs was lower with nevirapine than with efavirenz, whereas in tenofovir-containing regimen the opposite was true.
Conclusions
TAM-2 was the major NRTI resistance pathway for CRF01_AE, particularly with nevirapine; it appeared late after virological failure. In patients who failed, there appeared to be more second-line drug options when zidovudine was combined with nevirapine or tenofovir with efavirenz than with alternative combinations.
doi:10.1371/journal.pone.0027427
PMCID: PMC3223170  PMID: 22132100
7.  Hematological Safety of Perinatal Exposure to Zidovudine in Uninfected Infants Born to HIV Type 1-Infected Women in Thailand 
AIDS Research and Human Retroviruses  2010;26(10):1163-1166.
Abstract
The evolution of hematological parameters in HIV-1-exposed uninfected infants according to various durations of perinatal zidovudine exposure was studied. We used data prospectively collected among 1122 HIV-uninfected formula-fed infants born to HIV-infected mothers who participated in a clinical trial to prevent perinatal transmission in Thailand (PHPT-1). Infants were exposed to different durations of zidovudine both in utero and after birth. Hemoglobin level and leukocyte, absolute neutrophil, and lymphocyte counts were measured at birth and at 6 weeks of age. The association between hematological parameters at birth and the duration of zidovudine exposure in utero was studied using a linear regression model, and changes between birth and 6 weeks of age and the duration of postnatal zidovudine exposure using mixed effects models. At birth, the hemoglobin level was lower in newborns exposed to zidovudine for more than 7.5 weeks in utero (adjusted regression coefficient: −0.6 g/dl; 95% confidence interval: −1.1 to −0.1). Six weeks after birth, the hemoglobin level had decreased faster in infants administered zidovudine for more than 4 weeks (adjusted regression coefficient: −0.1 g/dl; 95% confidence interval: −0.2 to −0.1). The duration of perinatal zidovudine exposure was not associated with the evolution of leukocyte, neutrophil, and lymphocyte counts. Despite the differences in hemoglobin levels, grade 3 or 4 anemia did not significantly differ by maternal or infant zidovudine duration. The clinical impact appeared modest, but longer exposure may warrant close monitoring.
doi:10.1089/aid.2010.0034
PMCID: PMC2982712  PMID: 20854205
8.  Long-Term Effects of Highly Active Antiretroviral Therapy on CD4+ Cell Evolution among Children and Adolescents Infected with HIV: 5 Years and Counting 
Background
Lower percentages of CD4+ T lymphocytes are associated with adverse clinical outcomes among children and adolescents infected with human immunodeficiency virus (HIV). CD4+ lymphocyte percentage generally increases with receipt of highly active antiretroviral therapy (HAART), but long-term follow-up is required to assess whether these increases in CD4+ cell percentage are maintained and whether they lead to normal CD4+ cell percentages in children with severe immunosuppression.
Methods
The study population included 1236 children and adolescents perinatally infected with HIV who were enrolled in a US-based multicenter prospective cohort study (Pediatric AIDS Clinical Trials Group 219/219C) and who were not receiving HAART at study initiation. We estimated the effects of HAART, HAART with protease inhibitors, and HAART with nonnucleoside reverse-transcriptase inhibitors on CD4+ cell percentage, using marginal structural models to account for confounding by severity.
Results
Initiation of any type of HAART increased CD4+ cell percentage by 2.34% (95% confidence interval, 1.35%–3.33%) in the first year, relative to noninitiation of HAART. The substantial increases in CD4+ cell percentage observed after the first year of experience with these combination therapies were followed by relatively smaller increases that continued for 5 years after initiation. Although larger increases in CD4+ cell percentage were observed among children with a greater degree of immunosuppression at baseline, the mean CD4+ cell percentage after 5 years of HAART did not reach normal levels.
Conclusions
Our study supports the initiation of HAART in children before severe immunosuppression occurs for long-term maintenance of normal CD4+ cell percentages. This beneficial result must be weighed against the evidence of potential adverse events associated with the prolonged use of such therapy.
doi:10.1086/587900
PMCID: PMC3154876  PMID: 18426371
9.  Human immunodeficiency virus–hepatitis C virus co-infection in pregnant women and perinatal transmission to infants in Thailand 
Summary
Objectives
The objectives of this study were to assess the prevalence and factors associated with hepatitis C virus (HCV) infection in human immunodeficiency virus (HIV)-infected and -uninfected Thai pregnant women and the rate of HCV transmission to their infants.
Patients and methods
Study subjects included 1435 HIV-infected pregnant women and their infants, enrolled in a perinatal HIV prevention trial, and a control group of 448 HIV-uninfected pregnant women. Women were screened for HCV antibodies with an enzyme immunoassay. Positive results were confirmed by recombinant immunoblot and HCV RNA quantification. Infants were tested for HCV antibodies at 18 months or for HCV RNA at between 6 weeks and 6 months.
Results
Of the HIV-infected women, 2.9% were HCV-infected compared to 0.5% of HIV-uninfected women (p = 0.001). Only history of intravenous drug use was associated with HCV infection in HIV-infected women. Ten percent of infants born to co-infected mothers acquired HCV. The risk of transmission was associated with a high maternal HCV RNA (p = 0.012), but not with HIV-1 load or CD4 count.
Conclusions
Acquisition of HCV through intravenous drug use partially explains the higher rate of HCV infection in HIV-infected Thai women than in HIV-uninfected controls. Perinatal transmission occurred in 10% of infants of HIV–HCV-co-infected mothers and was associated with high maternal HCV RNA.
doi:10.1016/j.ijid.2009.09.002
PMCID: PMC2886172  PMID: 20047847
HIV; HCV; Risk factors; Perinatal transmission; Intravenous drug use; Thailand
10.  Efficacy and safety of one-month postpartum zidovudine and didanosine to prevent HIV-resistance mutations following intrapartum single-dose nevirapine 
Background
Intrapartum single-dose-nevirapine along with third trimester maternal and infant zidovudine are essential components of programs to prevent mother-to-child HIV transmission in resource-limited settings. The persistence of nevirapine in the plasma for three weeks postpartum risks selection of resistance mutations to non-nucleoside reverse transcriptase inhibitors (NNRTI). We hypothesized that a one-month zidovudine-plus-didanosine course initiated at the same time as single-dose nevirapine would prevent the selection of nevirapine resistance mutations.
Methods
PHPT-4 HIV-infected pregnant women with CD4 counts above 250 cells/mm3 received antepartum zidovudine from the third trimester until delivery, single-dose nevirapine during labor and one-month zidovudine-plus-didanosine postpartum. These women were matched on baseline viral load (VL), CD4 count and duration of antepartum zidovudine to women who received single-dose nevirapine in the PHPT-2 trial (controls). Consensus sequencing and the more sensitive oligonucleotide ligation assay (OLA) were performed on samples drawn at 7–10, 37–45 and 120 days postpartum (if VL>500 copies/mL) to detect K103N/Y181C/G190A mutations.
Results
The 222 PHPT-4 subjects did not differ from their matched controls in baseline characteristics except for age. Combined groups median CD4 count was 421 cells/mm3 [IQR: 322–549], VL 3.45 log10 copies/mL [2.79–4.00] and ZDV prophylaxis 10.4 weeks [9.1–11.4]. Using consensus sequencing, major NNRTI resistance mutations were detected postpartum in 0% of PHPT-4 subjects versus 10.4% of PHPT-2 controls. OLA detected resistance in 1.8% of PHPT-4 subjects versus 18.9% controls. Major NNRTI resistance mutations were detected by either method in 1.8% of PHPT-4 subjects versus 20.7% in controls (p<10−10).
Conclusions
One-month postpartum zidovudine-plus-didanosine prevented the selection of vast majority NNRTI resistance mutations.
doi:10.1086/650745
PMCID: PMC2922986  PMID: 20158398
Nevirapine resistance mutations; zidovudine-plus-didanosine; HIV/AIDS; maternal-fetal transmission; public health
11.  A Chewable Pediatric Fixed-dose Combination Tablet of Stavudine, Lamivudine, and Nevirapine 
Background
Pediatric fixed-dose combinations (FDCs) are needed to facilitate antiretroviral therapy in children. We evaluated the relative bioavailability, safety, and therapeutic adequacy of a novel chewable pediatric FDC tablet of stavudine (7 mg), lamivudine (30 mg), and nevirapine (50 mg), referred to as GPO-VIR S7, and compared it with the individual original brand-name liquid formulations in human immunode-ficiency virus-infected Thai children.
Methods
The International Maternal Pediatric Adolescent AIDS Clinical Trials group (IMPAACT) P1056 study was a phase I/II, 2-arm, randomized, open-label, multidose pharmacokinetic cross-over study. Children ≥6 to ≤30 kg receiving nevirapine-based HAART for at least 4 weeks were randomized to receive GPO-VIR S7 chewable tablets or the equivalent liquid formulations. Children were stratified by weight and dosing was weight-based. Intensive 12-hour blood sampling was performed on day 28, and subjects then crossed-over to the alternate formulation at equal doses with identical 12-hour sampling on day 56. Pharmacokinetic indices were determined by noncompartmental analysis.
Results
Thirty-four children completed the study. While taking Government Pharmaceutical Organization (GPO)-VIR S7 the geometric mean (90% CI) area under the curve was 1.54 μg · hr/mL (1.42–1.67) for stavudine, 6.39 (5.82–7.00) for lamivudine, and 74.06 (65.62–83.60) for nevirapine. Nevirapine drug exposure for GPO-VIR S7 was therapeutically adequate. Geometric mean area under the curve ratios (90% CI) of GPO-VIR S7/liquid formulation for stavudine, lamivudine, and nevirapine were 0.97 (0.92–1.02), 1.41 (1.30–1.53), and 1.08 (1.04–1.13), respectively. No serious drug-related toxicity was reported.
Conclusions
The chewable FDC was safe and provided therapeutically adequate plasma drug exposures in human immunodeficiency virus-infected children. Substituting the FDC for liquid formulations can simplify antiretroviral therapy.
doi:10.1097/INF.0b013e3181e2189d
PMCID: PMC2981099  PMID: 20453709
pharmacokinetics; antiretrovirals; fixed-dose combinations; children; Thailand
12.  Antiretroviral Exposure and Lymphocyte mtDNA Content Among Uninfected Infants of HIV-1-Infected Women 
Pediatrics  2009;124(6):e1189-e1197.
OBJECTIVE
Concern for potential adverse effects of antiretroviral (ARV) chemotherapy used to prevent mother-to-child HIV transmission has led the US Public Health Service to recommend long-term follow-up of ARV-exposed children. Nucleoside reverse transcriptase inhibitor ARV agents can inhibit DNA polymerase γ, impairing mitochondrial DNA (mtDNA) synthesis and resulting in depletion or dysfunction.
METHODS
We measured the mtDNA content of stored peripheral blood mononuclear cells (PBMCs) of 411 healthy children who were born to HIV-uninfected women and 213 uninfected infants who were born to HIV-infected women with or without in utero and neonatal ARV exposure. Cryopreserved PBMC mtDNA was quantified by using the Primagen Retina Mitox assay.
RESULTS
Geometric mean PBMC mtDNA levels were lower at birth in infants who were born to HIV-infected women. Among HIV-exposed children, mtDNA levels were lowest in those who were not exposed to ARVs, higher in those with exposure to zidovudine alone, and higher still in those with combination nucleoside reverse transcriptase inhibitor exposure. A similar pattern was observed in the corresponding women. Levels of mtDNA increased during the first 5 years of life in all HIV-exposed children but achieved normal levels only in those with ARV exposure.
CONCLUSIONS
Levels of mtDNA are lower than normal in HIV-exposed children. Contrary to expectation, PBMC mtDNA levels are significantly higher in ARV-exposed, HIV-uninfected infants and their infected mothers compared with ARV-unexposed infants and women. By 5 years, levels of PBMC mtDNA rise to normal concentrations in ARV-exposed children but remain depressed in ARV-unexposed children.
doi:10.1542/peds.2008-2771
PMCID: PMC2904486  PMID: 19933732
HIV; mitochondria; antiretroviral agents
13.  Development of Dual-class Antiretroviral Drug Resistance in a Child Coinfected with HIV and Tuberculosis: A Case Report from KwaZulu-Natal, South Africa 
Journal of Tropical Pediatrics  2008;55(1):60-62.
The treatment of concurrent HIV and tuberculosis (TB) in children <3 years of age has not been well-studied and is complicated by potential drug–drug interactions. The recommended antiretroviral therapy (ART) in coinfected children in South Africa consists of full-strength ritonavir, lamivudine and stavudine. We report on a child initiated on this regimen, during concurrent TB treatment, who promptly developed an adverse reaction, virologic failure and dual-class antiretroviral drug resistance, compromising subsequent salvage ART.
doi:10.1093/tropej/fmn074
PMCID: PMC2734312  PMID: 18786985
14.  Early Immunological Predictors of Neurodevelopmental Outcomes in HIV-Infected Children 
Background. A previous analysis of children infected with human immunodeficiency virus (HIV) in the Women and Infants Transmission Study showed a strong correlation between low activated CD8+ T lymphocytes in the first 2 months of life and good immunological prognosis. We sought to extend these observations to neurodevelopmental prognosis.
Methods. Ninety-eight HIV-infected children born before 1994 with flow cytometric data from the first 2 months of life and adequate neurodevelopmental testing through age 30 months were studied. Children were divided into those with low (⩽5% CD8+HLA-DR+ cells or ⩽25% CD8+CD38+ cells) or high (>5% CD8+HLA-DR+ cells or >25% CD8+CD38+ cells) immune activation at 1 and/or 2 months of age. Analysis was performed using survival analysis, Cox's proportional hazard regression, and longitudinal regression models.
Results. Absence of immune activation, measured as ⩽5% CD8+HLA-DR+ cells, was strongly associated with better performance on the psychomotor developmental index of the Bayley scales of infant development through the third year of life. This association persisted after adjustment for CD4 cell count, viral load, and progression to acquired immunodeficiency syndrome (P=.005). An association with the mental development index was also present (P=.048). Significant association between neurodevelopmental outcomes and ⩽25% CD8+CD38+ cells was not seen.
Conclusions. In this prospective cohort study of HIV-infected children, there was a significant favorable association of low immune activation in peripheral T cells at age 1 or 2 months, measured by a low percentage of CD8+HLA-DR+ cells, with subsequent psychomotor and mental development. This association was independent of other indices of severity and progression of HIV infection.
doi:10.1086/595885
PMCID: PMC3671733  PMID: 19115969
15.  The first influenza pandemic of the 21st century 
Annals of Saudi Medicine  2010;30(1):1-10.
The 2009 H1N1 influenza virus (formerly known as swine flu) first appeared in Mexico and the United States in March and April 2009 and has swept the globe with unprecedented speed as a result of airline travel. On June 11, 2009, the World Health Organization raised its pandemic level to the highest level, Phase 6, indicating widespread community transmission on at least two continents. The 2009 H1N1 virus contains a unique combination of gene segments from human, swine and avian influenza A viruses. Children and young adults appear to be the most affected, perhaps reflecting protection in the elderly owing to exposure to H1N1 strains before 1957. Most clinical disease is relatively mild but complications leading to hospitalization, with the need for intensive care, can occur, especially in very young children, during pregnancy, in morbid obesity, and in those with underlying medical conditions such as chronic lung and cardiac diseases, diabetes, and immunosuppression. Bacterial coinfection has played a significant role in fatal cases. The case of fatality has been estimated at around 0.4%. Mathematical modeling suggests that the effect of novel influenza virus can be reduced by immunization, but the question remains: can we produce enough H1N1 vaccine to beat the pandemic?
doi:10.4103/0256-4947.59365
PMCID: PMC2850175  PMID: 20103951
16.  Haematological Safety of Perinatal Zidovudine in Pregnant HIV-1–Infected Women in Thailand: Secondary Analysis of a Randomized Trial 
PLoS Clinical Trials  2007;2(4):e11.
Objectives:
To respond to the primary safety objective of the Perinatal HIV Prevention Trial 1 (PHPT-1) by studying the evolution of haematological parameters according to zidovudine exposure duration in HIV-1−infected pregnant women.
Design:
Multicenter, randomized, double-blind, controlled trial of different durations of zidovudine prophylaxis.
Setting:
27 hospitals in Thailand.
Participants:
1,436 HIV-infected pregnant women in PHPT-1.
Intervention:
Zidovudine prophylaxis initiation at 28 or 35 wk gestation.
Outcome measures:
Haemoglobin level, leucocytes, total lymphocyte counts, and absolute neutrophil counts were measured at 26, 32, and 35 wk and at delivery. The evolution of haematological parameters was estimated between 26 and 35 wk (zidovudine/placebo) and between 35 wk and delivery to compare a long versus short zidovudine exposure. For each parameter, linear mixed models were adjusted on baseline sociodemographic variables, HIV clinical stage, CD4 count, and viral load.
Results:
Between 26 and 35 wk, haemoglobin, leucocytes, and absolute neutrophil counts decreased in zidovudine-exposed compared to unexposed women (mean difference [95% CI] −0.4 [−0.5 to −0.3], −423 [−703 to −142], −485 [−757 to −213], respectively). However, between 35 wk and delivery, the haematological parameters increased faster in women exposed to long rather than short durations of zidovudine (0.1 [0.0 to 0.1]; 105 [18 to 191]; 147 [59 to 234], respectively). At delivery, the differences were not statistically significant, except for mean haemoglobin level, which remained slightly lower in the long zidovudine treatment group (difference: 0.2 g/dl). Zidovudine had no negative impact on the absolute lymphocyte counts.
Conclusion:
Zidovudine initiated at 28 wk gestation rather than 35 wk had a transient negative impact on the evolution of haematological parameters, which was largely reversed by delivery despite continuation of zidovudine. This result provides reassurance about the safety of early initiation of zidovudine prophylaxis during pregnancy to maximize prevention of perinatal HIV.
Editorial Commentary
Background: Pregnant women who are infected with HIV are at high risk of passing on the virus to their unborn baby during pregnancy, labour, and breastfeeding. Around 15%–30% of babies born to HIV-positive women will themselves become infected, if the woman avoids breast-feeding but does not use any other means of preventing the virus from being passed on. However, if a drug, zidovudine (AZT), is given during pregnancy the chance of HIV being passed on to a baby drops from around 23% to around 8%. In some settings it may not be realistic to give the standard course of zidovudine, from 28 weeks of pregnancy, because of its cost and complexity. A number of trials have therefore looked at whether standard-course and short-course zidovudine are equivalent at reducing the risk of passing on HIV from mother to baby. One trial, the Perinatal HIV Prevention Trial-1 (PHPT-1) found that the short treatment course was substantially less effective at preventing HIV from being passed on from mother to baby. Current international guidance therefore recommends starting zidovudine at 28 weeks of pregnancy. However, zidovudine does have several side effects, including anemia; it can also cause a drop in the levels of certain types of white blood cell, and is thought to be toxic to bone marrow. The researchers who had carried out the PHPT-1 trial therefore wanted to do a subsequent analysis of data from that trial to find out whether there were any differences in these safety outcomes between standard and short course zidovudine.
What the trial shows: In total 1,436 women were recruited into the trial and assigned to receive either zidovudine from 28 weeks of pregnancy until delivery (standard course; 769 women), or from 35 weeks to delivery (short course; 667). Blood tests were performed at 26, 32, and 35 weeks of pregnancy and then at delivery, and the main outcomes assessed in this secondary analysis were the hemoglobin levels (to check for anemia), and levels of white blood cells, including the levels of two particular types (neutrophils and lymphocytes). The researchers found that standard-course zidovudine resulted in a drop at 35 weeks in the levels of hemoglobin and white blood cells, relative to short-course zidovudine. However, by the time of delivery these levels had recovered and no significant differences could be observed between the two arms of the trial. Women receiving standard-course zidovudine were more likely to experience severe anemia, which although a rare event in both arms of the trial, could have serious outcomes.
Strengths and limitations: The original trial from which these data were collected was a relatively large, randomized study and in which there was a low rate of loss to follow up. Although no formal sample size calculation was performed for the analyses presented here, the study probably had sufficient power to detect small differences in the outcomes assessed. A key limitation of this study is that the analyses presented here are a secondary exploration of data from the PHPT-1 trial and should therefore be seen as hypotheses to test in further studies, rather than as definitive conclusions.
Contribution to the evidence: The analyses presented here add to the findings of the parent trial, PHPT-1, by providing additional data about the toxicity of zidovudine. Other trials have not clearly established whether there are differences between short- and standard-course zidovudine in terms of their toxicity. The findings support current guidelines recommending standard-course zidovudine therapy for HIV-positive pregnant women. It is also crucial that efforts are made to ensure women worldwide can get access to facilities for monitoring the status of their HIV infection, and then receive highly active antiretroviral therapy when it is needed.
doi:10.1371/journal.pctr.0020011
PMCID: PMC1863515  PMID: 17476315
17.  Baseline resistance to nucleoside reverse transcriptase inhibitors fails to predict virologic response to combination therapy in children (PACTG 338) 
Background
The association between baseline drug resistance mutations and subsequent increase in viral failure has not been established for HIV-infected children. We evaluated drug resistance mutations at 39 codon sites (21 protease inhibitor (PI) resistant codons and 18 nucleoside reverse transcriptase inhibitor (NRTI) resistant codons) for 92 clinically stable NRTI-experienced, PI-naive HIV-infected children 2 to 17 years of age who were initiating new therapy with ritonavir plus zidovudine (ZDV) and lamivudine or plus stavudine. The association between baseline drug resistance mutations and subsequent viral failure after 12 and 24 weeks of highly active antiretroviral therapy (HAART) was studied.
Results
There were few primary PI associated mutations in this PI-naïve population, but 84% had NRTI mutations – codons 215 (66%), 41 (42%), 67 (37%), 210 (33%) and 70 (32%). None of the specific baseline drug resistance mutations were associated with a higher rate of virologic failure after 12 or 24 weeks of HAART. Median week 12 viral load decreased as the total number of NRTI mutations at baseline increased (P = 0.006). Specifically, a higher level of baseline ZDV resistance mutation was associated with a decrease in viral failure after 12 weeks on a ZDV-containing HAART regimen (P = 0.017).
Conclusion
No increase was seen in the rate of viral failure after HAART associated with the presence of resistance mutations at baseline. This paradoxical result may be due to adherence, replicative capacity, or ZDV hypersusceptibility to the new regimen.
doi:10.1186/1742-6405-4-2
PMCID: PMC1802955  PMID: 17280617
18.  Functionally Inert HIV-Specific Cytotoxic T Lymphocytes Do Not Play a Major Role in Chronically Infected Adults and Children 
The Journal of Experimental Medicine  2000;192(12):1819-1832.
The highly sensitive quantitation of virus-specific CD8+ T cells using major histocompatibility complex–peptide tetramer assays has revealed higher levels of cytotoxic T lymphocytes (CTLs) in acute and chronic virus infections than were recognized previously. However, studies in lymphocytic choriomeningitis virus infection have shown that tetramer assays may include measurement of a substantial number of tetramer-binding cells that are functionally inert. Such phenotypically silent CTLs, which lack cytolytic function and do not produce interferon (IFN)-γ, have been hypothesized to explain the persistence of virus in the face of a quantitatively large immune response, particularly when CD4 help is impaired. In this study, we examined the role of functionally inert CTLs in chronic HIV infection. Subjects studied included children and adults (n = 42) whose viral loads ranged from <50 to >100,000 RNA copies/ml plasma. Tetramer assays were compared with three functional assays: enzyme-linked immunospot (Elispot), intracellular cytokine staining, and precursor frequency (limiting dilution assay [LDA]) cytotoxicity assays. Strong positive associations were observed between cell numbers derived by the Elispot and the tetramer assay (r = 0.90). An even stronger association between tetramer-derived numbers and intracellular cytokine staining for IFN-γ was present (r = 0.97). The majority (median 76%) of tetramer-binding cells were consistently detectable via intracellular IFN-γ cytokine staining. Furthermore, modifications to the LDA, using a low input cell number into each well, enabled LDAs to reach equivalence with the other methods of CTL enumeration. These data together show that functionally inert CTLs do not play a significant role in chronic pediatric or adult HIV infection.
PMCID: PMC2213508  PMID: 11120778
peptide–major histocompatibility complex tetrameric complexes; intracellular cytokine staining; limiting dilution assays; enzyme-linked immunospot; CD8+ T cells
19.  Identification of Dominant Optimal HLA-B60- and HLA-B61-Restricted Cytotoxic T-Lymphocyte (CTL) Epitopes: Rapid Characterization of CTL Responses by Enzyme-Linked Immunospot Assay 
Journal of Virology  2000;74(18):8541-8549.
Human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T-lymphocyte (CTL) responses play a major role in the antiviral immune response, but the relative contribution of CTL responses restricted by different HLA class I molecules is less well defined. HLA-B60 or the related allele B61 is expressed in 10 to 20% of Caucasoid populations and is even more highly prevalent in Asian populations, but yet no CTL epitopes restricted by these alleles have been defined. Here we report the definition of five novel HLA-B60-restricted HIV-1-specific CTL epitopes, using peripheral blood mononuclear cells in enzyme-linked immunospot (Elispot) assays and using CTL clones and lines in cytolytic assays. The dominant HLA-B60-restricted epitope, Nef peptide KEKGGLEGL, was targeted by all eight subjects with B60 and also by both subjects with B61 studied. This study additionally establishes the utility of the Elispot assay as a more rapid and efficient method of defining novel CTL epitopes. This approach will help to define new CTL epitopes that may play an important role in the immune control of HIV-1.
PMCID: PMC116366  PMID: 10954555
20.  Characterization of a Novel Respiratory Syncytial Virus-Specific Human Cytotoxic T-Lymphocyte Epitope 
Journal of Virology  2000;74(16):7694-7697.
Respiratory syncytial virus (RSV) infection is a major cause of morbidity in childhood worldwide. The first human RSV-specific cytotoxic T-lymphocyte epitope to be defined is described. This HLA B7-restricted epitope in nucleoprotein (NP) was detectable in four healthy, B7-positive adult subjects using B7-RSV-NP tetrameric complexes to stain CD8+ T cells.
PMCID: PMC112296  PMID: 10906229
21.  A Polymorphism in the Regulatory Region of the CC-Chemokine Receptor 5 Gene Influences Perinatal Transmission of Human Immunodeficiency Virus Type 1 to African-American Infants 
Journal of Virology  1999;73(12):10264-10271.
There are natural mutations in the coding and noncoding regions of the human immunodeficiency virus type 1 (HIV-1) CC-chemokine coreceptor 5 (CCR5) and in the related CCR2 protein (the CCR2-64I mutation). Individuals homozygous for the CCR5-Δ32 allele, which prevents CCR5 expression, strongly resist HIV-1 infection. Several genetic polymorphisms have been identified within the CCR5 5′ regulatory region, some of which influence the rate of disease progression in adult AIDS study cohorts. We genotyped 1,442 infants (1,235 uninfected and 207 HIV-1 infected) for five CCR5 and CCR2 polymorphisms: CCR5-59353-T/C, CCR5-59356-C/T CCR5-59402-A/G, CCR5-Δ32, and CCR2-64I. The clinical significance of each genotype was assessed by measuring whether it influenced the rate of perinatal HIV-1 transmission among 667 AZT-untreated mother-infant pairs (554 uninfected and 113 HIV-1 infected). We found that the mutant CCR5-59356-T allele is relatively common in African-Americans (20.6% allele frequency among 552 infants) and rare in Caucasians and Hispanics (3.4 and 5.6% of 174 and 458 infants, respectively; P < 0.001). There were 38 infants homozygous for CCR5-59356-T, of whom 35 were African-Americans. Among the African-American infants in the AZT-untreated group, there was a highly significant increase in HIV-1 transmission to infants with two mutant CCR5-59356-T alleles (47.6% of 21), compared to those with no or one mutant allele (13.4 to 14.1% of 187 and 71, respectively; P < 0.001). The increased relative risk was 5.9 (95% confidence interval, 2.3 to 15.3; P < 0.001). The frequency of the CCR5-59356-T mutation varies between population groups in the United States, a low frequency occurring in Caucasians and a higher frequency occurring in African-Americans. Homozygosity for CCR5-59356-T is strongly associated with an increased rate of perinatal HIV-1 transmission.
PMCID: PMC113080  PMID: 10559343
22.  AIDS in Children 
Western Journal of Medicine  1988;148(2):230.
PMCID: PMC1026084  PMID: 18750387
23.  Activation of Complement by Cells Infected with Respiratory Syncytial Virus 
Infection and Immunity  1981;33(1):43-48.
The ability of respiratory syncytial virus (RSV)-infected HEp-2 cells in culture to activate complement was investigated. After incubation of cells with various complement sources and buffer, binding of C3b to surfaces of infected cells was demonstrated by immunofluorescence with a double-staining technique. Nonsyncytial and syncytial (i.e., fused, multinucleated) cells were separately enumerated. Also, lysis of RSV-infected cells was assessed by lactic dehydrogenase release. In this system only RSV-infected cells stained for C3b, and they did so only after incubation with functionally active complement. Blocking of classical pathway activation with ethylenediaminetetraacetic acid diminished the number of infected nonsyncytial cells positively stained for C3b, but had no effect on staining of syncytial cells. Blocking of alternative pathway activation with either zymosan incubation or heat treatment decreased the number of both syncytial and nonsyncytial cells stained for C3b. Decreasing immunoglobulin concentration of the serum used as the complement source also decreased numbers of both cell types stained for C3b. Eliminating specific anti-RSV antibody diminished numbers of both cell types stained for C3b, but staining was not eliminated. Lastly, incubation with functionally active complement markedly increased lactic dehydrogenase release from infected cells. This study demonstrated that RSV-infected nonsyncytial and syncytial cells are able to activate complement by both classical and alternative pathways. Activation of complement by syncytial cells appears to be less dependent on the classical pathway than is activation by nonsyncytial cells, and activation by syncytial cells may require immunoglobulin but not specific antibody. These experiments suggest the possibility of complement activation during respiratory tract infection by RSV. Implications of this are discussed.
Images
PMCID: PMC350650  PMID: 7263071
24.  Effect of Heat-Labile Factors on the Neutralization of Vaccinia Virus by Human Sera 
Infection and Immunity  1973;8(4):582-589.
The effect of unheated guinea pig and human prevaccination serum on the neutralization of vaccinia virus was studied. Enhancement of neutralization was found in all sera containing antibody and was more marked (20- to 150-fold) in sera obtained in the first weeks after primary vaccination than in sera from immune adults or cord sera (4- to 25-fold). The enhancing factor was thought to be complement because it was destroyed by heating and ethylenediaminetetraacetic acid treatment. The fresh serum-enhanced neutralization test represents a highly sensitive and specific test which can be applied to measure low levels of vaccinia antibody not detectable by other means.
PMCID: PMC422895  PMID: 4200542
25.  Morphogenesis of Avian Infectious Bronchitis Virus and a Related Human Virus (Strain 229E) 
Journal of Virology  1967;1(5):1019-1027.
Avian infectious bronchitis virus (IBV) and strain 229E, a virus recently recovered from patients with colds, have been shown to possess a similar distinctive morphology in negatively stained preparations. An electron microscopic study of the morphogenesis of IBV in the chorioallantoic membrane and of strain 229E in WI-38 cells was performed. In infected cells, round electron-dense particles 82 mμ in diameter were observed to form by a process of budding from membranes of the endoplasmic reticulum and cytoplasmic vesicles. The particles in IBV-infected cells were similar in size and shape to those in strain 229E-infected cells but showed certain differences in internal structure. The evidence that the particles represent virions and the implications of these findings in the classification of this virus group are discussed.
Images
PMCID: PMC375381  PMID: 5630226

Results 1-25 (25)