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1.  Mortality and loss to follow-up among HIV-infected persons on long-term antiretroviral therapy in Latin America and the Caribbean 
Long-term survival of HIV patients after initiating highly active antiretroviral therapy (ART) has not been sufficiently described in Latin America and the Caribbean, as compared to other regions. The aim of this study was to describe the incidence of mortality, loss to follow-up (LTFU) and associated risk factors for patients enrolled in the Caribbean, Central and South America Network (CCASAnet).
We assessed time from ART initiation (baseline) to death or LTFU between 2000 and 2014 among ART-naïve adults (≥18 years) from sites in seven countries included in CCASAnet: Argentina, Brazil, Chile, Haiti, Honduras, Mexico and Peru. Kaplan-Meier techniques were used to estimate the probability of mortality over time. Risk factors for death were assessed using Cox regression models stratified by site and adjusted for sex, baseline age, nadir pre-ART CD4 count, calendar year of ART initiation, clinical AIDS at baseline and type of ART regimen.
A total of 16,996 ART initiators were followed for a median of 3.5 years (interquartile range (IQR): 1.6–6.2). The median age at ART initiation was 36 years (IQR: 30–44), subjects were predominantly male (63%), median CD4 count was 156 cells/µL (IQR: 60–251) and 26% of subjects had clinical AIDS prior to starting ART. Initial ART regimens were predominantly non-nucleoside reverse transcriptase inhibitor based (86%). The cumulative incidence of LTFU five years after ART initiation was 18.2% (95% confidence interval (CI) 17.5–18.8%). A total of 1582 (9.3%) subjects died; the estimated probability of death one, three and five years after ART initiation was 5.4, 8.3 and 10.3%, respectively. The estimated five-year mortality probability varied substantially across sites, from 3.5 to 14.0%. Risk factors for death were clinical AIDS at baseline (adjusted hazard ratio (HR)=1.65 (95% CI 1.47–1.87); p<0.001), lower baseline CD4 (HR=1.95 (95% CI 1.63–2.32) for 50 vs. 350 cells/µL; p<0.001) and older age (HR=1.47 (95% CI 1.29–1.69) for 50 vs. 30 years at ART initiation; p<0.001).
In this large, long-term study of mortality among HIV-positive adults initiating ART in Latin America and the Caribbean, overall estimates of mortality were heterogeneous, generally falling between those reported in high-income countries and sub-Saharan Africa.
PMCID: PMC4499577  PMID: 26165322
HIV; AIDS; ART; Latin America; the Caribbean; long-term mortality
2.  Th17 and Th17/Treg ratio at early HIV infection associate with protective HIV-specific CD8+ T-cell responses and disease progression 
Scientific Reports  2015;5:11511.
The aim of this study was to analyze Th17 and Treg subsets and their correlation with anti-HIV T-cell responses and clinical parameters during (acute/early) primary HIV infection (PHI) and up to one year post-infection (p.i). Samples from 14 healthy donors (HDs), 40 PHI patients, 17 Chronics, and 13 Elite controllers (ECs) were studied. The percentages of Th17 and Treg subsets were severely altered in Chronics, whereas all HIV-infected individuals (including ECs) showed Th17/Treg imbalance compared to HDs, in concordance with higher frequencies of activated CD8+ T-cells (HLA-DR+/CD38+). Better clinical status (higher CD4 counts, lower viral loads and activation) was associated with higher Th17 and lower Treg levels. We found positive correlations between Th17 at baseline and anti-HIV CD8+ T-cell functionality: viral inhibitory activity (VIA) and key polyfunctions (IFN-γ+/CD107A/B+) at both early and later times p.i, highlighting the prognostic value of Th17 cells to preserve an effective HIV T-cell immunity. Th17/Treg ratio and the IL-17 relative mean fluorescence intensity (rMFI of IL-17) were also positively correlated with VIA. Taken together, our results suggested a potential link between Th17 and Th17/Treg ratio with key HIV-specific CD8+ T-cell responses against the infection.
PMCID: PMC4477236  PMID: 26099972
3.  CD4 Response Up to 5 Years After Combination Antiretroviral Therapy in Human Immunodeficiency Virus-Infected Patients in Latin America and the Caribbean 
Open Forum Infectious Diseases  2015;2(2):ofv079.
We describe CD4 counts at 6-month intervals for 5 years after combination antiretroviral therapy initiation among 12 879 antiretroviral-naive human immunodeficiency virus-infected adults from Latin America and the Caribbean. Median CD4 counts increased from 154 cells/mm3 at baseline (interquartile range [IQR], 60–251) to 413 cells/mm3 (IQR, 234–598) by year 5.
PMCID: PMC4498272  PMID: 26180829
cART; cohort; combination antiretroviral therapy; HIV/AIDS; immune recovery; inverse probability of censoring weights; Latin America and the Caribbean
4.  Host Genetic Factors Associated with Symptomatic Primary HIV Infection and Disease Progression among Argentinean Seroconverters 
PLoS ONE  2014;9(11):e113146.
Variants in HIV-coreceptor C-C chemokine receptor type 5 (CCR5) and Human leukocyte antigen (HLA) genes are the most important host genetic factors associated with HIV infection and disease progression. Our aim was to analyze the association of these genetic factors in the presence of clinical symptoms during Primary HIV Infection (PHI) and disease progression within the first year.
Seventy subjects diagnosed during PHI were studied (55 symptomatic and 15 asymptomatic). Viral load (VL) and CD4 T-cell count were evaluated. HIV progression was defined by presence of B or C events and/or CD4 T-cell counts <350 cell/mm3. CCR5 haplotypes were characterized by polymerase chain reaction and SDM-PCR-RFLP. HLA-I characterization was performed by Sequencing.
Symptoms during PHI were significantly associated with lower frequency of CCR5-CF1 (1.8% vs. 26.7%, p = 0.006). Rapid progression was significantly associated with higher frequency of CCR5-CF2 (16.7% vs. 0%, p = 0.024) and HLA-A*11 (16.7% vs. 1.2%, p = 0.003) and lower frequency of HLA-C*3 (2.8% vs. 17.5%, p = 0.035). Higher baseline VL was significantly associated with presence of HLA-A*11, HLA-A*24, and absence of HLA-A*31 and HLA-B*57. Higher 6-month VL was significantly associated with presence of CCR5-HHE, HLA-A*24, HLA-B*53, and absence of HLA-A*31 and CCR5-CF1. Lower baseline CD4 T-cell count was significantly associated with presence of HLA-A*24/*33, HLA-B*53, CCR5-CF2 and absence of HLA-A*01/*23 and CCR5-HHA. Lower 6-month CD4 T-cell count was associated with presence of HLA-A*24 and HLA-B*53, and absence of HLA-A*01 and HLA-B*07/*39. Moreover, lower 12-month CD4 T-cell count was significantly associated with presence of HLA-A*33, HLA-B*14, HLA-C*08, CCR5-CF2, and absence of HLA-B*07 and HLA-C*07.
Several host factors were significantly associated with disease progression in PHI subjects. Most results agree with previous studies performed in other groups. However, some genetic factor associations are being described for the first time, highlighting the importance of genetic studies at a local level.
PMCID: PMC4236131  PMID: 25406087
5.  Changes in lipid levels after 48 weeks of dual versus triple therapy observed in the GARDEL study 
Journal of the International AIDS Society  2014;17(4Suppl 3):19554.
Treatment with ritonavir-boosted protease inhibitors and nucleoside analogues frequently leads to rises in lipids, which might increase the cardiovascular risk. The aim of this study was to describe changes in lipid levels among HIV positive patients participating in the GARDEL study.
Materials and Methods
The GARDEL study compared the efficacy and safety of a dual therapy (DT) combination of LPV/r 400/100 mg BID+3TC 150 mg BID to a triple therapy (TT) with LPV/r 400/100 mg BID+3TC or FTC and a third investigator-selected NRTI in fixed-dose combination among HIV+ treatment naïve patients. We compared changes in lipid levels from baseline to week 48 in both arms.
Patient's characteristics were well balanced regarding mean baseline total cholesterol (157 mg/dL DT, 154 mg/dL TT), triglycerides (142 mg/dL DT, 139 mg/Dl TT), LDL-C (94 mg/dL DT, 91 mg/dL TT) and HDL-C (36 mg/dL DT, 35 mg/dL TT). Changes in total cholesterol, LDL-C and HDL-C were higher in DT arm, compared to TT (32% DT vs 26% TT for cholesterol; 25% DT vs 16% TT for LDL and 33% DT vs 28% TT for HDL). Increase in triglycerides was higher in TT compared to DT (55% DT vs 92% TT) (Table 1). In TT arm LDL-C and total cholesterol elevations were lower among patients receiving TDF compared to those treated with ZDV or ABC.
Changes in lipid parameters were observed in both arms. Albeit the increase was numerically higher for cholesterol (total and LDL-C) in DT arm while TT arm had higher increases in TG; no difference was observed when week 48 values were compared with the NCEP ATP III goals for cardiovascular risk reduction [1]. So, the DT strategy, even missing the lipid-lowering effect observed with tenofovir, does not seem to add significant risk to patients treated with this novel strategy.
PMCID: PMC4224811  PMID: 25394061
6.  Switching to nevirapine-based regimens after undetectable viral load is not associated with increased risk of discontinuation due to toxicity 
Journal of the International AIDS Society  2014;17(4Suppl 3):19794.
Due to its good tolerability, favourable cardiovascular risk-profile, low-pill burden and cost, nevirapine-based regimens are an attractive simplification strategy for patients with suppressed viral load (VL). However, current guidelines recommend caution if nevirapine (NVP) is prescribed in males and females with CD4 counts above 400 or 250 cells/µL, respectively. The aim of this study is to determine the prevalence and risk factors associated with development of toxicity or treatment discontinuation in patients switching to NVP-based regimens.
Materials and Methods
Retrospective chart review of HIV-infected patients with suppressed VL who switched from a PI-based regimen to a NVP-based regimen in four HIV clinics in Argentina, between 1997 and 2013. Bivariate and multivariate analyses were performed to explore factors associated with treatment discontinuation. High CD4 count was defined as CD4-cell count ≥400 or 250 cells/µL in males and females, respectively.
Of 218 patients included, 165 (75.7%) were male; 21 (9.6%) were co-infected with HCV and/or HBV. Median baseline (BSL) CD4 count: 138 cells/µL (IQR: 64–276). At switch, patients had a median age of 38 years (IQR: 33.4–43.8) and had been suppressed for a median of 1.4 years (IQR: 0.6–2.2); 138 patients (63.3%) had high CD4-cell counts: among females, median CD4 count at switch was 462 (IQR: 330–709) cells/µL; among males, 433 (IQR: 305–595) cells/µL. Thirty-six patients (13.5%) presented NVP-related toxicity (30 skin toxicity, 6 hepatic toxicity), 29 (13.3%) discontinued NVP. Median time to development to toxicity: 32 days (IQR: 15–75). In bivariate analysis, chronic hepatitis was the only variable associated with development of toxicity (OR: 2.90, 95% CI 1.08–7.78). In multivariate analysis, no statistical significant associations were observed between either development of toxicity or treatment discontinuation and gender, chronic hepatitis, age or CD4-cell count at BSL or at switch (all p>0.05).
In our study, switching to a NVP-based regimen in patients with undetectable VL was associated with a low incidence of skin or liver toxicity, and treatment discontinuation. Moreover, these were unrelated to the CD4-cell count. Our findings suggest that, in contrast with ART-naïve patients, switching to NVP-based regimens could be a safe strategy for patients with suppressed viremia regardless of the CD4-cell count.
PMCID: PMC4225304  PMID: 25397538
7.  Factors associated with healthcare avoidance among transgender women in Argentina 
Transgender (TG) women in many settings continue to contend with barriers to healthcare, including experiences of stigma and discrimination. Argentina has a universal health care system and laws designed to promote healthcare access among TG women. However, little is known about barriers to healthcare access among TG women in this setting. The aim of this study was to explore individual, social-structural and environmental factors associated with healthcare avoidance among TG women in Argentina.
Data were derived from a 2013 nation-wide, cross-sectional study involving TG women in Argentina. We assessed the prevalence and factors associated with avoiding healthcare using multivariable logistic regression.
Among 452 TG women included in the study, 184 (40.7%) reported that they avoided seeking healthcare because of their transgender identity. In multivariable analysis, factors positively associated with avoiding seeking healthcare were: having been exposed to police violence (adjusted odd ratio [aOR] = 2.20; 95% CI: 1.26 – 3.83), internalized stigma (aOR = 1.60, 95% CI: 1.02–2.51), having experienced discrimination by healthcare workers (aOR = 3.36: 95% CI: 1.25 – 5.70) or patients (aOR = 2.57; 95% CI: 1.58 – 4.17), and currently living in the Buenos Aires metropolitan area (aOR = 2.32; 95% CI: 1.44 – 3.76). In contrast, TG women with extended health insurance were less likely to report avoiding healthcare (aOR = 0.49; 95% CI: 0.26 – 0.93).
A high proportion of TG women in our sample reported avoiding healthcare. Avoiding healthcare was associated with stigma and discrimination in healthcare settings, as well as police violence experiences. Although further research is warranted, these finding suggests that socio-structural interventions tailored TG women needs are needed to improve access to healthcare among this population.
PMCID: PMC4220051  PMID: 25261275
Transgender women; Argentina; Healthcare access; Police violence; Discrimination; Stigma
8.  Use of Third Line Antiretroviral Therapy in Latin America 
PLoS ONE  2014;9(9):e106887.
Access to highly active antiretroviral therapy (HAART) is expanding in Latin America. Many patients require second and third line therapy due to toxicity, tolerability, failure, or a combination of factors. The need for third line HAART, essential for program planning, is not known.
Antiretroviral-naïve patients ≥18 years who started first HAART after January 1, 2000 in Caribbean, Central and South America Network (CCASAnet) sites in Argentina, Brazil, Honduras, Mexico, and Peru were included. Clinical trials participants were excluded. Third line HAART was defined as use of darunavir, tipranavir, etravirine, enfuvirtide, maraviroc or raltegravir. Need for third line HAART was defined as virologic failure while on second line HAART.
Of 5853 HAART initiators followed for a median of 3.5 years, 310 (5.3%) failed a second line regimen and 44 (0.8%) received a third line regimen. Cumulative incidence of failing a 2nd or starting a 3rd line regimen was 2.7% and 6.0% three and five years after HAART initiation, respectively. Predictors at HAART initiation for failing a second or starting a third line included female sex (hazard ratio [HR] = 1.54, 95% confidence interval [CI] 1.18–2.00, p = 0.001), younger age (HR = 2.76 for 20 vs. 40 years, 95% CI 1.86–4.10, p<0.001), and prior AIDS (HR = 2.17, 95% CI 1.62–2.90, p<0.001).
Third line regimens may be needed for at least 6% of patients in Latin America within 5 years of starting HAART, a substantial proportion given the large numbers of patients on HAART in the region. Improved accessibility to third line regimens is warranted.
PMCID: PMC4164470  PMID: 25221931
9.  Early Skewed Distribution of Total and HIV-Specific CD8+ T-Cell Memory Phenotypes during Primary HIV Infection Is Related to Reduced Antiviral Activity and Faster Disease Progression 
PLoS ONE  2014;9(8):e104235.
The important role of the CD8+ T-cells on HIV control is well established. However, correlates of immune protection remain elusive. Although the importance of CD8+ T-cell specificity and functionality in virus control has been underscored, further unraveling the link between CD8+ T-cell differentiation and viral control is needed. Here, an immunophenotypic analysis (in terms of memory markers and Programmed cell death 1 (PD-1) expression) of the CD8+ T-cell subset found in primary HIV infection (PHI) was performed. The aim was to seek for associations with functional properties of the CD8+ T-cell subsets, viral control and subsequent disease progression. Also, results were compared with samples from Chronics and Elite Controllers. It was found that normal maturation of total and HIV-specific CD8+ T-cells into memory subsets is skewed in PHI, but not at the dramatic level observed in Chronics. Within the HIV-specific compartment, this alteration was evidenced by an accumulation of effector memory CD8+ T (TEM) cells over fully differentiated terminal effector CD8+ T (TTE) cells. Furthermore, higher proportions of total and HIV-specific CD8+ TEM cells and higher HIV-specific TEM/(TEM+TTE) ratio correlated with markers of faster progression. Analysis of PD-1 expression on total and HIV-specific CD8+ T-cells from PHI subjects revealed not only an association with disease progression but also with skewed memory CD8+ T-cell differentiation. Most notably, significant direct correlations were obtained between the functional capacity of CD8+ T-cells to inhibit viral replication in vitro with higher proportions of fully-differentiated HIV-specific CD8+ TTE cells, both at baseline and at 12 months post-infection. Thus, a relationship between preservation of CD8+ T-cell differentiation pathway and cell functionality was established. This report presents evidence concerning the link among CD8+ T-cell function, phenotype and virus control, hence supporting the instauration of early interventions to prevent irreversible immune damage.
PMCID: PMC4122399  PMID: 25093660
10.  MicroRNAs differentially present in the plasma of HIV elite controllers reduce HIV infection in vitro 
Scientific Reports  2014;4:5915.
Elite controllers maintain HIV-1 viral loads below the limit of detection. The mechanisms responsible for this phenomenon are poorly understood. As microRNAs (miRNAs) are regulators of gene expression and some of them modulate HIV infection, we have studied the miRNA profile in plasma from HIV elite controllers and chronically infected individuals and compared against healthy donors. Several miRNAs correlate with CD4+ T cell count or with the known time of infection. No significant differences were observed between elite controllers and healthy donors; however, 16 miRNAs were different in the plasma of chronic infected versus healthy donors. In addition, levels of hsa-miR-29b-3p, hsa-miR-33a-5p and hsa-miR-146a-5p were higher in plasma from elite controllers than chronic infected and hsa-miR-29b-3p and hsa-miR-33a-5p overexpression significantly reduced the viral production in MT2 and primary T CD4+ cells. Therefore, levels of circulating miRNAs might be of diagnostic and/or prognostic value for HIV infection, and hsa-miR-29b-3p and miR-33a-5p may contribute to the design of new anti-HIV drugs.
PMCID: PMC4118195  PMID: 25081906
11.  Patient–provider perceptions on engagement in HIV care in Argentina 
AIDS care  2013;26(5):602-607.
Approximately 30% of patients participating in the national antiretroviral therapy (ART) program in Argentina fail to achieve an undetectable viral load, and approximately 25% are not retained in care. This qualitative study was designed to explore and identify factors associated with engagement and retention in public and private health care in Buenos Aires, Argentina. Qualitative data from key informants (n = 12) and focus groups (n = 4 groups) of patients and providers from private and public HIV treatment facilities were recorded and transcribed. Predetermined and arising themes related to adherence, engagement, and retention in care were coded and analyzed using qualitative data analysis software. Reasons identified for patients’ lack of adherence or engagement in care differed between patients and providers, and patients attributed limitations to low self-efficacy, fear and concerns about HIV, and lack of provider involvement in treatment. In contrast, providers viewed themselves as decision-makers in patient care and patients as responsible for their own nonadherence due to lack of commitment to their own health or due to medication side effects. Patients reported health care system limitations and HIV concerns contributed to a lack of engagement, and providers identified limited HIV literacy and stigma as additional problems. Both agreed that chronic illness and substance addiction impacted adherence and retention, and agreed on the importance of trust, honesty, and communication in the patient–provider relationship. Results support the incorporation of system-, provider-, and patient-focused components into interventions to facilitate patient engagement, adherence, and retention in public and private settings in Argentina.
PMCID: PMC3966648  PMID: 24138788
HIV; adherence; engagement; communication; Argentina
12.  Early Gag Immunodominance of the HIV-Specific T-Cell Response during Acute/Early Infection Is Associated with Higher CD8+ T-Cell Antiviral Activity and Correlates with Preservation of the CD4+ T-Cell Compartment 
Journal of Virology  2013;87(13):7445-7462.
The important role of the CD8+ T-cell response on HIV control is well established. Moreover, the acute phase of infection represents a proper scenario to delineate the antiviral cellular functions that best correlate with control. Here, multiple functional aspects (specificity, ex vivo viral inhibitory activity [VIA] and polyfunctionality) of the HIV-specific CD8+ T-cell subset arising early after infection, and their association with disease progression markers, were examined. Blood samples from 44 subjects recruited within 6 months from infection (primary HIV infection [PHI] group), 16 chronically infected subjects, 11 elite controllers (EC), and 10 healthy donors were obtained. Results indicated that, although Nef dominated the anti-HIV response during acute/early infection, a higher proportion of early anti-Gag T cells correlated with delayed progression. Polyfunctional HIV-specific CD8+ T cells were detected at early time points but did not associate with virus control. Conversely, higher CD4+ T-cell set points were observed in PHI subjects with higher HIV-specific CD8+ T-cell VIA at baseline. Importantly, VIA levels correlated with the magnitude of the anti-Gag cellular response. The advantage of Gag-specific cells may result from their enhanced ability to mediate lysis of infected cells (evidenced by a higher capacity to degranulate and to mediate VIA) and to simultaneously produce IFN-γ. Finally, Gag immunodominance was associated with elevated plasma levels of interleukin 2 (IL-2) and macrophage inflammatory protein 1β (MIP-1β). All together, this study underscores the importance of CD8+ T-cell specificity in the improved control of disease progression, which was related to the capacity of Gag-specific cells to mediate both lytic and nonlytic antiviral mechanisms at early time points postinfection.
PMCID: PMC3700299  PMID: 23616666
13.  Antiretroviral Adherence During Pregnancy and Postpartum in Latin America 
AIDS Patient Care and STDs  2012;26(8):486-495.
Adherence to antiretrovirals by pregnant women (and postpartum women if breastfeeding) is crucial to effectively decrease maternal viral load and decrease the risk of mother-to-child transmission of HIV. Our objectives were to describe self-reported adherence to antiretrovirals during the antepartum (after 22 weeks of pregnancy) and postpartum periods (6–12 weeks and 6 months), and identify predictors of adherence among HIV-infected women enrolled and followed in a prospective cohort study from June 2008 to June 2010 at multiple sites in Latin America. Adherence was evaluated using the number of missed and expected doses during the 3 days before the study visit. At the pre-delivery visit, 340 of 376 women (90%) reported perfect adherence. This rate significantly decreased by 6–12 weeks (171/214 [80%]) and 6 months postpartum (163/199 [82%], p<0.01). The odds for less than perfect adherence at the pre-delivery visit was significantly higher for pregnant women with current tobacco use (odds ratio [OR]=2.9, 95% confidence interval [CI]: 1.46–6.14; p=0.0029). At 6–12 weeks postpartum, the probability of non-perfect adherence increased by 6% for each 1 year increase in age (OR=1.06, 95% CI: 1.00–1.12, p=0.0497). At 6 months postpartum, the odds of nonperfect adherence was higher for those who were currently using alcohol (OR=3.04, 95% CI: 1.34–6.90; p=0.0079). Although a self-report measure of adherence based on only 3 days may lead to overestimation of actual adherence over time, women with perfect adherence had lower viral loads and higher CD4 counts. Adherence to antiretrovirals decreased significantly postpartum. Interventions should target women at high risk for lower adherence during pregnancy and postpartum, including tobacco and alcohol users.
PMCID: PMC3462409  PMID: 22663185
14.  Routine HIV Testing among Hospitalized Patients in Argentina. Is It Time for a Policy Change? 
PLoS ONE  2013;8(7):e69517.
The Argentinean AIDS Program estimates that 110,000 persons are living with HIV/AIDS in Argentina. Of those, approximately 40% are unaware of their status, and 30% are diagnosed in advanced stages of immunosuppression. Though studies show that universal HIV screening is cost-effective in settings with HIV prevalence greater than 0.1%, in Argentina, with the exception of antenatal care, HIV testing is always client-initiated.
We performed a pilot study to assess the acceptability of a universal HIV screening program among inpatients of an urban public hospital in Buenos Aires.
Over a six-month period, all eligible adult patients admitted to the internal medicine ward were offered HIV testing. Demographics, uptake rates, reasons for refusal and new HIV diagnoses were analyzed.
Of the 350 admissions during this period, 249 were eligible and subsequently enrolled. The enrolled population was relatively old compared to the general population, was balanced on gender, and did not report traditional high risk factors for HIV infection. Only 88 (39%) reported prior HIV testing. One hundred and ninety (76%) patients accepted HIV testing. In multivariable analysis only younger age (OR 1.02; 95%CI 1.003-1.05) was independently associated with test uptake. Three new HIV diagnoses were made (undiagnosed HIV prevalence: 1.58%); none belonged to a most-at-risk population.
Our findings suggest that universal HIV screening in this setting is acceptable and potentially effective in identifying undiagnosed HIV-infected individuals. If confirmed in a larger study, our findings may inform changes in the Argentinean HIV testing policy.
PMCID: PMC3729969  PMID: 23936034
15.  Estimation of HIV-Testing Rates to Maximize Early Diagnosis-Derived Benefits at the Individual and Population Level 
PLoS ONE  2013;8(1):e53193.
In HIV infection, initiation of treatment is associated with improved clinical outcom and reduced rate of sexual transmission. However, difficulty in detecting infection in early stages impairs those benefits. We determined the minimum testing rate that maximizes benefits derived from early diagnosis.
We developed a mathematical model of HIV infection, diagnosis and treatment that allows studying both diagnosed and undiagnosed populations, as well as determining the impact of modifying time to diagnosis and testing rates. The model’s external consistency was assessed by estimating time to AIDS and death in absence of treatment as well as by estimating age-dependent mortality rates during treatment, and comparing them with data previously reported from CASCADE and DHCS cohorts.
In our model, life expectancy of patients diagnosed before 8 years post infection is the same as HIV-negative population. After this time point, age at death is significantly dependent on diagnosis delay but initiation of treatment increases life expectancy to similar levels as HIV-negative population. Early mortality during HAART is dependent on treatment CD4 threshold until 6 years post infection and becomes dependent on diagnosis delay after 6 years post infection. By modifying testing rates, we estimate that an annual testing rate of 20% leads to diagnosis of 90% of infected individuals within the first 8.2 years of infection and that current testing rate in middle-high income settings stands close to 10%. In addition, many differences between low-income and middle-high incomes can be predicted by solely modifying the diagnosis delay.
To increase testing rate of undiagnosed HIV population by two-fold in middle-high income settings will minimize early mortality during initiation of treatment and global mortality rate as well as maximize life expectancy. Our results highlight the impact of achieving early diagnosis and the importance of strongly work on improving HIV testing rates.
PMCID: PMC3538781  PMID: 23308161
16.  VS411 Reduced Immune Activation and HIV-1 RNA Levels in 28 Days: Randomized Proof-of-Concept Study for AntiViral-HyperActivation Limiting Therapeutics 
PLoS ONE  2012;7(10):e47485.
A new class of antiretrovirals, AntiViral-HyperActivation Limiting Therapeutics (AV-HALTs), has been proposed as a disease-modifying therapy to both reduce Human Immunodeficiency Virus Type 1 (HIV-1) RNA levels and the excessive immune activation now recognized as the major driver of not only the continual loss of CD4+ T cells and progression to Acquired Immunodeficiency Syndrome (AIDS), but also of the emergence of both AIDS-defining and non-AIDS events that negatively impact upon morbidity and mortality despite successful (ie, fully suppressive) therapy. VS411, the first-in-class AV-HALT, combined low-dose, slow-release didanosine with low-dose hydroxycarbamide to accomplish both objectives with a favorable toxicity profile during short-term administration. Five dose combinations were administered as VS411 to test the AV-HALT Proof-of-Concept in HIV-1-infected subjects.
Multinational, double-blind, 28-day Phase 2a dose-ranging Proof-of-Concept study of antiviral activity, immunological parameters, safety, and genotypic resistance in 58 evaluable antiretroviral-naïve HIV-1-infected adults. Randomization and allocation to study arms were carried out by a central computer system. Results were analyzed by ANOVA, Kruskal-Wallis, ANCOVA, and two-tailed paired t tests.
VS411 was well-tolerated, produced significant reductions of HIV-1 RNA levels, increased CD4+ T cell counts, and led to significant, rapid, unprecedented reductions of immune activation markers after 28 days despite incomplete viral suppression and without inhibiting HIV-1-specific immune responses. The didanosine 200 mg/HC 900 mg once-daily formulation demonstrated the greatest antiviral efficacy (HIV-1 RNA: −1.47 log10 copies/mL; CD4+ T cell count: +135 cells/mm3) and fewest adverse events.
VS411 successfully established the Proof-of-Concept that AV-HALTs can combine antiviral efficacy with rapid, potentially beneficial reductions in the excessive immune system activation associated with HIV-1 disease. Rapid reductions in markers of immune system hyperactivation and cellular proliferation were obtained despite the fact that VS411 did not attain maximal suppression of HIV RNA, suggesting this effect was due to the HALT component.
Trial Registration
ITEudraCT 2007-002460-98
PMCID: PMC3477169  PMID: 23094055
17.  Preferred antiretroviral drugs for the next decade of scale up 
Global commitments aim to provide antiretroviral therapy (ART) to 15 million people living with HIV by 2015, and recent studies have demonstrated the potential for widespread ART to prevent HIV transmission. Increasingly, countries are adapting their national guidelines to start ART earlier, for both clinical and preventive benefits. To maximize the benefits of ART in resource-limited settings, six key principles need to guide ART choice: simplicity, tolerability and safety, durability, universal applicability, affordability and heat stability. Currently available drugs, combined with those in late-stage clinical development, hold great promise to simplify treatment in the short term. Over the longer term, newer technologies, such as long-acting formulations and nanotechnology, could radically alter the treatment paradigm. This commentary reviews recommendations made in an expert consultation on treatment scale up in resource-limited settings.
PMCID: PMC3494169  PMID: 23010379
Antiretroviral therapy; regimen sequencing; treatment optimization
18.  Acute HIV Seroconversion Presenting with Active Tuberculosis and Associated with High Levels of T-Regulatory Cells 
Viral Immunology  2011;24(4):347-349.
A patient with well-defined acute HIV infection who developed concomitant pulmonary tuberculosis during the retroviral acute syndrome is reported here. In this patient high levels of T-regulatory cells (Tregs) and a low proliferation response to M. tuberculosis were initially detected, which normalized throughout follow-up. This case calls for the consideration of tuberculosis in patients in the early stages of HIV, and emphasizes the need for further study of the potential causal relationship between Treg cells and the risk of TB reactivation in HIV patients.
PMCID: PMC3192184  PMID: 21774688
19.  ICOS, SLAM and PD-1 expression and regulation on T lymphocytes reflect the immune dysregulation in patients with HIV-related illness with pulmonary tuberculosis 
Tuberculosis (TB) continues to be the most frequent cause of illness and death from an infectious agent globally, and its interaction with HIV is having devastating effects. To investigate how HIV alters the immune response to Mycobacterium tuberculosis (Mtb), we assessed basal and Mtb-induced proliferation, cytokine production, and expression of signalling lymphocytic activation molecule (SLAM), inducible costimulator (ICOS) and programmed death-1 (PD-1) on T lymphocytes from HIV-positive individuals coinfected with TB, HIV-positive subjects, TB patients and healthy donors (HD).
HIV-TB patients showed increased ICOS, SLAM and PD-1 basal levels on T lymphocytes, whereas HIV-positive individuals displayed elevated levels of SLAM and PD-1, TB patients high levels of SLAM, and HD low levels of the three proteins. Mtb-stimulation enhanced ICOS expression in the four groups, but only TB and HD increased SLAM and PD-1 levels.
These data show the immune deregulation that takes place during the immune response against TB in different study populations.
PMCID: PMC3499801  PMID: 22713261
human; AIDS; tuberculosis; T cells; ICOS; SLAM; PD-1; cytokines
20.  Prioritizing CD4 Count Monitoring in Response to ART in Resource-Constrained Settings: A Retrospective Application of Prediction-Based Classification 
PLoS Medicine  2012;9(4):e1001207.
Luis Montaner and colleagues retrospectively apply a potential capacity-saving CD4 count prediction tool to a cohort of HIV patients on antiretroviral therapy.
Global programs of anti-HIV treatment depend on sustained laboratory capacity to assess treatment initiation thresholds and treatment response over time. Currently, there is no valid alternative to CD4 count testing for monitoring immunologic responses to treatment, but laboratory cost and capacity limit access to CD4 testing in resource-constrained settings. Thus, methods to prioritize patients for CD4 count testing could improve treatment monitoring by optimizing resource allocation.
Methods and Findings
Using a prospective cohort of HIV-infected patients (n = 1,956) monitored upon antiretroviral therapy initiation in seven clinical sites with distinct geographical and socio-economic settings, we retrospectively apply a novel prediction-based classification (PBC) modeling method. The model uses repeatedly measured biomarkers (white blood cell count and lymphocyte percent) to predict CD4+ T cell outcome through first-stage modeling and subsequent classification based on clinically relevant thresholds (CD4+ T cell count of 200 or 350 cells/µl). The algorithm correctly classified 90% (cross-validation estimate = 91.5%, standard deviation [SD] = 4.5%) of CD4 count measurements <200 cells/µl in the first year of follow-up; if laboratory testing is applied only to patients predicted to be below the 200-cells/µl threshold, we estimate a potential savings of 54.3% (SD = 4.2%) in CD4 testing capacity. A capacity savings of 34% (SD = 3.9%) is predicted using a CD4 threshold of 350 cells/µl. Similar results were obtained over the 3 y of follow-up available (n = 619). Limitations include a need for future economic healthcare outcome analysis, a need for assessment of extensibility beyond the 3-y observation time, and the need to assign a false positive threshold.
Our results support the use of PBC modeling as a triage point at the laboratory, lessening the need for laboratory-based CD4+ T cell count testing; implementation of this tool could help optimize the use of laboratory resources, directing CD4 testing towards higher-risk patients. However, further prospective studies and economic analyses are needed to demonstrate that the PBC model can be effectively applied in clinical settings.
Please see later in the article for the Editors' Summary
Editors' Summary
AIDS has killed nearly 30 million people since 1981, and about 34 million people (most of them living in low- and middle-income countries) are now infected with HIV, the virus that causes AIDS. HIV destroys immune system cells (including CD4 cells, a type of lymphocyte and one of the body's white blood cell types), leaving infected individuals susceptible to other infections. Early in the AIDS epidemic, most HIV-infected people died within ten years of infection. Then, in 1996, antiretroviral therapy (ART) became available, and for people living in affluent countries, HIV/AIDS became a chronic condition. However, ART was expensive, and for people living in developing countries, HIV/AIDS remained a fatal illness. In 2003, HIV was declared a global health emergency, and in 2006, the international community set itself the target of achieving universal access to ART by 2010. By the end of 2010, only 6.6 million of the estimated 15 million people in need of ART in developing countries were receiving ART.
Why Was This Study Done?
One factor that has impeded progress towards universal ART coverage has been the limited availability of trained personnel and laboratory facilities in many developing countries. These resources are needed to determine when individuals should start ART—the World Health Organization currently recommends that people start ART when their CD4 count drops below 350 cells/µl—and to monitor treatment responses over time so that viral resistance to ART is quickly detected. Although a total lymphocyte count can be used as a surrogate measure to decide when to start treatment, repeated CD4 cell counts are the only way to monitor immunologic responses to treatment, a level of monitoring that is rarely sustainable in resource-constrained settings. A method that optimizes resource allocation by prioritizing who gets tested might be one way to improve treatment monitoring. In this study, the researchers applied a new tool for prioritizing laboratory-based CD4 cell count testing in resource-constrained settings to patient data that had been previously collected.
What Did the Researchers Do and Find?
The researchers fitted a mixed-effects statistical model to repeated CD4 count measurements from HIV-infected individuals from seven sites around the world (including some resource-limited sites). They then used model-derived estimates to apply a mathematical tool for predicting—from a CD4 count taken at the start of treatment, and white blood cell counts and lymphocyte percentage measurements taken later—whether CD4 counts would be above 200 cells/µl (the original threshold recommended for ART initiation) and 350 cells/µl (the current recommended threshold) for up to three years after ART initiation. The tool correctly classified 91.5% of the CD4 cell counts that were below 200 cells/µl in the first year of ART. With this threshold, the potential savings in CD4 testing capacity was 54.3%. With a CD4 count threshold of 350 cells/µl, the potential savings in testing capacity was 34%. The results over a three-year follow-up were similar. When applied to six representative HIV-positive individuals, the tool correctly predicted all the CD4 counts above 200 cells/µl, although some individuals who had a predicted CD4 count of less than 200 cells/µl actually had a CD4 count above this threshold. Thus, none of these individuals would have been exposed to an undetected dangerous CD4 count, but the application of the tool would have saved 57% of the CD4 laboratory tests done during the first year of ART.
What Do These Findings Mean?
These findings support the use of this new tool—the prediction-based classification (PBC) algorithm—for predicting a drop in CD4 count below a clinically meaningful threshold in HIV-infected individuals receiving ART. Further studies are now needed to demonstrate the feasibility, clinical effectiveness, and cost-effectiveness of this approach, to find out whether the tool can be used over extended periods of time, and to investigate whether the accuracy of its predictions can be improved by, for example, adding in periodic CD4 testing. Provided these studies confirm its early promise, the researchers suggest that the PBC algorithm could be used as a “triage” tool to direct available laboratory testing capacity to high-priority individuals (those likely to have a dangerously low CD4 count). By optimizing the use of limited laboratory resources in this and other ways, the PBC algorithm could therefore help to maintain and expand ART programs in low- and middle-income countries.
Additional Information
Please access these web sites via the online version of this summary at
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 HIV/AIDS treatment and care and on universal access to AIDS treatment (in English and Spanish)
The World Health Organization provides information about universal access to AIDS treatment (in several languages)
More information about universal access to HIV treatment, prevention, care, and support is available from UNAIDS
Patient stories about living with HIV/AIDS are available through Avert and through the charity website Healthtalkonline
PMCID: PMC3328436  PMID: 22529752
21.  Cancer in HIV-infected Persons from the Caribbean, Central and South America 
HIV infected individuals have heightened cancer risk. With the advent of HAART, the frequency of some AIDS defining cancers (ADC) has decreased while certain non-AIDS defining cancers (NADC) are becoming more frequent. Cancers among HIV-infected individuals in Latin American and the Caribbean have not yet been carefully studied.
Cancer cases among the Caribbean, Central and South American network for HIV Research (CCASAnet) cohort were identified reviewing clinical records and preexisting databases.
There were 406 cancers reported: 331 ADC (224 Kaposi´s sarcomas and 98 non Hodgkin lymphomas). Most frequent NADC (n=75) were Hodgkin lymphoma and skin cancers. Seventy-three percent of NADC and 45% of ADC were diagnosed >1 year after HIV diagnosis. 56% of ADC occurred before HAART start. Median time from HAART start until cancer diagnosis was 2.5 years for NADC and 0.5 years for ADC (p=<0.001). Within 3372 HAART starters, 158 were diagnosed with 165 cancers (82.4% ADC); 85 cases were previous to or concomitant with HAART initiation. Incidence of cancer after HAART initiation in 8080 person-years of follow-up was 7.2 per 1000 person-years (95%CI= 5.5–9.3) for ADC and 2.7 (95%CI= 1.8–4.1) for NADC; incidence was higher in the first two months, particularly for ADC (47.6). A pre-HAART ADC was a predictor of mortality after adjusting for age, sex, and CD4 at HAART initiation.
ADC were the most frequent cancers in this region and were often diagnosed close to HIV diagnosis and HAART start. Incidence of cancer was highest around HAART initiation.
PMCID: PMC3293455  PMID: 21239992
Neoplasms; HIV; Latin America; Caribbean; Cohort Studies
22.  Dynamics of Adrenal Steroids Are Related to Variations in Th1 and Treg Populations during Mycobacterium tuberculosis Infection in HIV Positive Persons 
PLoS ONE  2012;7(3):e33061.
Tuberculosis (TB) remains the most frequent cause of illness and death from an infectious agent, and its interaction with HIV has devastating effects. We determined plasma levels of dehydroepiandrosterone (DHEA), its circulating form DHEA-suphate (DHEA-s) and cortisol in different stages of M. tuberculosis infection, and explored their role on the Th1 and Treg populations during different scenarios of HIV-TB coinfection, including the immune reconstitution inflammatory syndrome (IRIS), a condition related to antiretroviral treatment. DHEA levels were diminished in HIV-TB and HIV-TB IRIS patients compared to healthy donors (HD), HIV+ individuals and HIV+ individuals with latent TB (HIV-LTB), whereas dehydroepiandrosterone sulfate (DHEA-s) levels were markedly diminished in HIV-TB IRIS individuals. HIV-TB and IRIS patients presented a cortisol/DHEA ratio significantly higher than HIV+, HIV-LTB and HD individuals. A positive correlation was observed between DHEA-s and CD4 count among HIV-TB individuals. Conversely, cortisol plasma level inversely correlated with CD4 count within HIV-TB individuals. M. tuberculosis-specific Th1 lymphocyte count was increased after culturing PBMC from HIV-TB individuals in presence of DHEA. We observed an inverse correlation between DHEA-s plasma level and Treg frequency in co-infected individuals, and CD4+FoxP3+ Treg frequency was increased in HIV-TB and IRIS patients compared to other groups. Strikingly, we observed a prominent CD4+CD25-FoxP3+ population across HIV-TB and HIV-TB IRIS patients, which frequency correlated with DHEA plasma level. Finally, DHEA treatment negatively regulated FoxP3 expression without altering Treg frequency in co-infected patients. These data suggest an enhancing role for DHEA in the immune response against M. tuberculosis during HIV-TB coinfection and IRIS.
PMCID: PMC3303789  PMID: 22431997
23.  Gender-sensitive reporting in medical research 
Sex and gender differences influence the health and wellbeing of men and women. Although studies have drawn attention to observed differences between women and men across diseases, remarkably little research has been pursued to systematically investigate these underlying sex differences. Women continue to be underrepresented in clinical trials, and even in studies in which both men and women participate, systematic analysis of data to identify potential sex-based differences is lacking. Standards for reporting of clinical trials have been established to ensure provision of complete, transparent and critical information. An important step in addressing the gender imbalance would be inclusion of a gender perspective in the next Consolidated Standards of Reporting Trials (CONSORT) guideline revision. Uniform Requirements for Manuscripts Submitted to Biomedical Journals, as a set of well-recognized and widely used guidelines for authors and biomedical journals, should similarly emphasize the ethical obligation of authors to present data analyzed by gender as a matter of routine. Journal editors are also promoters of ethical research and adequate standards of reporting, and requirements for inclusion of gender analyses should be integrated into editorial policies as a matter of urgency.
PMCID: PMC3313880  PMID: 22400977
24.  Pilot, Randomized Study Assessing Safety, Tolerability and Efficacy of Simplified LPV/r Maintenance Therapy in HIV Patients on the 1st PI-Based Regimen 
PLoS ONE  2011;6(8):e23726.
To compare the efficacy and safety of an individualized treatment-simplification strategy consisting of switching from a highly-active anti-retroviral treatment (HAART) with a ritonavir-boosted protease inhibitor (PI/r) and 2 nucleoside reverse-transcriptase inhibitors (NRTIs) to lopinavir/ritonavir (LPV/r) monotherapy, with intensification by 2 NRTIs if necessary, to that of continuing their HAART.
This is a one-year, randomized, open-label, multi-center study in virologically-suppressed HIV-1-infected adults on their first PI/r-containing treatment, randomized to either LPV/r-monotherapy or continue their current treatment. Treatment efficacy was determined by plasma HIV-1 RNA viral load (VL), time-to-virologic rebound, patient-reported outcomes (PROs) and CD4+T-cell-count changes. Safety was assessed with the incidence of treatment-emergent adverse events (AE).
Forty-one patients were randomized to LPV/r and 39 to continue their HAART. No statistically-significant differences between the two study groups in demographics and baseline characteristics were observed. At day-360, 71(39:LPV/r;32:HAART) patients completed treatment, while 9(2:LPV/r;7:HAART) discontinued. In a Last Observation Carried Forward Intent-to-Treat analysis, 40(98%) patients on LPV/r and 37(95%) on HAART had VL<200copies/mL (P = 0.61). Time-to-virologic rebound, changes in PROs, CD4+ T-cell-count and VL from baseline, also exhibited no statistically-significant between-group differences. Most frequent AEs were diarrhea (19%), headache (18%) and influenza (16%). Four (10%) patients on LPV/r were intensified with 2 NRTIs, all regaining virologic control. Eight serious AEs were reported by 5(2:LPV/r;3:HAART) patients.
At day-360, virologic efficacy and safety of LPV/r appears comparable to that of a PI+2NRTIs HAART. These results suggest that our individualized, simplified maintenance strategy with LPV/r-monotherapy and protocol-mandated NRTI re-introduction upon viral rebound, in virologically-suppressed patients merits further prospective long-term evaluation.
Trial Registration NCT00159224
PMCID: PMC3158782  PMID: 21886816

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