HIV treatment adherence, drug resistance, virologic failure: evolving concepts

Directed evolution of a recombinase that excises the provirus of most HIV-1 primary isolates with high specificity

Current combination antiretroviral therapies (cART) efficiently suppress HIV-1 reproduction in humans, but the virus persists as integrated proviral reservoirs in small numbers of cells. To generate an antiviral agent capable of eradicating the provirus from infected cells, we employed 145 cycles of substrate-linked directed evolution to evolve a recombinase (Brec1) that site-specifically recognizes a 34-bp sequence present in the long terminal repeats (LTRs) of the majority of the clinically relevant HIV-1 strains and subtypes. Brec1 efficiently, precisely and safely removes the integrated provirus from infected cells and is efficacious on clinical HIV-1 isolates in vitro and in vivo, including in mice humanized with patient-derived cells. Our data suggest that Brec1 has potential for clinical application as a curative HIV-1 therapy.

Application of an intracellular assay for determination of tenofovir-diphosphate and emtricitabine-triphosphate from erythrocytes using dried blood spots

This communication describes the application of an existing intracellular methodology to the quantitation of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) from erythrocytes using dried blood spots (DBS). Concentrations were determined from a 3mm DBS punch extracted into a 70:30 methanol:water solution (lysed cellular matrix). This extraction solution was then subjected to a previously validated analytical procedure for lysed cellular matrix. Experiments for DBS validation used replicate samples from study participants to demonstrate acceptable reproducibility with spot volumes ranging from 10-50 μL and punch location either from the edge or center of the spot. Analysis of paired DBS with purified red blood cells showed that a 3mm DBS punch contained an average of 11.9 million cells for the observed hematocrit range of the participants (35-50%). Numerous stability tests were completed showing that whole blood in an EDTA vacutainer could sit for 24h at room temperature prior to spotting, and DBS could remain at room temperature for up to five days including shipment at ambient using 2-days delivery. DBS stability in storage was acceptable up to 18 months at -20°C or -80°C and DBS could undergo 4 Freeze/Thaw cycles. The described method was applied to HIV prophylaxis studies, demonstrating powerful associations with HIV acquisition through its ability to discriminate gradients of adherence.

Comparisons of Adherence to Antiretroviral Therapy in a High-Risk Population in China: A Systematic Review and Meta-Analysis

Background

Reports on antiretroviral therapy (ART) adherence are scare in China; we performed this meta-analysis to estimate ART adherence rates in different populations at high risk for HIV transmission in China.

Methods

We searched PubMed, Chinese Biomedical Literature Database (Chinese), China National Knowledge Infrastructure (Chinese), and Wanfang (Chinese) to identify studies published from January 1985 to May 2015. We used random-effects meta-analysis to calculate weighted mean estimates across studies and 95% CIs. Data were pooled with proportions transformed prior to pooling using the Freeman–Tukey double arcsine transformation and then back transformed to the original scale. We calculated the I² (and its 95% confidence intervals) and tau² to assess between-study heterogeneity.

Results

We identified 36 eligible articles, including 6885 HIV-positive individuals, reporting ART adherence. Pooled analysis produced an estimate of 77.61% (95% CI = 71.63–83.08) of patients with HIV with adequate adherence; however, high heterogeneity was observed between studies (I² = 96.60%, 95%CI = 96.00%-97.20%; tau² = 0.16). Three studies, which included 149 old HIV-infected patients, reported the highest ART adequate adherence rate (89.39%, 95% CI = 72.01–99.26) with high heterogeneity between the studies (I² = 86.20%, 95%CI = 60.00–95.20%; tau² = 0.13). While, only two studies, which included 143 heterosexual transmission group (HTG) patients, reported the lowest ART adequate adherence rate (51.55%, 95% CI = 41.33–61.71) with low heterogeneity between the studies (I² = 31.3%, tau² = 0.007). In the multivariable meta-regression model, high-risk populations was the main factor explaining heterogeneity (variance explained 28.14%).

Conclusions

ART adherence in some high-risk populations (e.g., heterosexual transmission group) is below the recommended levels for maintaining virologic suppression. It is crucial to develop comprehensive intervention strategies to promote ART adherence in high-risk populations and effectively prevent the spread of HIV/AIDS in China.

Examining the relationship between psychological distress and adherence to anti-retroviral therapy among Ugandan adolescents living with HIV

Psychological distress is common among adolescents living with HIV (ALHIV) worldwide, and has been associated with non-adherence to anti-retroviral therapy (ART), leading to poor virologic suppression, drug resistance, and increased risk for AIDS morbidity and mortality. However, only a few studies have explored the relationship between psychological distress and ART adherence among adolescents in sub-Saharan Africa. The paper examines the relationship between psychological distress and ART adherence, and effect of psychosocial resources on ART adherence. We conducted a cross-sectional survey of 464 ALHIV (aged 12-19; 53% female) seeking HIV care at a large HIV treatment center in Kampala, Uganda. ALHIV were recruited during routine clinic visits. Three self-reported binary adherence measures were utilized: missed pills in the past three days, non-adherence to the prescribed medical regimen, and self-rated adherence assessed using a visual analog scale. Psychological distress was measured as a continuous variable, and computed as the mean score on a locally developed and validated 25-item symptom checklist for Ugandan ALHIV. Psychosocial resources included spirituality, religiosity, optimism, social support, and coping strategies. After adjusting for respondents' socio-demographic characteristics and psychosocial resources, a unit increase in psychological distress was associated with increased odds of missing pills in past 3 days (Odds Ratio(OR) = 1.75; Confidence Interval (CI): 1.04-2.95), not following the prescribed regimen (OR = 1.63; CI: 1.08-2.46), and lower self-rated adherence (OR = 1.79; CI: 1.19-2.69). Psychosocial resources were associated with lower odds for non-adherence on all three self-report measures. There is a need to strengthen the psychosocial aspects of adolescent HIV care by developing interventions to identify and prevent psychological distress among Ugandan ALHIV.

Description and Demonstration of Cognitive Behavioral Therapy to Enhance Antiretroviral Therapy Adherence and Treat Depression in HIV-Infected Adults

There are an estimated 1.1 million individuals living with HIV/AIDS in the United States. In addition to the various medical comorbidities of HIV infection, depression is one of the most frequently co-occurring psychiatric conditions among HIV-infected individuals. Furthermore, depression has been found to be associated with nonadherence to antiretroviral therapy (ART), as well as HIV disease progression. Cognitive behavioral therapy (CBT) has repeatedly been found to effectively treat depression in adult populations, and CBT for adherence and depression (CBT-AD) is an effective treatment for improving depressive symptoms and medication adherence in the context of various chronic health conditions, including diabetes and HIV-infection. This paper provides a description of the CBT-AD approach to treat depression and ART adherence in HIV-infected adults, which we have developed and tested in our clinic, and for which detailed therapist and client guides exist. To augment the description of treatment, the present article provides video component demonstrations of several core modules that highlight important aspects of this treatment, including Life-Steps for medication adherence, orientation to CBT-AD and psychoeducation, and suggestions for adaptation of core CBT modules for HIV-infected adults. Discussion of video demonstrations highlights differences in patient presentations and course of treatment between HIV-infected adults receiving CBT-AD and HIV-uninfected adults receiving traditional CBT for depression. This description and the accompanying demonstrations are intended as a practical guide to assist therapists wishing to conduct such a treatment in the outpatient setting.

A Social-Ecological View of Barriers and Facilitators for HIV Treatment Adherence: Interviews with Puerto Rican HIV Patients

Purpose

To identify perceived barriers and facilitators for HAART adherence among people living with HIV/AIDS in Southern Puerto Rico using a Social Ecological framework.

Patients and Methods

Individual in-depths interviews were conducted with 12 HIV patients with a history of HAART non-adherence. Interviews were audio-taped and transcribed. Content analysis was performed for each transcribed interview by three independent coders using a codebook. Using Atlas TI, super-codes and families were generated to facilitate the categorization tree as well as grounded analyses and density estimates

Results

Most participants reported a monthly income of $500 or less (n = 7), a high school education level (n = 7), being unemployed (n = 9) and being recipients of government health insurance (n = 11). Three out of six women reported living alone with their children and most men informed living with their parents or other relatives (n = 4). For the grounded analyses, the top four sub-categories linked to high number of quotations were mental health barriers (G = 32) followed by treatment regimen (G = 28), health system (G = 24) and interpersonal relations (G = 16). The top four sub-categories linked to high number of codes are treatment regimen (D = 4), health status perception (D = 3), interpersonal relations (D = 3) and health system (D = 3).

Conclusion

The results of this study suggest the interconnection of HIV treatment adherence barriers at various system levels. Future studies on HIV treatment barriers should explore these interactions and investigate the possible synergistic effect on non-adherent behavior

High Drop-off Along the HIV Care Continuum and ART Interruption Among Female Sex Workers in the Dominican Republic

BACKGROUND

Engagement in HIV care offers clear individual and societal benefits, but little evidence exists on the care experiences of key populations.

METHODS

A cross-sectional survey was conducted with 268 female sex workers (FSWs) living with HIV in Santo Domingo, Dominican Republic, to describe the HIV care continuum and to determine factors associated with antiretroviral therapy (ART) interruption.

RESULTS

FSWs disengaged throughout the care continuum with the highest drop-off after ART initiation. Most participants were linked to care (92%), retained in care (85%), and initiated onto ART (78%), but ART discontinuation and irregular adherence were frequent. Only 48% of participants had an undetectable HIV viral load. Overall, 36% of participants ever initiated onto ART reported lifetime experience with ART interruption. The odds of ART interruption were 3.24 times higher among women who experienced FSW-related discrimination [95% confidence interval (CI): 1.28 to 8.20], 2.41 times higher among women who used any drug (95% CI: 1.09 to 5.34), and 2.35 times higher among women who worked in an FSW establishment (95% CI: 1.20 to 4.60). Internalized stigma related to FSW was associated with higher odds of interruption (adjusted odds ratio: 1.09; 95% CI: 1.02 to 1.16), and positive perceptions of HIV providers were protective (adjusted odds ratio: 0.91; 95% CI: 0.85 to 0.98).

CONCLUSIONS

FSWs living with HIV confront multiple barriers throughout the HIV care continuum, many of which are related to the social context and stigmatization of sex work. Given the clear importance of maximizing the potential benefits of engagement in HIV care, there is an urgent need for interventions to support FSWs throughout the HIV care continuum.

Acceptability and Feasibility of a Cell Phone Support Intervention for Youth Living with HIV with Nonadherence to Antiretroviral Therapy

A pilot randomized clinical trial of youth ages 15-24 nonadherent to antiretroviral therapy (ART) utilizing daily cell phone support was found to have significant improvement in self-reported adherence and HIV RNA. Understanding acceptability and feasibility is critical for future implementation in clinic settings. Exit interviews were obtained from participants and adherence facilitators (AF). Acceptability was assessed from content analysis of exit interviews. Feasibility was assessed via intervention retention and study retention rates. Thirty-seven eligible youth were enrolled with 19 assigned to the intervention. Seven (37%) discontinued the intervention either due to missing over 20% of calls for two consecutive months (N=5) or missing 10 consecutive calls (N=2). Sixteen participants completed exit interviews, 15 reported the call length was just right, 13 reported they would have liked to continue calls after the 24-week intervention, and all participants reported they would recommend the intervention to friends. Scheduling and making calls required less than 1 h per week per participant. Providing cell phone support to youth nonadherent to ART was acceptable and feasible. While the cost is low compared to the price of ART, healthcare systems will need to explore how to cover the cost of providing cell phones (incentive).

Gender-specific risk factors for virologic failure in KwaZulu-Natal: automobile ownership and financial insecurity

We sought to examine which socioeconomic indicators are risk factors for virologic failure among HIV-1 infected patients receiving antiretroviral therapy (ART) in KwaZulu-Natal, South Africa. A case-control study of virologic failure was conducted among patients recruited from the outpatient clinic at McCord Hospital in Durban, South Africa between October 1, 2010 and June 30, 2012. Cases were those failing first-line ART, defined as viral load >1,000 copies/mL. Univariate logistic regression was performed on sociodemographic data for the outcome of virologic failure. Variables found significant (p < 0.05) were used in multivariate models and all models were stratified by gender. Of 158 cases and 300 controls, 35 % were male and median age was 40 years. Gender stratification of models revealed automobile ownership was a risk factor among males, while variables of financial insecurity (unemployment, non-spouse family paying for care, staying with family) were risk factors for women. In this cohort, financial insecurity among women and automobile ownership among men were risk factors for virologic failure. Risk factor differences between genders demonstrate limitations of generalized risk factor analysis.

Randomized clinical trial comparing the pharmacokinetics of standard- and increased-dosage lopinavir-ritonavir coformulation tablets in HIV-positive pregnant women

A lopinavir-ritonavir (LPV/r)-based regimen is recommended during pregnancy to reduce the risk of HIV mother-to-child transmission, but the appropriate dose is controversial. We compared the pharmacokinetics of standard and increased LPV/r doses during pregnancy. This randomized, open-label prospective study enrolled 60 pregnant women between gestational weeks 14 and 30. The participants received either the standard dose (400/100 mg twice a day [BID]) or increased dose (600/150 mg BID) of LPV/r tablets during pregnancy and the standard dose for 6 weeks after childbirth. Pharmacokinetics analysis was performed using a high-performance liquid chromatography-tandem mass spectrometry method. Adherent participants who received the standard dose presented minimum LPV concentrations of 4.4, 4.3, and 6.1 μg/ml in the second and third trimesters and postpartum, respectively. The increased-dose group exhibited values of 7.9, 6.9, and 9.2 μg/ml at the same three time points. Although LPV exposure was significantly higher in the increased-dose group, the standard dose produced therapeutic levels of LPV against wild-type virus in all adherent participants, except one patient in the third trimester; 50%, 37.5%, and 25%, and 0%, 15%, and 0% of the participants in the standard- and increased-dose groups failed to achieve therapeutic levels against resistant viruses during the second and third trimesters and after childbirth, respectively. After 12 weeks of treatment and after childbirth, all adherent participants achieved undetectable HIV viral loads, and their babies (49/54) were uninfected. No serious drug-related adverse events were observed. We conclude that the standard dose is appropriate for use during pregnancy and that an increased dose may be necessary for women harboring resistant HIV. (This study has been registered at ClinicalTrials.gov under registration no. NCT00605098.).

Early warning indicators for first-line virologic failure independent of adherence measures in a South African urban clinic

We sought to develop individual-level Early Warning Indicators (EWI) of virologic failure (VF) for clinicians to use during routine care complementing WHO population-level EWI. A case-control study was conducted at a Durban clinic. Patients after ≥ 5 months of first-line antiretroviral therapy (ART) were defined as cases if they had VF [HIV-1 viral load (VL)>1000 copies/mL] and controls (2:1) if they had VL ≤ 1000 copies/mL. Pharmacy refills and pill counts were used as adherence measures. Participants responded to a questionnaire including validated psychosocial and symptom scales. Data were also collected from the medical record. Multivariable logistic regression models of VF included factors associated with VF (p<0.05) in univariable analyses. We enrolled 158 cases and 300 controls. In the final multivariable model, male gender, not having an active religious faith, practicing unsafe sex, having a family member with HIV, not being pleased with the clinic experience, symptoms of depression, fatigue, or rash, low CD4 counts, family recommending HIV care, and using a TV/radio as ART reminders (compared to mobile phones) were associated with VF independent of adherence measures. In this setting, we identified several key individual-level EWI associated with VF including novel psychosocial factors independent of adherence measures.

Improved virological suppression in children on antiretroviral treatment receiving community-based adherence support: a multicentre cohort study from South Africa

Adherence to antiretroviral treatment (ART) is a challenge in childhood, and children on ART have reduced virological suppression compared to adults. This study evaluated the effect of community-based adherence support (CBAS) on virological outcomes amongst children receiving ART in four South African provinces. Patient Advocates are lay CBAS workers who provide adherence and psychosocial support for patients, undertaking home visits to address household challenges affecting adherence. Patient Advocates provide counselling for children's carers regarding adherence and psychosocial problems. A multicentre cohort study using routinely collected data was conducted at 57 public ART sites including ART-naive children (<16 years) starting ART. Virological suppression until four years of ART was compared between children who received and did not receive CBAS. Analyses were by intention-to-treat, controlling for confounding using multivariable generalised estimating equations. A total of 4853 children were included, of whom 982 (20.2%) received CBAS. The median baseline age was 6.3 years and the baseline CD4 cell percentage was 12.0%; both were equivalent between the two groups. CBAS children had more advanced baseline clinical disease (62.1% vs. 52.6% World Health Organisation stages III or IV; P < 0.0001). A total of 5908 viral load results were analysed. Virological suppression was 65.6% (95% confidence interval [CI]: 62.7-68.4%) vs. 55.5% (95% CI: 54.1-57.0%) in CBAS and non-CBAS children, respectively, at any time-point on treatment (P < 0.0001). In analyses controlling for baseline clinical, demographic, site-related variables and time on ART, children receiving CBAS were more likely to achieve virological suppression, adjusted odds ratio (aOR) 1.60 (95% CI: 1.35-1.89; P < 0.0001). The effect of CBAS increased in magnitude with increasing durations of ART, and CBAS particularly improved virological suppression in a higher-risk subgroup (children younger than two years, aOR 2.47 [95% CI: 1.59-3.84]). CBAS was associated with improved virological suppression in children receiving ART. Expanded implementation of this low-cost intervention should be considered in resource-poor settings.

HIV disease progression in the first year after delivery among African women followed in the HPTN 046 clinical trial

BACKGROUND

Starting lifelong antiretroviral therapy (ART) in HIV-infected pregnant women may decrease HIV progression and transmission, but adherence after delivery may be difficult, especially for asymptomatic women. We evaluated disease progression among HIV-infected women not on ART with CD4⁺ lymphocyte counts above 200 cells per microliter at delivery.

METHODS

We analyzed risk of death, progression to AIDS (stage IV or CD4 < 200 cells per microliter), or to CD4⁺ count <350 1 year after delivery among postpartum women enrolled to a prevention of breastfeeding transmission trial using the Kaplan-Meier method. In the primary analysis, women were censored if ART was initiated.

RESULTS

Among 1285 women who were not WHO stage IV or less at 6 weeks postpartum, 49 (4.3%) progressed to stage IV/CD4 <200 cells per microliter or death by 1 year. Progression to CD4 <200 cells per microliter or death occurred among 16 (4.3%) of 441 women with CD4 count of 350-549 cells per microliter and 10 (1.6%) of 713 with CD4 counts >550 cells per microliter at delivery. CD4 <350 cells per microliter by 12 months postpartum occurred among 116 (37.0%) of 350 women with CD4 count 400-549 cells per microliter and 48 (7.4%) of 713 with CD4 count >550 cells per microliter at delivery.

CONCLUSIONS

Progression to AIDS or CD4 count <350 cells per microliter is uncommon through 1 year postpartum for women with CD4 counts over 550 cells per microliter at delivery, but occurred in over one third of those with CD4 counts under 550 cells per microliter. ART should be continued after delivery or breastfeeding among women with CD4 counts <550 cells per microliter if follow-up and antiretroviral adherence can be maintained.

Safety, immunogenicity and efficacy assessment of HIV immunotherapy in a multi-centre, double-blind, randomised, Placebo-controlled Phase Ib human trial

BACKGROUND

Combination antiretroviral therapy (cART) is the main therapeutic management tool for HIV/AIDS. Despite its success in controlling viral load and disease progression, cART is expensive, associated with a range of significant side effects and depends for its efficacy on the patient's life-long commitment to high levels of treatment adherence. Immunotherapeutic agents can provide potential solutions to these shortcomings. Here we describe a Phase Ib trial of HIV-v, a synthetic immunotherapy that elicits T- and B-cell effector responses against HIV infected cells.

METHODS

Fifty-nine cART-naive HIV-infected males aged 18-50 years with viral load of 5000-500,000 copies/ml and CD4 counts >350/μl were recruited for this multi-centre, randomised, double blind study. Volunteers received one low (250 μg) or high (500 μg) dose of HIV-v, either alone or adjuvanted (ISA-51). Safety, immunogenicity, CD4 count and viral load were monitored over 168 Days.

RESULTS

HIV-v was well tolerated and the adjuvanted formulations elicited IgG responses in up to 75% of volunteers. The high adjuvanted dose also elicited cellular responses in 45% of tested volunteers. In these responding subjects viral loads were reduced by over 1 log (p=0.04) compared to Placebo and non-responders. No changes in CD4 count were observed.

CONCLUSIONS

HIV-v is safe and can elicit T- and B-cell responses in ART-naive HIV patients that significantly reduce viral load. Improved dosing regimens and further research on long term efficacy are required, but HIV-v appears to have potential as an immunotherapeutic anti-viral agent. Trial registered as EudraCT-2009-010593-37 (ClinicalTrials.gov Identifier: NCT01071031).

Use of Self-Reported Adherence and Keeping Clinic Appointments as Predictors of Viremia in Routine HIV Care in the Gambia

We followed 205 HIV-infected adults on antiretroviral therapy for at least 12 weeks in a Gambian clinic, where routine viral load monitoring was performed. The 1- and 4-week self-reported adherence and timeliness in keeping to scheduled appointments were recorded at each visit. Seventy patients had measurable viremia between the 12th week and the 3rd year of therapy. Survival analysis of the first detectable viral load on therapy demonstrated an association with 4-week (hazard ratio [HR] 2.6, 95% confidence interval [CI] 1.5-4.3, P=.001) and 1-week (HR 1.9, 95% CI 1.1-3.3, P=.024) self-reported suboptimal adherence and with 1 to 15 days of late presentation for appointments (HR 1.6-1.8, P .027-.109). In a multiple regression model, only 4-week self-reported adherence remained as a significant predictor of viremia.

Cost-effectiveness of a nurse-based intervention (AIMS) to improve adherence among HIV-infected patients: design of a multi-centre randomised controlled trial

BACKGROUND

Non-adherence to HIV-treatment can have a negative impact on patients treatment success rates, quality of life, infectiousness, and life expectancy. Few adherence interventions have shown positive effects on adherence and/or virologic outcomes. The theory- and evidence-based Adherence Improving self-Management Strategy (AIMS) is an intervention that has been demonstrated to improve adherence and viral suppression rates in a randomised controlled trial. However, evidence of its cost-effectiveness is lacking. Following a recent review suggesting that cost-effectiveness evaluations of adherence interventions for chronic diseases are rare, and that the methodology of such evaluations is poorly described in the literature, this manuscript presents the study protocol for a multi-centre trial evaluating the effectiveness and cost-effectiveness of AIMS among a heterogeneous sample of patients.

METHODS/DESIGN

The study uses a multi-centre randomised controlled trial design to compare the AIMS intervention to usual care from a societal perspective. Embedded in this RCT is a trial-based and model-based economic evaluation. A planned number of 230 HIV-infected patients are randomised to receive either AIMS or usual care. The relevant outcomes include changes in adherence, plasma viral load, quality of life, and societal costs. The time horizon for the trial-based economic evaluation is 12-15 months. Costs and effects are extrapolated to a lifetime horizon for the model-based economic evaluation.

DISCUSSION

The present multicentre RCT is designed to provide sound methodological evidence regarding the effectiveness and cost-effectiveness of a nurse-based counselling intervention (AIMS) to support treatment adherence among a large and heterogeneous sample of HIV-infected patients in the Netherlands. The objective of the current paper is to describe the trial protocol in sufficient detail to allow full evaluation of the quality of the study design. It is anticipated that, if proven cost-effective, AIMS can contribute to improved evidence-based counselling guidelines for HIV-nurses and other health care professionals.

TRIAL REGISTRATION

The study has been registered on clinicaltrials.gov (Identifier: NCT01429142).

Synthetic immunotherapy induces HIV virus specific Th1 cytotoxic response and death of an HIV-1 infected human cell line through classic complement activation

Background

This manuscript describes the development of a novel synthetic immunotherapy (HIV-v) composed of four multi-epitope polypeptides targeting conserved regions in the Nef, Rev, Vif and Vpr viral proteins. Immunogenicity and cytotoxicity of HIV-v are discussed.

Methods

Short conserved T-cell multi-epitope regions were identified in silico in the HIV proteome. The immunogenicity of the identified HIV-v polypeptides was assessed in vivo by immunisation of C57BLK6 mice transgenic for HLA-A*0201. Splenocytes from immunised animals were exposed in vitro to soluble HIV-v polypeptides or to syngeneic (T1) or allogeneic (Jurkat) cells transfected with these polypeptides. Specific T-cell reactivity was assessed by cell-based IFN-γ ELISA. Virus specific CD3 + CD8+ IFN-γ+ recall responses were also determined by flow cytometry following in vitro exposure of splenocytes from immunised mice to syngeneic (T1) and allogeneic (H9) cells infected with HIV-1 strain IIIB. HIV-v specific antibodies were quantified by ELISA whilst antibody mediated anti-viral immunotherapeutic effect on T1 cells infected with a laboratory adapted and a primary isolate of the HIV-1 virus was assessed in a LDH-based complement mediated lysis assay.

Results

HIV-v elicited antigen-specific IgG and IFN−γ responses against the synthetic polypeptides in the formulation. HIV-v specific T cells recognised polypeptides presented either as soluble antigen or complexed to HLA-A*0201 following natural processing and presentation by syngeneic human T1 cells. Moreover, the CD3 + CD8+ component of the response recognised syngeneic T1 cells naturally infected with HIV-1 in a virus-specific and MHC restricted-manner. The HIV-v specific IgG response was also able to recognise human T1 cells naturally infected with HIV-1 and induce cell death through classic activation of complement.

Conclusions

HIV-v induces a vaccine-specific type I immune response characterised by activation of effector CD8+ T cell and antibody responses that recognise and kill human cell lines naturally infected with a laboratory adapted and a primary isolate of the HIV-1 virus. The data supports the hypothesis that alternative HIV protein targets can be effectively used to prime both cellular and antibody immune responses of clinical value in the prevention and treatment of HIV infection.

Tenofovir, emtricitabine, and tenofovir diphosphate in dried blood spots for determining recent and cumulative drug exposure

Tenofovir (TFV) disoproxil fumarate (TDF)±emtricitabine (FTC) are widely used for HIV treatment and chemoprophylaxis, but variable adherence may lead to suboptimal responses. Methods that quantify adherence would allow for interventions to improve treatment and prevention outcomes. Our objective was to characterize the pharmacokinetics of TFV-diphosphate (TFV-DP) and FTC-triphosphate (FTC-TP) in red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs); to extend the RBC analysis to dried blood spots (DBSs); and to model how RBC/DBS monitoring could inform recent and cumulative drug exposure/adherence. Blood samples were collected from 17 HIV-negative adults at 5 visits over a 30-day pharmacokinetics study of daily oral TDF/FTC. Dosing was discontinued on day 30 and blood was collected on days 35, 45, and 60 during the washout period. Plasma/RBCs/PBMCs/DBSs were all quantified by liquid chromatography/tandem mass spectrometry. DBSs were paired with RBCs and plasma for comparisons. The median (interquartile range) RBC TFV-DP half-life was 17.1 (15.7-20.2) versus 4.2 (3.7-5.2) days in PBMCs. At steady state, TFV-DP was 130 fmol/10(6) RBCs versus 98 fmol/10(6) PBMCs. FTC-TP was not quantifiable in most RBC samples. TFV-DP in RBCs versus DBSs yielded an r(2)=0.83. TFV-DP in DBSs was stable at -20°C. Simulations of TFV-DP in RBCs/DBSs, when dosed from one to seven times per week, demonstrated that each dose per week resulted in an average change of approximately 19 fmol/10(6) RBCs and 230 fmol/punch. TFV and FTC in plasma versus DBSs was defined by y=1.4x; r(2)=0.96 and y=0.8x; r(2)=0.99, respectively. We conclude that DBSs offer a convenient measure of recent (TFV/FTC) and cumulative (TFV-DP in RBCs) drug exposure with potential application to adherence monitoring.

Improved survival and antiretroviral treatment outcomes in adults receiving community-based adherence support: 5-year results from a multicentre cohort study in South Africa

INTRODUCTION

A large increase in lay health care workers has occurred in response to shortages of professional health care staff in sub-Saharan African antiretroviral treatment (ART) programs. However, little effectiveness data of the large-scale implementation of these programs is available. We evaluated the effect of a community-based adherence-support (CBAS) program on ART outcomes across 57 South African sites.

METHODS

CBAS workers provide adherence and psychosocial support for patients and undertake home visits to address household challenges affecting adherence. An observational multicohort study of adults enrolling for ART between 2004 and 2010 was performed. Mortality, loss to follow-up, and virological suppression were compared by intention to treat between patients who received and did not receive CBAS until 5 years of ART, using multiple imputation of missing covariate values.

RESULTS

Of the 66,953 patients who were included, 19,668 (29.4%) patients received CBAS and 47,285 (70.6%) patients did not. Complete-case covariate data were available for 54.3% patients. After 5 years, patient retention was 79.1% [95% confidence interval (CI): 77.7% to 80.4%] in CBAS patients versus 73.6% (95% CI: 72.6% to 74.5%) in non-CBAS patients; crude hazard ratio (HR) for attrition was 0.68 (95% CI: 0.65 to 0.72). Mortality and loss to follow-up were independently lower in CBAS patients, adjusted HR (aHR) was 0.65 (95% CI: 0.59 to 0.72) and 0.63 (95% CI: 0.59 to 0.68), respectively. After 6 months of ART, virological suppression was 76.6% (95% CI: 75.8% to 77.5%) in CBAS patients versus 72% (95% CI: 71.3% to 72.5%) in non-CBAS patients (P < 0.0001), adjusted odds ratio was 1.22 (95% CI: 1.14 to 1.30). Improvement in virological suppression occurred progressively for longer durations of ART [adjusted odds ratio was 2.66 (95% CI: 1.61 to 4.40) by 5 years].

CONCLUSIONS

Patients receiving CBAS had considerably better ART outcomes. Further scale-up of these programs should be considered in low-income settings.

Adherence to antiretroviral therapy during and after pregnancy in low-income, middle-income, and high-income countries: a systematic review and meta-analysis

OBJECTIVE

To estimate antiretroviral therapy (ART) adherence rates during pregnancy and postpartum in high-income, middle-income, and low-income countries.

DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE, SCI Web of Science, NLM Gateway, and Google scholar databases were searched. We included all studies reporting adherence rates as a primary or secondary outcome among HIV-infected pregnant women. Two independent reviewers extracted data on adherence and study characteristics. A random-effects model was used to pool adherence rates; sensitivity, heterogeneity, and publication bias were assessed.

RESULTS

Of 72 eligible articles, 51 studies involving 20 153 HIV-infected pregnant women were included. Most studies were from United States (n =  14, 27%) followed by Kenya (n = 6, 12%), South Africa (n = 5, 10%), and Zambia (n = 5, 10%). The threshold defining good adherence to ART varied across studies (>80, >90, >95, 100%). A pooled analysis of all studies indicated a pooled estimate of 73.5% [95% confidence interval (CI) 69.3-77.5%] of pregnant women who had adequate (>80%) ART adherence. The pooled proportion of women with adequate adherence levels was higher during the antepartum (75.7%, 95% CI 71.5-79.7%) than during postpartum (53.0%, 95% CI 32.8-72.7%; P = 0.005). Selected reported barriers for nonadherence included physical, economic and emotional stresses, depression (especially postdelivery), alcohol or drug use, and ART dosing frequency or pill burden.

CONCLUSION

Our findings indicate that only 73.5% of pregnant women achieved optimal ART adherence. Reaching adequate ART adherence levels was a challenge in pregnancy, but especially during the postpartum period. Further research to investigate specific barriers and interventions to address them is urgently needed globally.

Update on World Health Organization HIV drug resistance prevention and assessment strategy: 2004-2011

The HIV drug resistance (HIVDR) prevention and assessment strategy, developed by the World Health Organization (WHO) in partnership with HIVResNet, includes monitoring of HIVDR early warning indicators, surveys to assess acquired and transmitted HIVDR, and development of an accredited HIVDR genotyping laboratory network to support survey implementation in resource-limited settings. As of June 2011, 52 countries had implemented at least 1 element of the strategy, and 27 laboratories had been accredited. As access to antiretrovirals expands under the WHO/Joint United Nations Programme on HIV/AIDS Treatment 2.0 initiative, it is essential to strengthen HIVDR surveillance efforts in the face of increasing concern about HIVDR emergence and transmission.

Transcriptional Gene Silencing (TGS) via the RNAi Machinery in HIV-1 Infections

Gene silencing via non-coding RNA, such as siRNA and miRNA, can occur at the transcriptional, post-transcriptional, and translational stages of expression. Transcriptional gene silencing (TGS) involving the RNAi machinery generally occurs through DNA methylation, as well as histone post-translational modifications, and corresponding remodeling of chromatin around the target gene into a heterochromatic state. The mechanism by which mammalian TGS occurs includes the recruitment of RNA-induced initiation of transcriptional gene silencing (RITS) complexes, DNA methyltransferases (DNMTs), and other chromatin remodelers. Additionally, virally infected cells encoding miRNAs have also been shown to manipulate the host cell RNAi machinery to induce TGS at the viral genome, thereby establishing latency. Furthermore, the introduction of exogenous siRNA and shRNA into infected cells that target integrated viral promoters can greatly suppress viral transcription via TGS. Here we examine the latest findings regarding mammalian TGS, specifically focusing on HIV-1 infected cells, and discuss future avenues of exploration in this field.

Deep sequencing reveals minor protease resistance mutations in patients failing a protease inhibitor regimen

Standard genotypic antiretroviral resistance testing, performed by bulk sequencing, does not readily detect variants that comprise <20% of the circulating HIV-1 RNA population. Nevertheless, it is valuable in selecting an antiretroviral regimen after antiretroviral failure. In patients with poor adherence, resistant variants may not reach this threshold. Therefore, deep sequencing would be potentially valuable for detecting minority resistant variants. We compared bulk sequencing and deep sequencing to detect HIV-1 drug resistance at the time of a second-line protease inhibitor (PI)-based antiretroviral regimen failure. Eligibility criteria were virologic failure (HIV-1 RNA load of >500 copies/ml) of a first-line nonnucleoside reverse transcriptase inhibitor-based regimen, with at least the M184V mutation (lamivudine resistance), and second-line failure of a lopinavir/ritonavir (LPV/r)-based regimen. An amplicon-sequencing approach on the Roche 454 system was used. Six patients with viral loads of >90,000 copies/ml and one patient with a viral load of 520 copies/ml were included. Mutations not detectable by bulk sequencing during first- and second-line failure were detected by deep sequencing during second-line failure. Low-frequency variants (>0.5% of the sequence population) harboring major protease inhibitor resistance mutations were found in 5 of 7 patients despite poor adherence to the LPV/r-based regimen. In patients with intermittent adherence to a boosted PI regimen, deep sequencing may detect minority PI-resistant variants, which likely represent early events in resistance selection. In patients with poor or intermittent adherence, there may be low evolutionary impetus for such variants to reach fixation, explaining the low prevalence of PI resistance.

Adherence with drug therapy in pregnancy

Available information suggests that nonadherence with medication is a common problem in pregnant women. Not taking prescribed drugs may have potentially negative consequences as patients may not achieve their therapeutic goal. In addition to the many factors that may influence medication-taking behaviour in the general population, unique challenges are encountered in pregnant women as both maternal health and fetal well-being must be considered. On the one hand, pregnant women may be motivated to keep their underlying disease under control, while, on the other hand, fear and anxiety regarding the potential harmful effects of their medication on their unborn child may result in poor adherence with needed medication. Providing evidence-based information, ideally preconceptually, regarding the effects of their medication during pregnancy may be important in avoiding misperceptions that lead to nonadherence.

Conceptual framework for behavioral and social science in HIV vaccine clinical research

HIV vaccine clinical research occurs within a context where biomedical science and social issues are interlinked. Previous HIV vaccine research has considered behavioral and social issues, but often treated them as independent of clinical research processes. Systematic attention to the intersection of behavioral and social issues within a defined clinical research framework is needed to address gaps, such as those related to participation in trials, completion of trials, and the overall research experience. Rigorous attention to these issues at project inception can inform trial design and conduct by matching research approaches to the context in which trials are to be conducted. Conducting behavioral and social sciences research concurrent with vaccine clinical research is important because it can help identify potential barriers to trial implementation, as well as ultimate acceptance and dissemination of trial results. We therefore propose a conceptual framework for behavioral and social science in HIV vaccine clinical research and use examples from the behavioral and social science literature to demonstrate how the model can facilitate identification of significant areas meriting additional exploration. Standardized use of the conceptual framework could improve HIV vaccine clinical research efficiency and relevance.

Treatment interruption and variation in tablet taking behaviour result in viral failure: a case-control study from Cape Town, South Africa

Background

Understanding of the impact of non-structured treatment interruption (TI) and variation in tablet-taking on failure of first-line antiretroviral therapy (ART) is limited in a resource-poor setting.

Methods

A retrospective matched case-control analysis. Individuals failing ART were matched by time on ART with 4 controls. Viral load (VL) and CD4 count were completed 4-monthly. Adherence percentages, from tablet returns, were calculated 4-monthly (interval) and from ART start (cumulative). Variation between intervals and TI (>27 days off ART) were recorded. Conditional multivariate logistic regression analysis was performed to estimate the effect of cumulative adherence <90%, at least one episode of adherence variation >10% and TI on virological failure. Age, gender, baseline log VL and CD4 were included as possible confounders in the multivariate model.

Results

244 patients (44 cases, 200 controls) were included. Median age was 32 years (IQR28–37), baseline CD4 108 cells/mm3 (IQR56–151), VL 4.82 log (IQR4.48–5.23). 94% (96% controls, 86% failures) had cumulative adherence >90%. The odds of failure increased 3 times (aOR 3.01, 95%CI 0.81–11.21) in individuals with cumulative adherence <90%, 2.2 times (aOR 2.20, 95%CI 1.04–4.64) in individuals with at least one episode of fluctuating adherence of >10% and 4.01 times (aOR 4.01, 95%CI 1.45–11.10) in individuals with TIs. For individuals with TI and cumulative adherence >95%, the odds of failing were 5.65 (CI 1.40–22.85).

Conclusion

It is well known that poor cumulative adherence increases risk of virological failure, but less well understood that TI and variations in tablet-taking also play a key role, despite otherwise excellent adherence.