Transmission of HIV-1 drug resistance

Antiretroviral (ARV) Drug Resistance and HIV-1 Subtypes among Injecting Drug Users in the Coastal Region of Kenya

HIV-1 genetic diversity results into the development of widespread drug-resistant mutations (DRMs) for the first-line retroviral therapy. Nevertheless, few studies have investigated the relationship between DRMs and HIV-1 subtypes among HIV-positive injecting drug users (IDUs). This study therefore determined the association between HIV-1 genotypes and DRMs among the 200 IDUs. Stanford HIV Drug Resistance Database was used to interpret DRMs. The five HIV-1 genotypes circulating among the IDUs were A₁ (25 (53.2%)), A₂ (2 (4.3%)), B (2 (4.3%)), C (9 (19.1%)), and D (9 (19.1%)). The proportions of DRMs were A₁ (12 (52.2%)), A₂ (1 (4.3%)), B (0 (0.0%)), C (5 (21.7%)), and D (5 (21.7%)). Due to the large proportion of drug resistance across all HIV-1 subtypes, surveillance and behavioral studies need to be explored as IDUs may be spreading the drug resistance to the general population. In addition, further characterization of DRMs including all the relevant clinical parameters among the larger population of IDUs is critical for effective drug resistance surveillance.

Next generation sequencing based in-house HIV genotyping method: validation report

Background

HIV genotyping has had a significant impact on the care and treatment of HIV/AIDS. At a clinical level, the test guides physicians on the choice of treatment regimens. At the surveillance level, it informs policy on consolidated treatment guidelines and microbial resistance control strategies. Until recently, the conventional test has utilized the Sanger sequencing (SS) method. Unlike Next Generation Sequencing (NGS), SS is limited by low data throughput and the inability of detecting low abundant drug-resistant variants. NGS can improve sensitivity and quantitatively identify low-abundance variants; in addition, it has the potential to improve efficiency as well as lowering costs when samples are batched. Despite the NGS benefits, its utilization in clinical drug resistance profiling is faced with mixed reactions. These are largely based on a lack of a consensus regarding the quality control strategy. Nonetheless, transitional views suggest validating the method against the gold-standard SS. Therefore, we present a validation report of an NGS-based in-house HIV genotyping method against the SS method in Uganda.

Results

Since there were no established proficiency test panels for NGS-based HIV genotyping, 15 clinical plasma samples for routine care were utilized. The use of clinical samples allowed for accuracy and precision studies. The workflow involved four main steps; viral RNA extraction, targeted amplicon generation, amplicon sequencing and data analysis. Accuracy of 98% with an average percentage error of 3% was reported for the NGS based assay against the SS platform demonstrating similar performance. The coefficient of variation (CV) findings for both the inter-run and inter-personnel precision showed no variability (CV ≤ 0%) at the relative abundance of ≥ 20%. For both inter-run and inter-personnel, a variation that affected the precision was observed at 1% frequency. Overall, for all the frequencies, CV registered a small range of (0–2%).

Conclusion

The NGS-based in-house HIV genotyping method fulfilled the minimum requirements that support its utilization for drug resistance profiling in a clinical setting of a low-income country. For more inclusive quality control studies, well-characterized wet panels need to be established.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-021-00390-8.

Qualitative Evaluation of Social Media and Mobile Technology Interventions Designed to Improve HIV Health Outcomes for Youth and Young Adults Living With HIV: A HRSA SPNS Initiative

Youth and young adults living with HIV (YYALH) are less likely to be engaged in HIV care, adhere to their medications, and achieve viral suppression compared to older adult populations. In the United States, the majority of YYALH belong to racial/ethnic, sexual, and gender minority groups. HIV care interventions are needed that specifically target YYALH and that exploit the use of social media and mobile technology (SMMT) platforms, where youth and young adults have a ubiquitous presence. We conducted a qualitative evaluation of SMMT interventions included in a Health Resources and Services Administration Special Projects of National Significance initiative designed to improve medical care engagement, retention, and medication adherence to achieve viral suppression among YYALH. However, in this study, only young adults living with HIV (YALH) ages 18 to 34 years participated. A total of 48 YALH were interviewed. The data were analyzed using thematic analysis and revealed three main themes supporting the usefulness of the SMMT interventions, which included (1) acceptability of SMMT interventions in managing HIV care with subthemes of medical information accessibility, reminders, and self-efficacy; (2) feelings of support and personal connection afforded by SMMT interventions; and (3) SMMT interventions help to alleviate negative feelings about status and mitigate HIV-related stigma. A few participants identified problems with using their respective intervention, primarily related to the functionality of the technologies. Overall, findings from our qualitative evaluation suggest that SMMT-based interventions have the potential to increase engagement and retention in care, support YALH in adhering to medication, and help them adjust to their diagnosis.

Pre-treatment drug resistance and HIV-1 subtypes in infants from Argentina with and without exposure to antiretroviral drugs for prevention of mother-to-child transmission

OBJECTIVES

To assess the prevalence and patterns of pre-treatment HIV drug resistance (PDR) and HIV-1 subtype in infants from Argentina with exposure to different antiretroviral drugs (ARVs) for the prevention of mother-to-child transmission (PMTCT).

PATIENTS AND METHODS

HIV-1 genotyping was performed in 115 infants (median age = 2.3 months) born between 2007 and 2014 to screen for drug resistance mutations (DRMs) before starting first-line ART. HIV-1 subtype was characterized by phylogenetic and recombination analysis.

RESULTS

Overall, DRMs were found in 34 of 115 infants (PDR level 30% to any ARV, 3.5% to PIs, 12% to NRTIs and 22% to NNRTIs). Of the 115 infants, 22 (19.1%) were ARV-unexposed. Another 93 were ARV-exposed: 28 (24.3%) to short-course zidovudine monotherapy ARV prophylaxis; 25 (21.7%) to nevirapine-based ARV prophylaxis; 12 (10.4%) to perinatal infant zidovudine prophylaxis + maternal combination ART with NNRTIs; and 28 (24.3%) to perinatal infant zidovudine prophylaxis+maternal combination ART with PIs. Transmitted drug resistance among ARV-unexposed infants was 32% (5% to PIs, 9% to NRTIs and 18% to NNRTIs). ART-exposed infants showed multi-class ARV resistance. Importantly, vertical transmission of a triple-class-resistant virus was confirmed in one case. Patterns of DRMs predicted high-level resistance to NNRTIs in a similar and high proportion (>50%) of infants with at least one DRM independently of ARV exposure. BF recombinants were found in 74%, subtype B in 20%, subtype C in 3% and novel AG and AB recombinants in 3%.

CONCLUSIONS

PDR in HIV-1-infected children from Argentina is among the highest reported, jeopardizing successful lifelong suppressive ART as well as the efficacy of current PMTCT regimens.

Adaptive Antiretroviral Therapy Adherence Interventions for Youth Living With HIV Through Text Message and Cell Phone Support With and Without Incentives: Protocol for a Sequential Multiple Assignment Randomized Trial (SMART)

BACKGROUND

Youth living with HIV (YLH) aged 13 to 24 years made up over a fifth (21%) of new HIV diagnoses in 2016, yet only 27% of YLH are virally suppressed. YLH have been shown to be poorly adherent to antiretroviral therapy (ART); however, there has been limited research investigating how to increase adherence in YLH. Mobile health (mHealth) interventions may be one promising way to do this.

OBJECTIVE

This study (ATN [Adolescent Trials Network] 144 SMART) aimed to compare adaptive interventions that could increase ART adherence in YLH aged 15 to 24 years. This includes mHealth initiatives, the tapering of interventions, and the use of incentives. Cost-effectiveness of sequencing the interventions without incentives before providing incentives and the savings on societal costs due to suppressed viral loads will be determined. This protocol is part of the ATN Scale It Up program described in this issue by Naar et al.

METHODS

This study uses a Sequential Multiple Assignment Randomized Trial design. Approximately 190 participants are being recruited, enrolled, and randomized to either cell phone support or text message support. Both intervention groups receive 3 months of intervention, followed by a second randomization based on response to the intervention. Responders test tapering their intervention, and nonresponders test receiving incentives.

RESULTS

Data collection for this study is projected to begin in August 2018 and last until June 2020.

CONCLUSIONS

This is an innovative study, particularly in terms of population, intervention types, focus on cost-effectiveness, and recruitment. This study could be particularly effective in improving adherence in YLH while reducing long-term individual and societal costs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03535337; https://clinicaltrials.gov/ct2/show/NCT03535337 (Archived by WebCite at http://www.webcitation.org/74alXb92z).

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/11183.

An Exploration of Syndemic Factors That Influence Engagement in HIV Care Among Black Men

Syndemic theory seeks to understand the interactions and clustering of disease and social conditions and explain racial disparities in HIV. Traditionally applied to HIV risk, this study characterizes the syndemic challenges of engagement in care among Black men living with HIV and provides insight into potential HIV treatment interventions to retain vulnerable individuals in care. Interviews were conducted with 23 HIV-positive men who were either out-of-care or nonadherent to antiretroviral therapy (ART). Interviews were audio recorded, transcribed verbatim, and coded using MAXQDA qualitative software. Researchers analyzed data using thematic content analysis to identify syndemic factors associated with disengagement in care or suboptimal ART adherence among Black men. Analyses revealed the syndemic nature of four themes: intersectional stigma, depression, substance use, and poverty. Findings from this study offer numerous opportunities for intervention including social and structural-level interventions to address syndemic processes and the influence of stigma and poverty on engagement in care.

A Longitudinal Analysis of Antiretroviral Adherence Among Young Black Men Who Have Sex With Men

PURPOSE

Young black men who have sex with men (YBMSM) experience poorer antiretroviral therapy (ART) medication adherence relative to their white counterparts. However, few studies have longitudinally examined factors that may correlate with various classifications of ART adherence among this population, which was the primary aim of this study.

METHODS

Project nGage was a randomized controlled trial conducted across five Chicago clinics from 2012 to 2015. Survey and medical records data were collected at baseline and 3- and 12-month periods to assess whether psychological distress, HIV stigma, substance use, family acceptance, social support, and self-efficacy predicted ART medication adherence among 92 YBMSM ages 16-29 years.

RESULTS

Major results controlling for the potential effects of age, education level, employment, and intervention condition indicated that participants with high versus low medication adherence were less likely to report daily/weekly alcohol or marijuana use, had higher family acceptance, and exhibited greater self-efficacy.

CONCLUSIONS

These findings identity important factors that can be targeted in clinical and program interventions to help improve ART medication adherence for YBMSM.

Exploring the Interaction between Comorbid Psychiatric and Medical Diagnoses: The Potential Impact of Borderline Personality Disorder on Adherence to Highly Active Antiretroviral Therapy (HAART)

It is well documented that patient adherence to medical advice and prescription medication is suboptimal. While the reasons for non-compliance are varied and complex, it is essential that they be expounded to facilitate the efficacy of medical interventions. In no other illness is this more pertinent than with the human immunodeficiency virus (HIV). Highly active antiretroviral therapy (HAART) has become the first line of treatment for HIV, but stringent adherence is a prerequisite for therapeutic efficacy. As with other treatments, adherence to HAART is problematic. One factor that may play a significant role is if the patient has a comorbid psychiatric illness. This article provides a theoretical exposition of how a patient with Borderline Personality Disorder (BPD) might suffer innumerable exigencies with adherence as a hypothesised function of the individual properties of his or her illness that is likely to be compounded when the properties interact with one another.

Low-Frequency Drug Resistance in HIV-Infected Ugandans on Antiretroviral Treatment Is Associated with Regimen Failure

Most patients failing antiretroviral treatment in Uganda continue to fail their treatment regimen even if a dominant drug-resistant HIV-1 genotype is not detected. In a recent retrospective study, we observed that approximately 30% of HIV-infected individuals in the Joint Clinical Research Centre (Kampala, Uganda) experienced virologic failure with a susceptible HIV-1 genotype based on standard Sanger sequencing. Selection of minority drug-resistant HIV-1 variants (not detectable by Sanger sequencing) under antiretroviral therapy pressure can lead to a shift in the viral quasispecies distribution, becoming dominant members of the virus population and eventually causing treatment failure. Here, we used a novel HIV-1 genotyping assay based on deep sequencing (DeepGen) to quantify low-level drug-resistant HIV-1 variants in 33 patients failing a first-line antiretroviral treatment regimen in the absence of drug-resistant mutations, as screened by standard population-based Sanger sequencing. Using this sensitive assay, we observed that 64% (21/33) of these individuals had low-frequency (or minority) drug-resistant variants in the intrapatient HIV-1 population, which correlated with treatment failure. Moreover, the presence of these minority HIV-1 variants was associated with higher intrapatient HIV-1 diversity, suggesting a dynamic selection or fading of drug-resistant HIV-1 variants from the viral quasispecies in the presence or absence of drug pressure, respectively. This study identified low-frequency HIV drug resistance mutations by deep sequencing in Ugandan patients failing antiretroviral treatment but lacking dominant drug resistance mutations as determined by Sanger sequencing methods. We showed that these low-abundance drug-resistant viruses could have significant consequences for clinical outcomes, especially if treatment is not modified based on a susceptible HIV-1 genotype by Sanger sequencing. Therefore, we propose to make clinical decisions using more sensitive methods to detect minority HIV-1 variants.

Detecting primary drug-resistant mutations in Korean HIV patients using ultradeep pyrosequencing

HIV primary resistance, drug resistance in treatment-naïve patients, is an emerging public health issue. The prevalence of HIV primary resistance mutations down to the level of 1% minor variants was investigated using ultradeep pyrosequencing (UDPS) in HIV-positive Korean blood donors and in treatment naïve chronic patients for the comparison. The entire pol region was sequenced from 25 HIV-positive blood donors, and 18 treatment-naïve chronic HIV patients. UDPS was successful in 19 blood donors and 18 chronic patients. In total, 1,011,338 sequence reads were aligned, and 28,093 sequence reads were aligned on average per sample. The prevalence of HIV primary resistance mutations in the HIV-positive blood donors and chronic HIV patients were 63.2% and 44.4% according to UDPS, respectively. Protease inhibitor (PI) drugs demonstrated different patterns in HIV-positive blood donors and chronic HIV patients, whereas non-nucleoside reverse transcriptase inhibitors (NNRTI), nucleoside reverse transcriptase inhibitors (NRTI), and integrase inhibitor (INI) drugs showed similar patterns between the two groups. Higher level of primary resistance prevalence was observed mainly because UDPS method could detect mutations in minor variants with 1-10% frequency. The higher resistance prevalence was observed in HIV-positive blood donors than in chronic patients. Considering that treatments for HIV-infected patients were recently amended to start at an earlier stage, information about degree of drug resistance to each drug between the two groups would help to establish future policies, design additional clinical trials, assess HIV patient care in Korea.

Predictors of Self-Reported Adherence to Antiretroviral Medication in a Multisite Study of Ethnic and Racial Minority HIV-Positive Youth

OBJECTIVE

To test social cognitive predictors of medication adherence in racial/ethnic minority youth living with HIV using a conceptual model.

METHODS

Youth were participants in two descriptive studies by the Adolescent Trials Network for HIV/AIDS Interventions. Minority youth ages 16-24 years who were prescribed antiretroviral medication were included (N = 956). Data were collected through chart extraction and/or laboratory testing and by Audio Computer-Assisted Self-Interview.

RESULTS

39% of youth reported suboptimal adherence. Path analysis was used to explore predictors of medication adherence. Higher self-efficacy predicted higher readiness and adherence. Greater social support predicted higher self-efficacy. Psychological symptoms and substance use were associated with several predictors and lower adherence.

CONCLUSIONS

The model provided a plausible framework for understanding adherence in this population. Culturally competent, but individually tailored, interventions focused on increasing self-efficacy to take medication and reducing risk behaviors (e.g., substance use) may be helpful for racial or ethnic minority youth with HIV.

A phylotype-based analysis highlights the role of drug-naive HIV-positive individuals in the transmission of antiretroviral resistance in the UK

OBJECTIVE

Antiretroviral-naive HIV-positive individuals contribute to the transmission of drug-resistant viruses, compromising first-line therapy. Using phylogenetic inference, we quantified the proportion of transmitted drug-resistance originating from a treatment-naive source.

METHODS

Using a novel phylotype-based approach, 24 550 HIV-1 subtype B partial pol gene sequences from the UK HIV Drug Resistance database were analysed. Ongoing transmission of drug resistance amongst HIV-positive individuals was identified as phylotypes of at least three sequences with at least one shared drug resistance mutation, a maximum intra-clade genetic distance of 4.0% and a basal branch support at least 90%. The time of persistence of the transmission chains was estimated using a fast least-squares molecular clock inference approach.

RESULTS

Around 70% of transmitted drug-resistance had a treatment-naive source. The most commonly transmitted mutations were L90M in the protease gene and K103N, T215D and T215S in reverse transcriptase. Reversion to wild type occurred at a low frequency and drug-independent reservoirs of resistance have persisted for up to 13 years.

CONCLUSION

These results illustrate the impact of viral fitness on the establishment of resistance reservoirs and support the notion that earlier diagnoses and treatment of HIV infections are warranted for counteracting the spread of antiretroviral resistance. Phylotype-based phylogenetic inference is an attractive approach for the routine surveillance of transmitted drug resistance in HIV as well as in other pathogens for which genotypic resistance data are available.

Impact of human immunodeficiency virus type-1 sequence diversity on antiretroviral therapy outcomes

Worldwide circulating HIV-1 genomes show extensive variation represented by different subtypes, polymorphisms and drug-resistant strains. Reports on the impact of sequence variation on antiretroviral therapy (ART) outcomes are mixed. In this review, we summarize relevant published data from both resource-rich and resource-limited countries in the last 10 years on the impact of HIV-1 sequence diversity on treatment outcomes. The prevalence of transmission of drug resistant mutations (DRMs) varies considerably, ranging from 0% to 27% worldwide. Factors such as geographic location, access and availability to ART, duration since inception of treatment programs, quality of care, risk-taking behaviors, mode of transmission, and viral subtype all dictate the prevalence in a particular geographical region. Although HIV-1 subtype may not be a good predictor of treatment outcome, review of emerging evidence supports the fact that HIV-1 genome sequence-resulting from natural polymorphisms or drug-associated mutations-matters when it comes to treatment outcomes. Therefore, continued surveillance of drug resistant variants in both treatment-naïve and treatment-experienced populations is needed to reduce the transmission of DRMs and to optimize the efficacy of the current ART armamentarium.

Retention in care and adherence to ART are critical elements of HIV care interventions

Retention in care and adherence to antiretroviral treatment (ART) are critical elements of HIV care interventions and are closely associated with optimal individual and public health outcomes and cost effectiveness. This literature review was conducted to analyse how the roles of clients in HIV care and treatment are discussed, from terminology used to measurement methods to consequences of a wide range of patient-related factors impacting client adherence to ART and retention in care. Unfortunately, data suggests that clients find it hard to follow recommended behaviour. For HIV, the greatest loss to follow-up occurs before starting treatment, though each step of the continuum of care is affected. Measurement approaches can be divided into 'direct' and 'indirect' methods; in practice, a combination is often considered the best strategy. Inadequate retention and adherence lead to decreased health outcomes (morbidity, mortality, drug resistances, risk of transmission) and cost effectiveness (increased costs and lower productivity).

Contribution of human immunodeficiency virus type 1 minority variants to reduced drug susceptibility in patients on an integrase strand transfer inhibitor-based therapy

The role of HIV-1 minority variants on transmission, pathogenesis, and virologic failure to antiretroviral regimens has been explored; however, most studies of low-level HIV-1 drug-resistant variants have focused in single target regions. Here we used a novel HIV-1 genotypic assay based on deep sequencing, DEEPGEN (Gibson et al 2014 Antimicrob Agents Chemother 58∶2167) to simultaneously analyze the presence of minority variants carrying mutations associated with reduced susceptibility to protease (PR), reverse transcriptase (RT), and integrase strand transfer integrase inhibitors (INSTIs), as well as HIV-1 coreceptor tropism. gag-p2/NCp7/p1/p6/pol-PR/RT/INT and env/C2V3 PCR products were obtained from twelve heavily treatment-experienced patients experiencing virologic failure while participating in a 48-week dose-ranging study of elvitegravir (GS-US-183-0105). Deep sequencing results were compared with (i) virological response to treatment, (ii) genotyping based on population sequencing, (iii) phenotyping data using PhenoSense and VIRALARTS, and (iv) HIV-1 coreceptor tropism based on the phenotypic test VERITROP. Most patients failed the antiretroviral regimen with numerous pre-existing mutations in the PR and RT, and additionally newly acquired INSTI-resistance mutations as determined by population sequencing (mean 9.4, 5.3, and 1.4 PI- RTI-, and INSTI-resistance mutations, respectively). Interestingly, since DEEPGEN allows the accurate detection of amino acid substitutions at frequencies as low as 1% of the population, a series of additional drug resistance mutations were detected by deep sequencing (mean 2.5, 1.5, and 0.9, respectively). The presence of these low-abundance HIV-1 variants was associated with drug susceptibility, replicative fitness, and coreceptor tropism determined using sensitive phenotypic assays, enhancing the overall burden of resistance to all four antiretroviral drug classes. Further longitudinal studies based on deep sequencing tests will help to clarify (i) the potential impact of minority HIV-1 drug resistant variants in response to antiretroviral therapy and (ii) the importance of the detection of HIV minority variants in the clinical practice.

R88-APOBEC3Gm Inhibits the Replication of Both Drug-resistant Strains of HIV-1 and Viruses Produced From Latently Infected Cells

Human immunodeficiency virus type 1 (HIV-1) drug resistance and the latent reservoir are the two major obstacles to effectively controlling and curing HIV-1 infection. Therefore, it is critical to develop therapeutic strategies specifically targeting these two obstacles. Recently, we described a novel anti-HIV approach based on a modified human intrinsic restriction factor, R88-APOBEC3G (R88-A3G). In this study, we further characterized the antiviral potential of R88-A3G_D128K (R88-A3Gm) against drug-resistant strains of HIV-1 and viruses produced from latently infected cells. We delivered R88-A3Gm into target cells using a doxycycline (Dox)-inducible lentiviral vector and demonstrated that its expression and antiviral activity were highly regulated by Dox. In the presence of Dox, R88-A3Gm–transduced T cells were resistant to infection caused by wild-type and various drug-resistant strains of HIV-1. Moreover, when the R88-A3Gm–expressing vector was transduced into the HIV-1 latently infected ACH-2 cell line or human CD4⁺ T cells, on activation by phorbol-12-myristate-13-acetate or phytohemaglutinin, R88-A3Gm was able to curtail the replication of progeny viruses. Altogether, these data clearly indicate that R88-A3Gm is a highly potent HIV-1 inhibitor, and R88-A3Gm–based anti-HIV gene therapy is capable of targeting both active and latent HIV-1–infected cells to prevent subsequent viral replication and dissemination.

Sensitive deep-sequencing-based HIV-1 genotyping assay to simultaneously determine susceptibility to protease, reverse transcriptase, integrase, and maturation inhibitors, as well as HIV-1 coreceptor tropism

With 29 individual antiretroviral drugs available from six classes that are approved for the treatment of HIV-1 infection, a combination of different phenotypic and genotypic tests is currently needed to monitor HIV-infected individuals. In this study, we developed a novel HIV-1 genotypic assay based on deep sequencing (DeepGen HIV) to simultaneously assess HIV-1 susceptibilities to all drugs targeting the three viral enzymes and to predict HIV-1 coreceptor tropism. Patient-derived gag-p2/NCp7/p1/p6/pol-PR/RT/IN- and env-C2V3 PCR products were sequenced using the Ion Torrent Personal Genome Machine. Reads spanning the 3' end of the Gag, protease (PR), reverse transcriptase (RT), integrase (IN), and V3 regions were extracted, truncated, translated, and assembled for genotype and HIV-1 coreceptor tropism determination. DeepGen HIV consistently detected both minority drug-resistant viruses and non-R5 HIV-1 variants from clinical specimens with viral loads of ≥1,000 copies/ml and from B and non-B subtypes. Additional mutations associated with resistance to PR, RT, and IN inhibitors, previously undetected by standard (Sanger) population sequencing, were reliably identified at frequencies as low as 1%. DeepGen HIV results correlated with phenotypic (original Trofile, 92%; enhanced-sensitivity Trofile assay [ESTA], 80%; TROCAI, 81%; and VeriTrop, 80%) and genotypic (population sequencing/Geno2Pheno with a 10% false-positive rate [FPR], 84%) HIV-1 tropism test results. DeepGen HIV (83%) and Trofile (85%) showed similar concordances with the clinical response following an 8-day course of maraviroc monotherapy (MCT). In summary, this novel all-inclusive HIV-1 genotypic and coreceptor tropism assay, based on deep sequencing of the PR, RT, IN, and V3 regions, permits simultaneous multiplex detection of low-level drug-resistant and/or non-R5 viruses in up to 96 clinical samples. This comprehensive test, the first of its class, will be instrumental in the development of new antiretroviral drugs and, more importantly, will aid in the treatment and management of HIV-infected individuals.

HIV genotypes and primary drug resistance among HIV-seropositive blood donors in Brazil: role of infected blood donors as sentinel populations for molecular surveillance of HIV

BACKGROUND

There are few surveillance studies analyzing genotypes or primary (transmitted) drug resistance in HIV-infected blood donors in Brazil. The aim of this study was to characterize patterns of HIV genotypes and primary resistance among HIV-seropositive donors identified at 4 geographically dispersed blood centers in Brazil.

METHODS

All HIV-infected donors who returned for counseling at the 4 REDS-II Hemocenters in Brazil from January 2007 to March 2011 were invited to participate in a case-control study involving a questionnaire on risk factors. Viral sequencing was also offered to positive cases to assign genotypes and to detect and characterize primary resistance to reverse transcriptase and protease inhibitors according to World Health Organization guidelines.

RESULTS

Of the 341 HIV-seropositive donors who consented to participate in the risk factor and genetics study, pol sequences were obtained for 331 (97%). Clade B was predominant (76%) followed by F (15%) and C (5%). Primary resistance was present in 36 [12.2%, 95% confidence interval (CI) 8.2 to 15.5] of the 303 individuals not exposed to antiretroviral therapy, varying from 8.2% (95% CI: 2.7 to 13.6) in Recife to 19.4% in São Paulo (95% CI: 9.5 to 29.2); there were no significant correlations with other demographics or risk factors.

CONCLUSIONS

Although subtype B remains the most prevalent genotype in all 4 areas, increasing rates of subtype C in Sao Paulo and F in Recife were documented relative to earlier reports. Transmitted drug resistance was relatively frequent, particularly in the city of Sao Paulo which showed an increase compared with previous HIV-seropositive donor data from 10 years ago.

Feasibility of interactive text message response (ITR) as a novel, real-time measure of adherence to antiretroviral therapy for HIV+ youth

Youth living with HIV/AIDS (YLH) face unique challenges to optimal adherence to antiretroviral therapy (ART). Accurate, real-time methods to assess adherence are needed to facilitate early intervention and promote viral suppression. The purpose of this study was to assess the feasibility and validity of interactive text message response (ITR) as a measure of adherence to ART among YLH. This study was part of a larger pilot text message reminder intervention conducted at a US community-based, LGBT-focused health center providing clinical services to YLH. Eligibility criteria for this pilot study included HIV-positive serostatus, aged 14-29, use of personal cell phone, English-speaking, and on ART with demonstrated adherence difficulties. During the 24-week study period, participants received personalized daily short message system reminders with a follow-up message 1 hour later asking whether they took medication and directing a response via return text message. To determine whether or not ITR would be a feasible, valid measure of adherence, we calculated the proportion of positive responses indicating medication had been taken divided by the total number of messages requesting a response and compared this response rate to a self-reported adherence measure, the visual analogue scale (VAS). Participants (n = 25) were on average 23 years old, largely male (92%), Black (60%) and behaviorally infected (84%). Over the course of the intervention, study participants responded to prompts via text to indicate whether or not they had taken their medication approximately 61% of the time. The overall mean ITR adherence rate (i.e., positive responses) was 57.4% (SD = 28.5%). ITR and VAS measures were moderately, positively correlated (r = 0.52, p < 0.05) during the first 6 weeks of the study period. ITR adherence rates were significantly higher on weekdays versus weekends (p < 0.05). This pilot study showed both moderate responsiveness of individuals to daily ITR and a moderate correlation of ITR adherence rates with a reliable measure during the first 6 weeks of the study, suggesting that this method, with additional effort and improvements, may be a helpful tool to identify and respond to adherence patterns in real-time.

Beating the placebo in HIV prevention efficacy trials: the role of the minimal efficacy bound

OBJECTIVES

To produce an effect on the HIV epidemic, preventive interventions need to achieve a minimum level of efficacy to offset potential indirect effects such as an increase in risky behavior. The current generation of HIV prevention trials on oral preexposure prophylaxis and on vaginal microbicides were designed using different set points for minimum individual-level efficacy (MIE). Some trials were designed not only to show superiority over placebo but also to rule out lower efficacies. The MIE has a substantial impact on the size and cost of a trial. Ideally, the MIE should be chosen to reduce uncertainty in the estimation of population-level effects. In this article, we investigate the effect of MIE on estimates of population-level impact to better inform trial design.

METHODS

We used mathematical model simulations assuming various rates of efficacy obtained from trials and different MIEs to study the impact of wide-scale interventions on 2 public health indicators.

RESULTS

Implementation factors were the main drivers of uncertainty in public health indicators for an intervention, although MIE also contributed. The level of uncertainty introduced by the MIE was substantially lower than that of the other factors.

CONCLUSIONS

Investigators in clinical trials have set the MIE solely on the basis of potential public health impact. However, the substantial increase in trial costs associated with a large MIE is unlikely to be justified. These additional funds would be better spent in evaluating more critical implementation factors that cannot be assessed in clinical trials.

Improving adherence to antiretroviral therapy for youth living with HIV/AIDS: a pilot study using personalized, interactive, daily text message reminders

BACKGROUND

For youth living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), nonadherence to antiretroviral therapy (ART) can lead to poor health outcomes and significantly decreased life expectancy.

OBJECTIVE

To evaluate the feasability, acceptability, and preliminary efficacy of short message service (SMS) or text message reminders to improve adherence to ART for youth living with HIV/AIDS.

METHODS

We conducted this prospective pilot study using a pre-post design from 2009 to 2010 at a community-based health center providing clinical services to youth living with HIV/AIDS. Eligibility criteria included HIV-positive serostatus, age 14-29 years, use of a personal cell phone, English-speaking, and being on ART with documented poor adherence. During the 24-week study period, participants received personalized daily SMS reminders and a follow-up message 1 hour later assessing whether they took the medication, and asking participants to respond via text message with the number 1 if they took the medication and 2 if they did not. Outcome measures were feasibility, acceptability, and adherence. Self-reported adherence was determined using the visual analog scale (VAS) and AIDS Clinical Trial Group (ACTG) questionnaire 4-day recall. Viral load and CD4 cell count were followed as biomarkers of adherence and disease progression at 0, 12, and 24 weeks.

RESULTS

Participants (N = 25) were mean age 23 (range 14-29) years, 92% (n = 23) male, 60% (n = 15) black, and 84% (n = 21) infected through unprotected sex. Mean VAS scores significantly increased at 12 and 24 weeks in comparison with baseline (week 0: 74.7, week 12: 93.3, P < .001; week 24: 93.1, P < .001). ACTG questionnaire 4-day recall also improved (week 0: 2.33, week 12: 3.24, P = .002; week 24: 3.19, P = .005). There was no significant difference in CD4 cell count or viral load between baseline and 12- or 24-week follow-up, although there was a trend toward improvement of these biomarkers and a small to moderate standardized effect size (range of Cohen d: -0.51 to 0.22). Of 25 participants, 21 (84%) were retained, and 20 of the 21 (95%) participants who completed the study found the intervention helpful to avoid missing doses.

CONCLUSIONS

In this pilot study, personalized, interactive, daily SMS reminders were feasible and acceptable, and they significantly improved self-reported adherence. Larger controlled studies are needed to determine the impact of this intervention on ART adherence and other related health outcomes for youth living with HIV/AIDS.

Development and evaluation of an assay for HIV-1 protease and reverse transcriptase drug resistance genotyping of all major group-M subtypes

BACKGROUND

High cost and varying sensitivity for non-B HIV-1 subtypes limits application of current commercial kits for HIV-1 drug resistance genotyping of all major HIV-1 group-M subtypes.

OBJECTIVES

Our research aimed to develop and validate an assay specific for all major HIV-1 group-M subtypes for use as an alternative to commercial assays for HIV-1 protease (PR) and reverse transcriptase (RT) drug resistance genotyping.

STUDY DESIGN

A nested RT-PCR encompassing the entire PR and RT up to amino acid 321 of HIV-1 was designed to detect HIV-1 group-M subtypes. Primers compatible with group-M subtypes were defined and analytical sensitivity of the assay evaluated using a panel of reference viruses for subtypes A-H and CRF01_AE. The assay was subsequently evaluated on 246 plasma samples from HIV-1 infected individuals harboring various group-M subtypes and viral loads (VLs).

RESULTS

All major group-M HIV-1 subtypes were detected with an overall analytical sensitivity of 1.00E+03 RNA copies/ml. Application of the genotyping assay on 246 primarily African clinical samples comprising subtypes A (n=52; 21.7%), B (n=12; 5.0%), C (n=127; 52.9%), D (n=25; 10.4%), CRF01_AE (n=10; 4.2%), and CRF02_AG (n=10; 4.2%), and unassigned variants (n=10; 4.2%), VL range 4.32E+02-8.63E+06 (median 2.66E+04) RNA copies/ml, was ∼98% successful.

CONCLUSIONS

A group-M subtype-independent genotyping assay for detection of HIV-1 drug resistance was developed. The described assay can serve as an alternative to commercial assays for HIV-1 drug resistance genotyping in routine diagnostics, and for surveillance and monitoring of drug resistance in resource-limited settings (RLS).

Health Protective Behaviors among Young People Living with HIV/AIDS

Young people living with HIV/AIDS (YPLH) in the post-HAART era have the potential to manage their HIV as a chronic illness rather than as an almost inevitable terminal disease. However, little is known about behaviors YPLH can engage in to promote or protect health beyond taking anti-retroviral (ARV) medicines. The current study fills an important gap in existing research by identifying correlates of Health Protective Behaviors (HPB) within an urban sample of YPLH. Participants (n=134) were recruited from two pediatric clinics serving adolescents living with HIV who met the following criteria: HIV-infected and aware of their status, 13-24 years old, residing in the Washington, DC metropolitan area, currently prescribed ARV or due to begin ARV within 3 months, and able to understand and sign a written consent form. Each participant was interviewed via Audio computer-assisted self-interview (ACASI) and reported the percentage of possible time they engaged in six HPB during the prior month using a 10-point scale (e.g., 5=50%). Results indicate that most patients engaged in the measured health protective behaviors more than half the time, although patients 18 and older engaged in all HPB less frequently than their younger counterparts. Patients with adherence > 90% were far more likely to engage in HPB than those with poorer adherence. The age differences in HPB highlight a need for broader scaffolding in the transition to independent living and adult health care. Given the relationship between adherence and HPB, the establishment and maintenance of healthy lifestyle practices early in adolescence can translate into positive long-term health outcomes.

Addressing HIV knowledge, risk reduction, social support, and patient involvement using SMS: results of a proof-of-concept study

Men who have sex with men continue to be severely and disproportionately affected by the HIV/AIDS epidemic in the United States. Effective antiretroviral therapy has altered the HIV epidemic from being an acute disease to a chronic, manageable condition for many people living with HIV. The pervasiveness, low cost, and convenience of short message service suggests its potential suitability for supporting the treatment of conditions that must be managed over an extended period. The purpose of this proof-of-concept study was to develop, implement, and test a tailored short message service-based intervention for HIV-positive men who have sex with men. The messages focused on reducing risk-taking behaviors and enhancing HIV knowledge, social support, and patient involvement. Participants reported strong receptivity to the messages and the intervention. The authors detected a statistically significant increase in HIV knowledge and social support from baseline to follow-up. Among participants who received sexual risk reduction messages, the authors also detected a statistically significant reduction in reported risk behaviors from baseline to follow-up. Results confirm the feasibility of a tailored, short message service-based intervention designed to provide ongoing behavioral reinforcement for HIV-positive men who have sex with men. Future research should include a larger sample, a control group, multiple sites, younger participants, and longer term follow-up.

The Role of RNA Polymerase II Elongation Control in HIV-1 Gene Expression, Replication, and Latency

HIV-1 usurps the RNA polymerase II elongation control machinery to regulate the expression of its genome during lytic and latent viral stages. After integration into the host genome, the HIV promoter within the long terminal repeat (LTR) is subject to potent downregulation in a postinitiation step of transcription. Once produced, the viral protein Tat commandeers the positive transcription elongation factor, P-TEFb, and brings it to the engaged RNA polymerase II (Pol II), leading to the production of viral proteins and genomic RNA. HIV can also enter a latent phase during which factors that regulate Pol II elongation may play a role in keeping the virus silent. HIV, the causative agent of AIDS, is a worldwide health concern. It is hoped that knowledge of the mechanisms regulating the expression of the HIV genome will lead to treatments and ultimately a cure.

Beyond reminders: a conceptual framework for using short message service to promote prevention and improve healthcare quality and clinical outcomes for people living with HIV

The availability of effective antiretroviral therapy has altered HIV from being an acute disease to being a chronic, manageable condition for many people living with HIV (PLWH). Because of their ubiquity and flexibility, mobile phones with short message service (SMS) offer a unique opportunity to enhance treatment and prevention for people managing HIV. To date, very few US studies using SMS for HIV self-management have been published. In this article, we review the published SMS-based intervention research that aimed to improve healthcare quality and outcomes for PLWH and other chronic health conditions, and propose a conceptual model that integrates the communication functionality of SMS with important psychosocial factors that could mediate the impact of SMS on health outcomes. We posit that an SMS-based intervention that incorporates the elements of interactivity, frequency, timing, and tailoring of messages could be implemented to encourage greater medication adherence as well as impact other mutually reinforcing behaviors and factors (e.g., increasing patient involvement and social support, reducing risk behaviors, and promoting general health and well-being) to support better healthcare quality and clinical outcomes for PLWH. We recommend that future studies explore the potential linkages between variations in SMS characteristics and these mediating factors to determine if and how they influence the larger outcomes.

Why don't patients take their drugs? The role of communication, context and culture in patient adherence and the work of the pharmacist in HIV/AIDS

OBJECTIVE

This study examined facilitators and barriers to adherence in four South African antiretroviral therapy (ART) clinic sites and explored context and communication factors in relation to the role of the pharmacist.

METHODS

Data were collected from interviews and narratives of patients and health professionals around the issues of adherence and qualitatively analysed using principles of Thematic Content Analysis.

RESULTS

Findings confirm the complex interplay between illness, communication, sociocultural, economic, context and systemic issues. Analysis suggests adherence is multifaceted and reinforces the critical role of communication factors in achieving concordance between patient and pharmacist.

CONCLUSION

Successful treatment of HIV/AIDS depends on pharmacists and healthcare teams understanding contextual and interactional factors which play a role in adherence.

PRACTICE IMPLICATIONS

The findings reinforce the importance of embedding a patient-centred approach in the training and everyday practice of pharmacists. The value of qualitative methods in understanding barriers to adherence and the potential value of the cultural broker in intercultural settings is discussed. Some suggestions are made as to how adherence counselling can be made relevant and effective.

Novel method for simultaneous quantification of phenotypic resistance to maturation, protease, reverse transcriptase, and integrase HIV inhibitors based on 3'Gag(p2/p7/p1/p6)/PR/RT/INT-recombinant viruses: a useful tool in the multitarget era of antiretroviral therapy

Twenty-six antiretroviral drugs (ARVs), targeting five different steps in the life cycle of the human immunodeficiency virus type 1 (HIV-1), have been approved for the treatment of HIV-1 infection. Accordingly, HIV-1 phenotypic assays based on common cloning technology currently employ three, or possibly four, different recombinant viruses. Here, we describe a system to assess HIV-1 resistance to all drugs targeting the three viral enzymes as well as viral assembly using a single patient-derived, chimeric virus. Patient-derived p2-INT (gag-p2/NCp7/p1/p6/pol-PR/RT/IN) products were PCR amplified as a single fragment (3,428 bp) or two overlapping fragments (1,657 bp and 2,002 bp) and then recombined into a vector containing a near-full-length HIV-1 genome with the Saccharomyces cerevisiae uracil biosynthesis gene (URA3) replacing the 3,428 bp p2-INT segment (Dudley et al., Biotechniques 46:458-467, 2009). P2-INT-recombinant viruses were employed in drug susceptibility assays to test the activity of protease (PI), nucleoside/nucleotide reverse transcriptase (NRTI), nonnucleoside reverse transcriptase (NNRTI), and integrase strand-transfer (INSTI) inhibitors. Using a single standardized test (ViralARTS HIV), this new technology permits the rapid and automated quantification of phenotypic resistance for all known and candidate antiretroviral drugs targeting all viral enzymes (PR, RT, including polymerase and RNase H activities, and IN), some of the current and potential assembly inhibitors, and any drug targeting Pol or Gag precursor cleavage sites (relevant for PI and maturation inhibitors) This novel assay may be instrumental (i) in the development and clinical assessment of novel ARV drugs and (ii) to monitor patients failing prior complex treatment regimens.

Changes in the HIV-1 mutational profile before first-line HAART in the RESINA cohort

Sporadic observations have shown changing patterns of transmitted drug resistance mutations (TDRMs) in HIV infection even without selection pressure by antiretroviral treatment (ART). Repeated genotypic resistance analyses in treatment-naïve patients were performed, in order to analyze intraindividual variances of resistance patterns over time. Between the years 2001 and 2008 two genotypic resistance tests were performed at different time-points in 49 treatment-naïve HIV-positive patients aged >18 years. Wild-type virus was found at baseline and during follow-up in 31 patients (group A, median time between resistance tests 146 days), while resistance mutations were found either at baseline or during follow-up in 18 patients (group B, median time between resistance tests 297 days). In group B, the pattern of resistance changed in eight out of 18 patients over time, with three patients showing decreasing numbers and five patients showing increasing numbers of resistance mutations. The pattern of resistance mutations remained unchanged in 10 out of 18 patients. The mutational pattern in untreated HIV infection may change over time and a single resistance analysis may underestimate the true prevalence of preserved resistance mutations. If these findings can be confirmed in a larger number of patients, it would be prudent to perform genotypic resistance testing both at baseline and prior to the start of ART in order to capture a more complete picture of preserved mutations before initiating ART.

Increased detection of the HIV-1 reverse transcriptase M184V mutation using mutation-specific minority assays in a UK surveillance study suggests evidence of unrecognized transmitted drug resistance

OBJECTIVES

The aim of the study was to estimate the levels of transmitted drug resistance (TDR) in HIV-1 using very sensitive assays to detect minority drug-resistant populations.

METHODS

We tested unlinked anonymous serum specimens from sexual health clinic attendees, who had not received an HIV diagnosis at the time of sampling, by both standard genotyping and using minority detection assays.

RESULTS

By standard genotyping, 21 of 165 specimens (12.7%) showed evidence of drug resistance, while, using a combination of standard genotyping and minority mutation assays targeting three commonly observed drug resistance mutations which cause high-level resistance to commonly prescribed first-line antiretroviral therapy (ART), this rose to 32 of 165 (19.4%). This increase of 45% in drug resistance levels [95% confidence interval (CI) 15.2-83.7%; P=0.002] was statistically significant. Almost all of this increase was accounted for by additional detections of the M184V mutation.

CONCLUSIONS

Future surveillance studies of TDR in the United Kingdom should consider combining standard genotyping and minority-specific assays to provide more accurate estimates, particularly when using specimens collected from chronic HIV infections in which TDR variants may have declined to low levels.

Use of phylogenetics in the molecular epidemiology and evolutionary studies of viral infections

Since DNA sequencing techniques first became available almost 30 years ago, the amount of nucleic acid sequence data has increased enormously. Phylogenetics, which is widely applied to compare and analyze such data, is particularly useful for the analysis of genes from rapidly evolving viruses. It has been used extensively to describe the molecular epidemiology and transmission of the human immunodeficiency virus (HIV), the origins and subsequent evolution of the severe acute respiratory syndrome (SARS)-associated coronavirus (SCoV), and, more recently, the evolving epidemiology of avian influenza as well as seasonal and pandemic human influenza viruses. Recent advances in phylogenetic methods can infer more in-depth information about the patterns of virus emergence, adding to the conventional approaches in viral epidemiology. Examples of this information include estimations (with confidence limits) of the actual time of the origin of a new viral strain or its emergence in a new species, viral recombination and reassortment events, the rate of population size change in a viral epidemic, and how the virus spreads and evolves within a specific population and geographical region. Such sequence-derived information obtained from the phylogenetic tree can assist in the design and implementation of public health and therapeutic interventions. However, application of many of these advanced phylogenetic methods are currently limited to specialized phylogeneticists and statisticians, mainly because of their mathematical basis and their dependence on the use of a large number of computer programs. This review attempts to bridge this gap by presenting conceptual, technical, and practical aspects of applying phylogenetic methods in studies of influenza, HIV, and SCoV. It aims to provide, with minimal mathematics and statistics, a practical overview of how phylogenetic methods can be incorporated into virological studies by clinical and laboratory specialists.

Hidden drug resistant HIV to emerge in the era of universal treatment access in Southeast Asia

BACKGROUND

Universal access to first-line antiretroviral therapy (ART) for HIV infection is becoming more of a reality in most low and middle income countries in Asia. However, second-line therapies are relatively scarce.

METHODS AND FINDINGS

We developed a mathematical model of an HIV epidemic in a Southeast Asian setting and used it to forecast the impact of treatment plans, without second-line options, on the potential degree of acquisition and transmission of drug resistant HIV strains. We show that after 10 years of universal treatment access, up to 20% of treatment-naïve individuals with HIV may have drug-resistant strains but it depends on the relative fitness of viral strains.

CONCLUSIONS

If viral load testing of people on ART is carried out on a yearly basis and virological failure leads to effective second-line therapy, then transmitted drug resistance could be reduced by 80%. Greater efforts are required for minimizing first-line failure, to detect virological failure earlier, and to procure access to second-line therapies.

Who will Benefit from a Wide-Scale Introduction of Vaginal Microbicides in Developing Countries?

Vaginal microbicides (VMB) are currently among the few biomedical interventions designed to help women reduce their risk of acquiring HIV infection. However, the microbicide containing antiretroviral (ARV-VMB) may lead to the development of antiretroviral resistance and could paradoxically become more beneficial to men at the population level. We developed a mathematical model to study the impact of a wide-scale population usage of VMB in a heterosexual population. Gender ratios of prevented infections and prevalence reduction are evaluated in 63 different intervention schedules including continuous and interrupted ARV-VMB use by HIV-positive women. The influence of different factors on population-level benefits is also studied through Monte Carlo simulations using parameters sampled from primary ranges representative of developing countries. Our analysis indicates that women are more likely than men to benefit from ARV-VMB use since 78-80% of the total 63,000 simulations investigated (under different parameter sets) showed a female advantage whether benefit is measured as cumulative number of infections prevented, the percentage of cumulative infections prevented, or the expected reduction in prevalence. Stratified analysis by scenarios indicates that the likelihood of a male advantage with respect to the fractions of prevented infections varies from 6% to 49% among the scenarios. It is substantial only if the risk of systemic absorption and development of resistance to ARV-VMB is high and the HIV-positive women use VMB indefinitely without interruption. Therefore, the use of ARV-VMB, with successful control measures restricting usage by HIV-positive women, is still very much a female prevention tool.

The effect of intrinsic stochasticity on transmitted HIV drug resistance patterns

Estimates of transmitted HIV drug-resistance prevalence vary widely among and within epidemiological surveys. Interpretation of trends from available survey data is therefore difficult. Because the emergence of drug-resistance involves small populations of infected drug-resistant individuals, the role of stochasticity (chance events) is likely to be important. The question addressed here is: how much variability in transmitted HIV drug-resistance prevalence patterns arises due to intrinsic stochasticity alone, i.e., if all starting conditions in the different epidemics surveyed were identical? This 'thought experiment' gives insight into the minimum expected variabilities within and among epidemics. A simple stochastic mathematical model was implemented. Our results show that stochasticity alone can generate a significant degree of variability and that this depends on the size and variation of the pool of new infections when drug treatment is first introduced. The variability in transmitted drug-resistance prevalence within an epidemic (i.e., the temporal variability) is large when the annual pool of all new infections is small (fewer than 200, typical of the HIV epidemics in Central European and Scandinavian countries) but diminishes rapidly as that pool grows. Epidemiological surveys involving hundreds of new infections annually are therefore needed to allow meaningful interpretation of temporal trends in transmitted drug-resistance prevalence within individual epidemics. The stochastic variability among epidemics shows a similar dependence on the pool of new infections if treatment is introduced after endemic equilibrium is established, but can persist even when there are more than 10,000 new infections annually if drug therapy is introduced earlier. Stochastic models may therefore have an important role to play in interpreting differences in transmitted drug-resistance prevalence trends among epidemiological surveys.

"Tell me so I know you understand": pharmacists' verification of patients' comprehension of antiretroviral dosage instructions in a cross-cultural context

OBJECTIVE

Patient comprehension of dosage instructions is an essential condition for adherence to treatment regimens, but previous studies show that pharmacists do not generally check understanding. This study aims to describe and discuss the effectiveness of various strategies for verifying patients' understanding of ARV dosage instructions in a cross-cultural context.

METHODS

Twenty-six cross-cultural pharmacist-patient interactions in an ARV pharmacy in South Africa were analysed using Conversation Analysis techniques. Interviews with participants were analysed using Thematic Content Analysis.

RESULTS

Various strategies for verifying patient understanding were identified in the data, including eliciting a demonstration of understanding, using specific questions to verify understanding, using response solicitations and monitoring patients' verbal and non-verbal responses. These strategies are illustrated with relevant data extracts. Interviews revealed that patients appeared to have good understanding of ARV-related concepts.

CONCLUSION

These strategies for verification of patient understanding appear to be effective tools which enable pharmacists to identify misunderstandings or initiate clarification sequences.

PRACTICE IMPLICATIONS

The strategies are felt to be particularly useful in cross-linguistic pharmacy interactions and have implications for other professionals.

Oral complications of HIV disease

Oral lesions are among the early signs of HIV infection and can predict its progression to acquired immunodeficiency syndrome (AIDS). A better understanding of the oral manifestations of AIDS in both adults and children has implications for all health care professionals. The knowledge of such alterations would allow for early recognition of HIV-infected patients. The present paper reviews epidemiology, relevant aspects of HIV infection related to the mouth in both adults and children, as well as current trends in antiretroviral therapy and its connection with orofacial manifestations related to AIDS.

Demonstration of sustained drug-resistant human immunodeficiency virus type 1 lineages circulating among treatment-naïve individuals

Transmission of human immunodeficiency virus (HIV) drug resistance is well-recognized and compromises response to first-line therapy. However, the population dynamics of transmitted resistance remains unclear, although previous models have assumed that such transmission reflects direct infection from treated individuals. We investigated whether population-based phylogenetic analyses would uncover lineages of resistant viruses circulating in untreated individuals. Through the phylogenetic analysis of 14,061 HIV type 1 (HIV-1) pol gene sequences generated in the United Kingdom from both treatment-naïve and -experienced individuals, we identified five treatment-independent viral clusters containing mutations conferring cross-resistance to antiretroviral drugs prescribed today in the United Kingdom. These viral lineages represent sustainable reservoirs of resistance among new HIV infections, independent of treatment. Dated phylogenies reconstructed through Bayesian Markov chain Monte Carlo inference indicated that these reservoirs originated between 1997 and 2003 and have persisted in the HIV-infected population for up to 8 years. Since our cohort does not represent all infected individuals within the United Kingdom, our results are likely to underestimate the number and size of the resistant reservoirs circulating among drug-naïve patients. The existence of sustained reservoirs of resistance in the absence of treatment has the capacity to threaten the long-term efficacy of antiretroviral therapy and suggests there is a limit to the decline of transmitted drug resistance. Given the current decrease in resistance transmitted from treated individuals, a greater proportion of resistance is likely to come from drug-naïve lineages. These findings provide new insights for the planning and management of treatment programs in resource-rich and developing countries.

New methods for the surveillance of HIV drug resistance in the resource poor world

PURPOSE OF REVIEW

As antiretroviral therapy scale-up proceeds in developing countries, simple and inexpensive procedures are required to monitor the prevalence and transmission of drug-resistant HIV strains to ensure optimal use of antiviral therapy. This article reviews new surveillance methods and practices used to monitor drug resistance in the developing world.

RECENT FINDINGS

Several recently published studies report the successful development of methods using dried blood spots, collected on filter paper, for HIV drug resistance genotyping tests. In concert to antiretroviral therapy rollout, the WHO has developed a laboratory network and sought to implement surveillance of transmitted drug resistance in developing countries. A small number of developing world prevalence studies have thus far been published using dried blood spots. These studies reveal low rates of transmitted drug resistance. Other studies indicate that the use of dried blood spots for HIV drug resistance surveillance may possibly lead to overestimates.

SUMMARY

The use of dried blood spots as a method of specimen collection and storage is simple, inexpensive and is an appropriate technique for the surveillance of transmitted HIV drug resistance.

Short communication: high prevalence of drug-resistant human immunodeficiency virus type 1 in treatment-naïve patients in Greenland

A molecular epidemiologic study of HIV-1 in Greenland showed distinct transmission clusters correlated with demographic and behavioral data. Resistance mutations were found in a majority of the pol sequences. The objective of the present study was to estimate prevalence of drug resistance in Greenland and identify transmission chains by comparing resistance data with phylogeny and treatment history. Of 60 untreated patients, 15 (25%) had primary resistance mutations. The most prevalent mutations were T69D/N (15%), K70R (15%), and M184V (10%). Four possible transmission chains were identified based on phylogeny and mutation profiles. The clusters consisted of treated and untreated patients and showed the same mutation profiles in both resistance and nonresistance positions. Prevalence of transmitted drug resistance in Greenland (25%) is higher than in Denmark where only 3% transmission was observed. Suboptimal use of nucleoside reverse transcriptase inhibitor (NRTI) in Greenland was reflected in the high prevalence of NRTI-related resistance in the patients. A combination of phylogeny and genotypic resistance tests enabled us to study the number of transmissions and how the virus was transmitted. Resistance mutations detected in untreated patients were backed up by the treatment history of index patients in the possible transmission chains and indicated that these drug-resistant variants were in fact transmitted and had not emerged due to unregistered drug intake.

Fusion of Epstein-Barr virus nuclear antigen-1-derived glycine-alanine repeat to trans-dominant HIV-1 Gag increases inhibitory activities and survival of transduced cells in vivo

Trans-dominant human immunodeficiency virus type 1 (HIV-1) Gag derivatives have been shown to efficiently inhibit late steps of HIV-1 replication in vitro by interfering with Gag precursor assembly, thus ranking among the interesting candidates for gene therapy approaches. However, efficient antiviral activities of corresponding transgenes are likely to be counteracted in particular by cell-mediated host immune responses toward the transgene-expressing cells. To decrease this potential immunogenicity, a 24-amino acid Gly-Ala (GA) stretch derived from Epstein-Barr virus nuclear antigen-1 (EBNA1) and known to overcome proteasomal degradation was fused to a trans-dominant Gag variant (sgD1). To determine the capacity of this fusion polypeptide to repress viral replication, PM-1 cells were transduced with sgD1 and GAsgD1 transgenes, using retroviral gene transfer. Challenge of stably transfected permissive cell lines with various viral strains indicated that N-terminal GA fusion even enhanced the inhibitory properties of sgD1. Further studies revealed that the GA stretch increased protein stability by blocking proteasomal degradation of Gag proteins. Immunization of BALB/c mice with a DNA vaccine vector expressing sgD1 induced substantial Gag-specific immune responses that were, however, clearly diminished in the presence of GA. Furthermore, recognition of cells expressing the GA-fused transgene by CD8(+) T cells was drastically reduced, both in vitro and in vivo, resulting in prolonged survival of the transduced cells in recipient mice.

An HIV-1 215V mutant shows increased phenotypic resistance to d4T

Human immunodeficiency virus type 1 (HIV-1) viruses with C/S/D/E at 215 codon of the reverse transcriptase (RT) have been associated with the T215Y/F HIV-1 resistant viruses transmission to naïve patients. The uncommon T215V mutation was detected in DNA proviral samples of a treatment-naïve patient. Virus T215V was obtained after cloning the patient-RT into a molecular clone. Wild-type (T215) and resistant (T215F) clones, were obtained in T215V clone by "in vitro" site-directed mutagenesis. Phenotypic resistance against AZT, ddI and d4T, replication kinetics and the selection of resistance mutations were estimated "in vitro". The T215V virus replicated as efficiently as the wild-type (T215) without antivirals and in the presence of AZT or ddI. The T215V virus showed higher replicative capacity than the wild-type and a 4.3-fold increase in the IC(50) values in cultures with d4T. Selection of resistance mutations was not observed in viral quasispecies of the T215V virus after serial passages in culture in presence of increasing concentrations of AZT, ddI or d4T. This work demonstrates that the T215V mutation decreases the susceptibility of HIV-1 to d4T, and consequently, it could compromise the response to regimens containing this antiviral.

Chronic hepatitis B: preventing, detecting, and managing viral resistance

Licensed oral agents for antiviral therapy in patients with chronic hepatitis B virus (HBV) infection include lamivudine, adefovir, entecavir, and telbivudine. Emtricitabine, tenofovir, and the combination of tenofovir plus emtricitabine in 1 tablet, which are licensed for the treatment of human immunodeficiency virus infection, are additional off-label options for treating HBV infection. Preventing HBV antiviral drug resistance to nucleoside/nucleotide analogues and appropriate management when resistance occurs has become a major focus in the management of chronic hepatitis B. HBV antiviral drug resistance may be best prevented by using an agent or combination of agents with a high genetic barrier to resistance, and 2 potent nucleoside and nucleotide drugs with different resistance profiles may prove to be the optimal first-line treatment for chronic hepatitis B. Frequent assessment of quantitative serum HBV DNA remains the best approach to early detection of resistance, and antiviral therapy should be modified as soon as resistance is detected. Results from several clinical trials have shown that the addition or substitution of newer antiviral agents can restore suppression of viral replication, normalize alanine aminotransferase levels, and reverse histologic progression in patients with resistance to lamivudine, but little information exists regarding the long-term benefits of second-line treatment regimens. Despite the substantial advances in treatment made to date, new agents with novel viral targets will be needed for patients who ultimately may fail second- or third-line therapy.

Inhibition of HIV replication: A powerful antiviral strategy by IFN-β gene delivery in CD4+ cells

In this study, we demonstrated the efficiency and feasibility of a gene therapy protocol against HIV infection using the antiviral effects of IFN-beta expression. Lentiviral vectors containing the human or the simian IFN-beta sequences under the influence of the murine moderate H2-kb promoter were constructed. To examine the capacity of IFN-beta to inhibit the replication of HIV in human CD4(+) cells, a transduction protocol permitting to efficiently transduce CD4(+) cells or PBMC (85+/-12% of CD4(+)-transduced cells) with a moderate expression of IFN-beta was developed. Results indicate that enforced expression of IFN-beta has no negative effects in terms of apoptosis and proliferation. In human CD4(+) cells, it drastically inhibits (up to 99.9%) replication after challenging with different strains of HIV-1. The expression of exogenous IFN-beta leads to an amplification of the CD4(+) cells (11-fold) and to a drastic decrease of the p24 protein. Micro-array analyses indicated that antiviral effect of IFN-beta could be due to a major regulation of the inflammatory response. These results are encouraging for the development of a clinical study of gene therapy against AIDS using IFN-beta.

Inhibition of HIV-1 replication by P-TEFb inhibitors DRB, seliciclib and flavopiridol correlates with release of free P-TEFb from the large, inactive form of the complex

Background

The positive transcription elongation factor, P-TEFb, comprised of cyclin dependent kinase 9 (Cdk9) and cyclin T1, T2 or K regulates the productive elongation phase of RNA polymerase II (Pol II) dependent transcription of cellular and integrated viral genes. P-TEFb containing cyclin T1 is recruited to the HIV long terminal repeat (LTR) by binding to HIV Tat which in turn binds to the nascent HIV transcript. Within the cell, P-TEFb exists as a kinase-active, free form and a larger, kinase-inactive form that is believed to serve as a reservoir for the smaller form.

Results

We developed a method to rapidly quantitate the relative amounts of the two forms based on differential nuclear extraction. Using this technique, we found that titration of the P-TEFb inhibitors flavopiridol, DRB and seliciclib onto HeLa cells that support HIV replication led to a dose dependent loss of the large form of P-TEFb. Importantly, the reduction in the large form correlated with a reduction in HIV-1 replication such that when 50% of the large form was gone, HIV-1 replication was reduced by 50%. Some of the compounds were able to effectively block HIV replication without having a significant impact on cell viability. The most effective P-TEFb inhibitor flavopiridol was evaluated against HIV-1 in the physiologically relevant cell types, peripheral blood lymphocytes (PBLs) and monocyte derived macrophages (MDMs). Flavopiridol was found to have a smaller therapeutic index (LD₅₀/IC₅₀) in long term HIV-1 infectivity studies in primary cells due to greater cytotoxicity and reduced efficacy at blocking HIV-1 replication.

Conclusion

Initial short term studies with P-TEFb inhibitors demonstrated a dose dependent loss of the large form of P-TEFb within the cell and a concomitant reduction in HIV-1 infectivity without significant cytotoxicity. These findings suggested that inhibitors of P-TEFb may serve as effective anti-HIV-1 therapies. However, longer term HIV-1 replication studies indicated that these inhibitors were more cytotoxic and less efficacious against HIV-1 in the primary cell cultures.

Epidemiology of human immunodeficiency virus in the United States

The human immunodeficiency virus (HIV) epidemic emerged in the early 1980s with HIV infection as a highly lethal disease among men who have sex with men and among frequent recipients of blood product transfusions. Advances in the treatment of HIV infection have resulted in a fundamental shift in its epidemiology, to a potentially chronic and manageable condition. However, challenges in the prevention of this infection remain. In particular, increasing evidence suggests that transmission of drug-resistant virus is becoming more common and that the epidemic is having a profound impact on morbidity and mortality in ethnic and racial minority subgroups in the United States. New population-based data collection systems designed to describe trends in behaviors associated with HIV transmission and better methods for measuring the true incidence of transmission will better elucidate the characteristics of HIV infection in the United States and inform future public health policies.

Emergence of HIV-1 Drug Resistance During Antiretroviral Treatment

Treating HIV-infected patients with a combination of several antiretroviral drugs usually contributes to a substantial decline in viral load and an increase in CD4(+) T cells. However, continuing viral replication in the presence of drug therapy can lead to the emergence of drug-resistant virus variants, which subsequently results in incomplete viral suppression and a greater risk of disease progression. In this paper, we use a simple mathematical model to study the mechanism of the emergence of drug resistance during therapy. The model includes two viral strains: wild-type and drug-resistant. The wild-type strain can mutate and become drug-resistant during the process of reverse transcription. The reproductive ratio [Symbol: see text](0) for each strain is obtained and stability results of the steady states are given. We show that drug-resistant virus is more likely to arise when, in the presence of antiretroviral treatment, the reproductive ratios of both strains are close. The wild-type virus can be suppressed even when the reproductive ratio of this strain is greater than 1. A pharmacokinetic model including blood and cell compartments is employed to estimate the drug efficacies of both the wild-type and the drug-resistant strains. We investigate how time-varying drug efficacy (due to the drug dosing schedule and suboptimal adherence) affects the antiviral response, particularly the emergence of drug resistance. Simulation results suggest that perfect adherence to regimen protocol will well suppress the viral load of the wild-type strain while drug-resistant variants develop slowly. However, intermediate levels of adherence may result in the dominance of the drug-resistant virus several months after the initiation of therapy. When more doses of drugs are missed, the failure of suppression of the wild-type virus will be observed, accompanied by a relatively slow increase in the drug-resistant viral load.

The global status of resistance to antiretroviral drugs

Since 1989, the emergence of resistant human immunodeficiency virus mutants has been documented for any new antiretroviral agent introduced in the clinical setting; it is a major cause of failure of antiretroviral therapy that may ultimately compromise the antiretroviral's efficacy in the general population. In most cases, resistance is due to poor adherence by the patient and/or to low potency of the therapeutic regimen. Resistance is called "primary" if detected in treatment-naive persons and is called "acquired" when it develops in treatment-experienced persons. This latter population represents potential transmitters of resistant viruses to newly infected persons. Data about the actual prevalence of resistance are derived from studies that differ in design, sample size, geographic area, and definitions. For this reason, a limited number of surveillance programs have been established in the past, both in countries where highly active antiretroviral therapy is widely accessible and in geographic areas where it is being introduced.

The emergence of HIV transmitted resistance in Botswana: "when will the WHO detection threshold be exceeded?"

Background

The Botswana antiretroviral program began in 2002 and currently treats 42,000 patients, with a goal of treating 85,000 by 2009. The World Health Organization (WHO) has begun to implement a surveillance system for detecting transmitted resistance that exceeds a threshold of 5%. However, the WHO has not determined when this threshold will be reached. Here we model the Botswana government's treatment plan and predict, to 2009, the likely stochastic evolution of transmitted resistance.

Methods

We developed a model of the stochastic evolution of drug-resistant strains and formulated a birth-death Master equation. We analyzed this equation to obtain an analytical solution of the probabilistic evolutionary trajectory for transmitted resistance, and used treatment and demographic data from Botswana. We determined the temporal dynamics of transmitted resistance as a function of: (i) the transmissibility (i.e., fitness) of the drug-resistant strains that may evolve and (ii) the rate of acquired resistance.

Results

Transmitted resistance in Botswana will be unlikely to exceed the WHO's threshold by 2009 even if the rate of acquired resistance is high and the strains that evolve are half as fit as the wild-type strains. However, we also found that transmission of drug-resistant strains in Botswana could increase to ∼15% by 2009 if the drug-resistant strains that evolve are as fit as the wild-type strains.

Conclusions

Transmitted resistance will only be detected by the WHO (by 2009) if the strains that evolve are extremely fit and acquired resistance is high. Initially after a treatment program is begun a threshold lower than 5% should be used; and we advise that predictions should be made before setting a threshold. Our results indicate that it may be several years before the WHO's surveillance system is likely to detect transmitted resistance in other resource-poor countries that have significantly less ambitious treatment programs than Botswana.