How reliable is an undetectable viral load?

Comparing dedicated and designated approaches to integrating task-shared psychological interventions into chronic disease care in South Africa: a three-arm, cluster randomised, multicentre, open-label trial

BACKGROUND

Community health workers (CHWs) are increasingly providing task-shared psychological interventions for depression and alcohol use in primary health care in low-income and middle-income countries. We aimed to compare the effectiveness of CHWs dedicated to deliver care with CHWs designated to deliver care over and above their existing responsibilities and with treatment as usual for patients with a chronic physical disease.

METHODS

We did a three-arm, cluster randomised, multicentre, open-label trial done in 24 primary health-care clinics (clusters) within the Western Cape province of South Africa. Clinics were randomly assigned (1:1:1) to implement dedicated care, designated care, or treatment as usual, stratified by urban-rural status. Patients with HIV or type 1 or type 2 diabetes were eligible if they were 18 years old or older, taking antiretroviral therapy for HIV or medication to manage their diabetes, had an Alcohol Use Disorders Identification Test (AUDIT) score of eight or more or a Center for Epidemiologic Studies Depression Scale score of 16 or more, and were not receiving mental health treatment. In the intervention arms, all participants were offered three sessions of an evidence-based psychological intervention, based on motivational interviewing and problem-solving therapy, delivered by CHWs. Our primary outcomes were depression symptom severity and alcohol use severity, which we assessed separately for the intention-to-treat populations of people with HIV and people with diabetes cohorts and in a pooled cohort, at 12 months after enrolment. The Benjamini-Hochberg procedure was used to adjust for multiple testing. The trial was prospectively registered with the Pan African Clinical Trials Registry, PACTR201610001825403.

FINDINGS

Between May 1, 2017, and March 31, 2019, 1340 participants were recruited: 457 (34·1%) assigned to the dedicated group, 438 (32·7%) assigned to the designated group, and 445 (33·2%) assigned to the treatment as usual group. 1174 (87·6%) participants completed the 12 month assessment. Compared with treatment as usual, the dedicated group (people with HIV adjusted mean difference -5·02 [95% CI -7·51 to -2·54], p<0·0001; people with diabetes -4·20 [-6·68 to -1·72], p<0·0001) and designated group (people with HIV -6·38 [-8·89 to -3·88], p<0·0001; people with diabetes -4·80 [-7·21 to -2·39], p<0·0001) showed greater improvement on depression scores at 12 months. By contrast, reductions in AUDIT scores were similar across study groups, with no intervention effects noted.

INTERPRETATION

The dedicated and designated approaches to delivering CHW-led psychological interventions were equally effective for reducing depression, but enhancements are required to support alcohol reduction. This trial extends evidence for CHW-delivered psychological interventions, offering insights into how different delivery approaches affect patient outcomes.

FUNDING

British Medical Research Council, Wellcome Trust, UK Department for International Development, the Economic and Social Research Council, and the Global Challenges Research Fund.

Single-Agent and Fixed-Dose Combination HIV-1 Protease Inhibitor Drugs in Fission Yeast (Schizosaccharomyces pombe)

Successful combination antiretroviral therapies (cART) eliminate active replicating HIV-1, slow down disease progression, and prolong lives. However, cART effectiveness could be compromised by the emergence of viral multidrug resistance, suggesting the need for new drug discoveries. The objective of this study was to further demonstrate the utility of the fission yeast cell-based systems that we developed previously for the discovery and testing of HIV protease (PR) inhibitors (PIs) against wild-type or multi-PI drug resistant _M11PR that we isolated from an infected individual. All thirteen FDA-approved single-agent and fixed-dose combination HIV PI drugs were tested. The effect of these drugs on HIV PR activities was tested in pure compounds or formulation drugs. All FDA-approved PI drugs, except for a prodrug FPV, were able to suppress the wild-type PR-induced cellular and enzymatic activities. Relative drug potencies measured by EC₅₀ in fission yeast were discussed in comparison with those measured in human cells. In contrast, none of the FDA-approved drugs suppressed the multi-PI drug resistant _M11PR activities. Results of this study show that fission yeast is a reliable cell-based system for the discovery and testing of HIV PIs and further demonstrate the need for new PI drugs against viral multi-PI resistance.

Development of A Fission Yeast Cell-Based Platform for High Throughput Screening of HIV-1 Protease Inhibitors

BACKGROUND

HIV-1 protease inhibitor (PI) is one of the most potent classes of drugs in combinational antiretroviral therapies (cART). When a PI is used in combination with other anti- HIV drugs, cART can often suppress HIV-1 below detection thus prolonging the patient's lives. However, the challenge often faced by patients is the emergence of HIV-1 drug resistance. Thus, PIs with high genetic-barrier to drug-resistance are needed.

OBJECTIVE

The objective of this study was to develop a novel and simple fission yeast (Schizosaccharomyces pombe) cell-based system that is suitable for high throughput screening (HTS) of small molecules against HIV-1 protease (PR).

METHODS

A fission yeast RE294-GFP strain that stably expresses HIV-1 PR and green fluorescence protein (GFP) under the control of an inducible nmt1 promoter was used. Production of HIV-1 PR induces cellular growth arrest, which was used as the primary endpoint for the search of PIs and was quantified by an absorbance-based method. Levels of GFP production were used as a counter-screen control to eliminate potential transcriptional nmt1 inhibitors.

RESULTS

Both the absorbance-based HIV-1 PR assay and the GFP-based fluorescence assay were miniaturized and optimized for HTS. A pilot study was performed using a small drug library mixed with known PI drugs and nmt1 inhibitors. With empirically adjusted and clearly defined double-selection criteria, we were able to correctly identify the PIs and to exclude all hidden nmt1 inhibitors.

CONCLUSION

We have successfully developed and validated a fission yeast cell-based HTS platform for the future screening and testing of HIV-1 PR inhibitors.

A fission yeast cell-based system for multidrug resistant HIV-1 proteases

Background

HIV-1 protease (PR) is an essential enzyme for viral production. Thus, PR inhibitors (PIs) are the most effective class of anti-HIV drugs. However, the main challenge to the successful use of PI drugs in patient treatment is the emergence of multidrug resistant PRs (_mdrPRs). This study aimed to develop a fission yeast cell-based system for rapid testing of new PIs that combat _mdrPRs.

Results

Three _mdrPRs were isolated from HIV-infected patients that carried seven (_M7PR), ten (_M10PR) and eleven (_M11PR) PR gene mutations, respectively. They were cloned and expressed in fission yeast under an inducible promoter to allow the measurement of PR-specific proteolysis and drug resistance. The results showed that all three _mdrPRs maintained their abilities to proteolyze HIV viral substrates (MA↓CA and p6) and to confer drug resistance. Production of these proteins in the fission yeast caused cell growth inhibition, oxidative stress and altered mitochondrial morphologies that led to cell death. Five investigational PIs were used to test the utility of the established yeast system with an FDA-approved PI drug Darunavir (DRV) as control. All six compounds suppressed the wildtype PR (_wtPR) and the _M7PR-mediated activities. However, none of them were able to suppress the _M10PR or the _M11PR.

Conclusions

The three clinically isolated _mdrPRs maintained their viral proteolytic activities and drug resistance in the fission yeast. Furthermore, those viral _mdrPR activities were coupled with the induction of growth inhibition and cell death, which could be used to test the PI activities. Indeed, the five investigational PIs and DRV suppressed the _wtPR in fission yeast as they did in mammalian cells. Significantly, two of the high level _mdrPRs (_M10PR and _M11PR) were resistant to all of the existing PI drugs including DRV. This observation underscores the importance of continued searching for new PIs against _mdrPRs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-016-0131-5) contains supplementary material, which is available to authorized users.

HIV viral load: a concept analysis and critique

In this article, we examine the concept of HIV viral load and how it has evolved over time (1995-2013) in the field of HIV/AIDS. Although the term viral load is used extensively in this field, few efforts have been directed toward the conceptualization of HIV viral load, which is often left unquestioned, undertheorized, and portrayed as a neutral and objective laboratory value that has remained relatively stable over time--with the exception of progressive advancements in technology, techniques, and sensitivity. The purpose of this article is to apply the evolutionary concept analysis method developed by Rodgers (1989, 2000a) to the concept of HIV viral load. To set the stage, we establish the need for a concept analysis of HIV viral load and provide an overview of the evolutionary view. Then, drawing on the steps proposed by Rodgers (2000a), we outline the process of data collection, management, and analysis. We then offer an in-depth discussion of the findings (attributes, antecedents, and consequences) informed by Wuest's (2000) critical approach to concept analysis. We conclude by highlighting the implications of this analysis for clinical practice, research, and theory.

The criminal transmission of HIV: issues with condom use and viral load

This article considers two issues in relation to the criminal transmission of HIV. Currently, the use of condoms, and a defendant's viral load, has not been an issue that has been raised in the courts. The article considers how the defence, prosecution and judge may deal with such evidential issues. It will discuss how an expert opinion may be utilised or discredited by counsel for the defendant and counsel for the prosecution. The article will consider how the defence can demonstrate that the defendant was not reckless and how the prosecution can establish that the defendant was actually reckless. It will also assess how the judge, in trial, may address condom use and the level of the defendant's viral load when directing the jury. Finally, it is argued that it is in the public interest to allow condom use and viral loads to be used to negate recklessness.

Microbicides in the prevention of HIV infection: current status and future directions

More than 28 years since the first cases of HIV/AIDS, there is still no cure or vaccine. The worst affected region is sub-Saharan Africa and, increasingly, it is young women who are bearing the brunt of the epidemic. Consequently, there is an urgent need for HIV prevention options for women in developing countries. Microbicides are topical products that can be used vaginally by women to impede sexual transmission of HIV and thus represent one of the most promising prevention strategies. Efficacy trials with early nonspecific microbicide gels have so far been unsuccessful, but the field has now switched its focus to products containing highly potent and highly specific antiretroviral drugs that are easier to use, and can be formulated in a variety of dosage forms to suit individual and regional preferences. However, these products have their own challenges, with a greater likelihood of absorption, and the potential for systemic toxicities or the development of resistance in infected individuals who are unaware of their HIV status. The conduct of clinical trials is complex for all microbicides, with limited availability of trial sites, difficulties in dose selection and safety monitoring, and a lack of a truly objective measure of adherence. Once a microbicide has been shown to be safe and effective, there will need to be a clear pathway to regulatory approval, and the successful launch of a product will depend on having in place appropriate methods for distribution to the women who need it, along with a strategy for ensuring that they use it correctly. This will require substantial effort in terms of education and community engagement, and these activities need to be initiated well in advance of microbicide rollout.

Sexually transmitted infections and infectiousness beliefs among people living with HIV/AIDS: implications for HIV treatment as prevention

OBJECTIVES

Sexually transmitted infections (STIs) significantly impact the health of people living with HIV/AIDS, increasing HIV infectiousness and therefore transmissibility. The current study examined STIs in a community sample of 490 HIV-positive men and women.

METHODS

Assessments were performed using confidential computerized interviews in a community research setting.

RESULTS

Fourteen per cent of the people living with HIV/AIDS in this study had been diagnosed with a new STI in a 6-month period. Individuals with a new STI had significantly more sexual partners in that time period, including non-HIV-positive partners. Participants who had contracted an STI were significantly more likely to have detectable viral loads and were less likely to know their viral load than participants who did not contract an STI. Multivariate analysis showed that believing an undetectable viral load leads to lower infectiousness was associated with contracting a new STI.

CONCLUSIONS

Individuals who believed that having an undetectable viral load reduces HIV transmission risks were more likely to be infectious because of STI coinfection. Programmes that aim to use HIV treatment for HIV prevention must address infectiousness beliefs and aggressively control STIs among people living with HIV/AIDS.