The role of drug resistance in poor viral suppression in rural South Africa: findings from a population-based study

The association between HIV pretreatment drug resistance and virological outcomes in children and adults in sub-Saharan Africa: A systematic review and meta-analysis

INTRODUCTION

Pretreatment drug resistance (PDR) could occur in antiretroviral treatment (ART) naïve individuals, those previously exposed to ART, or individuals re-initiating ARV after a long period of interruption. Few studies have shown its association with virological outcomes, although inconsistent. The objective of this review was to provide a synthesis of the association between PDR and virological outcomes (virological failure or suppression).

METHODS

This report is presented following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The method was subdivided into three main phases: record identification, screening, and report inclusion. Record identification consisted of an initial search with search term "HIV pretreatment drug resistance". Another search was done using terms "Pretreatment drug resistance OR pre-treatment drug resistance OR Pretreatment drug resist* OR pre-treatment drug resist* OR pretreatment antiretroviral resistance OR pretreatment medic* OR pretreatment medic* resist*" and a list of all the countries in sub-Saharan Africa. After the electronic search, studies were screened from full list based on their title and abstract and then full articles retrieved and studies were assessed based on set criteria. Inclusion criteria involved observational studies that report the association between PDR and virological failure. Data from trials that reported the association were also included. Published articles like modelling studies and reviews, and studies with data that had been previously included in the review were excluded. The Mantel Haenszel method with odds ratios was used for synthesis (meta-analyses) with the weights of each study which depends on the number of events and totals.

RESULTS

A total of 733 records(studies) were obtained from all database search of which 74 reported on PDR, virological outcomes in sub-Saharan Africa (SSA). Out of the 74 articles, 11 were excluded and 26 did not explicitly report data needed, and 5 did not meet the inclusion criteria. Of the remaining 32 studies, 19 studies that had complete data on the number of participants with PDR and no PDR according to virological failure (VF) were included in the metanalyses. The pooled results from eleven (13) of these studies showed those with PDR had higher odds of virological failure compared to those without PDR OR 3.64[95% CI 2.93, 4.52]. The result was similar when stratified in adults and in children. In six (6) studies that had Virological suppression (VS) as outcome, there was a reduction in the odds of VS in those with PDR compared to those without PDR, OR 0.42 (95% CI 0.30, 0.58).

CONCLUSION

In conclusion, this systematic review indicates that PDR increases the risk of virological failure in sub-Saharan Africa. The risk could be reduced by PDR monitoring for NNRTIs and INSTIs.

Correlation between gender-based violence and poor treatment outcomes among transgender women living with HIV in Brazil

BACKGROUND

Transgender women are disproportionately affected by both HIV and gender-based violence (GBV), defined as physical, sexual, or emotional violence perpetrated against an individual based on their gender identity/expression. While a growing body of evidence demonstrates that GBV leads to poor HIV care and treatment outcomes among cisgender women, less research has examined this association among transgender women. We assessed the impact of lifetime experiences of GBV on subsequent retention in HIV care and laboratory confirmed viral suppression among a sample of transgender women living with HIV (TWH) in Brazil.

METHODS

A pilot trial of a peer navigation intervention to improve HIV care and treatment among TWH was conducted in São Paulo, Brazil between 2018 and 2019. TWH were recruited and randomized into the intervention or control arm and participated in a baseline and 9-month follow-up survey and ongoing extraction of clinical visit, prescribing, and laboratory data. Generalized linear model regressions with a Poisson distribution estimated the relative risk (RR) for the association of lifetime physical and sexual violence reported at baseline with treatment outcomes (retention in HIV care and viral suppression) at follow-up, adjusting for baseline sociodemographic characteristics.

RESULTS

A total of 113 TWH participated in the study. At baseline, median age was 30 years, and the prevalence of lifetime physical and sexual violence was 62% and 45%, respectively. At follow-up, 58% (n = 66/113) were retained in care and 35% (n = 40/113) had evidence of viral suppression. In adjusted models, lifetime physical violence was non-significantly associated with a 10% reduction in retention in care (aRR: 0.90, 95% CI: 0.67, 1.22) and a 31% reduction in viral suppression (aRR: 0.69; 95% CI: 0.43, 1.11). Lifetime sexual violence was non-significantly associated with a 28% reduction in retention in HIV care (aRR: 0.72, 95% CI: 0.52, 1.00) and significantly associated with a 56% reduction in viral suppression (aRR: 0.44; 95% CI: 0.24, 0.79).

CONCLUSION

Our findings are among the first to demonstrate that lifetime experiences with physical and sexual violence are associated with poor HIV outcomes over time among transgender women. Interventions seeking to improve HIV treatment outcomes should assess and address experiences of GBV among this population.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03525340.

Dried Blood Spots-A Platform for Therapeutic Drug Monitoring (TDM) and Drug/Disease Response Monitoring (DRM)

This review provides an overview on the current applications of dried blood spots (DBS) as matrices for therapeutic drug (TDM) and drug or disease response monitoring (DRM). Compared with conventional methods using plasma/serum, DBS offers several advantages, including minimally invasiveness, a small blood volume requirement, reduced biohazardous risk, and improved sample stability. Numerous assays utilising DBS for TDM have been reported in the literature over the past decade, covering a wide range of therapeutic drugs. Several factors can affect the accuracy and reliability of the DBS sampling method, including haematocrit (HCT), blood volume, sampling paper and chromatographic effects. It is crucial to evaluate the correlation between DBS concentrations and conventional plasma/serum concentrations, as the latter has traditionally been used for clinical decision. The feasibility of using DBS sampling method as an option for home-based TDM is also discussed. Furthermore, DBS has also been used as a matrix for monitoring the drug or disease responses (DRM) through various approaches such as genotyping, viral load measurement, assessment of inflammatory factors, and more recently, metabolic profiling. Although this research is still in the development stage, advancements in technology are expected to lead to the identification of surrogate biomarkers for drug treatment in DBS and a better understanding of the correlation between DBS drug levels and drug responses. This will make DBS a valuable matrix for TDM and DRM, facilitating the achievement of pharmacokinetic and pharmacodynamic correlations and enabling personalised therapy.

Resource and infrastructure challenges on the RESIST-2 Trial: an implementation study of drug resistance genotype-based algorithmic ART switches in HIV-2-infected adults in Senegal

BACKGROUND

Second-line treatment of HIV-2 in resource-limited settings (RLS) is complicated by a lack of controlled trial data, limited availability of HIV-2-active antiretroviral drugs, and inadequate access to drug resistance testing. We conducted an implementation trial of a dried blood spot- (DBS) based, drug resistance genotype-informed antiretroviral therapy (ART) switching algorithm for HIV-2-infected patients in Senegal.

METHODS

HIV-2-infected adults initiating or receiving ART through the Senegalese national AIDS program were invited to participate in this single-arm trial. DBS from participants with virologic failure (defined as viral load (VL) > 250 copies/mL after > 6 months on the current ART regimen) were shipped to Seattle for genotypic drug resistance testing. Participants with evidence of drug resistance in protease or reverse transcriptase were switched to new regimens according to a pre-specified algorithm. Participant clinical and immuno-virologic outcomes were assessed, as were implementation challenges.

RESULTS

We enrolled 152 participants. Ten were initiating ART. The remainder were ART-experienced, with 91.0% virologically suppressed (< 50 copies/mL). Problems with viral load testing capability resulted in obtaining VL results for only 227 of 613 (37.0%) participant-visits. Six of 115 participants (5.2%) with VL available after > 6 months on current ART regimen experienced virologic failure, with per-protocol genotypic testing attempted. One additional test was performed for a participant with a VL of 222 copies/mL. Genotypes from three participants showed no evidence of major drug resistance mutations, two showed nucleoside reverse transcriptase inhibitor (NRTI) resistance, one showed both NRTI and protease inhibitor resistance, and one test failed. No integrase inhibitor resistance was observed. Five of six successfully-tested participants switched to the correct regimen or received additional adherence counseling according to the algorithm; the sixth was lost to follow-up. Follow-up VL testing was available for two participants; both of these were virally suppressed (< 10 copies/mL). The trial was terminated early due to the COVID-19 pandemic (which prevented further VL and genotypic testing), planned rollout of dolutegravir-based 1st-line ART, and funding.

CONCLUSIONS

The RESIST-2 trial demonstrated that a DBS-based genotypic test can be used to help inform second-line ART decisions as part of a programmatic algorithm in RLS, albeit with significant implementation challenges.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03394196 . Registered on January 9, 2018.

Tenofovir diphosphate levels in dried blood spots are associated with virologic failure and resistance to first-line therapy in South Africa: a case-control cohort study

INTRODUCTION

Tenofovir diphosphate (TFV-DP) in dried blood spots (DBS), a measure of cumulative antiretroviral therapy (ART) adherence, is associated with viral suppression and predicts future viremia in persons with HIV (PWH). However, its utility to identify those at risk for virologic failure (VF) and drug resistance is unknown. To address this, we aimed to establish the association between this adherence biomarker and VF with drug resistance in a cohort of PWH initiating first-line ART in KwaZulu-Natal, South Africa.

METHODS

PWH initiating TFV disoproxil fumarate (TDF)-based ART within a parent prospective cohort were evaluated. Using a nested design, DBS for TFV-DP were collected from cases who developed VF (HIV-1 RNA ≥1000 copies/ml) after ≥5 months on ART versus controls, matched 1:2 by site, age, gender, race and ART duration. Cases were categorized as having VF with or without resistance using genotyping. One-way analysis of variance (ANOVA) was used to compare TFV-DP for controls, cases with VF and resistance, and cases with VF without resistance. Data are presented as mean (standard deviation, SD) or geometric mean [95% confidence interval, 95% CI].

RESULTS AND DISCUSSION

One thousand participants were enrolled in the parent study between 2014 and 2016, of which 288 (29%) had DBS available. Of these, 94 (33%) were cases and 194 (67%) were controls; 59% were women. Mean age of our population was 33 (SD 8) years. Genotyping was available in 50 (53%) of the 94 cases. Geometric mean TFV-DP in DBS from controls was 708 [95% CI; 647-773] fmol/punch, which was higher compared to participants having VF with resistance (n = 36), 386 [95% CI; 241-617] fmol/punch and VF without resistance (n = 14), 61 [95% CI; 22-164] fmol/punch; p<0.001. Genotype could not be obtained in 44 (47%) cases.

CONCLUSIONS

TFV-DP in DBS showed a stepwise association with VF and drug resistance in South African PWH. Participants having VF with resistance had mid-range concentrations of TFV-DP, which were higher than those for PWH without resistance. Future research on the clinical utility of TFV-DP concentrations in DBS to predict and prevent the development of VF and drug resistance is needed.

HIV viral load suppression following intensive adherence counseling among people living with HIV on treatment at military-managed health facilities in Uganda

BACKGROUND

Uniformed service personnel have an increased risk of poor viral load suppression (VLS). This study was performed to evaluate the outcomes of interventions to improve VLS in the 28 military health facilities in Uganda.

METHODS

This operational research was conducted between October 2018 and September 2019, among people living with HIV (PLHIV) in the 28 health facilities managed by the military in Uganda. Patients with a viral load (VL) >1000 copies/ml received three sessions of intensive adherence counselling (IAC), 1 month apart, after which a repeat VL was done. The main outcome was the proportion with a suppressed VL following IAC.

RESULTS

Of the 965 participants included in this analysis, 592 (61.4%) were male and 367 (38.3%) were female. Average age was 35.5 ± 13.7 years, and 87.8% had at least one IAC session. At least 48.2% had a suppressed repeat VL. IAC increased the odds of VLS by 82% (P = 0.004), with adjusted OR of 1.56 (P = 0.054). An initial VL >10 000 copies/ml, being on antiretroviral therapy for at least 2 years, being male, and being <18 years of age were associated with repeat VL non-suppression.

CONCLUSIONS

IAC marginally improved VL suppression. There is a need to improve IAC in military health facilities.

Uptake of antiretroviral treatment and viral suppression among men who have sex with men and transgender women in sub-Saharan Africa in an observational cohort study: HPTN 075

Objectives:

HPTN 075 enrolled men who have sex with men (MSM) and transgender women (TGW) in sub-Saharan Africa. Persons in HIV care or on antiretroviral treatment (ART) were not eligible to enroll. We evaluated antiretroviral (ARV) drug use, viral suppression, and drug resistance in this cohort over a 12-month follow-up period.

Methods:

Assessments included 64 participants with HIV (39 MSM, 24 TGW, and one gender not specified). ARV drugs were detected using a qualitative assay. Viral load (VL) and drug resistance testing were performed using commercial assays.

Results:

Over 12 months, the proportion of participants using ARV drugs increased from 28.1% to 59.4% and the proportion with VLs <400 copies/mL increased from 21.9% to 57.8%. The rate of ART failure (detection of drugs without viral suppression) was similar at screening and 12 months (12.0% and 11.1%, respectively) and was similar among MSM and TGW. Two participants developed HIV drug resistance during follow-up.

Conclusions:

Over 12 months, ARV drug use in the cohort more than doubled and viral suppression increased nearly threefold without a significant increase in ART failure or drug resistance. These results suggest that ART can be successfully scaled up for HIV prevention and treatment in this high-risk population.