Detectability of HIV Residual Viremia despite Therapy Is Highly Associated with Treatment with a Protease Inhibitor-Based Combination Antiretroviral Therapy

Integrated analysis of viral blips, residual viremia, and associated factors in people with HIV: Results from a retrospective cohort study

The etiology of viral blips is not yet fully elucidated. One of the hypotheses is that blips reflect variations in residual viremia (RV) near the detectability threshold. In this study, we evaluated whether RV is associated with viral blips and which factors are associated with RV. All treatment regimens in 2010-2020 consisting of two nucleos(-t)ide reverse transcriptase inhibitors and one anchor (integrase strand transfer inhibitor [INSTI], non-nucleoside reverse transcriptase inhibitor [NNRTI], or protease inhibitor [PI]) in people with HIV (PWH) were evaluated for RV (detectable viremia <50 cp/mL) and blips (isolated viral loads [VLs] 50-499 cp/mL between measurements <50 cp/mL). All medical records were reviewed and regimens in which a VL ≥ 50 cp/mL was deemed to result from non-adherence (based on the documented conclusion by the treating physician) were excluded. Factors associated with blips and RV were identified using generalized linear mixed models. In total, 24 518 VLs from 1658 PWH were analyzed. VLs were measured during INSTI- (n = 5119; 20.9%), PI- (n = 8935; 36.4%), and NNRTI-use (n = 10 464; 42.7%). VLs were categorized as blips in 1.4% (n = 332). The 24,186 non-blip VLs were RNAneg (no RV) (n = 15 326; 63.4%), 1-19 cp/mL (n = 6318; 26.1%), 20-49 cp/mL (n = 1620; 6.7%), or <50 cp/mL with an unknown RV level (n = 922; 3.8%). In 193/1658 PWH (11.6%), the RV level was RNAneg in all VLs assessed. RV 1-19 cp/mL and 20-49 cp/mL (vs. RNAneg ) were significantly associated with subsequent viral blips (respective odds ratio 2.66 and 4.90 [95% confidence intervals: 1.98-3.58 and 3.41-7.04]). Zenith VL and use of PIs (vs. INSTIs/NNRTIs) were associated with higher RV and blip odds. This large cohort study showed that blips were associated with higher preceding RV. Both the anchor type and factors previously linked to the latent viral reservoir were associated with RV, suggesting blips having a multifactorial origin.

Qualitative plasma viral load determination as a tool for screening of viral reservoir size in PWH

OBJECTIVES

Suppression of viral replication in patients on antiretroviral therapy (ART) is determined by plasma viral load (pVL) measurement. Whenever pVL reaches values below the limit of quantification, the qualitative parameter 'target detected' or 'target not detected' is available but often not reported to the clinician. We investigated whether qualitative pVL measurements can be used to estimate the viral reservoir size.

DESIGN

The study recruited 114 people with HIV (PWH) who are stable on ART between 2016 and 2018. The percentage of pVL measurements qualitatively reported as 'target detected' (PTD) within a 2-year period was calculated.

METHODS

t-DNA and US-RNA were used to estimate viral reservoir size and were quantified on peripheral blood mononuclear cells (PBMCs) using droplet digital PCR.

RESULTS

A median of 6.5 pVL measurements over a 2-year period was evaluated for each participant to calculate PTD. A positive correlation was found between t-DNA and PTD (r = 0.24; P = 0.011) but not between US-RNA and PTD (r = 0.1; P = 0.3). A significantly lower PTD was observed in PWH with a small viral reservoir, as estimated by t-DNA less than 66 copies/106 PBMCs and US-RNA less than 10 copies/106 PBMCs, compared with PWH with a larger viral reservoir (P = 0.001). We also show that t-DNA is detectable whenever PTD is higher than 56% and that ART regimen does not affect PTD.

CONCLUSION

Our study shows that PTD provides an efficient parameter to preselect participants with a small viral reservoir based on already available pVL data for future HIV cure trials.

Pitfalls of Antiretroviral Therapy: Current Status and Long-Term CNS Toxicity

HIV can traverse the BBB using a Trojan horse-like mechanism. Hidden within infected immune cells, HIV can infiltrate the highly safeguarded CNS and propagate disease. Once integrated within the host genome, HIV becomes a stable provirus, which can remain dormant, evade detection by the immune system or antiretroviral therapy (ART), and result in rebound viraemia. As ART targets actively replicating HIV, has low BBB penetrance, and exposes patients to long-term toxicity, further investigation into novel therapeutic approaches is required. Viral proteins can be produced by latent HIV, which may play a synergistic role alongside ART in promoting neuroinflammatory pathophysiology. It is believed that the ability to specifically target these proviral reservoirs would be a vital driving force towards a cure for HIV infection. A novel drug design platform, using the in-tandem administration of several therapeutic approaches, can be used to precisely target the various components of HIV infection, ultimately leading to the eradication of active and latent HIV and a functional cure for HIV. The aim of this review is to explore the pitfalls of ART and potential novel therapeutic alternatives.

Two-Drug Regimens for HIV-Current Evidence, Research Gaps and Future Challenges

During the last 30 years, antiretroviral treatment (ART) for human immunodeficiency virus (HIV) infection has been continuously evolving. Since 1996, three-drug regimens (3DR) have been standard-of-care for HIV treatment and are based on a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus two nucleoside reverse transcriptase inhibitors (NRTIs). The effectiveness of first-generation 3DRs allowed a dramatic increase in the life expectancy of HIV-infected patients, although it was associated with several side effects and ART-related toxicities. The development of novel two-drug regimens (2DRs) started in the mid-2000s in order to minimize side effects, reduce drug-drug interactions and improve treatment compliance. Several clinical trials compared 2DRs and 3DRs in treatment-naïve and treatment-experienced patients and showed the non-inferiority of 2DRs in terms of efficacy, which led to 2DRs being used as first-line treatment in several clinical scenarios, according to HIV clinical guidelines. In this review, we summarize the current evidence, research gaps and future prospects of 2DRs.

Impact of switch from tenofovir disoproxil fumarate-based regimens to tenofovir alafenamide-based regimens on lipid profile, weight gain and cardiovascular risk score in people living with HIV

Background

As cardiovascular diseases represent the main cause of non-AIDS related death in people living with HIV (PLWH) with undetectable viral load, we evaluated lipid profile, weight gain and calculated cardiovascular risk change after switching from tenofovir disoproxil fumarate (TDF)-based regimens to tenofovir alafenamide (TAF)-based regimens.

Methods

For this retrospective study, we selected HIV-infected patients with suppressed viral load who fitted in one of the two groups below: First group (TDF/TDF): Patients treated continuously with TDF-based regimens. Second group (TDF/TAF): Patients treated with TDF-regimens during at least 6 months then switched to TAF-regimens while maintaining other drugs unchanged. Available data included date of birth, gender, ethnicity, lymphocyte T CD4⁺ count, weight, height, blood pressure, current/ex/non-smoker, diabetes mellitus, familial cardiovascular event, lipid profile, duration and nature of antiretroviral therapy. Lipid parameters, weight and calculated cardiovascular risk using 5-year reduced DAD score algorithm [Friis-Møller et al. in Eur J Cardiovasc Prev Rehabil 17:491–501, 2010] were analyzed in each groups.

Results

Switching from TDF to TAF resulted in a significant increase in triglycerides levels, total cholesterol and HDL cholesterol. LDL cholesterol and total cholesterol/HDL ratio did not show significant changes. Calculated cardiovascular risk increased after switch from TDF- to TAF-based therapy.

Conclusions

Together with favorable outcomes at the bone and kidney levels, potential negative impact of TAF on lipid profile should be included in the reflection to propose the most appropriate and tailored ARV treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06479-9.

Non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy is associated with lower cell-associated HIV RNA and DNA levels as compared with therapy based on protease inhibitors

Background:

It remains unclear whether combination antiretroviral therapy (ART) regimens differ in their ability to fully suppress human immunodeficiency virus (HIV) replication. Here, we report the results of two cross-sectional studies that compared levels of cell-associated (CA) HIV markers between individuals receiving suppressive ART containing either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI).

Methods:

CA HIV unspliced RNA and total HIV DNA were quantified in two cohorts (n = 100, n = 124) of individuals treated with triple ART regimens consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) plus either an NNRTI or a PI. To compare CA HIV RNA and DNA levels between the regimens, we built multivariable models adjusting for age, gender, current and nadir CD4⁺ count, plasma viral load zenith, duration of virological suppression, NRTI backbone composition, low-level plasma HIV RNA detectability, and electronically measured adherence to ART.

Results:

In both cohorts, levels of CA HIV RNA and DNA strongly correlated (rho = 0.70 and rho = 0.54) and both markers were lower in NNRTI-treated than in PI-treated individuals. In the multivariable analysis, CA RNA in both cohorts remained significantly reduced in NNRTI-treated individuals (p_adj = 0.02 in both cohorts), with a similar but weaker association between the ART regimen and total HIV DNA (p_adj = 0.048 and p_adj = 0.10). No differences in CA HIV RNA or DNA levels were observed between individual NNRTIs or individual PIs, but CA HIV RNA was lower in individuals treated with either nevirapine or efavirenz, compared to PI-treated individuals.

Conclusions:

All current classes of antiretroviral drugs only prevent infection of new cells but do not inhibit HIV RNA transcription in long-lived reservoir cells. Therefore, these differences in CA HIV RNA and DNA levels by treatment regimen suggest that NNRTIs are more potent in suppressing HIV residual replication than PIs, which may result in a smaller viral reservoir size.

Funding:

This work was supported by ZonMw (09120011910035) and FP7 Health (305522).

Prospective evaluation of accuracy of HIV viral load monitoring using the Aptima HIV Quant Dx assay with fingerstick and venous dried blood spots prepared under field conditions in Kenya

Quantification of HIV-1 RNA is essential for clinical management of HIV patients. The limited throughput and significant hands-on time required by most HIV Viral load (VL) tests makes it challenging for laboratories with high test volume, to turn around patient results quickly. The Hologic Aptima HIV-1 Quant Dx Assay (Aptima), has the potential to alleviate this burden as it is high throughput and fully automated. This assay is validated for both plasma and dried blood spots (DBS), which are commonly used in resource limited settings. The objective of this study was to compare the performance of Aptima to Abbott RealTime HIV-1 Assay (Abbott RT), which was used as reference. This was a cross-sectional prospective study where HIV VL in finger stick (FS) DBS, venous blood (VB) DBS and plasma, collected from 258 consenting adults visiting 5 medical facilities in Kenya, Africa were tested in Aptima. The results were compared to plasma VL in Abbott RT at the medical decision point (MDP) of 1000 copies/mL and across Aptima assay range. The total agreement at MDP between plasma HIV VL in Abbott RT and plasma, FS and VB DBS tested in Aptima were 97.7%, 92.2% and 95.3% respectively with kappa statistic of 0.95, 0.84 and 0.90. The positive and negative agreement for all 3 sample types were >92%. Regression analysis between VL in Abbott RT plasma and various sample types tested in Aptima had a Pearson’s correlation coefficient ≥0.91 with systematic bias of < 0.20 log copies/mL on Bland-Altman analysis. The high level of agreement in Aptima HIV VL results for all 3 sample types with Abbott RT plasma VL along with the high throughput, complete automation, and ease of use of the Panther platform makes Aptima a good option for HIV VL monitoring for busy laboratories with high volume of testing.

Differences in HIV Markers between Infected Individuals Treated with Different ART Regimens: Implications for the Persistence of Viral Reservoirs

In adherent individuals, antiretroviral therapy (ART) suppresses HIV replication, restores immune function, and prevents the development of AIDS. However, ART is not curative and has to be followed lifelong. Persistence of viral reservoirs forms the major obstacle to an HIV cure. HIV latent reservoirs persist primarily by cell longevity and proliferation, but replenishment by residual virus replication despite ART has been proposed as another potential mechanism of HIV persistence. It is a matter of debate whether different ART regimens are equally potent in suppressing HIV replication. Here, we summarized the current knowledge on the role of ART regimens in HIV persistence, focusing on differences in residual plasma viremia and other virological markers of the HIV reservoir between infected individuals treated with combination ART composed of different antiretroviral drug classes.