Search

Objective: People with HIV rarely control viral replication after cessation of antiretroviral therapy (ART). We present a person with HIV with extraordinary posttreatment control (PTC) for over 23 years after temporary ART during acute HIV infection (AHI) leading to a new insight in factors contributing to PTC., Design/methods: Viral reservoir was determined by HIV qPCR, Intact Proviral DNA Assay, and quantitative viral outgrowth assay. Viral replication kinetics were determined in autologous and donor PBMC. IgG levels directed against HIV envelope and neutralizing antibodies were measured. Immune phenotyping of T cells and HIV-specific T-cell responses were analyzed by flow cytometry., Results: The case presented with AHI and a plasma viral load of 2.7 million copies/ml. ART was initiated 2 weeks after diagnosis and interrupted after 26 months. Replicating virus was isolated shortly after start ART. At 18 years after treatment interruption, HIV-DNA in CD4 + T cells and low levels of HIV-RNA in plasma (<5 copies/ml) were detectable. Stable HIV envelope glycoprotein-directed IgG was present during follow-up, but lacked neutralizing activity. Strong antiviral CD8 + T-cell responses, in particular targeting HIV-gag, were detected during 25 years follow-up. Moreover, we found a P255A mutation in an HLA-B∗44 : 02 restricted gag-epitope, which was associated with decreased replication., Conclusion: We describe an exceptional case of PTC, which is likely associated with sustained potent gag-specific CD8 + T-cell responses in combination with a replication attenuating escape mutation in gag. Understanding the initiation and preservation of the HIV-specific T-cell responses could guide the development of strategies to induce HIV control., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction: Standard-of-care antiretroviral treatment (ART) monitoring in low and middle-income countries consists of annual determination of HIV-RNA viral load with confirmatory viral load testing in case of viral rebound. We evaluated an intensified monitoring strategy of three-monthly viral load testing with additional drug exposure and drug resistance testing in case of viral rebound., Methods: We performed an open-label randomized controlled trial (RCT) at a rural South African healthcare clinic, enrolling adults already receiving or newly initiating first-line ART. During 96 weeks follow-up, intervention participants received three-monthly viral load testing and sequential point-of-care drug exposure testing and DBS-based drug resistance testing in case of rebound above 1000 copies/ml. Control participants received standard-of-care monitoring according to the WHO guidelines., Results: Five hundred one participants were included, of whom 416 (83.0%) were randomized at 24 weeks. Four hundred one participants were available for intention-to-treat analysis. Viral rebound occurred in 9.0% (18/199) of intervention participants and in 11.9% (24/202) of controls ( P  = 0.445). Time to detection of rebound was 375 days [interquartile range (IQR): 348-515] in intervention participants and 360 days [IQR: 338-464] in controls [hazard ratio: 0.88 (95% confidence interval (95% CI): 0.46-1.66]; P  = 0.683]. Duration of viral rebound was 87 days [IQR: 70-110] in intervention participants and 101 days [IQR: 78-213] in controls ( P  = 0.423). In the control arm, three patients with confirmed failure were switched to second-line ART. In the intervention arm, of three patients with confirmed failure, switch could initially be avoided in two cases., Conclusion: Three-monthly viral load testing did not significantly reduce the duration of viraemia when compared with standard-of-care annual viral load testing, providing randomized trial evidence in support of annual viral load monitoring., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction: Pretreatment drug resistance (PDR) prevalence in sub-Saharan Africa is rising, but evidence of its impact on efavirenz (EFV)-based antiretroviral treatment (ART) is inconclusive. We determined the impact of PDR on outcomes of EFV-based ART in a subanalysis of a randomized clinical trial comparing different ART monitoring strategies implemented at a rural treatment facility in Limpopo, South Africa., Methods: Participants initiating EFV-based first-line ART (2015-2017) were enrolled and received 96 weeks follow-up. Resistance to nucleos(t)ide reverse transcriptase inhibitors (NRTIs) and non-NRTI's (NNRTIs) was retrospectively assessed by population-based sequencing. Virological failure was defined as a viral load of at least 1000 copies/ml after at least 24 weeks of ART., Results: A total of 207 participants were included, 60.4% (125/207) of whom were female. Median age was 38.8 (interquartile range: 31.4-46.7) years. Median CD4+ cell count was 191 (interquartile range: 70-355) cells/μl. PDR was detected in 12.9% (25/194) of participants with available sequencing results; 19 had NNRTI-resistance, and six had NRTI- and NNRTI-resistance. 26.0% of participants (40/154) with sequencing results and virological follow-up developed virological failure. PDR was independently associated with failure (adjusted hazard ratio: 3.7 [95% confidence interval: 1.68.5], P = 0.002). At failure, 87.5% (7/8) of participants with PDR harboured dual-class resistant virus, versus 16.7% (4/24) of participants without PDR (P = 0.0007). Virological resuppression after failure on first-line ART occurred in 57.7% (15/26) of participants without PDR versus 14.3% (1/7) of participants with PDR (P = 0.09)., Conclusion: PDR was detected in 13% of study participants. PDR significantly increased the risk of virological failure of EFV-based ART. Accumulation of resistance at failure and inability to achieve virological resuppression illustrates the profound impact of PDR on treatment outcomes., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives and Design: CD8+ cytotoxic T lymphocytes (CTL) are important in the control of HIV infection. Although CTL are thought to reduce the lifespan of productively infected cells, CD8+ T-cell depletion in simian immunodeficiency virus-infected rhesus-macaques showed no effect on the lifespan of productively infected cells. As CD8+ T-cell responses that successfully delay HIV disease progression occur only in a minority of HIV-infected individuals, we studied the hypothesis that the ability of CTL to reduce the lifespan of productively infected cells is limited to protective CTL responses only., Methods: We correlated features of CD8+ T cells that are associated with control of HIV infection, namely restriction by protective human leukocyte antigen (HLA) alleles, and/or a broad, high or poly-functional Gag-specific CD8+ T-cell response, to the lifespan of productively infected cells in 36 HIV-infected individuals, by measuring their plasma viral load declines immediately after start of combined antiretroviral therapy., Results: The average lifespan of productively HIV-infected cells varied greatly between individuals, from 1.01 to 3.68 days (median 1.82 days) but was not different between individuals with or without the protective HLA molecules B27 or B57 (P=0.76, median 1.94 and 1.79 days, respectively). Although the CD8+ T-cell response against HIV Gag was the dominant HIV-specific T-cell response, its magnitude (r=0.02, P = 0.5), breadth (r = 0.03, P = 0.4), and poly-functionality (r = 0.01, P = 0.8), did not correlate with the lifespan of productively HIV-infected cells., Conclusion: The features of CD8+ T-cell responses that have clearly been associated with control of HIV infection do not correlate with a reduced lifespan of productively infected cells in vivo. This suggests that protective CD8+ T cells exert their effect on target-cells before onset of productive infection, or via noncytolytic mechanisms.

Objective: Bevirimat is the first drug of a new class of antivirals that hamper the maturation of HIV. The objective of this study was to evaluate the sequence variability of the gag region targeted by bevirimat in HIV subtype-B isolates., Methods: Of 484 HIV subtype-B isolates, the gag region comprising amino acids 357-382 was sequenced. Of the patients included, 270 were treatment naive and 214 were treatment experienced. In the latter group, 48 HIV isolates harboured mutations associated with reverse transcriptase inhibitor resistance only, and 166 HIV isolates carried mutations associated with protease inhibitor resistance., Results: In the treatment-naive patient population, approximately 30% harboured an HIV isolate with at least one mutation associated with a reduced susceptibility to bevirimat (H358Y, L363M, Q369H, V370A/M/del and T371del). In HIV isolates with protease inhibitor resistance, the prevalence of bevirimat resistance mutations increased to 45%. Accumulation of mutations at four positions in the bevirimat target region, S368C, Q369H, V370A and S373P, was significantly observed. Mutations associated with bevirimat resistance were detected more frequently in HIV isolates with three or more protease inhibitor resistance mutations than in those with less than three protease inhibitor mutations., Conclusion: Reduced bevirimat activity can be expected in one-third of treatment-naive HIV subtype-B isolates and significantly more in protease inhibitor-resistant HIV. These data indicate that screening for bevirimat resistance mutations before administration of the drug is essential.

Objective: It is thought as a consequence of continuous replication, HIV-1 has acquired an optimal fitness state and that suboptimal antiretroviral therapy selects for drug resistant variants which show impaired fitness in the absence of the drug. In this paper we studied the evolution and fitness of viral populations appearing in a patient who received protease monotherapy., Methods: Two factors contributing to fitness, drug resistance and protease catalytic activity, were studied at the enzymatic and virological level., Results: The first drug resistant viral variants that were selected in vivo harboured one to three protease substitutions. These mutants showed reduced protease activity and consequently a reduction in viral replication capacity. During continued in vivo replication of these viruses in the presence of the drug, novel variants harbouring additional substitutions in the viral protease appeared. These variants did not display any further increase in drug resistance but demonstrated clearly increased protease activity. Consequently the replication capacity of these viruses was raised to a level at which they replicated better than the original wild-type virus., Conclusion: This study indicates that the viral population in the patient does not have to represent the fittest possible variants, and thus antiretroviral therapy may drive the viral population first through a lower fitness level and then to a higher fitness level.

Objective: To determine the effect of lamivudine (3TC) on syncytium-inducing (SI) and non-SI (NSI) HIV-1 populations in vivo., Design: Responses in virus load and 3TC resistance in 40 3TC-treated subjects were analysed in relation to the presence or absence of SI HIV-1 variants., Methods: Peripheral blood samples were collected at regular intervals from 40 HIV-1-infected subjects during 3TC treatment. Virus isolates obtained at the start of treatment were typed for SI-capacity by coculture with MT-2 cells. Changes in levels of viral RNA in plasma were determined by quantitative reverse transcriptase PCR. The relative amount of wild-type and mutant virus at codon 184, associated with HIV resistance to 3TC, was determined using a primer-guided nucleotide incorporation assay after amplification of part of the reverse transcriptase gene. In five subjects the frequency of productively infected CD4+ cells with SI or NSI variants was determined in relation to codon 184 genotype., Results: Twenty-six subjects harboured only NSI variants at baseline, whereas 14 subjects also harboured SI variants. Although baseline plasma viral RNA load and CD4 cell counts were different between the two groups, no differences in the response to 3TC therapy were observed for these parameters. In-depth analysis of five subjects showed that the kinetics of virus load changes and emergence of 3TC resistance mutations were similar in plasma and cells, and comparable for the SI and NSI populations present in one individual., Conclusions: These data show that, in contrast to didanosine and zidovudine, the pressure exerted by 3TC is similar for SI and NSI M184 populations.