Evaluating predictive markers for viral rebound and safety assessment in blood and lumbar fluid during HIV-1 treatment interruption

Background: Validated biomarkers to evaluate HIV-1 cure strategies are currently lacking, therefore requiring analytical treatment interruption (ATI) in study participants. Little is known about the safety of ATI and its long-term impact on patient health. Objectives: ATI safety was assessed and potential biomarkers predicting viral rebound were evaluated. Methods: PBMCs, plasma and CSF were collected from 11 HIV-1-positive individuals at four different timepoints during ATI (NCT02641756). Total and integrated HIV-1 DNA, cell-associated (CA) HIV-1 RNA transcripts and restriction factor (RF) expression were measured by PCR-based assays. Markers of neuroinflammation and neuronal injury [neurofilament light chain (NFL) and YKL-40 protein] were measured in CSF. Additionally, neopterin, tryptophan and kynurenine were measured, both in plasma and CSF, as markers of immune activation. Results: Total HIV-1 DNA, integrated HIV-1 DNA and CA viral RNA transcripts did not differ pre- and post-ATI. Similarly, no significant NFL or YKL-40 increases in CSF were observed between baseline and viral rebound. Furthermore, markers of immune activation did not increase during ATI. Interestingly, the RFs SLFN11 and APOBEC3G increased after ATI before viral rebound. Similarly, Tat-Rev transcripts were increased preceding viral rebound after interruption. Conclusions: ATI did not increase viral reservoir size and it did not reveal signs of increased neuronal injury or inflammation, suggesting that these well-monitored ATIs are safe. Elevation of Tat-Rev transcription and induced expression of the RFs SLFN11 and APOBEC3G after ATI, prior to viral rebound, indicates that these factors could be used as potential biomarkers predicting viral rebound

Interruption of reverse transcriptase inhibitors or a switch from reverse transcriptase to protease inhibitors resulted in a fast reappearance of virus strains with a reverse transcriptase inhibitor-sensitive genotype.

Objectives: To study the effect of the interruption of reverse transriptase inhibitor (RTI) therapy or a switch from RTI to protease inhibitors, on the genotypic drug-resistance pattern of plasma HIV-1. Methods: Nine patients who completely stopped all medication, and five patients who switched from a treatment with RTI to a regimen containing protease inhibitors only, were studied. Direct sequencing of the plasma HIV-1 RT and protease gene was performed on follow-up samples taken before and after the interruption of treatment. Results: Comparison of the amino acid sequence of the RT and protease genes in successive samples showed the rapid reappearance of wild-type viral variants in 12 of the 14 patients studied. Wild-type virus replaced the mutant strains 14 days to 2 months after the interruption of therapy, even in patients with a long treatment history. Conclusion: The results of this study indicate the sustained lower fitness of mutant strains in vivo. As a result, wild-type virus remains capable of outcompeting the RT or protease mutant strains very fast after removal of the drug. These findings highlight the importance of 'treatment history' in addition to genotypic and phenotypic markers determined at one time-point, when making therapeutic decisions for patients

Drug-resistant variants that evolve during nonsuppressive therapy persist in HIV-1-infected peripheral blood mononuclear cells after long-term highly active antiretroviral therapy

The aim of this study was to determine whether drug-resistant virus persists in peripheral blood mononuclear cells (PBMCs) after long-term suppression of virus replication. Proviral DNA was extracted from the PBMCs of I I patients on long-term highly active antiretroviral therapy (HAART). Genotyping of the reverse transcriptase (RT) and protease gene of several proviral variants was performed using limiting dilution polyincrase chain reaction and single-copy sequencing. All patients were on successful HAART for a mean period of 59 months but had a history of suboptimal therapy and genotypic drug resistance before. Comparison of the amino acid sequence of the RT and protease gene in the different proviral variants, with that of the plasma virus isolated before HAART treatment, revealed that the different drug-resistant viral variants that evolved during the process of gradually building up resistance were still detectable in the PBMCs in 10 of the 11 patients tested. The proportion of resistant variants was found to correlate with the time that the resistant variants had been able to replicate. These data clearly show that virus variants that are able to replicate for a certain period enter the latent reservoir and remain archived in the PBMCs for a very long period

Impact of Delta 32-CCR5 heterozygosity on HIV-1 genetic evolution and variability - A study of 4 individuals infected with closely related HIV-1 strains

A cluster of four patients acutely infected with a genetically almost identical virus, allowed us to investigate genetic variability and disease progression in early HIV-1 infection with minimal interference of Virus specific factors. Two of the patients were heterozygous for the 32-bp deletion in the CCR5 coreceptor gene. Both showed a slower disease progression with lower viral load levels and a reduced rate of genetic evolution compared to the patients with normal CCR5 alleles. During 3 years of treatment-free follow-up, the mean pairwise genetic distance increased with 1.45% and 1.58% in the two patients with a 32-bp deletion allele Compared to 3.05% and 3.57% in the two patients with normal CCR5 alleles. The observed relation between slower disease progression and a reduced evolutionary rate illustrates the influence of the virus replicative capacity, here most possibly hampered by the CCR5 heterozygosity in two of the four individuals, on the genetic evolution of the virus in the host. (C) 2008 Elsevier Inc. All rights reserved

Determinants of adherence in a cohort of Belgian HIV patients: a pilot study

Since the era of highly active antiretroviral therapy (HAART), HIV is considered a chronic disease. Adherence to HAART is crucial for effectiveness. Non-adherence negatively impacts patient outcome and the larger economy. However, data on adherence among the Belgian HIV cohort are scarce. Therefore, the purpose of this pilot study was to identify determinants of adherence among HIV patients treated in Belgium. The study was conducted at the Aids Reference Centre of Ghent University Hospital between 1 January and 31 December 2012. Sociodemographic data were collected, along with the Simplified Medication Adherence Questionnaire (SMAQ), the Center for Adherence Support Evaluation (CASE) Adherence Index, the EuroQol-6D, the Medical Outcomes Study-HIV (MOS-HIV), the Beck Depression Inventory-II, and three neurocognitive complaints screening questions. To date, 218 patients participated in the study, among whom 173 (79·4%) were male. Mean age was 46·0±10·6 years and 133 patients (63·9%) were homosexual. According to the SMAQ and the CASE, 78·5% and 93·5% of the patients were adherent to antiretroviral therapy. Logistic regression analysis revealed that smoking, neurocognitive complaints, and female sex were independent determinants of non-adherence. In conclusion, there is an elevated risk for non-adherence in smokers, people experiencing neurocognitive problems, and women in our sample. The latter could reflect differences between male and female HIV patients in Belgium. Adherence improving initiatives should be tailored to these three risk groups

Association of haptoglobin phenotypes with the development of Kaposi's sarcoma in HIV patients

Kaposi's sarcoma (KS) is a rare cutaneous tumor caused by human herpes virus-8 (HHV-8) infection that preferentially develops in case of severe immunosuppression, such as in HIV/AIDS disease. Haptoglobin (Hp), a polymorphic multifunctional plasma protein, exerts several immunomodulatory effects and is characterized by a genetic polymorphism leading to three major phenotypes (Hp 1-1, Hp 2-1 and Hp 2-2). This study investigated the influence of Hp genetic polymorphism on the development of KS in HIV-positive patients. 661 HIV patients were enrolled in the study with a median age of 35 years and a median follow-up time of 57 months. Hp phenotyping was performed using hemoglobin-supplemented starch gel electrophoresis. In case of low Hp concentration high pressure gel permeation chromatography (HPGPC) was used. The Hp 1-1 phenotype was associated with a significant higher risk of KS compared to the combined group of Hp 2-1 and Hp 2-2 patients (p < 0.0005) which remained significant after adjustment for possible confounding variables (age, gender and AIDS status) (p < 0.001). In contrast, the Hp 2-1 phenotype carried the lowest risk. These findings point to the involvement of Hp phenotypes in the pathogenesis of KS, which may be due to a difference in skin immunosurveillance between the Hp phenotype