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.

Belgian guidelines for non-occupational HIV post-exposure prophylaxis 2017.

We present the updated Belgian guidelines for the use of non-occupational HIV post-exposure prophylaxis (NONOPEP). This document is inspired by UK guidelines 2015, adapted to the Belgian situation and approved by all AIDS reference centers in Belgium. When recommended, NONOPEP should be initiated as soon as possible, preferably within 24 h of exposure but can be offered up to 72 h. The duration of NONOPEP should be 28 days. These current guidelines include epidemiologic estimations, which can be used to calculate the risk of infection after a potential exposure and help to decide whether or not to start prophylaxis. We review which medications to use in the context of the last Belgian NONOPEP convention, provide a checklist for initial assessment, and make recommendations for monitoring individuals receiving NONOPEP.

Socio-economic, behavioural, (neuro)psychological and clinical determinants of HRQoL in people living with HIV in Belgium: a pilot study.

INTRODUCTION: Due to highly active antiretroviral therapy (HAART), HIV-1 infection has evolved from a lethal to a chronic disease. As such, health-related quality of life (HRQoL) has become an important outcome variable. The purpose of this study was to identify socio-economic, behavioural, (neuro)psychological and clinical determinants of HRQoL among people living with HIV (PLHIV). METHODS: This study was conducted between 1 January and 31 December 2012 at the AIDS Reference Centre of Ghent University Hospital, a tertiary care referral centre in Belgium. Validated self-report questionnaires were administered to collect socio-demographic data, to assess HRQoL (Medical Outcomes Study-HIV), depressive symptoms (Beck Depression Inventory-II) and adherence to HAART (Short Medication Adherence Questionnaire) and to screen for neurocognitive dysfunction. RESULTS: A total of 237 people participated, among whom 187 (78.9%) were male. Mean age was 45.8±10.7 years and 144 (63.7%, 144/226) participants were homosexual. Median physical and mental health score (PHS, MHS) were 55.6 (IQR 48.2-60.6) and 52.0 (IQR 44.2-57.9), respectively. Multivariable regression analysis revealed that incapacity to work, depressive symptoms, neurocognitive complaints (NCCs), dissatisfaction with the patient-physician relationship and non-adherence were all negatively associated with HRQoL. CONCLUSIONS: Socio-economic (work status), behavioural (adherence) and (neuro)psychological (depressive symptoms, NCCs) determinants independently impact HRQoL among this cohort of PLHIV. Clinical parameters (viral load, CD4 cell count) were not independently associated with HRQoL.

Frequency and predictors of HIV-1 co-receptor switch in treatment naive patients.

BACKGROUND: Determination of HIV-1 co-receptor use is a necessity before initiation of a CCR5 antagonist but the longevity of a CCR5-use prediction remains unknown. METHODS: Genotypic co-receptor tropism determination was performed in 225 newly diagnosed individuals consulting an AIDS Reference Centre. Samples were collected at diagnosis and at initiation of antiretroviral therapy or just before closure of the study for patients who did not initiate therapy. For individuals with a discordant tropism prediction on the two longitudinal samples, analysis of intermediate samples and single genome sequencing of proviral DNA was performed to confirm the tropism switch. Deep sequencing was done to identify minor CXCR4 or CCR5-using populations in the initial sample. RESULTS: Overall, tropism switches were rare (7.6%). Only a geno2pheno false positive rate of <50% at baseline was retained as predictive for a subsequent switch from CCR5-use only to predicted CXCR4-use. Minor CXCR4-using virus populations were detected in the first sample of 9 of the 14 R5-to-X4 switchers but the subsequent outgrowth of these minor populations was documented in only 3. CONCLUSIONS: With the current guidelines for treatment initiation at CD4(+) T cell counts of <500 cells/mm(3), co-receptor switch between diagnosis and starting antiretroviral therapy is rare. Patients with R5 viruses and a geno2pheno FPR of <50% are more prone to subsequent co-receptor switch than patients with an FPR of >50% and will need repeat tropism testing if initiation of maraviroc is considered and previous testing dates from more than a year before.

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 phenotypes.

Viral load assay sensitivity and low level viremia in HAART treated HIV patients.

BACKGROUND: The recent introduction of highly sensitive viral load assays resulted in a significant increase in number of treated HIV-infected patients with a detectable viral load. The significance of a viral load between 20 and 50 copies/mL remains unclear. OBJECTIVES: To compare the performance of three viral load assays, with special attention for specificity and sensitivity at the lowest level of quantification. STUDY DESIGN: Samples (n=181) were selected from 62 HIV-positive individuals that experience viral blips or episodes of low but detectable viremia under antiretroviral treatment, and from 216 HIV-negative individuals. Each sample was tested in at least two of three assays: the Cobas Amplicor HIV-1 Monitor (CAP/CA), the Cobas Ampliprep/Cobas TaqMan HIV-1 version 1 (CAP/CTM1) and the Cobas Ampliprep/Cobas TaqMan HIV-1 version 2 (CAP/CTM2). RESULTS: No false positive results were recorded. Kappa statistics revealed fair to moderate agreement between the results of the three assays, but important differences in sensitivity were observed, with the highest sensitivity reported for CAP/CTM2 followed by CAP/CTM1 and CAP/CA. The differences in sensitivity remained after equalization of the detection limit for all assays at 50 copies/mL. Analysis of samples collected over time showed that patients with single blips in CAP/CA present with recurrent blips in CAP/CTM1 and persistent detectable viremia in CAP/CTM2. CONCLUSIONS: Viral load results between 20 and 50 copies/mL in either CAP/CTM1 or CAP/CTM2, indicate true viremia. The availability of highly sensitive assays force reconsideration of the terms 'undetectable' viral load and 'virological success' of antiretroviral treatment.

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.

Detection of drug resistance mutations as a predictor of subsequent virological failure in patients with HIV-1 viral rebounds of less than 1,000 RNA copies/ml.

In order to evaluate the usefulness of resistance testing after a viral rebound with plasma HIV RNA levels of less than 1,000 copies (c)/ml, genotyping was performed on 39 samples from patients on highly active antiretroviral therapy (HAART) showing a viremia of over 50 c/ml up to a maximum of 1,000 c/ml after at least one undetectable viral load result. Protease and reverse transcriptase (RT) sequences were obtained for all 39 samples. In 10 (25.6%) of the samples, mutations not seen before the initiation of the regimen were observed. The M184V/I mutation was the most prevalent but in several patients a combination of multiple mutations was detected. Follow-up samples were available for 34 patients. In six (85.71%) out of seven patients with new mutations, the viral load on the follow-up visit remained detectable, indicating true failure, compared to 6 (31.6%) true failures out of 19 patients in whom only wild type virus was detected (P = 0.02) and three (37.5%) out of eight patients in whom only the mutations already present at the initiation of HAART were seen (P = 0.08). The results indicate that reliable resistance testing can be performed on samples with a viral burden of less than 1,000 c/ml and demonstrate that multiple drug resistance mutations can be selected at low viral load rebounds. Most importantly, detection of resistance mutations in viral rebound samples was predictive of subsequent virological failure.

Inhibition of replication of primary HIV-1 isolates in huPBL-NOD/Scid mice by antibodies from HIV-1 infected patients.

Although a limited number of HIV-infected patients have broadly neutralizing antibodies, it has not been examined whether these antibodies can protect against infection with primary virus in vivo. Here we screened the plasma of 23 HIV-1-infected patients for broadly neutralizing antibodies. Purified antibodies from subjects with broad and more narrow responses were administered to huPBL-NOD/Scid mice that were subsequently challenged with primary viruses of clade A, B and CRF01_AE. Although we observed a lack of correlation between the data from the in vitro neutralization assay and the results from the passive immunization experiments, we report for the first time that antibodies from HIV-infected persons can inhibit replication of primary virus isolates in an animal model.

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 11 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 polymerase 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.