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.

Presence of CXCR4-using HIV-1 in patients with recently diagnosed infection: correlates and evidence for transmission.

BACKGROUND: The prevalence and correlates of CXCR4-use in recently diagnosed patients and the impact of X4/DM transmission remain largely unknown. METHOD: Genotypic coreceptor use determination on the baseline sample of 539 recently diagnosed individuals. Correlation of coreceptor use with clinical, viral and epidemiological data and with information on transmission events as obtained through phylogenetic analysis of protease and reverse transcriptase sequences. Results. CXCR4-use was predicted in 12 to 19% of the patients, depending on the interpretative cutoff used. CXCR4-use was correlated with lower CD4(+) T cell counts and subtype 01_AE infection. No association with viral load was observed. Seven (11%) of 63 transmission clusters and 4 (31%) of 13 donor-source pairs resulted from X4/DM transmission. CONCLUSION: The results confirmed the relation between CXCR4-use at diagnosis and low baseline CD4+ T cell counts. Significantly more CXCR4-use was predicted in 01_AE infections, which may impose constraints on the use of CCR5 antagonists in certain regions of the world. Observations from the transmission cluster analysis contradict the hypothesis that R5 viruses are selected at transmission, and support the idea that R5 or X4/DM infections result from a stochastic process.

Prevalence and epidemiology of HIV type 1 drug resistance among newly diagnosed therapy-naive patients in Belgium from 2003 to 2006.

This study is the first prospective study to assess the prevalence, epidemiology, and risk factors of HIV-1 drug resistance in newly diagnosed HIV-infected patients in Belgium. In January 2003 it was initiated as part of the pan-European SPREAD program, and continued thereafter for four inclusion rounds until December 2006. Epidemiological, clinical, and behavioral data were collected using a standardized questionnaire and genotypic resistance testing was done on a sample taken within 6 months of diagnosis. Two hundred and eighty-five patients were included. The overall prevalence of transmitted HIV-1 drug resistance in Belgium was 9.5% (27/285, 95% CI: 6.6-13.4). Being infected in Belgium, which largely coincided with harboring a subtype B virus, was found to be significantly associated with transmission of drug resistance. The relatively high rate of baseline resistance might jeopardize the success of first line treatment as more than 1 out of 10 (30/285, 10.5%) viruses did not score as fully susceptible to one of the recommended first-line regimens, i.e., zidovudine, lamivudine, and efavirenz. Our results support the implementation of genotypic resistance testing as a standard of care in all treatment-naive patients in Belgium.

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.

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.

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.