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See detailComparison of phenotypic and genotypic tropism determination in triple-class-experienced HIV patients eligible for maraviroc treatment.
Vandekerckhove, Linos; Verhofstede, Chris; Demecheleer, Els et al

in Journal of Antimicrobial Chemotherapy (2011), 66(2), 265-72

BACKGROUND: Determination of HIV-1 tropism is a pre-requisite to the use of CCR5 antagonists. This study evaluated the potential of population genotypic tropism tests (GTTs) in clinical practice, and the ... [more ▼]

BACKGROUND: Determination of HIV-1 tropism is a pre-requisite to the use of CCR5 antagonists. This study evaluated the potential of population genotypic tropism tests (GTTs) in clinical practice, and the correlation with phenotypic tropism tests (PTTs) in patients accessing routine HIV care. METHODS: Forty-nine consecutive plasma samples for which an original Trofile(TM) assay was performed were obtained from triple-class-experienced patients in need of a therapy change. Viral tropism was defined as the consensus of three or more tropism calls obtained from the combination of two independent population PTT assays (Trofile Biosciences, San Francisco, CA, USA, and Virco, Beerse, Belgium), population GTTs and GTTs based on ultra-deep sequencing. If no consensus was reached, a clonal PTT was performed in order to finalize the tropism call. This two-step approach allowed the definition of a reference tropism call. RESULTS: According to the reference tropism result, 35/49 samples were CCR5 tropic (R5) (patients eligible for maraviroc treatment) and 14/49 were assigned as non-R5 tropic. The non-R5 samples [patients not eligible for maraviroc treatment according to the FDA/European Medicines Agency (EMEA) label] group included both the CXCR4 (X4) samples and the dual and mixed CCR5/CXCR4 (R5/X4) samples. Compared with Trofile(TM) population PTTs, population GTTs showed a higher sensitivity (97%) and a higher negative predictive value (91%), but almost equal specificity and an equal positive predictive value. CONCLUSIONS: In line with recent reports from clinical trial data, our data support the use of population genotypic tropism testing as a tool for tropism determination before the start of maraviroc. [less ▲]

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See detailHIV-1 V3 envelope deep sequencing for clinical plasma specimens failing in phenotypic tropism assays.
Vandenbroucke, Ina; Van Marck, Herwig; Mostmans, Wendy et al

in AIDS Research and Therapy (2010), 7

ABSTRACT : BACKGROUND : HIV-1 infected patients for whom standard gp160 phenotypic tropism testing failed are currently excluded from co-receptor antagonist treatment. To provide patients with maximal ... [more ▼]

ABSTRACT : BACKGROUND : HIV-1 infected patients for whom standard gp160 phenotypic tropism testing failed are currently excluded from co-receptor antagonist treatment. To provide patients with maximal treatment options, massively parallel sequencing of the envelope V3 domain, in combination with tropism prediction tools, was evaluated as an alternative tropism determination strategy. Plasma samples from twelve HIV-1 infected individuals with failing phenotyping results were available. The samples were submitted to massive parallel sequencing and to confirmatory recombinant phenotyping using a fraction of the gp120 domain. RESULTS : A cut-off for sequence reads interpretation of 5 to10 times the sequencing error rate (0.2%) was implemented. On average, each sample contained 7 different V3 haplotypes. V3 haplotypes were submitted to tropism prediction algorithms, and 4/14 samples returned with presence of a dual/mixed (D/M) tropic virus, respectively at 3%, 10%, 11%, and 95% of the viral quasispecies. V3 tropism prediction was confirmed by gp120 phenotyping, except for two out of 4 D/M predicted viruses (with 3 and 95%) which were phenotypically R5-tropic. In the first case, the result was discordant due to the limit of detection for the phenotyping technology, while in the latter case the prediction algorithms were not computing the viral tropism correctly. CONCLUSIONS : Although only demonstrated on a limited set of samples, the potential of the combined use of "deep sequencing + prediction algorithms" in cases where routine gp160 phenotype testing cannot be employed was illustrated. While good concordance was observed between gp120 phenotyping and prediction of R5-tropic virus, the results suggest that accurate prediction of X4-tropic virus would require further algorithm development. [less ▲]

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See detailTransmitted drug resistance, selection of resistance mutations and moderate antiretroviral efficacy in HIV-2: analysis of the HIV-2 Belgium and Luxembourg database.
Ruelle, jean; Roman, francois; Vandenbroucke, Anne-Thérèse et al

in BMC Infectious Diseases (2008), 8

BACKGROUND: Guidelines established for the treatment of HIV-1 infection and genotype interpretation do not apply for HIV-2. Data about antiretroviral (ARV) drug efficacy and resistance mutations is scarce ... [more ▼]

BACKGROUND: Guidelines established for the treatment of HIV-1 infection and genotype interpretation do not apply for HIV-2. Data about antiretroviral (ARV) drug efficacy and resistance mutations is scarce. METHODS: Clinical data about HIV-2 infected patients in Belgium and Luxembourg were collected and the effect of ARV therapy on plasma viral load and CD4 counts were analysed. Viral RNA encoding for protease (PR) and reverse transcriptase (RT) from ARV-naive and treated patients were sequenced. RESULTS: Sixty-five HIV-2 infected patients were included in this cohort. Twenty patients were treated with 25 different ARV combinations in a total of 34 regimens and six months after the start of ARV therapy, only one third achieved viral load suppression. All of these successful regimens bar one contained protease inhibitors (PIs). Mean CD4 gains in the group of viral load suppressors and the group of patients treated with PI-containing regimens were respectively significantly higher than in the group of non-suppressors and the group of PI-sparing regimens. The most frequent mutations selected under therapy (compared to HIV-2 ROD) were V71I, L90M and I89V within PR. Within RT, they were M184V, Q151M, V111I and K65R. All of these mutations, except K65R and M184V, were also found in variable proportions in ARV-naive patients. CONCLUSION: Despite a high rate of ARV treatment failure, better virological and immunological results were achieved with PI-containing regimens. The analysis of polymorphic positions and HIV-2 specific mutations selected during therapy showed for the first time that transmission of drug resistant viruses has occurred in Belgium and Luxembourg. The high heterogeneity in ARV combinations reflects a lack of guidelines for the treatment of HIV-2 infection. [less ▲]

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See detailPrevalence and epidemiology of HIV type 1 drug resistance among newly diagnosed therapy-naive patients in Belgium from 2003 to 2006.
Vercauteren, Jurgen; Derdelinckx, Inge; Sasse, Andre et al

in AIDS Research and Human Retroviruses (2008), 24(3), 355-62

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 ... [more ▼]

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. [less ▲]

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See detailCurrent levels of drug resistance among therapy-naive HIV-infected patients have significant impact on treatment response
Derdelinckx, Inge; Van Laethem, Kristel; Maes, Bart et al

in Journal of Acquired Immune Deficiency Syndromes [=JAIDS] (2004), 37(5), 1664-1666

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See detailVirologic therapy response significantly correlates with the number of active drugs as evaluated using a LiPA HIV-1 resistance scoring system
Ziermann, Rainer; Celis, Linda; Derdelinckx, Inge et al

in Journal of Clinical Virology (2004), 31(Suppl. 1), 7-15

Background: Resistance testing is increasingly accepted as a tool in guiding the selection of human immunodeficiency virus type 1 (HIV-1) antiretroviral therapy in HIV-1 infected individuals who fail ... [more ▼]

Background: Resistance testing is increasingly accepted as a tool in guiding the selection of human immunodeficiency virus type 1 (HIV-1) antiretroviral therapy in HIV-1 infected individuals who fail their current regimen. Objectives: To descriptively compare the correlation between virologic treatment response and results using three genotypic HIV-1 drug resistance interpretation systems: the VERSANT(R) HIV-1 Resistance Assay (LiPA) system and two sequence-based interpretation systems. Study design: Specimens from 213 HIV-1-infected subjects, either starting (n = 104) or switching to (n = 109) a regimen of three or four antiretroviral drugs, were collected retrospectively at baseline and after 3 months of uninterrupted therapy. The correlation between viral load change and the number of predicted active drugs in the treatment regimen was assessed. An interpretation algorithm was recently developed to process VERSANT(R) HIV-1 Resistance Assay (LiPA) data. The number of active drugs predicted using this algorithm was rank correlated with the viral load change over a 3-month treatment period. For comparison, a similar calculation was made using two sequence-based algorithms (REGA version 5.5 and VGI GuideLines(TM) Rules 4.0), both applied on the same sequences. Results: Statistically significant (p < 0.05) correlation coefficients for each of the three HIV-1 drug resistance interpretation systems were observed in the treatment-experienced subjects on a 3-drug regimen (-0.39, -0.38, and -0.42, respectively) as well as on a 4-drug regimen (-0.33, -0.31, and -0.37, respectively). However, no significant correlation was observed in treatment-naive subjects, probably due to the very low frequency of drug resistance in these subjects. Conclusion: All three genotypic drug resistance interpretation systems (LiPA version 1, REGA version 5.5, and VGI GuideLines(TM) Rules 4.0) were statistically significantly correlated with virologic therapy response as measured by viral load testing. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailPerformance of the VERSANT (R) HIV-1 Resistance Assays (LiPA) for detecting drug resistance in therapy-naive patients infected with different HIV-1 subtypes
Derdelinckx, Inge; Van Laethem, Kristel; Maes, Baert et al

in FEMS Immunology & Medical Microbiology (2003), 39(2), 119-124

In this study we evaluated the performance of the VERSANT((R)) HIV-1 Resistance Assays (LiPA) in detecting drug resistance in therapy-naive HIV-infected patients diagnosed in Belgium in 2000. We compared ... [more ▼]

In this study we evaluated the performance of the VERSANT((R)) HIV-1 Resistance Assays (LiPA) in detecting drug resistance in therapy-naive HIV-infected patients diagnosed in Belgium in 2000. We compared the results with population sequencing and found concordance to be in line with previous studies in treatment-experienced patients (86.87% for reverse transcriptase (RT); 92.77% for protease (PRO)). Discordance was mainly due to indeterminate reactions on LiPA (8.45% for RT; 6.85% for PRO) and minor discordances (4.13% for RT; 0.25% for PRO). Major discordances were rare (0.46% for RT; 0.12% for PRO). Indeterminate reactions were significantly associated with strains belonging to non-B subtypes. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V.. All rights reserved. [less ▲]

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