JAC Advance Access originally published online on August 11, 2009
Journal of Antimicrobial Chemotherapy 2009 64(4):845-849; doi:10.1093/jac/dkp293
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Original research |
Correlation between the Trofile® test and virological response to a short-term maraviroc exposure in HIV-infected patients
1 Laboratory of Immunovirology, Biomedicine Institute of Seville (IBIS), Service of Infectious Diseases, Virgen del Rocío University Hospital, Seville, Spain 2 Paediatrics Service, Virgen del Rocío University Hospital, Seville, Spain 3 Service of Immunology, Virgen del Rocío University Hospital, Seville, Spain 4 Molecular Immunobiology Laboratory, Gregorio Marañón University Hospital, Madrid, Spain
Received 26 June 2009; returned 8 July 2009; revised 9 July 2009; accepted 19 July 2009
* Corresponding author. Tel: +34-955013291; Fax: +34-955013292; E-mail: mleal{at}telefonica.net
Objectives: The current validated assay to determine tropism of HIV variants is Trofile®, which has some limitations. The aim of this work was to correlate the virological response to a short-term maraviroc exposure with Trofile®.
Methods: From 1 July 2008 to 1 March 2009, 34 consecutive HIV-infected patients with detectable viral load during the last 6 months began an 8 day exposure to maraviroc (MCT group); six HIV-infected patients without antiretroviral therapy received no treatment (control group). Plasma viral load was evaluated on days 0, 2, 5 and 8. Baseline Trofile® was performed in MCT group patients. The maraviroc clinical test (MCT) was considered positive if viral load was undetectable (<40 HIV-RNA copies/mL) or a reduction 
1 log10 HIV-RNA copies/mL was achieved after 8 days of maraviroc exposure.
Results: Global concordance between MCT and Trofile® was 93.5%. In patients with R5 virus according to Trofile®, MCT was positive in 19/20 (concordance 95%); in patients with dual/mixed virus, MCT was negative in 10/11 (concordance 90.9%). An additional phenotypic tropism assay was performed in patients with discordance between MCT and Trofile®, being concordant with MCT in both cases. Three patients showed a non-reportable Trofile® result, and all of them achieved undetectability after MCT.
Conclusions: A clinical approach like short-term maraviroc exposure could be an additional resource to genetic and phenotypic HIV tropism assays. This clinical approach shows high concordance with Trofile®, and could allow patients with non-reportable results by Trofile® to benefit from maraviroc therapy.
Keywords: CCR5 antagonists , tropism assays , antivirals