icon-folder.gif   Conference Reports for NATAP  
  Glasgow HIV
28 - 31 October 2018
Glasgow, UK
Back grey_arrow_rt.gif
Predicting 2-drug antiretroviral regimen efficacy by genotypic susceptibility score: results from a cohort study
  Reported by Jules Levin
Glasgow 2018 Oct 27-31
B. Rossetti1, D. Redi2, S. Di Giambenedetto3, F. Lombardi3, S. Paolucci4, L.I. Bellazzi5, A. Di Biagio6, G. Penco7, L. Lepore8, L. Monno9,
S. Rusconi10, T. Carli11, S. Modica2, R. Gagliardini2,12, M. Zazzi2, A. De Luca1,2 and ARCA collaborative group
1.Infectious Diseases Unit, Siena University Hospital, Siena, Italy; 2. Department of Medical Biotechnologies, University of Siena, Siena Italy; 3. Institute of Clinical Infectious Diseases, Catholic University of Sacred Heart, Policlinico Gemelli, Rome, Italy; 4. Virology Unit, S.
Matteo Hospital, Pavia, Italy; 5. Infectious Diseases Unit, S. Matteo Hospital, Pavia, Italy; 6. Infectious Diseases Unit, IRCCS S. Martino-IST, Genova, Italy; 7. Infectious Diseases Unit, Ospedali Galliera, Genova, Italy; 8. Virology Unit, Bari Hospital, Bari, Italy; 9. Infectious
Diseases Unit, Bari Hospital, Bari, Italy; 10. Infectious and Tropical Diseases Unit, DIBIC L. Sacco Hospital, University of Milano, Milano, Italy; 11. Infectious Diseases Unit, Grosseto Hospital, Grosseto, Italy; 12. INMI L.Spallanzani IRCCS, Rome, Italy
Higher viral load at switch and the presence of less than 1 fully active drug strongly influence virological efficacy of 2-drug regimens in treatment experienced HIV-1 infected patients. The most recent GSS seems more predictive of the outcome as compared to the cumulative GSS of these switch regimens.
HIV drug resistance has a deleterious effect on the virological outcome of antiretroviral therapy (ART). The aim of the study is to evaluate the ability of genotypic susceptibility score (GSS) to predict virological outcome following an ART switch to a 2-drug regimen in pretreated HIV-1 infected patients.
From the ARCA database we selected HIV-1 infected treatment-experienced patients switching to 2-drug ART (2007-2017, time of switch=baseline), with pre-baseline resistance genotype and at least one HIV-1 RNA determination during follow up. Primary endpoint was virological failure (VF, defined as an HIV-1 RNA, VL, >400 copies/mL).
Survival analysis was used to investigate predictors of VF. The genotypic susceptibility score (GSS) predicted by the latest and the cumulative genotype (CGSS, summing all the historical resistance mutations) was calculated using the Stanford hivdb (v.8.5) interpretation with respect to the 2-drug regimen started. Pre-baseline viremia copy-years (VCY) were calculated using the trapezoidal rule on the VL log10 scale using all the available VL results.