Assessment of residual HIV-1 viremia and persistent viral replication in highly suppressed patients: comparison of direct and indirect methods. B. Hernández-Novoa, N. Madrid, A. Vallejo, C. Gutiérrez, L. Díaz, M. Abad, E. Domínguez, V. Dahl, R. Rubio, E. Navas, J. Zamora, H. Valdez, S. Palmer, M.A. Muñoz-Fernández, S. Moreno. Direct (Single copy assay-SCA) and indirect (2-LTR episomal DNA detection and immune activation) methods have been used to measure residual replication during suppressive HAART. Results have been contradictory and comparisons of these methods are needed. Clinical trial (NCT ) of maraviroc (MVC) intensification SCA with an optimal threshold of 0.3 copies/ml Qualitative 2-LTR PCR: 1st round: LA3 + LA7 2nd round: Jct f + LA1 Flow cytometry of double positive CD4 and CD8 T cells (CD38+HLA-DR+).

Significant changes were observed at week 12 (p=0.02) for SCA and at both timepoints (weeks 12 and 24) for 2- LTR-DNA detection (p=0.037 and p=0.012, respectively). Agreement between both techniques was poor (Kappa=0.115). A decrease in the median proportion of CD3+CD4+CD38+HLA-DR+ was observed at week 24 which was not statistically significant (1.6%, IQR: ; 2.9%, IQR: at BL). This was also de case for activated CD8 T cells. No correlation with the two other techniques was observed. Conclusions 1.There was no correlation in the results obtained by the three methods used to measure residual viremia and persistent viral replication. 2.The reduction in CD4 and CD8 T cell activation, transient increase in residual viremia, and increase in patients with detectable 2-LTR DNA at week 24 suggest that different events are taking place at the same time and warrants further research.

Thanks! Hospital Ramón y Cajal – Santiago Moreno – Carolina Gutiérrez – Alex Vallejo – Nadia Madrid – María Abad – Esther Domínguez – Carmen Page – Jose L. Casado – Fernando Dronda – Ana Moreno – M. Jesús Pérez Elías – Paloma Martí-Belda – María Pumares – Javier Zamora H. Gregorio Marañón −M. Angeles Muñoz −Laura Díaz −Raquel Lorente Karolinska Institute −Sarah Palmer −Viktor Dahl H. 12 Octubre − Rafael Rubio Pfizer Inc. −Hernán Valdez Our patients!