Lopinavir/ritonavir resistance in patients infected with HIV-1: two divergent resistance pathways?

The HIV-1 protease L76V mutation has been described recently as conferring high-level resistance to lopinavir/ritonavir (LPV/r). The aim was to identify the factors and particularly protease mutations associated with the presence of L76V in treatment-experienced patients infected with HIV-1 who have failed virologically an LPV/r-based antiretroviral therapy regimen. This is a retrospective exploratory study.