This residual viraemia might potentially induce a substantial increase in IA [19]; however, no studies of mtPI/rtv have addressed this issue to date. In this study, we assessed IA evolution throughout a period of darunavir/ ritonavir monotherapy (mtDRV/rtv), and particularly the influence that blip, intermittent viraemia and virological failure (VF) episodes have on the IA profile of HIV-1-infected patients