Further, as lymphoid tissue is considered the primary site of HIV reservoirs and a critical site affected by CD4+ T cells depletion, the HCQ concentration was assessed in the plasma and adenoid tissue (At) of 8 HIV-infected patients administrating 400 or 800 mg of HCQ for eight weeks. After taking these dosages, it was demonstrated that the mean HCQ concentration was significantly higher in At than in plasma [21]. This different drug distribution was also confirmed by an in vivo study using rabbits as an experimental model, receiving 15 mg/kg of HCQ subcutaneously [22]. Thus, the anti-HIV activity of HCQ could be linked to its accumulation in lymphoid tissue, a relevant site for HIV immunopathogenesis and replication.