The results of a stem cell transplant received by ‘Berlin Patient’ Timothy Ray Brown in 2007 “strongly suggest that the cure of HIV infection has been achieved.” (Allers, et al. 2010) The transplant was originally made in treatment of leukemia, though now supports the possibility of a permanent HIV solution.
The cells in question are CCR5Δ32/Δ32 progenitors. Following transplantation, despite a long-lived viral population, the patient remained without sign of HIV infection and regained a substantial systemic population of CD4+ cells. HIV rebound with CXCR4-tropic variant was not observed, and the reduction of the viral reservoir was suggested by the replacement of host tissue with donor-derived cells. Antiretroviral treatment was discontinued following transplant.