This week's New England Journal of Medicine has an interesting case report on a man who was having an allogeneic stem cell transplant to treat his acute myeloid leukemia (AML), but also happened to be HIV positive. The transplant team theorised that:
They therefore took this into consideration and specifically chose a donor who had a naturally occurring gene mutation that confers resistance to HIV. The mutation, CCR5 delta32, occurs naturally in 1-3% of the European population.
Two years after the transplant, the patient is alive, well and seemingly free of HIV still.
This procedure, while offering some early encouragement, is not going to be a panacea for all patients, mainly because of the mortality associated with ablation (wiping out) of a person's immune cells rendering them susceptible to fatal infection. 20% of SCT patients die from the procedure alone, so it is a very risky one indeed.
Jay Levy from UCSF wrote an accompanying editorial in which in he noted:
In the past, there were several attempts to control HIV-1 infection by means of allogeneic stem cell transplantation without regard to the donor's CCR5 delta32 status, but these efforts were not successful. This fascinating study demonstrated the critical role CCR5 plays in maintaining HIV-1 infection and the need to consider it in treatment with SCT for HIV-1.
Gero Hütter, Daniel Nowak, Maximilian Mossner, Susanne Ganepola, Arne Müßig, Kristina Allers, Thomas Schneider, Jörg Hofmann, Claudia Kücherer, Olga Blau, Igor W. Blau, Wolf K. Hofmann, Eckhard Thiel (2009). Long-Term Control of HIV by CCR5 Delta32/Delta32 Stem-Cell Transplantation New England Journal of Medicine, 360 (7), 692-698