We keep hearing people tell us that there is no cure for HIV, but it appears that this may not be the case following a patient in Berlin who was given a stem cell transplant, which resulted in him being cured of HIV. This is a very interesting discovery, but it is important to highlight from the beginning that some unusual circumstances lead to the patient being cured of HIV. The patient is Timothy Brown, a US citizen who lives in Berlin.
According to Aidsmap, doctors carried out a stem cell transplant on an HIV-infected man with leukemia in 2007 and they believe the man has been cured of HIV infection as a result of the treatment, which introduced stem cells which happened to be resistant to HIV infection. This is an important note, because the stem cells featured an unusual genetic profile inherited from both parents that resulted in CD4 cells that lacked the CCR5 receptor. This mutation, called CCR5 delta 32 homozygosity, is present in less than 1% of Caucasians in northern and western Europe, and is associated with a reduced risk of becoming infected with HIV.
The article states that before the stem cell transplant the patient received chemotherapy treatment that destroyed most immune cells and total body irradiation and also received immunosuppressive drugs to prevent rejection of the stem cells. Antiretroviral therapy was halted on the day of the transplant and the patient had to receive a second stem cell transplant 13 days after the first one, due to a further relapse of leukemia. The patient continued to receive immunosuppressive treatment to prevent rejection for 38 months, and at 5, 24 and 29 months post-transplant colon biopsies were taken to investigate possible graft-versus-host disease in the intestine. The patient did not resume antiretroviral therapy after the transplant.
During an interview with German news magazine Stern, Dr Gero Hütter who was the doctor in charge of Timothy Brown’s surgery said that as a scientist he was “in the right place, at the right time” and that “for me it is important to have overthrown the dogma that HIV can never be cured. Something like this is the greatest thing one can achieve in medical research”.
Researchers are now trying to establish ways to identify CCR5-delta32 homozygous donors and expand the supply of stem cells from these donors in order to eventually facilitate stem-cell therapy. The NAM article finishes by saying “As Timothy Brown’s experience shows, curing HIV infection through ablative chemotherapy, immunosuppressive drugs and stem cell transfer is not a course of treatment for the faint-hearted. It has required courage, determination and a lot of support to become the first person to be pronounced ‘cured’ of HIV infection.”
- Stem cell transplant has cured HIV infection in ‘Berlin patient’, say doctors – Aidsmap