Finding a cure for AIDS has proven one of medicine’s more difficult puzzles. But now, over 35 years after the first cases, a new technique involving stem-cell transplantation has been attempted- could this be the long-awaited cure?
Earlier this month (8th Dec), the scientific jorunal “Blood” published a study reporting “the apparent cure of AIDS in a German patient“. The paper, by Kristina Allers, Gero Hütter, Jörg Hofmann, Christoph Loddenkemper, Kathrin Rieger, Eckhard Thiel and Thomas Schneider details the results of the transplantation of stem cells into a a Berlin man- Timothy Ray Brown. Mr Brown was treated back in 2007 for leukaemia with a stem cell transplant; however, he also had HIV, but, following his transplant, both diseases appear to have been cured. The HIV-virus appears to have been totally eliminated from his body.
There is a short version of the article in Tuesday’s Huffington Post here-
One of the big problems in HIV treatment to date has been that, although the powerful drug combinations (triple therapy regimes) used in contemporary HAART (Highly Active Anti-Retroviral Therapy) treatment programmes reduce the viral load in a patient’s body to undetectable levels, if treatment is stopped, the virus “reappears”. Because HAART drugs are quite highly toxic to patients- causing various unpleasant side-effects, such as loss of peripheral nerve sensation, major derangement of liver enzymes and kidney problems- the ideal situation would be to eliminate the virus completely from a patient. It has long been thought that there are “reservoirs” of (hidden) virus within HIV positive patients, that multiply once/if HAART treatment is stopped. If this stem-cell treatment really is effective, the implication is that in this patient, not only has the detectable HIV virus been eliminated from this patient, but the transplanted stem cells have also eliminated the viral reservoirs.
The stem cells used for the transplant were a naturally occurring “mutant” type, which lack the ability to produce a protein called CCR5. This matters because CCR5 is used by the HIV virus to enter those cells it attacks and to cause disease. For over 10 years, it has been known that there were individuals who were apparently totally healthy, but who had mutant forms of the CCR5 protein and who were highly, if not totally, resistant to HIV. The fact that these people were unaware of their resistance and their “mutant” helper T-cells and were in all other ways, apparently totally healthy- implied that the CCR5 protein and its precise shape was not important to the human body, but it did matter to the HIV virus. The mutant forms of CCR5 resulted from a natural deletion in part of the gene that gave instructions for manufacturing the CCR5 protein- and was called delta 32 CCR5.
CCR5 is not the only protein involved in allowing HIV to enter its target cells and people with mutations in one of the other proteins involved (”CXCR4″) are also known to have enhanced resistance to HIV infection and to AIDS.
The abstract for the scientific paper by Kristina Allers and colleagues is available online here-
If this “cure” turns out to be as promising as it appears, not only is this a huge leap for science and potentially the dawn of a new approach to disease treatment, but it seems likely that some of the scientists involved will receive Nobel prizes.