If you read any news sites out there by now you've seen the many headlines splashed across front pages proclaiming a cure for HIV. While I am the first person who would love to be able to jump up and down and shout from the rooftops, this potential cure is not actually a cure in the way you would think it would be. In this case, the patient in question was a young man who was both HIV positive and had acute myeloid leukemia. To treat his cancer, he was given extremely hard core chemotherapy and radiation to completely wipe out his immune system and in addition received a transplant of healthy stem cells. This first treatment ultimately failed and he received another round after his cancer relapsed. In this particular case, the patient received stem cells that contained a rare, inherited gene mutation conferring natural resistance to HIV infection. Although the researchers thought he would relapse, he hasn't yet so they're calling it a cure.
While there is a good chance that this patient is in fact cured of HIV, this is unfortunately not an HIV cure. The idea behind this is to eliminate every single cell containing HIV, especially the activated memory CD4(+) T cells. Doing this is extremely dangerous as no immune system means no way of fighting any infection, including HIV which is why the researches anticipated that their patient would end up free from leukemia but with AIDS. Adding stem cell transplant on top means the patient is open to a whole host of common complications including graft-versus-host disease. To have this treatment to cure HIV a patient would have to:
- Be HIV positive
- Have a cancer requiring a bone marrow transplant
- Be able to find a compatible transplant match with a rare genetic mutation found in only 1% of the Caucasian population, and at 0% in the Black population
- Have hundreds of thousands of dollars or the worlds most amazing insurance
Many of the patients receiving treatment like this don't have HIV and will die from this treatment. Which brings us to the next consideration.
With the right medications, a person who is HIV positive can have a long life. Every day, the life expectancy for an HIV positive person is extended through the development of new treatments. While it's still one of the worlds most crushing and devastating diseases, it's no longer the immediate death sentence it used to be. I'm not sure it would be worth it for an HIV patient to risk immediate death for the slim to none chance that they might be cured. The most important aspect of this study is certainly the definitive understanding we have gained about the HIV virus, one of the smartest, sneakiest viruses we've seen yet. Although we don't have a cure yet, we now know that it is possible to eradicate it.
The Researcher's Abstract:
HIV entry into CD4(+) cells requires interaction with a cellular receptor, generally either CCR5 or CXCR4. We have previously reported the case of an HIV-infected patient in whom viral replication remained absent despite discontinuation of antiretroviral therapy after transplantation with CCR5Δ32/Δ32 stem cells. However, it was expected that the long-lived viral reservoir would lead to HIV rebound and disease progression during the process of immune reconstitution. In the present study, we demonstrate successful reconstitution of CD4(+) T cells at the systemic level as well as in the gut mucosal immune system following CCR5Δ32/Δ32 stem cell transplantation, while the patient remains without any sign of HIV infection. This was observed although recovered CD4(+) T cells contain a high proportion of activated memory CD4(+) T cells, i.e. the preferential targets of HIV, and are susceptible to productive infection with CXCR4-tropic HIV. Furthermore, during the process of immune reconstitution, we found evidence for the replacement of long-lived host tissue cells with donor-derived cells indicating that the size of the viral reservoir has been reduced over time. In conclusion, our results strongly suggest that cure of HIV has been achieved in this patient.
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