The mystery of Timothy Ray Brown being the only man known to have escaped from the grips of the deadly HIV has stirred researchers to find out the secret behind. The theory goes as follows, bearing in mind that the patient was also a cancer patient: the radiation Brown went through to kill the cancer cells might have also killed the remaining HIV reservoir, or that the bone-marrow transplant done thereafter on him might have constituted the key to the cure: it is believed that the donor’s rare genetic mutation might have played a role in doing away with the HIV in Brown’s system.
HIV remains a deadly virus that cannot be completely done away with, in spite of the advances made by man in the medical field. How on earth did Timothy Ray Brown become cured from HIV thus remains a mystery. He is the only HIV-positive patient that has shown signs of the virus retreating below detectable levels – he is known as the only person having been cured from HIV. A new study might have provided the explanation as to why the HIV concentration in his system decreased and it was deduced that the key might have been in the genetics of the bone marrow donor of Timothy Ray Brown.
Timothy Ray Brown was also a cancer patient – he was suffering from leukemia. During his treatment in Germany he was made to undergo radiation meant to kill the cancer cells together with the stem cells (the parent cells) that were manufacturing the diseased cells. Thereafter, he was grafted with a bone-marrow transplant from a donor so that his body could manufacture new blood cells. Now, it seems that the healthy donor had a rare genetic mutation that might have accounted for the miracle that occurred right after. After the treatment and the transplant, the cancer abated and simultaneously, the HIV levels decreased. That happened in 2007, and the man is still in the same state with the HIV sticking to the undetectable levels. It is also to be noted that he did not take any drug to keep the virus concentration at bay.
Researchers have therefore suggested that the bone-marrow transplant might have provided a cure of some kind. The donor had the genetic mutation, known as delta 32, whereby a certain type of immune system cells which are targetted by the HIV – the CD4-T cells – is made to become resistant to the virus. The mutation entailed a different form of a cell receptor, the CCR5, which blocks entry of the virus into the cell.
However, the possibility that the radiation the patient was subject to might have destrovyed all the cells housing the HIV cannot be ignored either.
Yet another scenario that might have done away with the HIV might have involved the new immune cells made from the new bone-marrow cells wkilling the HIV content of the cells – graft-versus-host disease.
In order to find out which of the three is the answer, researchers administered the same treatment Brown was given to three monkeys. The latter were also made to be infected with the monkey-equivalent of the HIV that infects humans, the Simian-Human Immunodeficiency Virus, SHIV. The animals were also made to go through radiation, to reproduce what Brown went through during the treatment.
The results, which were published in the journal PLOS Pathogens, showed that the radiation killed most of the blood and immune cells (including the CD4-T cells). The observations also demonstrated that the transplant gave way to HIV-free cells.
However, when the monkeys were no more given the antiretroviral drugs which are known to keeping the HIV levels down, the virus increased again in two of the monkeys.
The results did show that radiation might reduce HIV but it is not adequate to kill all of the virus on its own. Therefore, the conclusion was that, either the rare genetic mutation of the donor might have played a fundamental role in keeping the HIV down, or that the graft-versus-host disease, whereby the new immune cells produced killed the remaining of the HIV reservoirs, might have done the trick.