One man may have been cured. ‘The London Patient’ (as he is being called) was diagnosed with both HIV and Hodgkin’s lymphoma simultaneously. He was resistant to standard chemotherapy and so doctors advised more intensive chemotherapy along with a bone marrow transplant. The transplant is what appears to have cured him.
HIV enters cells by using proteins on the cell surface. Epidemiological studies have found that some people can be repeatedly exposed to HIV but never contract it. Scientists now believe that this is because they have inherited a mutation, called the CCR5-delta 32 mutation, which means a protein called CCR5 is not present on their immune cells, the same protein that is now believed to be the protein the HIV virus uses to enter cells. This meant that these people are virtually HIV resistant.
The London Patient received his bone marrow transplant from a donor who had the mutation. When his immune system regrew, the CCR5 protein was no longer present on his immune cells. The HIV virus appears to have passed, having no way to take root in his cells. In fact, the London Patient has been off ARVs (antiretroviral drugs used to suppress the HIV virus) for eighteen months and there is no detectable virus in his system.
This has happened once before, with a man called Timothy Ray Brown, also referred to as ‘The Berlin Patient’, who contracted leukemia. He too received a bone marrow transplant from a donor with the CCR5-delta 32 mutation and appears to have been cured of HIV.
Although it is not certain that this ‘cure’ has been completely successful and although it by no means will be possible for this to be used as a widespread treatment anytime soon, it is certainly a huge breakthrough in the search for a cure.