Timothy Ray Brown

Procedure

In 2007, Brown, who was HIV positive, underwent a procedure known as hematopoietic stem cell transplantation to treat leukemia (performed by a team of doctors in Berlin, Germany, including Gero Hütter). From 60 matching donors, they selected a [CCR5]-Δ32 homozygous individual with two genetic copies of a rare variant of a cell surface receptor. This genetic trait confers resistance to HIV infection by blocking attachment of HIV to the cell. Roughly 10% of people of European ancestry have this inherited mutation, but it is rarer in other populations. The transplant was repeated a year later after a relapse. Over three years after the initial transplant and despite discontinuing antiretroviral therapy, researchers cannot detect HIV in the transplant recipient's blood or in various biopsies. Levels of HIV-specific antibodies have also declined, leading to speculation that the patient may have been functionally cured of HIV. However, scientists emphasise that this is an unusual case. Potentially fatal transplant complications (the "Berlin patient" suffered from graft-versus-host disease and leukoencephalopathy) mean that the procedure should not be performed in others with HIV, even if sufficient numbers of suitable donors were found.

There is now doubt however that Timothy Brown's apparent cure was due to the unusual nature of the stem cells he received. As mentioned, he suffered graft-versus-host disease. Six more people seem (as of 2017) to have been freed of HIV after getting graft-versus-host disease, and only one of them had received CCR5 mutant stem cells, so it appears that when a transplant recipient has graft-versus-host disease the transplanted cells may kill off the host's HIV-infected immune cells.

Timothy Ray Brown Foundation

In July 2012, Brown announced the formation of the Timothy Ray Brown Foundation in Washington, DC, a foundation dedicated to fighting HIV/AIDS.