Adam Castillejo endured a decade of treatments and has now been free of the virus for over two years – we ask an expert to weigh in
Last year, it was announced that a man in London had been cured of HIV following a bone marrow transplant, making him the second person ever to be cured of the virus. But the ‘London patient’, as they dubbed 40-year-old Adam Castillejo, wasn’t cured using conventional HIV medication, but rather a stem cell treatment he received for lymphoma, a cancer of the immune system.
Castillejo, who has been free of the virus for two and a half years now, is the second case where stem cell transplantation has been used as a cure for HIV. The first, ‘Berlin patient’ Timothy Brown, was reported nine years ago, and while the aggressive therapy was used to treat the patient’s cancer, not their HIV, it’s thought to be a landmark moment in the quest for a widespread cure, which could pave the way for future therapies.
No longer perceived as a ‘death sentence’, the last few years have seen an increase in conversations surrounding HIV and Aids, with the likes of artist Wolfgang Tillmans and TV personality Jonathan Van Ness speaking openly about living with the disease. Last year, Frank Ocean opened his club night, PrEP+, named after the drug that reduces the risk of HIV transmission, as an homage to what could have been of the 1980s’ NYC club scene if the drug PrEP had been invented in that era.
Below, we speak to Manon Ragonnet-Cronin, a specialist in HIV at Imperial College London, who works in collaboration with the UK HIV Drug Resistance Database, to explain the treatment further.
WHAT IS THE TREATMENT?
A part of Castillejo’s cancer treatment meant that all of the cells in his immune system were removed and replaced with donor cells with a mutation resistant to HIV infection. “Most HIV needs to attach itself to the CD4 receptor and the CD5 receptor to get into the cell and become infected,” Ragonnet-Cronin tells Dazed, “but some people have a mutation in their CCR5 receptor called Delta 32, which means it’s really difficult for HIV to attach itself to the cell.” The cells in Castillejo’s immune system were replaced with donor cells with the Delta 32 mutation. “This meant that the HIV was no longer able to replicate within the patient’s cells,” Ragonnet-Cronin explains.
WHO CAN RECEIVE THE TREATMENT?
According to Ragonnet-Cronin, the treatment is only available for those who test positive for both HIV and leukemia. “In the case of the London and Berlin patients, we removed all of the CD4 cells from someone’s body, but you would never do something that risky on someone who doesn’t have leukemia too,” she explains. “When the Berlin patient had the therapy, his chances of dying just from removing his immune system was between 25 and 50 per cent.”
A breakthrough in understanding of the cellular mechanisms controlling #HIV multiplication within the body could lead to development of drug therapies and targets that could kill HIV reservoirs in the body. https://t.co/5kg0uR2ibo#hivcurepic.twitter.com/B69SXK2lKR
— defeatHIV (@defeatHIV) January 29, 2020
WHAT ARE THE MISCONCEPTIONS?
Understandably, there has been a lot of misinformation surrounding the treatment, but Ragonnet-Cronin maintains that the treatment is not applicable to HIV patients who do not have leukemia. “People get really excited because they say it’s a HIV cure,” she says, “but the exciting thing is that it’s opened the way for different ways of thinking of an HIV cure.”
WHAT DOES THIS MEAN FOR HIV PATIENTS?
Sadly, the treatment is not applicable to a majority of those affected by the virus, but Ragonnet-Cronin is hopeful: “In this context, it’s been possible to eliminate HIV from someone, so using gene therapy as a whole could also be more applicable to those who don’t have leukemia. The CCR5 receptor is a really great target.”