Tests show no trace of the man’s previous HIV infection after stem cells donation
A man in Britain has become the second known adult worldwide to be cleared of HIV after he received a bone marrow transplant from a virus-resistant donor, his doctors said.
Almost three years after receiving bone marrow stem cells from a donor with a rare genetic mutation that resists HIV infection – and more than 18 months after he came off antiretroviral drugs – highly sensitive tests still show no trace of the man’s previous HIV infection.
“There is no virus there that we can measure. We can’t detect anything,” said Ravindra Gupta, a professor and HIV biologist who co-led a team of doctors treating the man. He described his patient as “functionally cured” and “in remission”, but cautioned: “It’s too early to say he’s cured.“
The man is being called “the London patient”, in part because his case is similar to the first known case of a functional cure of HIV, “the Berlin patient” – American Timothy Brown, who underwent similar treatment in Germany in 2007 which also cleared his HIV. He is still HIV-free.
The Aids pandemic has killed about 35 million people worldwide since it began in the 1980s and about 37 million people are infected with HIV. Scientific research into the complex virus has led to the development of drug combinations that can keep it at bay in most patients.
Gupta, now at Cambridge University, treated the London patient when he was working at University College London. The man had contracted HIV in 2003, Gupta said, and in 2012 was also diagnosed with a type of blood cancer called Hodgkin’s lymphoma.
In 2016, when he was very ill with cancer, doctors decided to seek a transplant match for him. “This was really his last chance of survival,” Gupta said. The donor – who was unrelated – had a genetic mutation known as CCR5 delta 32, which confers resistance to HIV.
The transplant went relatively smoothly, Gupta said, but there were some side effects, including the patient suffering a period of “graft-versus-host” disease – a condition in which donor immune cells attack the recipient’s immune cells.
Most experts say it is inconceivable such treatments could be a way of curing all patients. The procedure is expensive, complex and risky. Exact match donors would have to be found in the tiny proportion of people – most of them of northern European descent – who have the CCR5 mutation.
Specialists said it was not yet clear whether the CCR5 resistance is the only key – or whether the graft-versus-host disease may have been just as important. The Berlin and London patients both had this complication, which may have played a role in the loss of HIV-infected cells, Gupta said.
He said his team planned to use these findings to explore potential HIV treatment strategies. “We need to understand if we could knock out this [CCR5] receptor in people with HIV, which may be possible with gene therapy,” he said.
The London patient, whose case will be reported in the journal Nature and presented at a medical conference in Seattle on Tuesday, has asked his medical team not to reveal his name, age, nationality or other details.