Nearly three years after he received 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.
Both the London and Berlin patients received stem cell transplants from donors carrying a genetic mutation that prevents expression of an HIV receptor, known as CCR5.
Achieving remission in a second patient with HIV using similar methods demonstrated that the first occurrence was not anomalous.
"It shows the Berlin patient was not just a one-off, that this is a rational approach in limited circumstances", Daniel Kuritzkes, chief of infectious diseases at Brigham and Women's Hospital (who was not involved in the study), told the paper.
Professor Eduardo Olavarria, from Imperial College London, said: "While it is too premature to say with certainty that our patient is now cured of HIV, he is clearly in a long-term remission".
After HIV-resistant cells from the transplant replaced the men's vulnerable cells, both men stopped taking the ARV therapy that had been suppressing their infections.
"Finding a way to eliminate the virus entirely is an urgent global priority, but is particularly hard because the virus integrates into the white blood cells of its host", said the study's lead author, Professor Ravindra Gupta from the University of Cambridge, who led the study while at UCL.
American journalist and southwest Virginia native released from Venezuelan custody
After the expulsion order, German Foreign Minister Heiko Maas said he had chose to recall Kriener to Berlin for consultations. The Trump administration refused to obey Maduro's order. "The U.S. will not stand for this kind of intimidation", he added.
"Finding a way to eliminate the virus entirely is an urgent global priority, but is particularly hard because the virus integrates into the white blood cells of its host".
The London patient received a bone-marrow transplant to treat his Hodgkin's lymphoma along with immunosuppressive drugs. Indeed, 16 months later, his virus remains at below detectable levels, and his immune cells all contain the HIV-fighting CCR5 mutation. The man suffered from post-procedure complications whereby the donor's immune cells attacked his own. Exact match donors would have to be found in the tiny proportion of people - majority of northern European descent - who have the CCR5 mutation.
The team also found that the patient's white blood cells are resistant to CCR5-dependent HIV strains, which suggests the donated cells have become engrafted.
Regular testing has confirmed that the patient's viral load remained undetectable since then. This indicates that other patients, in the same circumstances, should where possible receive transplants from a donor with this same gene mutation.
The case was published online Monday by the journal Nature and will be presented at an HIV conference in Seattle.
The case report is carried out by researchers at University College London (UCL) and Imperial College London, together with teams at the University of Cambridge and the University of Oxford.