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HIV Remission Achieved in Second Patient

06 Mars 2019

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 patients had received bone marrow transplants to treat blood cancers, receiving stem cells from donors with a rare genetic mutation that prevents HIV from taking hold.

The UK researchers say it may be possible to use gene therapy to target the CCR5 receptor in people with HIV, now they know the Berlin patient's recovery was not a one-off. Brown was treated using stem cells, effectively transplanting his immune system, because he had an unrelated cancer, and the chemotherapy was interfering with the antiretroviral drugs that had previously controlled his infection.

Any story about an HIV cure is bound to stir excitement.

"This is not a treatment appropriate for people with HIV who do not have cancer", the Treatment Action Group said in a statement. Almost one million people die annually from HIV-related causes.

"The London Patient", as he is known, had a form of blood cancer that was not responding to chemotherapy and underwent a bone marrow transplant which required a replenishment of white blood cells via stem cells.

Calling the London patient "cured" is tricky, Gupta said, because there is no standard definition for how long someone must remain free of virus and off treatment drugs. He is tested often, and his HIV viral load is undetectable. They also plan to present details in Seattle at the Conference on Retroviruses and Opportunistic Infections, which began Monday. There are now 37 million people infected with HIV, 21 million are on antiretroviral treatment, but drug-resistant strains are becoming more widespread. "After a ten year gap it provides important confirmation that the "Berlin patient" was not simply an anomaly".

Gero Hütter, the German hematologist who treated Timothy Ray Brown, said: "By repeating the procedure in another patient, there is more evidence that the "Berlin patient" is not a sole exception". Also, lead researcher Ravindra Gupta told Wired the transplant was a "last chance of survival" for a patient with Hodgkin's lymphoma.

The first man called the "Berlin patient" was later revealed to be Timothy Ray Brown, the Washington Post reported. People who have two mutated copies of the CCR5 allele are resistant to the HIV-1 virus strain that uses this receptor, as the virus can not enter host cells. The case report has been published in Nature. However, this new case adds to the evidence that using gene therapy to delete CCR5 receptors from T cells may be a feasible approach.

In some of the past transplant failures, the donor did not have a mutated CCR5, but the conditioning regimen seemed to have significantly reduced the "reservoirs" of cells in the recipient that have latent HIV infections, invisible to the immune system.

Experts have also warned that the treatment carried out is not practical or healthy for people living with HIV, reports the BBC, but could ultimately help to find a cure.

HIV Remission Achieved in Second Patient