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A U.S. woman appears to be free of her HIV infection after receiving closely matched blood from a relative and HIV-resistant umbilical cord blood, researchers reported.

Following the general game plan of two European men who required bone marrow transplantation for cancer and received their transplant from donors with rare HIV-resistant blood, the middle-age woman in this case has been off antiretroviral therapy for 14 months, reported Yvonne Bryson, MD, of the David Geffen School of Medicine at the University of California Los Angeles.

The patient had developed acute myeloid leukemia while on suppressive antiretroviral therapy for her HIV, and has now been free of her cancer for 4 and a half years, Bryson said in her late-breaker presentation at the virtual Conference on Retroviruses and Opportunistic Infections.

"This is the third known case of HIV-1 remission, the first known case in a woman of mixed race, and the first known case with haplo-cord CCR5-∆32∆32 stem cell transplant," she said. "Broader use of CCR5-∆32∆32 haplo-cord transplantation should be considered to achieve HIV-1 remission and cure for persons living with HIV-1 requiring stem cell transplant for other diseases."

International AIDS Society President-Elect Sharon Lewin, MD, of the University of Melbourne in Australia, called the new case a "very exciting finding."

"A bone marrow transplant is not a viable large-scale strategy for curing HIV," she cautioned, "but it does present a proof-of-concept that HIV can be cured. It also further strengthens using gene therapy as a viable strategy for an HIV cure."

The woman had achieved undetectable HIV viral loads before her cancer diagnosis and continued to have no evidence of HIV after the stem cell transplant, Bryson told MedPage Today, adding that further testing more than a year after stopping treatment showed no sign of HIV and no sign of antiretroviral drugs.

In the two previous cases, the men in Germany and London also developed blood cancers and their treatment option was stem cell transplant, but before undergoing the transplant, their medical team scoured Europe to find a suitable donor with the CCR5-∆32∆32 variant that is resistant to HIV. Those men then became free of their HIV and were able to go off antiretroviral medication.

So when the U.S. woman developed leukemia and was scheduled for stem cell transplantation, Bryson and her team followed the script. The women underwent chemotherapy and whole body radiation therapy to destroy the her cancer-ridden blood and bone marrow so it could be reconstituted with donor stem cell transplants -- that blood came from partially matched banked CCR5-∆32∆32 cord blood (StemCyte).

She also received blood from a relative, also partially haploidentical, because there was not enough cord blood to carry the patient through the first period of reconstitution of her immune system. Eventually, the cord blood with the HIV-resistant mutation completely engrafted, Bryson explained.

Bryson said the patient's recovery was rapid -- out of the hospital cancer-free in 17 days -- and without experiencing graft-versus-host complications. She also tested negative for HIV.

"This is the third such case," said Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, commenting on the study on the TV show Conversations on Health Care. "The first one was the famous Berlin patient who subsequently expired due to his leukemia."

"This person happened to have an underlying disease that required a stem cell transplant," Fauci explained. "I don't want people to think that now this is something that can be applied to the 36 million people who are living with HIV," Fauci said. "This is much more of a proof-of-concept that one can actually get the virus out and be suppressed for a long period of time. It is not practical to think that this is something that is going to be widely available."

Fauci did say, "We do have medication now that are spectacular in reducing levels of HIV to undetectable levels for virtually unlimited periods of time, not only saving the lives and providing good quality of life for those who are being treated, but also making it virtually impossible for them to transmit the virus to others through sexual contact, merely because their viral load is so low."

"Having said that," he added, "we are always trying to cure HIV so that you don't require daily or even intermittent therapy."

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