Bone Marrow Transplant May Have Cured AIDS

An AIDS victim who suffered from the disease for more than a decade appears to have been cured 20 months after receiving a targeted bone marrow transplant, normally used to combat leukemia.

Researchers at Charite Medical University (Berlin, Germany) had been treating the patient for both AIDS and leukemia, which had developed unrelated to the HIV infection. One of the researchers, hematologist Gero Huetter, M.D., while preparing to treat the patient's leukemia with a bone marrow transplant, recalled that some people carry a genetic mutation called Delta 32 that seems to make them resistant to HIV infection. If this mutation is inherited from both parents, it prevents the HIV virus from attaching itself to cells by blocking the chemokine (C-C motif) receptor 5 (CCR5). Dr. Huetter set out to find among the potential donors that matched the patient's marrow type one that carried the mutation; out of a pool of 80 suitable donors, the 61st person tested carried the proper mutation, which is present in about 1% of the European population.

Before the transplant, the patient underwent both chemotherapy and radiotherapy to destroy his own infected bone marrow cells and disable his immune system, a treatment fatal to between 20% and 30% of recipients. He was also taken off the potent drugs used to treat his AIDS, since the researchers feared that the drugs might interfere with the new marrow cells' survival. They risked lowering his immune defenses in the hope that the new, mutated cells from the marrow transplant would reject the virus on their own. The patient has since then been tested continuously for HIV in his bone marrow, blood, and other organ tissues, and remains virus-free even in known HIV "hiding spots” in the brain and rectal tissue. The patient has not received antivirals for two years.

"This is an interesting case for research,” said Professor Rodolf Tauber, M.D., Ph.D., of the Charite. "But to promise to millions of people infected with HIV that there is hope of a cure would not be right.”

"It helps prove the concept that if somehow you can block the expression of CCR5, maybe by gene therapy, you might be able to inhibit the ability of the virus to replicate,” said Anthony Fauci, director of the U.S. National Institute of Allergy and Infections Diseases (NIAID, Bethesda, MD, USA) who added that the procedure was too costly and too dangerous to employ as a first-line cure. "But it could inspire researchers to pursue gene therapy as a means to block or suppress HIV.”

Related Links:
Charite Medical University
U.S. National Institute of Allergy and Infections Diseases