Newspapers Examine Possible HIV/AIDS Treatment Through Bone Marrow Transplant
Several newspapers recently profiled the case of an HIV-positive person who underwent a bone marrow transplant to treat leukemia and who has had undetectable HIV viral loads for almost two years. For the procedure -- performed by German hematologist Gero Hutter of Berlin's Charite Medical University on a 42-year-old American living in the city -- the patient's bone marrow cells were replaced with those from a donor with a naturally occurring gene mutation that provides immunity to almost all strains of HIV by preventing the CCR5 molecule from appearing on the surface of cells. Prior to the transplant, Hutter administered a standard regimen of drugs and radiation to kill the patient's bone marrow cells and many immune-system cells, which may have helped the treatment succeed because the procedure killed many cells that harbor HIV, according to an earlier Wall Street Journal report. Transplant specialists then ordered the patient to stop taking his antiretroviral drugs when they transfused the donor cells because they were concerned that the drugs might undermine the cells' ability to survive in their new host. Although the plan was to resume the antiretroviral regimen once HIV re-emerged in the patient's blood, more than 600 days later, standard tests have not detected HIV in his blood, or in brain and rectal tissues where the virus often hides (Kaiser Daily HIV/AIDS Report, 11/7). Summaries appear below.
New York Times: According to some U.S. researchers, the treatment has "novel medical implications" but will ultimately "be of little immediate use" in treating HIV/AIDS, the Times reports. Anthony Fauci, director of NIH's National Institute of Allergy and Infectious Diseases, said the treatment is "very nice" and "not even surprising," but "just off the table of practicality." The Times reports that many researchers said the treatment is "unthinkable" for the millions of people living with HIV/AIDS in Africa and "impractical even for insured patients in top research hospitals." The patient had leukemia in addition to AIDS, which warranted the high risk of a blood stem cell transplant, but 10% to 30% of people who receive bone marrow transplants die. According to the Times, the odds of locating a donor who is both a good tissue match for the patient and has the CCR5 genetic mutation are "extremely small." Robert Gallo, director of the Institute of Human Virology at the University of Maryland School of Medicine, said, "Frankly, I'd rather take" antiretroviral drugs. However, the Times reports that the success reported for this patient is "evidence that a long-dreamed-of therapy for AIDS -- injecting stem cells that have been genetically reengineered with the mutation -- might work" (McNeil, New York Times, 11/14).
AP/Google.com: Although researchers and the physicians involved in the case caution that it "might be no more than a fluke, others say it may inspire a greater interest in gene therapy to fight the disease that claims two million lives each year," the AP/Google.com reports. Although the patient 20 months after the procedure has not shown signs of the virus, Andrew Badley -- director of HIV and immunology research at the Mayo Clinic in Rochester, Minn. -- said the tests that determine the patient's HIV viral loads likely have not been extensive enough. "A lot more scrutiny from a lot of different biological samples would be required to say it's not present," Badley said. Fauci said the procedure was too expensive and dangerous to use as a first-line therapy. However, he said it could inspire researchers to pursue gene therapy as a way to block or suppress HIV. "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," Fauci said. David Roth, a professor of epidemiology and international public health at the London School of Hygiene and Tropical Medicine, added that gene therapy as inexpensive and effective as current drug treatments is in the very early stages of development. "That's a long way down the line because there may be other negative things that go with that mutation that we don't know about," he said (McGroarty, AP/Google.com, 11/13).
Reuters: Hutter and his team said that although they have not been able to find any traces of HIV in the patient, it does not mean he has been cured. "The virus is tricky. It can always return," Hutter said. According to Reuters, the researchers said that bone marrow transplants could never become a standard HIV/AIDS treatment because the transplants are "rigorous and dangerous and require the patient to first have his or her own bone marrow completely destroyed." In addition, the procedure can be fatal because patients have no immune system until the stem cells can grow and replace theirs, leaving them susceptible to even minor infections (Reuters, 11/12).
Deutsche Welle: According to physicians at the Berlin hospital, they are continuing to monitor the patient's health and are prepared to put him back on antiretrovirals if the virus reappears. Thomas Schneider, Charite's director of infectology, said, "We cannot say with certainty that the virus won't begin replicating itself in the future," adding, "But the mere fact that it hasn't yet done so is a minor sensation" (Deutsche Welle, 11/13).