Imagine discovering a cure for a disease that kills 2 million men, women, and children each year around the world. German doctor Gero Hütter believes he's found such a cure for AIDS. Two years ago he performed a bone marrow transplant on a 40-year-old American patient with both advanced leukemia and HIV, the virus that causes AIDS. Hütter aimed to wipe out the leukemia, but as an experimental measure, he used bone marrow from a donor who was naturally resistant to HIV (1 percent of Europeans are). Today, over two years later, his patient shows no signs of the virus. Yet the procedure remains far too risky to perform on most HIV carriers: Bone marrow transplants kill one-third of the patients who receive them.
Many doctors are even skeptical that Hütter's transplant in February 2007 totally removed the virus, since HIV is known to lie dormant in certain parts of the body (researchers are currently testing ways of knocking out these latent viruses). For now, most agree that the best avenue for treatment continues to be antiretroviral drugs, which can extend the life of an HIV-positive person for several decades. Hütter's work, though, may increase support for related techniques: One involves removing a patient's own bone marrow cells, genetically modifying them to resist HIV, and reinserting them. A California biotech company is already conducting a clinical trial to test the safety of that approach. But the expense of such therapy would likely bar it from under-developed countries where HIV and AIDS are most prevalent.
The possibility of developing embryo-free stem-cell therapies got an injection of enthusiasm this month, despite the president's March 9 announcement to restart federal funding for embryonic stem cell projects. Researchers in Canada and the UK announced they'd sidestepped a major problem in the creation of induced pluripotent stem cells (iPS cells), which can transform into any other cell type in the body. What was that problem? Since 2007 iPS cells have been genetically engineered from adult skin cells with the help of viruses, but viruses disrupt the cells' DNA and make them dangerous to implant in humans.
The new technique doesn't use viruses at all. Instead the researchers developed a gene insertion procedure that reprograms the skin cell into behaving like a stem cell-and then removes all traces of the inserted genes. The result is a versatile stem cell believed to be safe for human therapies, which could one day treat diseases like Parkinson's and diabetes. Announcing the breakthrough, U.K. research team leader Dr. Keisuke Kaji suggested the process could eliminate "the need for human embryos as a source of stem cells." Although the technique still needs improvement, Kaji said, "Nobody, including me, thought it was really possible." This month a U.S. team said it also had produced virus-free iPS cells using a different process.
The ever-mutating influenza virus turned out especially shrewd this season: It developed a surprising resistance to prescription drug Tamiflu and circled the globe in one year. Medical researchers want to outsmart it (again) by making a "universal" flu vaccine, one that would be effective against many strains of the virus, even H5N1 "bird flu." Teams in Japan, the United States, and Great Britain are experimenting with antibodies that target nontraditional parts of the virus. Human trials are already underway, but a universal vaccine likely won't be ready for public use for several more years.