美国国家公共电台 NPR Researchers Question Safety, Value Of Untested Stem Cell Treatments（在线收听）

Researchers Question Safety, Value Of Untested Stem Cell Treatments 

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First, we explore stem cell treatments. Hundreds of clinics in the United States are using them to treat medical conditions. The questions are whether stem cell treatments work and whether they work safely.

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This week, the Food and Drug Administration will start considering how to regulate those clinics. NPR's Rob Stein reports.

ROB STEIN, BYLINE: If you search the web, you'll find clinics all over the country like this one in Sunrise, Fla. They offer stem cell treatments for all sorts of health problems, from arthritic joints and torn tendons to spinal cord injuries, multiple sclerosis and stroke.

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UNIDENTIFIED WOMAN: At the U.S. Stem Cell Clinic, we're utilizing what are called adipose derived stem cells, or fat-derived stem cells.

STEIN: As this promotional video makes clear, these aren't human embryonic stem cells, which are controversial because embryos are destroyed to get them. And they're not the type of stem cells that scientists create in the lab.

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UNIDENTIFIED WOMAN: These are considered autologous stem cells, which means you're utilizing stem cells from your own body.

STEIN: And, the clinic claims, have amazing healing powers.

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UNIDENTIFIED WOMAN: All of these cells have different growth factors and can help to promote healing.

STEIN: And other clinics are using other kinds of stem cells from bone marrow, blood and even placentas. But there are big questions about all this.

GEORGE DALEY: There's a lot of sketchy stuff going on.

STEIN: George Daley is a stem cell researcher at Harvard. He says stem cells are really promising and someday could revolutionize medicine by providing healthy cells and tissues for damaged parts of the body. But he says we're still years away from that.

DALEY: You've got clinics springing up, taking a patient's own cells. And practitioners are then injecting these cells into arthritic joints, into spinal cords, into the brain. And there's really no evidence that this is going to work. And in fact, there are major concerns about safety.

STEIN: The procedures could cause life-threatening infections. The cells could turn into tumors or trigger dangerous reactions by patients' immune systems. And these supposed treatments don't come cheap. Paul Knoepfler is a stem cell scientist at the University of California Davis. He estimates there are more than 500 of these clinics treating as many as 100,000 patients a year in the United States.

PAUL KNOEPFLER: We're talking about really big bucks here. The therapies can run anywhere from five to $100,000 a shot.

STEIN: And they're not covered by insurance. Knoepfler thinks the Food and Drug Administration should crack down on these clinics.

KNOEPFLER: The FDA needs to step up its game on this because otherwise, this could continue to grow as an industry. And it's just going to put more and more people at risk.

STEIN: For their part, the stem cell clinics defend what they're doing. Kristin Comella is the chief scientific officer of the Florida clinic we heard about at the beginning of the story. She says they're helping a lot of sick people.

KRISTIN COMELLA: Patients should have access to their own body tissue, in particular for diseases where they have not had much success with traditional medicine. And if they are able to provide and give informed consent to move forward with these treatments, that is their right.

STEIN: Comella acknowledges that two of her clinic's patients suffered detached retinas when they had stem cells injected into their eyes. So the clinic has stopped treating eye conditions. But otherwise, Comella says, they've had no serious problems.

COMELLA: There are always risks, no matter what you're doing. Now, that being said, our group has treated more than 6,000 cases. And we've had very few safety events associated with these treatments.

STEIN: The FDA's first hearing about how best to regulate these stem cell clinics is scheduled for Thursday, followed by another two-day hearing next week. Rob Stein, NPR News.