I was struck by this story on NPR about so-called “stem cell tourists.” Stem cell tourists are parents taking their children to China for injections of stem cells in hopes of curing a wide variety of diseases. I want to convey at least in some small way what an insanely bad idea this is:
Jena Teague and her husband Terry Williams are among these new visitors. They traveled to China to seek stem-cell treatment for their blind, 7-month-old baby daughter, Laylah. She was born with optic nerve hypoplasia, or ONH — when the optic nerves fail to develop properly in the womb. Conventional medicine offers no treatment and no cure.
But Teague came across a Web site about stem-cell treatments offered by Beike Biotechnology in China and decided to try it — against advice from specialists at home in Georgia.
“None of the specialists had heard of the stem cells, of what they’re doing here. They didn’t believe it would work. They told me not to expect anything to happen out of it,” Teague says.
Nonetheless, the family traveled to the eastern Chinese city of Hangzhou, where Beike is based. They are spending $23,000 for Laylah to have infusions of stem cells harvested from umbilical cords — not the more controversial embryonic stem cells. In the U.S., cord blood stem cells are used for treating blood diseases, but are not used for treating other conditions, such as Laylah’s vision problem.
Listen to the whole thing. They have an interview with the guy who started the company.
While I don’t doubt that these parents are at their wits end trying to help their child, this is a dangerous and untested way to do it.
They are injecting these stem cells (from cord blood) either into the blood or into the CSF with no mechanism for specifying how they will become the desired cell type. The company advertises this as a sort of one-size-fits-all therapy to cure whatever ails you (from Lancet coverage):
The procedure is the same for all diseases: intravenous and/or intrathecal injections of stem cells, followed by daily infusions of growth factors. Chin describes this as “one treatment fits all”. Unusually, patients get to decide how the cells are given, which depends on their willingness to endure painful spinal puncture, and how many times the procedure is done, which depends on their budget.
That claim is just plain hookum for two reasons.
First, there is not a shred of evidence to suggest that you can just inject stem cells, and they will become whatever the hell you want. Stem cells differentiate in a certain proscribed millieu based on the presence of certain growth factors and signals from neighboring cells. Specifically in the case of the girl with optic nerve hypoplasia, you want these stem cells to become neurons and the appropriate supporting cells. There is no research to suggest that stem cells derived from cord blood are capable of doing this. We have no idea what growth factors would be necessary to make them make this transition.
Second, I would love to believe there is some magic cure for everything that ails you, but medicine doesn’t work that way. Specific medical conditions have specific pathophysiologies that require specific interventions to cure them. Specifically in the case of ONH, we don’t really know what causes it. In addition to the failure of the optic nerve to grow, patients with ONH often have a variety of pituitary hormone disturbances. (More on ONH here.) Because we don’t know what causes this disease, we should only intervene when there is considerable evidence from animals that what we are doing works. There is no such evidence in this case.
Now this company claims that people are getting good results, and the parents of the child described above report that their child is seeing better:
Dr. Sean Hu, the 40-year-old chairman of Beike Biotechnology, is a medical doctor-turned-entrepreneur with a doctorate in biochemistry from a Swedish university.
Less than three years ago, he set up Beike. Since then, 3,000 patients — most of them from China — have received Beike’s stem-cell treatments for a wide range of conditions. He says 70 percent have seen improvements, but he admits he can’t explain why.
“In the clinical areas, we know there are improvements. We don’t know the mechanism behind it,” Hu says.
That raises many concerns. Any improvement could be due to the placebo effect — or other factors besides the stem-cell therapy — and may not lead to longer-term functional gains. No rigorous, controlled clinical trials were carried out before the treatment was offered to patients. No research has yet been published in established peer-review journals overseas. And no one knows for sure what the possible risks might be.
There are several reasons to be skeptical of claims of improvement in these cases. With respect to the child with optic nerve hypoplasia, ONH does spontaneously improve in some cases as the child gets older regardless of what you intervene or not. This point is made on an off-radio interview with Dr. Mark Borchert (scroll to the bottom), head of the vision center at Children’s Hospital Los Angeles:
What happens in children who are getting an experimental treatment?
We currently know that regardless of whether or not they are treated, at least 50 percent of children get some improvement up until five years of age. We don’t know whether they can improve beyond that.
It is totally possible that the incremental improvements the parents observed have nothing to do with the experimental treatment, but they don’t do the experiment that is the only way that we could be sure whether the treatment is effective. This is my second reason to be skeptical: none of the studies reported by this company have controls or are published in peer-reviewed journals. When you don’t have a control group, you have no idea whether the improvement was do to a placebo effect. (And as was reiterated by a meta-analysis of antidepressant medications published last month, placebo effects can be quite large.) Any peer-review of their findings would demand that they provide controls, but they haven’t done that.
Why all the fuss though? So what if it is a placebo? At least it is making the parents feel better.
While we don’t know enough about the side effects of injecting stem cells into a person, we can reasonably expect some — a number of the serious. Not the least is that in animal studies injecting stem cells into the animal can cause cancer. Stem cells are undifferentiated cells not that different from the cells that cause cancer, and it is a highly risky proposition to just put them in someone’s body. (The relationship between stem cells and cancer is reviewed here.)
(As an aside, this is still a concern in spite of the fact that these stem cell transplants do not appear to be autologous [meaning that they come from the same person]. An autologous transplant would not be recognized as foreign by the immune system. Thus, an autologous transplant would be much more likely to cause cancer because of more limited immune surveillance. However, Beike technology can’t have it both ways. You either acknowledge that immune cells are killing your transplanted cells — rendering your treatment a sham — or you acknowledge that you transplant poses a reasonable risk of cancer.)
Besides the medical risk on for the recipients, these people are lying to the parents when they suggest they have the slightest reason to believe that these injections help. Surely, these patients may improve, but there is no reason to believe that these injections made that so. Taking into account the considerable cost and this company’s exploitation of people’s ignorance, this company is doing something deeply ethically wrong.
Parents should not be subjecting their kids to this treatment, and China needs to exercise some scientific oversight over this company. Stem cells do show tremendous promise in curing numerous different diseases — ONH may well be one of them — but it shouldn’t be used until we understand how to apply the technology better. Exaggerated claims of the effectiveness of stem cells will only draw the entire field into disrepute, and it may hurt a lot of people in the process.
(Ed. I made some grammar and spelling corrections after posting this.)