For-profit stem cell clinics have popped up around California in recent years, advertising that they can treat everything from arthritis to Alzheimer’s, without FDA approval.
They claim that injections of stem cells (naturally occurring “blank slate” cells that can grow into any type of cell) can help alleviate pain or illness by replacing or regenerating diseased tissue – claims that are not supported by existing research. The procedures can cost thousands of dollars out-of-pocket, and regulators have warned that patients have developed tumors, suffered infections and even lost eyesight after unapproved procedures.
No one knows how many clinics there are, but California reportedly has more than any other state. We asked Arnold Kriegstein, MD, PhD, director of the UC San Francisco Developmental & Stem Cell Biology Program, about what’s real and what’s not in stem cell medicine.
How do these clinics operate?
There has been an explosion of so-called clinics offering stem cell treatments for a wide range of ailments, none of which have been shown to be effective. They are largely unregulated. Many clinics claim that they can treat untreatable illnesses like Alzheimer's disease, autism, muscular dystrophy, or stroke. The list is quite extensive.
The majority are using fat tissue for their stem cells, obtained through liposuction. These are usually autologous cells, which means that they are taking the patient's own tissue and extracting cells to re-administer to the same patient, usually through an intravenous route. In addition to fat cells, some clinics administer bone marrow stem cells or umbilical cord or placental stem cells, which come from unrelated donors.
The clinics often advertise through testimonials from patients who've received their therapies. Many of the conditions that the testimonials address are the kinds that normally improve or fluctuate over time, such as joint pain, low back pain, arthritis, or multiple sclerosis.
The problem is that patients will receive a treatment, and then, within a month or two, they'll notice that the aches and pains in the joints are improving, and they will attribute the improvement to the stem cell therapy, when in fact it would've happened regardless.
What is the risk of trying an unproven stem cell treatment?
Reports of physical harm have included infections and the development of tumors. When using cells that are not the patient’s own, umbilical cord cells for example, immune responses can occur – often triggering inflammatory conditions.
In cases where stem cells have been delivered into the eye, blindness has been reported, and when they have been delivered to the central nervous system through lumbar puncture (spinal tap), adverse outcomes including serious infections of the central nervous system and tumors have occurred.
Then there's the emotional cost associated with raising false hope, and the financial loss that comes from exorbitant fees charged for ineffective, potentially harmful therapies.
Why aren’t there more legitimate stem cell therapies available?
Stem cells have been in the news so much over the last decade or so that I think it has created the impression that therapies are already on the market. The reality is that it is very early days for the science. The most interesting, most promising animal studies are only now beginning to be translated into clinical trials, and the process for approval of therapies takes many years and very few are likely to succeed.
Unfortunately, the public needs to be patient, but the good news is that potential treatments are progressing along the pipeline.
What are some examples of proven stem cell therapies?
For the last 50 years or so, there have been countless patients successfully treated with hematopoietic stem cells, commonly known as bone marrow transplants. This remains the prototype for how a stem cell therapy can work. Other successful examples include corneal stem cell grafts for certain eye conditions, and skin grafts for burn victims.
There are efforts to see if stem cells could successfully treat diseases like Parkinson's and diabetes, particularly type 1 diabetes. There are clinical trials testing whether stem cell therapy might work against macular degeneration, a blinding disease that is very common as people age. There are also early stage clinical trials for nervous system disorders including stroke, spinal cord injury, and ALS (Lou Gehrig’s disease).
All of these examples are still at a very early stage, where the primary goal is to make sure that the approaches are safe. To determine if they are effective will require large, well-controlled, relatively long-term clinical trials.
What will it take to advance stem cell therapy into more real treatments?
This is where basic research comes in. The field is evolving quickly, there's much to be done, and there's still a huge amount of promise in stem cell therapies down the road. But it's going to take a lot of very careful and very laborious research before we get there.