Got questions about stem cells? I’ll answer them.

Do you have a question about stem cells?

Post it in the comment sections of this blog post and I’ll do my best to answer it. If I don’t know, I’ll look into it.

The best comments/questions may end up as blog posts of their own.

Questions can be about anything ranging from molecular or cell biology to stem cell treatments to specific diseases to politics and beyond.

Fire away!


  1. With the frequent political turmoil and constant shrinking of money for research by the government along with political hurdles that face stem cells, when would you say that stem cell therapies will become more mainstream? I recall that a few years ago UC Irvine opened a stem cell clinic, which was initially hailed as a momentous achievement and a palace of hope for patients (especially for those whom modern treatments are ineffective), but sadly more of such clinics have not spawned. When do you feel that we will see another stem cell boom, like that after 2007, since I feel that stem cell advancements have become more stagnant within the past few years? Out of the different types of stem cells out there (adult, iPSCs, embryonic, etc) which ones who you feel will ultimately be the most effective and most likely to be used in the clinic in the future? I am also interested to hear your thoughts about the potential of stem cells in organ regeneration and when you feel such technology will be available to patients?

    Thanks again for your informative blogs.

    • Hi John,
      Thanks for the great questions.
      There is a quite a lot going on with stem cell research and I believe the field is gaining some momentum toward getting more treatments to patients, but speed is all relative. I just gave a lecture to med students on how stem cells will be a new part of their practice of medicine, but the timeline is not very fast. It’s frustrating, but we’ve got to do this right. On the other hand, the number of those taking shortcuts and taking stem cell-based treatments directly to patients without FDA approval is on the rise and I expect to double in the next year or so. It’s a dicey situation.
      I am a fan of all 3 main types of stem cells and I expect each to be particularly effective for certain conditions. None are a panacea.
      Stem cell-based organ regeneration is coming and it’s very exciting. Perhaps in a decade it’ll be having a significant clinical impact.

  2. Dr. Knoepfler,

    I have a 14 year old autistic son who has been through almost every biomedical and behavioral treatment known to man. My wife now has her heart set on trying Adipose-Derived Stem Cell Therapy for him.

    In doing just a little digging, this sure looks to me like another 1 in a billion shot in the dark thing that will cost a lot of money. Just like chelation and other biomedical interventions, I see some anecdotal stories of success but nothing that has been truly scientifically proven to work (we don’t even know what causes the disease, so how can we really know how to cure it!) So, I have very low expectations for any success, but I have found to keep peace at home, I have to keep trying treatments.

    My big concern centers on safety.

    Some of the questions I am looking to get answered before getting on a flight to Costa Rica…

    1.) What are the health risks associated with doing Adipose-derived Stem Cell Therapy? Several doctors and patients claim that since the stem cells come directly from the patient, there is almost no chance of any patient harm The doctors claim the greatest risk is in the liposuction surgery to get the patient’s fat cells. Is this really true? What are the potential risks of injecting one’s own adipose-derived cells into their blood stream?

    2.) Are there any specific questions I should be asking the doctors to help determine both safety and expertise of this practice? The name of the organization is “The Stem Cell Project” in the Dominican Republic. The leaders are Dr. Gene Anthony and Robert Hartsoe…both Americans.

    3.) Is the Stem Cell Project “reputable”?

    4.) assuming there is very low probability of harm, is there any plausibility that the Adipose-based stem cell therapy could really assist/help a teenage autistic boy? I realize there is no research-based proof of viability; I am just trying to understand, in laymans terms, the plausibility of success. Some basic quesitons…
    In my son’s treatment, they inject the cells into the blood stream through IV drip. How would the cells know what part of the brain to heal? Will the stem cells actually make it to the brain? In what quantity? Are there any brain injuries that have research-backed success? Which ones? What distinguished these diseases? Since researchers are still trying to determine which parts of the brain are affected by autism, how are these doctors claiming to know how to process stem cells to actually heal parts of the brain they are not even sure are damaged? What’s the science behind this treatment for Autism?

    Again, I have very low expectations for any real benefits; I really am more concerned about health risks, but any added insight into the science behind the therapy would help.

    Thanks again.

    John in North Carolina

    • Thanks for sharing your story, John. You are not alone. I’m getting more and more emails, calls, etc. from patients in the same kind of situation.
      Regarding your questions-
      1) There are quite a number of potential risks from the stem cell transplant (in descending order of likelihood): Infection. Autoimmune reaction. Cancer. Overall the risks are relatively low compared to an allogeneic therapy (where you get someone else’s cells) or to say a major surgical procedure, but odds are tricky things. If the “unlikely” risk happens to you it becomes a 100% chance, right? The liposuction can cause infection and bleeding.I think the body also views it as trauma. The biggest risk arguably is the unknown.

      2) Yes, quite a few questions. Has your work been published? If not, why not? If the answer they give is that they can’t publish because of some conspiracy against adult stem cell therapies that right there is a big red flag. Are patients at your clinic treated as part of a clinical trial? If not, why not? I would also ask them the question #4 that you asked me: how could this actually work? If you docs are Americans why aren’t you operating in the U.S.? After you isolate fat stem cells, do you grow them in culture prior to transplant? If so, do you have a GMP facility? Do you have practices in place to ensure sterility? Do you monitor the cells after growth to see their properties did not change?

      3) I don’t know. I’ve never head of them.

      4) I can see no logical basis for how such a treatment could possibly help a teen with autism. It makes no sense to me. Generally when stem cells are injected IV, the vast majority get filtered out in the lungs where they are mostly killed. Some also end up in the liver. Very few would be left to even have a chance to get to the brain. To my knowledge, most likely a few would make it to the brain, but not many especially when compared to the hundreds of billions of cells already in the brain….I would say it is like the old saying “a drop in the bucket”. Best case scenario let’s assume that a significant # of the stem cells got to the brain, I have no clear idea how they would help an autistic patient and how would the cells get to the right place? Some say the stem cells would home in on the “damage” in the autistic brain. But autism may not be due to “damage” in the classical pathological sense of the word. To my knowledge there is no real science to support this treatment.

      I’m not a medical doctor and before making decisions about your son’s health care, I’d recommend absolutely talking to your own doctors. However, as a stem cell scientist and parent myself, I can say if I were in your shoes I would not get this treatment for my child. Given essentially 0% chance of it working, the associated risks (while not overwhelmingly high relative to other procedures) are still too high. One of the biggest risks is the unknown….we do not know long term how safe stem cell transplants are…some unknown risks and negative outcomes could become apparent in a few years.

      Finally, I really like the analogy of aspirin. If you take aspirin there is risk and if you have a problem/side effect, you stop taking aspirin. As soon as you stop taking it, your body gets rid of it over a period of days so that relatively soon there is none left. Problem solved. The same is true of any traditional prescription drug. Have a problem? Stop taking it and it goes away.

      With stem cells, it’s a different story. They are alive. Once transplanted into the body, we have no control over them. Have a problem due to a stem cell transplant? Basically you are out of luck. You can’t make them go away. They can even grow and increase in # in your body. They can and will move around the body especially if given IV. There’s a reason that nature doesn’t allow fat stem cells to tool around in our bodies from one place to another naturally. For example, abdominal fat doesn’t just move to your brain or your arm spontaneously.

  3. Dr. Knoepfler, I hope I’m wrong (and your responses were terrific), but I think I smell a rat. A bit of recon tells me that John from NC is really Robert Hartsoe from NC, who is running a Yahoo group as a facilitator to recruit autistic children for a bargain basement clinic in Costa Rica. Here is a link from a DAN Doctor.

    • I don’t think so, Super. Why would a pro-clinic person ask all these questions knowing I’m probably going to lay out a logical case against the treatments?

      • I thought about that before I posted. It could be an attempt to tease out a conversation in the comments with others that might not end up being as logical or helpful as your responses. Appealing to the desperate parent.

        Frankly the odds of the parents being still at the point of desperate measures when the kid is 14 makes no sense at all based on my experience with special needs parents. At this point, overwhelmingly, they are all about acceptance and the future of the child when they can no longer care for them.

        Snake oil facilitators are getting more desperate, greedy and will try anything to talk people out of their money. The voice is way to low key,reasonable and effortless for a dad that’s been put through the mill that long, from my point of view. Looks like that clinic been around for a while so his story just seems odd to me given the kid is 14.

        • Hey Super and Dr. Knoepfler,

          No rat…I really am a father in NC with a 14 year old Autistic son. Dr. Knoepfler’s response was EXTREMELY helpful.

          Funny thing is, my wife has her heart set on going to Hartsoe’s clinic in the DR! The whole thing has smelled rotten to me for a long time, but my wife is adamant she wants to try this, and she is ready to buy plane tickets. Believe me, these are not pretty conflicts.

          Most parents of 14 year old autistic kids are past the miracle cures….but not everyone.. There is a virulent underground community of alternative medicine practitioners, coupled with irrational/desperate parents that are doing all kinds of unconventional things. I have doctors writing me and telling me their kids are seeing great improvements with these adipose stem cell procedures (funny thing is these are the same doctors doing other unconventional procedures while badmouthing the medical establishment.) I seen this movie before.

          I’ve kept low expectations of cure, coupled with a risk/reward mindset that has steered us away from the really risky/crazy procedures. I’ve got enough insight to feel confident now that this one has more significant risks, (coupled with hocus pocus science). Now, try to explain this to a desperate Mom who loves her son and has had her heart set on a “cure”…..that is the hard part….

          Thanks again for your blog….very helpful for a guy like me trying to make some decisions.

          John in NC.

          • Thanks, John. I appreciate your questions and sharing your story. My new post today on stem cells “good guys” and “bad guys” and how to tell the difference might be helpful as well. I don’t know if you want to introduce this blog to your wife. I hope it might be helpful, but I suppose could complicate things as well.

            • Just saw it (your post). I already check the Dr’s publications (there are none that I could find)

              Thanks a ton, Doc. Your advice has been very helpful.

  4. Dr. Knoepfler,

    Thank you so much for your previous replies and all of your other posts about stem cells. I have been researching into this field for months now (reading scientific studies, articles, etc.) and it is very helpful to have finally found someone that explains a lot of this stuff in a way that someone without a degree in biology can understand.

    I have several questions for you:

    1) In the case of a spinal cord injury, is there any reason to believe that getting stem cell therapy sooner rather than later would be beneficial? In other words, if the damage to the spine has already been done and there is nothing making it worse, is time an issue in getting the treatment? Or, would the treatment have the same effect if it was administered five years from now as opposed to being administered today? My reason for asking is thanks to your posts and a lot of the studies I’ve read, it sounds like waiting until a lot of the bugs are worked out of stem cell therapy is the safest way to go. But, if stem cell therapy would be ineffective in treating a spinal cord injury if the injury is four or five years old that changes things.

    2) Can you explain why autoimmune reactions are still a risk? A lot of the articles I read about induced pluripotent stem cells seemed to indicate that since such cells could be harvested from the individual’s own body this would eliminate these risks. I’ll believe when you say it is still a risk, just curious why. Perchance, could you point me to any studies on this issue as well?

    3) Have scientists found a way, or do they even think it is possible, to isolate stem cells that will only target the areas they want to target? For instance, if they are trying to target neural cells in a spinal cord injury, is it possible for them to take stem cells and differentiate them to a point in the lab to where they will only repair or replace damaged neural cells? Or, is every injection of stem cells just a soup of cells with the potential to treat and/or turn into anything (liver cells, heart cells, cancer cells, etc.). In other words, can they focus the stem cell treatments or do they think this will be a possibility in the future?

    4) In my research I can’t help but come across the testimonials. Some people are claiming to have had some incredible results. Are they all bogus? It seems hard to believe that all of these people are lying and I can’t see what they would get out of doing so (besides the clinics encouraging these testimonials obviously). I’m not one to buy something off a testimonial on an infomercial but at least some of these people seem to have had some pretty remarkable success. What’s your take on this?

    5) Lastly, in several of your posts you have mentioned people that have been seriously harmed by shady clinics claiming to be experts in stem cell therapies. Do you have more case specific information on any of these people? I would be really interested in reading about them. I have heard about a law suit in California but that is about it so far.

    Thank you so much for all you do and for taking the time to answer my questions.

    Jerel Lillywhite

    • Jerel,
      Thanks for the comment and great questions.
      1. Spinal cord injury. Based on all the data to date, timing is very crucial. A key factor in this reality is that after a spinal cord injury things change over time and it is thought that there is a unique window of time a few weeks out from the injury that may be optimal because while inflammation that immediately follows the injury has calmed down at least somewhat by that point, the environment of the spinal cord at that time may be more receptive to transplant-mediated repair. Also the injury may be progressive meaning it gets worse over time. However, there is some hope that even after the acute phase, perhaps even years later stem cells could help. I think it is just a much bigger challenge the longer the patient is out from the injury. For more on the issue of what happens after such an injury over time check out this earlier post:
      2. Immune reactions. This turns out to be trickier than scientists first thought. There’s even an iPS cell paper ( ) suggesting that at least in mice, iPS cells that should have been recognized as “self” in some cases weren’t and were attacked by the immune system. In addition, once you take cells out of the body and grow them, the antigens (the stuff immune cells respond to) could change somewhat. It is still unclear how often this could happen to the extent that it ends up changing things clinically. Another concern is related to the quality of the cell prep. If there are a lot of dead cells or debris that get injected this could stimulate a potentially dangerous autoimmune reaction. I’m guessing this would not happen very often, but it’s a risk. I need to dig, but I believe there are couple papers out there reporting immune reactions to autologous transplants. Of course for allogenic, it’s a whole different kettle of fish and there is debate over stem cells being somewhat immunoprivileged.
      3. Targeted differentiation. Scientists are getting better at differentiating pluripotent stem cells into only specific lineages (e.g. ACT’s work make RPE from ESC). I think with adult stem cells and in particular MSCs mostly they are transplanted without prior differentiation so they retain some degree of multipotency. Another issue of targeting is spatial–how do you get the cells to the right place? Will they stay there? This is not so easy. If one injects them IV, mostly they end up in the lung.
      4. I don’t think all testimonials are bogus and I do NOT believe that most patients are lying. I think many people believe they’ve been helped by stem cells and are enthusiastic to help promote the field. A small number are bad actors who are paid to promote clinics and/or direct patients to specific clinics. Getting back to real testimonials where the patients believe what they are saying, the problem is that testimonials are very unscientific. There can be placebo effects. This highlights the larger issue of these transplants occurring outside the context of real, rigorous clinical trials and a failure by most clinics to do rigorous long-term patient follow up….it makes it very hard to know if good things (or bad things) are happening. If I were a patient considering a stem cell transplant, I’d be very cautious.
      5. As you said there’s the RNL fraud lawsuit, but there’s also patients who died in Florida whose deaths may or may not be related to stem cells. There’s a baby who died in Germany. There’s a kid who died of a brain tumor. I also know there are several other instances that I will look for include in the literature. However, a big part of the risk is the unknown. Even so risk vs potential reward needs to be evaluated by each patient and their physician. I personally believe in most cases at most clinics the potential reward (benefit) of the dubious stem cell treatments is near zero so even relatively low risk may not be worth it.

      • Dr. Knoepfler,

        Thanks a hundred times over! This was very helpful and saved me (a history grad) a lot of time and effort researching a field I still don’t know a lot about yet.

        Jerel Lillywhite

  5. 1. what are the procedures a doctor would take to use adult stem cells?

    2. What kinds of treatments can adult stem cells be used for?

    3. what are some examples of what has been done in and out of our country in terms of adult stem cells research?

  6. I’m doing this essay on stem cell therapy and wondered when are stem cell therapies going to be more affordable? Please answer as soon as possible. I need it by tomorrow at 11:59 p.m.

    • It depends on what you mean by affordable. The typical unvalidated, non-FDA approved stem cell “treatment” sold today costs about $10,000-$30,000 in the US, but can sometimes be as much as $100K. The cost isn’t going to come down until supply meets demand.

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