January 15, 2021

The Niche

Trusted stem cell blog & resources

Stem cells for autism: time to hit pause in 2018?

Stem cells for autism?

After watching this area for many years, I’m not sure there’s any “there there”.

There are logical reasons to think that certain stem cells might help many specific diseases, but in my view autism isn’t likely to be one of them. I hope I’m wrong, but today at least in 2018, it’s not looking promising.

To be clear, I’m not talking about indirectly using stem cells for non-clinical trial research to provide conceptual and translational insights into autism spectrum disorder, which makes very good sense (e.g. see this paper studying autism using IPS cells and a figure from it, which showed changes in neural cell properties using IPS cells derived from autistic patients as compared to controls), but rather my concern is over transplanting stem cells into autistic patients with some expectation of benefit.

stem cells autism
Marchetto, et al. figure panel

There is no concrete, common sense connection between autism and any stem cell treatment that I can think of, but others have speculated on possible roles that infusions of stem cells could have in being helpful. Yes, something doesn’t necessarily have to make sense to work in science or medicine, but common sense sure is the best place to start an experiment.

Conversely, the lack of a solid, logical foundation is always going to be worrisome, especially when experimenting with children as the research subjects.

Since I last did a piece on autism in 2017, a couple new studies have come out but they don’t give much reason for enthusiasm on the idea of stem cells for autism. Why am I still so skeptical? I can’t articulate it much better than this list of concerns and open questions I had last year:

  • “There is no compelling, preclinical evidence that I know of that stem cells can help autism and that they would be definitely safe in kids.
  • The most common route of administration, IV into the blood stream, doesn’t make much sense to me. Do a meaningful number of cells even get into the brain that way?
  • If cells don’t get into the brain, they do something systemically that helps the autistic brain? Some folks believe that there is a definite autoimmune component to autism and that flooding the bloodstream with stem cells might reduce autoimmunity, but there’s little hard evidence for either of these ideas.
  • If yes they do get into the brain, what do the cells that get into the brain do that is helpful and where do they do it inside the brain? Which brings me to the next question.
  • What causes autism spectrum disorder? The field doesn’t really know so how can you treat it if you don’t understand it?
  • Under that umbrella “spectrum” term there are many manifestations and probably many causes so stem cells are unlikely to be an autism panacea.
  • Is there any evidence that once autism manifests that it is reversible?”

I don’t really see any new data to challenge these points or answers the questions now versus a year ago.

A central issue worth reiterating is that the causes of autism aren’t well understood so why throw stem cells at it? There are so many proposed causes of autism (and forms of autism) including some listed here at Autism Speaks and many more ideas that can easily be found on the web, but the fact is that even the top experts don’t know definite etiologies. Without better understanding of the causes of various forms of autism, things like stem cell transplants are really shots in the dark at best.

In terms of cell types, the most common focus in this area is on using umbilical cord blood or umbilical cord stem cells to try to help the symptoms of autistic children, but certain for-profits will inject just about any kind of stem cells to “treat” autism for cash.

Of course, some excellent scientists are doing real clinical trials with good intentions and again a couple new papers have reported study results. Most recently, a study in part based here in Sacramento that I covered at its start 6 years ago, reported no statistically significant positive effects from stem cells in autistic kids. This pioneering study was just recently published in Stem Cells Translational Medicine and was entitled, “Safety and Observations from a Placebo-Controlled, Crossover Study to Assess Use of Autologous Umbilical Cord Blood Stem Cells to Improve Symptoms in Children with Autism.” As a randomized, placebo-controlled, blinded study, it had a much more rigorous design than other studies that by contrast lacked controls and blinding. From the paper:

“There were also no statistically significant differences between scores on the two primary or secondary endpoints after infusion with AUCB versus infusion of placebo.”

The other study that comes to mind is the Duke, open-label, uncontrolled trial by Joanne Kurtzberg and Geraldine Dawson using umbilical cord blood published last year and now with a secondary follow up paper recently this year. The trial does not have the design (again not blinded, no controls, etc.) nor power to make clear conclusions about efficacy. Therefore, I’m concerned when I see it portrayed as indicating that umbilical cord blood helped the kids who were participants. For instance, this quote in a newspaper piece raises questions:

“And we found that about 70 percent of the children improved getting their own cord blood,” said Kurtzberg.”

This statements sounds very definitive, but are there solid data there to back up such a claim? The authors themselves wrote in their paper something that instead sounds much more neutral:

“As an uncontrolled open‐label study, it is not possible to determine whether the observed behavioral changes were due to the treatment or reflect the natural course of development during the preschool period.”

Maybe they have rigorous data that is unpublished to back up the 70% claim? 

For background you can see some of my past posts on the Duke work and other posts that at least mention it here. More specifically you can see that I was pretty skeptical 4 years ago as this study was launched and again I don’t feel any more encouraged today.

At that time, Arnold Kriegstein, Director of UCSF’s Broad Center of Regenerative Medicine and Stem Cell Research, was highly skeptical too and this quote from him hit on specific issues related to the seemingly weak rationale for this and other similar studies that still resonates today:

“These are not cells that can treat a laundry list of diseases,” he says. Because the stem cells are similar to those that normally give rise to blood cells, he says, it is unlikely that they can repair or replace neurons in the brain. Also, because autism results from errors during development, it is unlikely that the stem cells can reverse those effects.”

Another concern about the whole notion of stem cells for autism is that it indirectly helps to fuel aspects of the unproven stem cell clinic industry both here in the U.S. and in other countries, such as Panama. For-profit clinics selling stem cells for autism do a great job marketing in many ways and sometimes play off of the discussion of results from studies at universities portrayed as encouraging in the media.

While the university/medical center studies mentioned in this post have generally reported a good safety profile for umbilical cord blood for autistic patients, there are always going to be some risks. Certainly some of the stem cell clinics increase the risks with their practices including sometimes not using proper lab technique and also growing the cells in culture prior to transplantation. Furthermore, the fact is that although stem cells used in the two actual clinical trials mentioned here had solid safety profiles so far, longer term we just don’t know if there could be unanticipated risks for these kids.

More trial work specifically on stem cell infusions or similar types of transplants for autism will surely continue, but given all of this, it’s reasonable to ask, “should it?” I realize patients and families are looking for hope (I get many emails from parents), but is this a direction still worth pursuing with limited resources and energy or is it time to hit the pause button?

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