Autism: The Role Of Stem Cells

Potential of Stem Cell Treatments for Autismof CD34+ stem cells [reviewed in 1]. Umbilical cord
In June of 2007 an article was published in ablood has highly active CD34+ cells that, following
peer-reviewed journal (1) proposing a role for steminjection into a patient, should induce angiogenesis in
cell therapy in treating autism. The account thatareas of cerebral hypoperfusion. Consequently
follows provides a perspective on the implications andimproved blood flow and oxygen to the brain should
prevalence of autism, as well as a synopsis and aalso improve nervous system functioning.
critique of the proposed use of stem cells to treat
the major symptoms of autism disorder.Safety: Allogeneic cord blood CD34+ cells are needed
Autismif this therapy is to be made available for widespread
Autism is a complex brain developmental disorderuse because few, if any, patients will have access to
that is characterised by impaired social interactions,autologous cord blood. Safety concerns regarding
communication difficulties, obsessive attachment toallogeneic CD34+ cells centre on fears of graft / host
routines and repetition, and often an extreme dislikereactions. It is believed that allogeneic cord blood cells
of certain sounds, textures and tastes. Autism usuallycan not be used without immune suppression
surfaces in the first three years of life and may varyhowever Riordan et al (6) have recently published an
in severity from mild to disabling. Depending onaccount of the feasibility of cord blood cells
degree of severity, some children with autism mayadministration in absence of immune suppression.
develop into independent adults with full timeAlso, there are reports of stem cell treatments
employment and self-sufficiency; however this iswhere no immune suppression was used in over 500
seldom the case (2). There is no known single causepatients without a single one suffering graft vs. host
but abnormalities in brain function are generallydisease [reviewed in 1].
attributed to environmental, immunological andImmune modulation by mesenchymal stem cells
neurological factors.The treatment of immune dysregulation in autism is
Social costsexpected to profoundly influence neurological function.
It is reported as one of the fastest-growingThe ability of mesenchymal stem cells to suppress
developmental disabilities in the US, with diagnosespathological immune responses (e.g. inflammation) and
having increased by staggering proportions in the lastto stimulate haematopoiesis (blood cell regeneration)
decade (2). An estimated 1.5 million children and adultsleads to the possibility that these cells may also be
in the U.S. currently (as at 2007) have some form ofuseful for treatment of the defect in T cell numbers
autism (2). Presenting these statistics another way;associated with autism(3).
autism spectrum disorders are believed to affectSafety: The review by Ichim et al (1) suggests that
approximately 1 in 166 children (1).allogeneic mesenchymal stem cells administered to
Children with autism suffer from two majorsuppress inflammation may be used without fear of
conditions: Hypoperfusion and Immune Dysregulationimmune-mediated rejection.
Hypoperfusion of the brain in autismPractical clinical entry
Children with autism have shown impaired blood flowThe following passage is quoted directly from the
(hypoperfusion) to the brain. Hypoperfusion mayauthors' proposal in ‘Stem Cell Therapy for
contribute to functional defects not only by inducingAutism'(1) and outlines their suggestions for clinical
hypoxia (an oxygen deficit that prevents normal braintrials : "We propose a Phase I/II study investigating a
function) but also by allowing for abnormal metabolitecombination of cord blood expanded CD34+ cells
or neurotransmitter accumulation. Hypothetically, iftogether with mesenchymal stem cells for the
perfusion can be improved through the revitalisationtreatment of autism and clinical manifestations of
of blood vessels (angiogenesis), then this should alsoinflammatory intestinal disease. One of the authors
allow for metabolite clearance and restoration of(*Fabio Solano) has utilized both CD34+ and
functionality.mesenchymal stem cells clinically for treatment of
Immune dysregulation in autismvarious diseases. In some case reports, the
Successful neurodevelopment is contingent upon acombination of CD34+ and mesenchymal stem cells
normal balanced immune response. Children withwas noted to induce synergistic effects in
autism have immune systems that do not functionneurological diseases, although the numbers of
normally; instead an autoimmune response of thepatients are far too low to draw any conclusions. We
nervous system appears to prevail (3). Astrocytespropose to conduct this study based on the previous
(supportive brain cells) that normally play a critical roleexperiences of our group in this field, as well as
in regulating perfusion [reviewed in 1] and protectionnumerous other groups that have generated
against central nervous system infection, have theanecdotal evidence of stem cell therapy for autism
potential to cause damage to the host whenbut have not published in conventional journals. We
functioning in an aberrant (i.e. auto-immune) manner.believe that through development of a potent clinical
Autistic children often have continually suppressedstudy with appropriate endpoints, much will be
immune systems and chronic inflammation. Immunelearned about the pathophysiology of autism
dysregulation is very apparent in gastrointestinalregardless of trial outcome."
health - most autistics experience symptoms rangingCautionary arguments
from diarrhea, gas, and bloating to intestinal lesionsWhile the rationale for using stem cells to treat
and inflammation of their gastrointestinal systemautism is indeed sound, many proponents of stem cell
(3,4).treatment for autism (6,7,8,9) are in agreement that
Autism treatmentsclinical trials with sufficient patient numbers are
At this time there is no universally-accepted therapyneeded to assess treatment efficacy. When patients
or cure for autism. Current approaches are eitherand their families consider new treatments, the
behavioural, medical (treatment of anxiety andproposals need to be interpreted in a discerning
depression), nutritional (restriction ofmanner that can be balanced with scientific evidence.
allergy-associated dietary components/REFERENCES
supplementation of minerals and vitamins/antioxidant1. Review: Stem Cell Therapy for Autism Thomas
therapy) or a combination of these. Research hasIchim, Fabio Solano, Eduardo Glenn, Frank Morales,
increasingly focused on the connections between theLeonard Smith, George Zabrecky, Neil H Riordan
immune system and the nervous system (4) yet toJournal of Translational Medicine June 2007, 5:30
date no approach has been successful in correcting2. Alliance for Stem Cell Research
immune dysregulation/chronic inflammation in autism.3. The immune response in autism: a new frontier for
Rationale for using Stem Cells to treat autismautism research Paul Ashwood, Sharifia Wills, Judy vd
The administration of CD34+ umbilical cord cells andWater Journal of Leukocyte Biology. 80:1–15;
mesenchymal cells are proposed as novel treatments2006
for the two pathologies associated with autism –4. The Stem Cell and Autism Connection
hypoperfusion to the brain and immune dysregulation5. Autism: stemcelltherapies.org
(1). Using these two kinds of stem cells together6. Cord blood in regenerative medicine: do we need
may potentially heal both the brain and the gut (3,4).immune suppression? Riordan N, Chan K, Marleau A,
Treatment of hypoperfusion defect with umbilicalIchim T. Journal of Translational Medicine. Jan 2007 5:8
cord blood CD34+ stem cells7. Kristina Chew, July 2007
Angiogenesis - the formation of collateral blood8. (publication is equivalent to Review: Stem Cell
vessels - is believed to be fundamental in neurologicalTherapy for Autism Ichim et al.)
recovery. A promising method of increasing9.
angiogenesis into damaged areas is by administration