Abstract
Stem cells portend promising cell-based modalities for treating a variety of illnesses.
Animal models and, in certain instances, limited clinical trials suggest effective
interventions for diseases like myocardial infarction and heart failure, Parkinson’s
disease, multiple sclerosis, sensorineural hearing loss, spinal cord injury, and even
perinatal conditions like periventricular leukomalacia. Properties of stem cells that are
essential to many of these applications include:
- certain cell lines exhibit pathotropism, the ability to home into areas of disease
activity, providing a means of selectively targetting diseased tissue.
- stem cells can be induced to engraft into host tissues. Subsequently, engrafted
donor cells may support or restore biologic functioning of damaged tissues
through a variety of hypothesized local effects, including:
 differentiation into local cell-types (explain more?)
 differentiation into non-local cell-types, altering the physical
properties of the tissue.
 release of local (paracrine) factors supporting cellular regeneration
 potentiate endogenous repair mechanisms
 fusion with local cells
 modulation of the local inflammatory response
- stem cell lines are self-renewing. Stem cells can be cultured in sufficient
quantities to provide cellular grafts.
- Stem cells are potential vectors for genetic engineering.
Their therapeutic promise notwithstanding, unknowns and potential risks forestall broad
access to cell-based therapies. Animal models and clinical studies report functional and
symptomatic benefits for cardiac transplants with bone marrow stem cells and skeletal
muscle stem cells. Animal models suggest benefits from transplantation with ACS,
mesenchymal cells, and embryonic stem cells. However, the optimal cell types, patient
selection and delivery protocols, comparative efficacies, mechanisms of action, and
longer term risks of these treatments are largely unelucidated. Two particular risks relate
to embryonic stem cell transplants, which, necessarily, are allogeneic: immunogenicity,
and teratoma formation. In many cases, scant knowledge of disease pathogenesis limits
the ability to understand or predict the effects of stem cell therapies. Adjunctive
technologies have not advanced to a sufficient stage for rigorous evaluation of these
therapies on a trial basis, let alone support of broad access. Current imaging technologies
are limited in their abilities to detect, localize, and quantify the transplanted cells in vivo,
so that transplant engraftment and survival can be analyzed clinically. Beyond that,
standardized protocols for acquisition, expansion, storage, distribution, and quality
assurance of stem cell lines are in their infancy. These unknowns might be tolerable for
clinical trials, where clinical consent guidelines are rigorous, studies are carefully
scrutinized for scholarly merit, and where the unusual risk knowingly accepted by
patients is justified by potential patient and social benefit. However, there is widespread
agreement that stem cell therapeutics are unready for routine access outside of clinical
trials.
Yet numerous organizations are providing exactly this sort of access, to patients who are
willing and able to pay their prices and travel to their clinics, often located in locales
where regulation is more lax or loosely enforced. EmCell, in Ukraine, provides
embryonic stem cell transplantation, applying “several kinds of cell suspensions
comprising different kinds of stem cells of different embryonic layers” against a long list
of diseases that ranges from impotency to lymphoma. Medra Inc. provides “human fetal
stem cell therapy”. On their websites, EmCell and Medra list neither contraindications
nor risks of treatment, except to mention that immune rejection and graft versus host
disease do not apply. Costs of treatment, borne entirely by the patient, are $10 000 to $15
000 and $25 000, respectively.
This poster will identify organizations offering stem cell therapies by internet search.
Commercial websites will be archived and analyzed, with particular attention to the
- nature of treatment offered and conditions of access
- therapeutic claims
- indications
- substantiation and evidence
- risks
- providers
- aesthetic website impression
We hypothesize that many of these sites will feature misleading and unsubstantiated
claims, understated risks, and spurious indications. Documenting and analyzing stem cell
offerings will demonstrate potential dangers to patients and to the public attendant on
biotech hype and commercialization. Premature offerings that blur the line between
“quackery” and legitimate science may set unrealistic public expectations, with
implications for public attitudes towards the clinical research community and government
regulators. Finally, the commercial nature of today’s stem cell offerings may be
predictive of a commercial “frenzy” waiting on the heels of successful clinical trials.