Stem cell banking: Frequently asked questions (FAQ)
Why should I use my own stem cells and not someone else's?
There are two sources of adult stem cells that can be used for regenerative medicine; allogeneic stem cells (derived from other people), or autologous stem cells (derived from yourself).
Unless you have a genetic condition or a transmissible disease; the medical scientific answer is to use your own autologous stem cells for the simple but critical reason that your body's immune system is not going to reject what it recognises as it's own; and so you are not running the 60% to 80% risks of acute to severe GVDF using allogeneic stem cells.
Using your own stem cells is more affordable. Ironically the 'one-for-many' allogeneic industrial stem cells costs more. If your body's immune system will reject the vast majority of these industrial allogeneic stem cells; then the number of cells needed by the physician will be higher, and so costs will be higher to try and achieve the same treatment endpoint. Putting this cost in perspective; ten treatments of Prochymal® MSC costs $200,000 for one pediatric course and requires 10 million allogeneic MSC per kilogram of patient bodyweight, and for the average person in the UK that means using 690-840 million cells. Using your own autologous cells typically requires between 5-30 million MSC and costs a fraction of Prochymal® - a staggering difference; and must change healthcare funder thinking.
An advantage of banking your own stem cells is that they can be immediately available if stocked in case of a sudden (stroke/heart-attack) medical need, or traumatic accident.
Why not postpone banking my stem cells until I need them?
It takes many days to process stem cells from tissues; and your physical condition may prevent you from making a self-donation of tissue due to the progression of your illness or state of injury.
As we get older, the number and the quality of stem cells in our body decreases for intrinsic and extrinsic reasons; and fewer stem cells means less body tissue maintenance and repair capability. If you've ever seen how quickly a baby's cut heals compared to those of a geriatric or diabetic (these can also become a chronic long term wound), you'll get the picture.
Stem cells age as we age (cellular failure is responsible for 90% of deaths worldwide), and for many medical scientific reasons it makes sense to capture and indefinitely store your 'biological age' taking advantage of stem cell banking as early as possible in adult life. MSC are also being used in difficult to treat HIV-1 studies for immune non-responders and have been shown to effectively improve patient immune reconstitution; although use of cell-based therapy for HIV is in its early stages, storing a healthy population of your MSC may prove invaluable one day.
What about other sources of mesenchymal stem cells; are they better?
As can be seen in the graph, adipose (fat) derived MSC come out as the sample that can be acquired latest in life to purpose, are easier to harvest, and have the greatest number of potential therapeutic uses in comparison to those obtained from umbilical cord blood and bone marrow.
Very few humans have cryopreserved their umbilical cord from birth, so generally these MSC are not accessible. This leaves autologous adipose (fat) derived and bone marrow derived MSC for adult MSC banking purposes.
Bone marrow derived MSC are the oldest and therefore most well characterised source of MSC, hence most clinical data has been based on this source. However, there are limitations: e.g., a painful acquisition process, use of extensive anesthesia during the harvest, and a much lower cell yield of MSC compared to fat. Further, bone marrow MSC have been shown to exhibit a decline in; cell numbers, proliferation; wound healing properties; and, cell differentiation potential, along with enhanced cell death traits with advancing donor age.
What about using stromal vascular fraction instead?
Stromal vascular fraction (SVF) is an initial fraction derived from an adipose (fat) sample, and as such is a tissue. SVF still requires much laboratory processing for clinical grade MSC to be obtained from this tissue. SVF has been used to reduce the rejection of fat autografts in reconstructive surgery. It's also been employed in clinical trails for heart disease, neurological and many other conditions due to MSC being present. However, SVF has consistently failed in terms of efficacy in clinical trials.
We therefore would only recommend SVF storage as a lower cost MSC tissue banking option to partly defer future costs of MSC processing from this stem cell rich 'raw material'.
What about using allogeneic embryonic stem cells later instead?
Embryonic stem cells (ESC) are highly ethically controversial due to the tissue source; and, there's a major safety issue with them. ESC don't stop growing, as the pre-birth 'off switch' is absent, hence an 'off switch' has to be engineered. Teratoma formation remains the big safety concern with ESC. If not problematical, the clinical use of ESC seems almost impossible; they're no longer considered the potential 'holy grail' of regenerative medicine.
What about using autologous iPS stem cells later instead?
Induced pluripotent stem cells (iPS) cells have been much heralded as another potential 'holy grail' of regenerative medicine. iPS behave like EPS but are engineered from an autologous skin cell biopsy that's then backward engineered to produce autologous stem cell lines. iPS solve the issues with allogeneic stem cells. However, it costs USD 50,000 plus to derive a single iPS cell line over 4-5 months in the lab. In addition to Teratoma safety concerns; iPS also escape your immune surveillance system, which is undesirable for clinical use as (e.g. viruses) might not be detected by your body's immune system leading to viremia and serious consequences.
Why reinvent your own 'medicine cabinet'?
It's difficult to see how multinational drug companies are going to engineer something better than your own stem cells or their natural secretions. So why have others reinvent what you already own today - your body's own 'medical cabinet'?
