Just how safe are stem cell transplants?
Is an autologous stem cell transplant always safe?
Is it really true, as one stem cell transplant doc once said of autologous stem cell treatments, that “the worst thing that could happen is the treatment won’t work”?
Are adult stem cell treatments by definition safe?
The reality is that there are more questions than answers about the safety of stem cell treatments, and each treatment (depending on the institution, the doctor, and the patient) is likely to have a variable and perhaps unpredictable level of safety.
However, in this post I cite just three papers from 2012 that raise enough safety concerns in my mind to make me think patients should use extreme caution in decision-making.
In the first paper, Jonsson, et al, the researchers report termination (for safety reasons) of a study for the treatment of critical limb ischemia using autologous peripheral blood stem cell transplants. The study found evidence of some efficacy, but in about half of patients there were such severe complications that the study overall was terminated. Complications included heart attacks and thrombosis (blood clotting). Limitations of the study include its small size (N= 9 patients) and the age of the patients (mean ~77 years old). Still one clear take home message from this study is that “autologous” and “adult stem cells” do NOT automatically equal safe.
In the second paper, Alderazi, et al, the scientists report a case study (so by definition a limitation is that N=1 patient) in which a 17-year-old girl nearly died from intrathecal (in the spine) and IV transplants of stem cells for MS. She received both autologous and allogeneic treatment, with the procedures done in Costa Rica. The girl developed catastrophic demyelinating encephalomyelitis after the treatment, a condition where one’s immune system attacks the brain.
In the third paper, Martin-Padura, et al, researchers report that adipose stem/progenitor cells typically used in fat transfer and stem cell procedures, have a powerful pro-cancer function. What these means is that transplants of adipose MSCs could stimulate other cells to become cancer.
Bottom line. These papers each have limitations and by no means are they telling us that adult stem cell treatments are inherently dangerous in every case, but they should dispel the myth that the cells are inherently safe. These papers also illustrate why patient follow up, which for-profit clinics so often fail to do, is so critically important and should last years if not decades.