Autologous stem cells are very safe. To date, there are no publications which present stem cells as harmful. In fact, in a systematic review by Benoit et al. [3], autologous cell therapy in critical limb ischemia was found to be 100 % safe in treated patients. Meta-analysis of autologous stem cell transplantation for the treatment of limb ischemia similarly showed a 100 % safety success rate [4]. Meta-analysis of autologous stem cell transplantation for the treatment of patients with type 1 and type 2 diabetes mellitus has also shown a 100 % safety rate [5, 6]. Furthermore, autologous stem cell therapy for end-stage liver cirrhosis [7], osteoarthritis [8], and limbal stem cell deficiency [9] is reported to be 100 % safe. Subsequent clinical trials using autologous stem cell transplantation will therefore also determine that this cell source is 100 % safe.
With respect to autologous patients, some countries usually apply to repeat clinical trials for new drugs and for imported approved drugs. Indeed, they need to check the pharmacology of the drugs within the local patient population. However, for autologous stem cell therapy, the “drug” is from the patients themselves. Although the quality of the stem cell drug may differ between patients, the pharmacological effects may also differ in different patients. We therefore cannot control the quality of autologous stem cell products, meaning that efficacy may also differ between patients.