Stem Cells and Safety

Making wide-ranging generalizations about the applicability of animal-based stem cell research, or even research on a select group of human patients is dangerous. Studies looking at autoimmune disorders, for example, have found that the down-regulation of autoimmune cells by myeloablation and stem cell therapy may indeed aid a ‘resetting’ of the immune system; they also have implications for the self-regulated death of cancer cells, meaning that stem cell therapy may inadvertently aid tumor growth in some patients. More research needs doing on this type of reaction as it appears that the time of stem cell implantation has a major effect on the anti-cancer, and cancer-promoting effects of the treatments.

The use of embryonic stem cells in treatments has also come under fire due to the potential for tumor growth after implantation. There have been a small number of reports of patients who travelled to clinics in Israel, Germany, and China developing serious complications following abnormal cell proliferation, tumor growth, or dysfunctional vascularity after stem cell treatments not approved by regulators such as the FDA. Whilst it may sometimes seem that the FDA exists purely to antagonize patients wanting a promised cure for their illness made available immediately, the painstaking process of Phase I, II, and III trials is considerably safer than allowing untested therapies to be used ad hoc.

References

John J. Pippin, M.D., F.A.C.C., The Need for Revision of Pre-Market Testing, The Failure of Animal Tests of COX-2 Inhibitors, FDA Open Public Hearing, Arthritis Advisory Committee, Drug Safety and Risk Management Advisory Committee, February 17, 2005, http://j.mp/eZSmcF

Ivana Nikiæ, Doron Merkler, Catherine Sorbara, Mary Brinkoetter, Mario Kreutzfeldt, Florence M Bareyre, Wolfgang Brück, Derron Bishop, Thomas Misgeld & Martin Kerschensteiner, A reversible form of axon damage in experimental autoimmune encephalomyelitis and multiple sclerosis, Nature Medicine online, 27 March.

Kimiskidis, V., Fassas, A., Sakellari, I., Kapinas, K.m Anagnostopoulos, A., Tsimourtou, V., Sotirakoglou, K., Kazis, A., (2011), Long-term results of stem cell transplantation for MS, Neurology, Vol.76, no.12, pp.1066-1070. http://www.neurology.org/content/76/12/1066.full