Stem Cell Tourism: A Miracle Or A Modern Quackery?
Abstract
Stem cell biology is one of science’s most promising field. Stem cell-based interventions have been showing a great potential in treating serious conditions and in facilitating tissue/organ regeneration and replacement. However, despite of its therapeutic uses, stem cell therapies may still pose risks to patients receiving them, especially when there are not enough evidences yet supporting its efficacy on various diseases and unregulated implementation of procedures by certain clinics worldwide. Nevertheless, stem cell medicine is still young and has still a lot of refinements to be done.
Keywords: Stem cell biology, stem cell-based interventions, stem cell therapies, therapeutic uses, efficacy, clinics, implementation
Stem cell research is one of science’s most promising field. Scientists have been studying the properties of stem cells and their potential use in medicine. They have been looking for various ways on using stem cells to repair or replace tissues and organ lost, and cure diseases, such as brain cardiovascular, and blood diseases (Medical News Today, 2018).
What are stem cells?
Stem cells are unspecialized cells that have the ability to develop into many different types of cells, such as blood, muscle, and nerve cells (Wan and McGinley, 2018). They are characterized by two things. First, stem cells have the ability to unlimitedly self-renew, producing new sets of stem cells. Second, they give rise to specialized adult cell types (Biehl and Russell, 2009). Furthermore, stem cells serve as a sort of internal repair system in many tissues, replacing other cells during both normal and challenged conditions (National Institutes of Health, 2018). However, not all stem cells are created equally. Some are pluripotent which have the ability to develop into all specialized cell types, such as embryonic stem cells and induced pluripotent stem cells. Others, on the other hand, are multipotent giving rise to several types of specialized cells. Multipotent stem cells include somatic or adult stem cells (Biehl and Russell, 2009).
What is stem cell tourism?
Because of its ability to turn into various types of cells, stem cells have been offering a great promise (Regenberg, Hutchinson, Schanker, and Mathews, 2009) in treating and understanding diseases, and in cell-based therapies (Cafasso, 2018). It has been gaining public interest globally (Lau et al. , 2008). Certain clinics worldwide have been offering stem cell-based treatments and services for people suffering from a wide array of conditions for tens or thousands of dollars. Despite of this and the unproven effects of these therapies, people are still flocking over these clinics (Hsci. harvard. edu, 2018). Patients have been travelling around the world in search of clinics performing stem cell-based treatments to be cured from serious conditions they are experiencing. Among these frequently visited countries are China, India, Mexico, Panama, Thailand, and Ukraine (Brown, 2012). What risk do stem cell clinics pose to patients?
Stem cell medicine is still on its early stages. Despite of this, a lot of people have been already patronizing stem cell-based services, from cardiovascular-related diseases to nervous system-related diseases, albeit little evidences supporting their efficacies.
In an article published in the New England Journal of Medicine (2016), a 66-year old man named Jim Gass developed a glioproliferative neoplasm on his spinal cord after receiving stem cell transplants at commercial stem-cell clinics in China, Argentina, and Mexico. Gass suffered from a stroke in 2009 before undergoing stem cell-based intervention from the said clinics. It was also stated in the case report that Gass was not taking any immunosuppressive medications, and that the infusions injected to him are composed of mesenchymal, embryonic, and fetal neural stem cells. As cited by Leventhal et al. (2012) in their paper, post-transplantation immune rejection of donor cells by the host immune system is a primary concern in stem cell-based therapies. Such occurrence limits the efficacy and therapeutic potential of these interventions (Robey et al. , 2008). Moreover, pluripotent stem cells like embryonic stem cells have tumorigenic potential, resulting in the undesirable formation of teratomas (Biehl and Russell, 2009). Such proliferative graft cells require assessments of genome integrity (Mandai et al. , 2017).
In a separate article published in the Washington Post (2018), a 77-year old woman named Doris Tyler had also experienced the peril of stem cell-based intervention from a clinic in Georgia. Tyler, whom was looking for a cure to her macular degeneration, received an injection of stem cells extracted from her adipose tissue. Few days after the treatment, she began experiencing blurred vision, which eventually resulted in total blindness. Surgeries conducted to save her eyesight did not succeed in repairing the damage. Similarly, three more cases about the unproven clinical trial of stem-cell treatment to macular degeneration have been reported in an article by the New England Journal of Medicine (McGinley, 2017). Injected pluripotent stem cells, such as adipose tissue-derived stem cells, into vitreous of the eyes may differentiate into myofibroblast-like cells, causing vitreoretinopathy and retinal detachment (Kuriyan et al. , 2017). Although evidences supporting the use of stem cells for treating macular degeneration is still scarce, transplanting a sheet of retinal pigment epithelial (RPE) cells from induced pluripotent stem cells have been showing positive effects (Mandai et al. , 2017).
In contrast to the previous case reports, as reported by Shroff (2016), a stem cell-based therapy conducted to a 21-year old male suffering from Crohn’s disease – a chronic inflammatory disease of the intestines related with ulcers and fistulae – showed a positive outcome. The patient was treated with human embryonic stem cells (hESC) after undergoing all possible treatment modalities. Two months of hESC therapy had already resulted to a systematic relief in the patient without any complications. A separate meta-analysis study suggests stem cell therapy has good potential with relatively low risk of adverse effects for patients with Crohn’s disease (Qiu et al. , 2017). However, such findings still entail further clinical trials with large sample size (Shroff, 2016).
Stem cell-based interventions are not only being used for treating diseases. Its applicability has been already explored in reconstructive medicine like plastic surgery. In the case reports cited by Sung et al. , (2012), adipose-derived stem cell therapy has resulted to successful reconstruction of the inflamed and necrotized nasal area after filler injection, suggesting the potential therapeutic use of ADSCs for ameliorating skin necrosis. It was also supported by the paper of Zarei and Negahdari (2017), stating that ADSCs, in combination with angiogenic growth factors, help induce the formation of new blood vessels in plastic surgeries.
Conclusion
Stem cell medicine, despite being still infant, has, indeed, opened new horizons for treating and understanding certain diseases, and tissue/organ rehabilitation. Nonetheless, safe implementation and regulation of these therapies must be systematically addressed, and further investigations on its therapeutic potential must be explored.
