Personalized medicine is a rapidly expanding field offering patient-specific therapies to treat disease. Autologous cell transplantation may be a form of personalized medicine that could afford many benefits in the clinical setting, such as the elimination of graft versus host disease. Transplantation of autologous stem cells may circumvent the need for immunosuppressants, which can cause many deleterious side effects to the patient. Increased availability is another advantage of autologous stem cell transplantation. Ethical controversy surrounding the collection of a patient's own stem cells is greatly reduced, thus increasing the accessibility of these cells. Unlike embryonic and fetal stem cells, harvesting autologous stem cells from the patient does not harm another organism. Embryonic stem cells carry an increased risk of tumor formation, a characteristic not exhibited in autologous adult stem cells. Increased safety and decreased ethical controversy make autologous stem cells an appealing therapeutic option for neurological disease. The debate currently surrounding not only embryonic stem cell retrieval but also stem cell usage in general has sparked issues with the usage. Obtaining cells from a patient's own body would circumvent the ethical controversy as it is not harvesting viable cells from one individual donor to another individual recipient, but it is entirely for the same patient. Additionally, these cells would not be taken in ways possibly deemed as “therapeutic cell cloning,” such as the current debate following embryonic and fetal stem cells.
Menstrual blood cells are a promising source of repair. Their immature behavior warrants migration, immunomodulation, secretion of growth factors, and, in some cases, differentiation. These properties, coupled to the angiogenic potential of the cells, make them attractive for restorative approaches following ischemic stroke, as already demonstrated by translational research [11
]. Moreover, these cells are optimal candidates for autologous therapy, following the current trend to cryopreserve biological products intended for future use. Although stromal cells have low immunogenicity due to the lack of MHC class II expression [41
], therefore enabling allogeneic application, autologous use is still preferred. Some advantages are guaranteed lack of immunogenicity, reverting in longer cell survival and no induction of local inflammatory reaction, safety, and diminished risk of ethical conflicts.
The one-week time window that follows stroke seems the best opportunity for cell therapy. While inflammation is at its best degree, there is enough time to stabilize the patient, complete physical examination and laboratory tests, discuss the therapeutic options with the patient and family, and, finally, apply the cells. Unfortunately, the time window is still short for expansion of autologous cells in vitro, as the procedure usually requires a few weeks to obtain minimum number of cells. Menstrual blood cell banking, thus, seems to be the best strategy and may become a strong competitor to the already available umbilical cord blood banks.
Safety is one important concern regarding the use of menstrual blood. Since the blood is collected through the placement of a silicone cup inside the donor's vagina, therefore exposed to microbial contamination, some precautions are required, such as refrigeration of the collected specimens and use of antibiotics [34
]. Additionally, the cells should be processed, expanded, and stored in a certified facility, under strict rules of cleanliness and safety. Additional safety measures include phenotypical verification of the cells after expansion, ensuring that they maintain the original markers and cytogenetic evaluations, excluding chromosomal aberrations and microbiological tests.
A hypothetical scenario would be a woman, in postmenopausal age, recently affected by an ischemic stroke. Due to the limited timeframe between the beginning of symptoms and final diagnosis, she would be part of the majority of patients that are excluded from tPA treatment. After further examinations, evaluation of the extension of the infarct and prognostic evaluations would be completed, estimating the degree of future, long-term disability. Finally, given the information that the patient has menstrual blood cells cryopreserved and ready for use, the therapy would be considered. After patient or familial consent, the cell banking facility would be contacted by the responsible physician, settling date and time for the infusion. The cells would be transported cryopreserved, being thawed at bedside and immediately infused intravenously, under physician supervision and cardiorespiratory monitoring. A second peripheral venous line would be available for emergency medication, if needed. After infusion, the patient would stay in the hospital during at least 24 hours, for adverse reaction monitoring, especially due to the possible toxic effects of dimethyl sulfoxide (DMSO) used in cell cryopreservation and to remaining traces of antibiotics in the cell suspension (). After discharge, periodical evaluations would evaluate the patient's progress, establishing goals for the complimentary treatments such as physical and speech therapies, nutrition, and, finally, ability to resume work.
Figure 1 Isolation and transplantation of autologous menstrual blood-derived cells. Menstrual blood cells can be collected and stored prior to injury or the development of a neurodegenerative disease. At the time of injury, the cells can then be thawed and expanded (more ...)
For a stroke-affected patient, the slightest improvement in neurological function can be decisive for self-sufficiency and, even, for ability to work, which are ultimately translated into financial independence. Therefore, investing in cell banking as a safety measure against possible future events may be a wise and even profitable step. While cell banking is already widely accessible for umbilical cord blood, only recently has it also become available for menstrual blood cells. Women in child-bearing age may donate multiple samples of menstrual blood, enabling storage of large amounts of cells for future use. As a further possibility, the cells could be expanded and differentiated into specific tissues and be ready for eventual transplantation use [42
]. An efficient banking system for menstrual blood cells would require an organized and updated registration system, enabling prompt identification and rapid retrieval of the cryopreserved cells, just in time for therapeutic application.