Clean Run - September 2012 - 53

Recently, veterinary oncologists have promoted the use of total or partial body irradiation to treat lymphomas and leukemias. This therapy requires autologous stem cell therapy because of the diﬃculty in locating a donor that matches genetically with the recipient.

mesenchymal stem cell patient is treated for injury using one to two therapies either through intralesional injection or intravenous infusion. However, in chronic disease states, ongoing treatment as often as monthly has been necessary. There are many companies now that promote the use of adipose derived stromal vascular fractions for use in veterinary patients. Stromal vascular fractions consist of mesenchymal stem cells along with other endothelial cells, white cells, and red blood cells. The two largest in the United States are Vet Stem and Medi-Vet America. These two companies have taken very different pathways to provide mesenchymal stem cells to the practicing veterinarian. Vet Stem’s model certifies veterinarians in the adipose collection, tissue handling, and administration of mesenchymal stem cells but requires cell processing to occur in the central Vet Stem laboratory. Further information on this model and the company can be found at their website, www.vet-stem.com. Medi-Vet America’s model trains the veterinarian in the adipose collection, cellular preparation, tissue handling, and administration. This method requires the purchase of the laboratory equipment to process the adipose tissue by the individual veterinarian and recovery of the mesenchymal stem cells is same day, onsite. Further information on this model is available at the company website, www.medivetamerica.com. To date, no direct clinical trials are available comparing the two modalities. Both of these modalities employ the use of platelet concentrate/platelet rich plasma as a matrix for the isolated cells. There does appear to be a documentable enhancement by utilizing the platelet as a matrix for mesenchymal stem cells. In addition, both techniques “wake up” the stem cells through exposure to LED. Standard total therapy costs in the two systems average between $1,800 and $3,500. It is important to note that the donor of the mesenchymal stem cells matters. The FDA has stated that autologous (self donated) stem cells are a treatment that is determined between the veterinarian and the client. This does not require licensure or certification of the manufacture or production facility, nor does the veterinarian need to be licensed to practice this technique. Cells donated by an allogeneic donor (not self) do require FDA licensure just like any new drug product. MSCs, platelets, and hematopoietic stem cells can be marketed from donor animals, but their use in regenerative medicine, outside of hematopoietic support, is considered o label use. Therefore, the market is not likely to develop around allogeneic cell therapies without significant financial
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Mesenchymal Stem Cells
Mesenchymal stem cells (MSCs) are certainly the most talked about when considering cellular therapy. To understand how they work, you must first understand what they are. These stem cells are found throughout the body. Collections for this type of cell are either through bone marrow aspiration or surgical recovery of body fat (adipose). Both collections provide ample cells for use in therapy. To get a pure culture of MSCs, recovered tissues must be selectively cultured for several days to allow the MSCs to “stick” to the culture plate. MSCs are capable of maturing to muscle, nerves, cartilage, liver, adipose, and bone. These stem cells are useful in regenerative medicine because their lineage is limited. Early stem cell trials using embryonic or “younger” stem cells led to a higher than expected incidence of tumor formation at the site of infusion. The advantage over embryonic stem cells or cord blood stem cells provided by mesenchymal stem cells is actually their limited repertoire. Mesenchymal stem cells are more “tame” and less likely to initiate tumor growth. These more mature stem cells retain the ability to orchestrate the cytokine, or chemical cascade, capable of promoting healing and regeneration. As an aside, this cytokine cascade is also responsible for moderating the local tissue environment and decreasing pain in the region. This type of stem cell therapy is currently used for relief of chronic osteoarthritis, immune mediated polyarthritis, tendon injury, and ligament injury. Ongoing research at University of California Davis and Colorado State University veterinary regenerative medicine programs, as well as others, is currently exploring the differences between these harvested cells, collection techniques, and use for injury and disease. The largest portion of research has been done in equine clinical medicine. Small animal practitioners are only now growing comfortable with the use of these cells to promote healing in damaged tendons, ligaments, and joints. Regenerative medicine offers new hope to veterinarians and owners when dealing with a number of frustrating chronic diseases. Recent clinical trials using mesenchymal stem cells in the area of chronic hepatic disease, cardiac disease, and chronic renal disease suggest that we may be able to avoid the pursuit of solid organ transplant (like humans) and maintain a high quality of life for our dogs through their own mesenchymal stem cells without daily medical intervention. Inflammatory conditions like immune mediated polyarthritis, inflammatory bowel disease, and rheumatoid arthritis appear to be controlled by these cellular therapies as well. Skin regeneration for burn patients is also possible using the mesenchymal stem cells. The average
September 12 | Clean Run

http://www.vet-stem.com http://www.medivet-america.com http://www.medivet-america.com

Clean Run - September 2012

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