Follow Veterinary Practice News on Twitter at @vetpetnews A Siamese cat named Arthur is doing well after receiving a new kidney, according to veterinarians who led the procedure at the University of Georgia (UGA) Veterinary Teaching Hospital. The kidney transplant, performed on May 15, involved using stem cells harvested from the patient to optimize the cat’s acceptance of the new kidney. The surgery is the hospital’s second successful feline kidney transplant using feline adult stem cells. “To the best of our knowledge, UGA is the only veterinary facility in the world to use adult stem cells in feline kidney transplantation,” said Chad Schmiedt, DVM, a board-certified small animal surgeon who heads UGA’s feline kidney transplant program. The male cat is nearly four years old and was diagnosed with chronic renal failure about a year ago. Two other veterinary teaching hospitals had previously declined to perform Arthur’s surgery due to possible complications, according to UGA, including concerns that tests showed Arthur’s body did not absorb as much cyclosporine as desired. When Dr. Schmiedt met Arthur’s owners, he suggested using feline adult stem cells, also known as mesenchymal stem cells (MSCs), as part of Arthur’s immunosuppressive protocol. “We used feline adult stem cells in one other transplant that we did last year,” said Schmiedt, who noted a growing body of studies detailing the successful use of adult stem cells in human renal transplants. “A study published in 2012 found the use of MSCs during renal transplant surgery in humans lowered the risk of acute organ rejection, decreased the risk of infection and the patients had better estimated renal function one year after surgery.” The first cat to receive MSCs during a kidney transplant at UGA’s Veterinary Teaching Hospital is doing well a year after surgery, which was performed in 2013. “We closely follow all of our transplant cases, and stay in touch with both the referring veterinarians as well as the owners for the life of the patient,” Schmiedt said. MSCs can be derived from fat, bone marrow and neonatal tissues such as placenta or umbilical cord. Schmiedt harvested fat cells from Arthur, and the UGA Regenerative Medicine Service grew the stem cells from the fat sample prior to Arthur’s surgery. Arthur’s new kidney was donated by a cat named Joey, who had been part of a research program in the College of Veterinary Medicine. The feline transplant program at the UGA Veterinary Teaching Hospital requires that the donor cat be adopted by the recipient cat’s family. Joey and Arthur will now be lifelong playmates. “Cat owners who seek kidney transplants for their sick cats have to very dedicated,” Schmiedt said. “They will give their cat medication twice a day for the rest of its life. They also must be willing to take their cats to the veterinarian for frequent medical checkups…a significant amount of time and expense is involved in keeping the recipient and donor cats healthy. But cat lovers who will go to this extent typically are willing to extend this kind of care to all cats they own.” Arthur will continue to receive stem cell treatments. His initial treatment was given during the transplant surgery, and additional stem cells will be shipped to Arthur’s regular veterinarian, who will then give repeated doses to Arthur as he recovers. The stem cells do not replace the need for antirejection medication, UGA noted. Since Arthur’s system does not adequately absorb cyclosporine, he will take a second antirejection medication (currently mycophenolate) to help his body accept his new kidney. Schmiedt as well as UGA Regenerative Medicine Service head John Peroni, DVM, see promise in using mesenchymal stem cells in the transplant setting. “MSCs in veterinary species have been primarily used to treat musculoskeletal injury—problems with bones, tendons and joints—and those are our most frequent uses here at the UGA College of Veterinary Medicine,” said Dr. Peroni, who is also past chairman of the North American Veterinary Regenerative Medicine Association’s board. “But there is good evidence to support using stem cells to modulate the immune system and regulate inflammation. So, the transplant setting might be another optimal use for these types of stem cells.” In the broader realm of treating feline renal disease, there are ongoing studies to determine the efficacy of using stem cells to treat the disease, Schmiedt noted. Findings thus far suggest the use of stem cells does not improve kidney function, but it may slow down the progression of the disease. But in the transplant setting, Schmiedt said he feels they offer great benefits to the patient. “The only down side is harvesting the cells seven to 10 days ahead of the surgery, which adds to the cost of the transplant procedure,” Schmiedt said.
