VOL. 123 | NO. 100 | Wednesday, May 21, 2008
Vet’s Stem Cell Work May Lead To Human Treatments
Scott Shepard | Special to The Daily News
LIFE FORCE: Memphis veterinarian Kathy Mitchener gives a German shepherd named Blue an acupuncture treatment for arthritis. Mitchener also uses stem cell treatments to help animals regain mobility. -- PHOTO BY SCOTT SHEPARD
A medical technology that’s been highly controversial for humans is having significant, positive results for veterinarians and the animals they treat.
Memphis vet Kathy Mitchener has performed four stem cell transplants on dogs to treat arthritis in the knees or hips; owners said they began to see improvement within days, based on their pets’ activity and range of motion. Since all human medicine begins in animals, good outcomes in pets could pave the way for further research.
Arthritis is the most common cause of disability in the United States, limiting the activities of more than 46 million people, according to the Centers for Disease Control and Prevention’s National Center for Chronic Disease Prevention and Health Promotion. The CDC estimates the ailment costs $81 billion in medical care and $47 billion in lost earnings per year, with the total cost, $128 billion, equaling 1.2 percent of the 2003 U.S. gross domestic product.
All the benefits without the guilt
Mitchener harvests a small amount of fat from the patient, which provides the source material for the transplant in what’s known as an autologous donation: the patient’s own stem cells are processed from the fat and returned to the body. The stem cells that cause controversy are harvested from embryos or aborted fetuses, raising ethical concerns about producing people in test tubes only to harvest their tissue.
“This type of treatment helps to overcome both the moral downsides associated with stem cell therapy as well as the little-discussed possibility of rejection of foreign stem cells,” Mitchener said. “Autologous adult stem cells are immunologically compatible, can be harvested through a minor procedure from a patient’s fat and have no ethical issues related to their use.”
The immune system produces stem cells specifically for repair and maintenance. Stem cells have all the genetic information of the body and take instruction from nearby cells; when Mitchener injects stem cells into an arthritic joint, the surrounding tissue tells the stem cells how to become cartilage.
Survival of the fittest
It’s unclear why in many creatures those cells get locked up in fat instead of circulating to where they are needed.
Two tablespoons of fat will yield 6 million to 8 million stem cells; the fat is sent overnight for processing by Vet-Stem Regenerative Veterinary Medicine in the San Diego suburb of Poway, Calif.
For an animal with joint arthritis that’s enough stem cells to treat three joints.
Prevalence of arthritis, 2005
Adults with arthritis: 1.3 million
Adults limited by arthritis: 608,000
Estimated cost: $3.3 billion
Adults with arthritis: 674,000
Adults limited by arthritis: 296,000
Estimated cost: $1.5 billion
Adults with arthritis: 626,000
Adults limited by arthritis: 243,000
Estimated cost: $1.4 billion
Source: The Centers for Disease Control and Prevention
Twyla Waters, a paralegal instructor at Southwest Tennessee Community College, opted for stem cell therapy for her 4-year-old German shepherd, Blue, in late January. Depending on the extent of disease, stem cell therapy costs about $4,000, comparable to a total hip replacement.
“Blue was always active; we go to Shelby Farms three times a week to run in the no-leash area,” Waters said. “One day in November I noticed she was limping on her back left leg. I thought it was muscle strain.”
X-rays showed Blue had a serious case of hip dysplasia, a degenerative disease so crippling that many dog owners ultimately choose euthanasia as the most humane treatment. Waters decided to fight the disease with stem cell therapy, believing Blue still had plenty of life in her.
Within a few days the dog was sitting better and had a stronger gait.
Mitchener said she believes the dysplasia had been festering for a long time, so Blue’s bones and muscles adapted. Today the animal gets physical therapy and acupuncture. But diagnosing arthritis in dogs is tricky.
“Dogs are genetically programmed to hide pain,” she said. “They are pack animals and in the wild the weak get left behind.”
Road to a better way
The doctor’s other patients have had outcomes similar to Blue.
Mitchener’s first stem cell patient was a 16-year-old chow, too old for surgery and so crippled that she could not squat to urinate. Three days after treatment, the dog was moving about and taking care of her business in the yard again.
The procedure is so new that proving it works is a work in progress. Pet owners are generally attuned to their animals, but also are very hopeful for improvement so they can see something that’s not there, Mitchener said. Animals also respond to their owners and may figure out how to better mask their pain.
“People invest their emotions, their hope and their money, so you have to expect a huge placebo effect,” she said.
However, a double-blinded, placebo-controlled study funded by Vet-Stem last year found that dogs treated with stem cells do, indeed, have improvements in lameness, pain and range of motion.
The procedure, available since 2003, is derived from technology first developed to regenerate torn ligaments in horses. Mitchener is prepared to treat horses but only in conjunction with a large-animal veterinarian.
She’s been a veterinary oncologist for 20 years, but hit the clinical wall three years ago when she was doing everything in her realm but still not getting the outcomes she sought, particularly pain control in animals with cancer.
She earned a certification in animal acupuncture from Colorado State University, which opened her eyes to other treatments. At a Montreal meeting last fall of the International Veterinary Academy of Pain Management, stem cells were the hot topic, and Mitchener completed the online certification course when she returned home.
Mitchener’s practice is Angel Care Cancer Clinic for Animals, housed at Shelby Center Hospital for Animals on Stage Road. That business belongs to veterinarian Robert Parker. Mitchener also operates Pins & Needles, an acupuncture clinic with a branch office in Midtown.
Quality of life
Stem cells actually have a deep connection to Memphis.
In 1998 Edwin Horwitz was part of the Division of Experimental Hematology at St. Jude Children’s Research Hospital when he answered a question that had lingered for years: Why do leukemia patients often respond to bone marrow transplants?
Horwitz discovered it was stem cells. Horwitz is now affiliated with several ventures that hope to commercialize stem cell science.
Another St. Jude hematologist, Brian Sorrentino, took it a step further. Even in the richest environments stem cells may be only one in 100,000, but Sorrentino figured out how to mark and separate them from the rest.
Mitchener likes the idea of being so close to such discoveries. Veterinary medicine, she said, is important for furthering human medicine because they have the same goals.
“I’m not only doing this to give my patients a better quality of life now,” Mitchener said. “In cancer treatment you learn that good medicine is about quality of life. Long term, I want to give my patients a healthy life as long as they own that life.”