Q My Labrador retriever is 12 and is in generally good health for his age. But he has hip dysplasia, and recently his hips have become very arthritic. I have heard that stem cell therapy is now being used to treat arthritis in dogs. How does this work and what is your opinion of this option?
A: The use of stem cells falls into an emerging field known as regenerative medicine. This is the use of biologic products to enhance the body's ability to repair itself. Biologic materials, which include stem cells, are expected to fulfill myriad tasks, namely production of new cells, stimulation of resident cells, and provision of a scaffolding to support cellular development.
What is the therapy?Our understanding of stem cell dynamics has rapidly evolved. For example, we used to think of the progression from an embryonic stem cell to a fully differentiated cell type, such as skin, as a one-way street. Current research shows us that fully differentiated cells can be turned back into embryos with the right environmental cues. This is called plasticity.
Another change is our understanding of how stem cells exert their effects. Rather than exclusively turning into the cell type they are meant to replace, such as cartilage, we know they serve to modulate their local environment and may act to reduce inflammation, recruit local stem cells and improve vascularity.
Stem cell therapy has tremendous potential in the management of musculoskeletal disease. Stem cells may be obtained from placentas, bone marrow, adipose tissue (fat), etc.
When you read about stem cells in dogs and cats, they have likely been derived from the patient's own fat, which is obtained surgically. The fat is then processed in the hospital or is sent to an outside lab, where stem cells are concentrated from the fat. The stem cells are then injected into the site of interest (arthritic joint) or given through an IV.
Does it work?The widespread, clinical application of these treatments unfortunately has preceded proof that it actually works.
Interest in the application of stem cells for everything from arthritis to spinal cord disease has exploded in veterinary medicine in recent years. This has been driven by a combination of effective marketing, anecdotal reports and a pinch of desperation. There remains, however, little objective support for it as an evidence-based therapy.
This doesn't necessarily mean it does not work. It simply means that no objective scientific studies have proven it to be beneficial.
If I (Dr. Henri Bianucci) sound like a skeptic, it's because I am. I see it as my job as a health care professional to be a skeptic and not succumb to hype and hope. My clients come to me and expect that the treatments I am proposing are based on objective data. It has always surprised me how objectivity flies out the window when we want to believe in a treatment.
I am, however, open minded about this and I do feel that despite a current paucity of objective supporting data, this therapy may be beneficial in certain cases. I do believe that we have a long way to go in further refining and standardizing the techniques before widespread application can be advocated.
Cost of therapyThere is a saying in medicine: “First do no harm.” Often this maxim is applied as justification for the use of stem cells. However, these procedures are not necessarily harmless.
Harvesting fat requires anesthesia and, sometimes, invasive surgery. Although uncommon, joint infections and allergic reactions have been reported.
Furthermore, the cost of these procedures is high. It is not “harmless” if finances are exhausted on unproven treatment modalities in lieu of more proven medical or surgical approaches. For the price of stem cell therapy in two hips, you could practically pay for a hip replacement.
Most agree that even in the best of cases the benefits of stem cells are short lived, usually under a year. So in severe cases, where all proven therapies both medical and surgical have been evaluated or applied, weight/obesity issues have been addressed, financial resources are not an obstacle, client expectations are low, and the patient can tolerate surgery and anesthesia, this may be tried.
An emerging area of research in stem cell-based tissue engineering is “In Situ engineering.” Here, the goal is to design a molecule that would attract the body's own stem cells to the area and stimulate tissue repair. This and many other breakthroughs are certainly on the horizon for this type of therapy, and as they become proven treatment modalities, we will be among the first to offer them.
Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to firstname.lastname@example.org.