Though I write frequently about potential arthritis therapies, particularly emerging treatments and those that are established but seem to have a questionable evidence base, I haven’t yet run across the therapy evaluated in a study recently published in the journal of the American veterinary Medical Association: injection of a dog’s own platelets into an arthritic joint.
Fahie MA, Ortolano GA, Guercio V, et al. A randomized controlled trial of the efficacy of autologous platelet therapy for the treatment of osteoarthritis in dogs. JAVMA 2013;243(9):1291-7.
This was a small but nicely done trial which involved dogs with documented symptomatic arthritis in a single joint. Though this is an unusual situation, since most dogs with arthritis have it in multiple joints, this population was selected to minimize confounding variables and simplify the evaluation of the test treatment.
Subjects were appropriately randomized to placebo or the test treatment, and all treatments and evaluations were done by individuals blind to the treatment group. This helps to minimize potential bias or placebo effects. At the start of the study, two subjective measures of comfort and function (questionnaires) were completed by owners, and an objective measure (amount of weight placed on the affected leg) was also evaluated. Dogs in the test group received a single injection of their own concentrated blood platelets in the affected joint, and control group dogs received a saline injection in the affected joint. The subjective and objective measures were repeated at 12 weeks after treatment.
One encouraging feature of this study was the consistency of the outcomes. Both subjective and outcome measures were statistically improved in dogs in the treatment group and not in dogs in the control group. Subjective measures improved by 55%, and the objective measure improved by 12%.
There are, of course, a few caveats. The study was quite small, and in some of the objective tests only 5 dogs were evaluated in each group. The influence of chance on the results, and the potential applicability of the results to the general population, are always uncertain with such a small number of subjects.
And there is also always the question about the clinical significance of the effect. A 55% change in perceived symptoms seems a large enough difference to be meaningful, though as always it is being assessed indirectly through the owner, so whether the discomfort experienced by the dog is truly that much improved is impossible to know. However, a 12% difference in the measure of weight bearing is quite a bit smaller, and it is not clear how significant such an improvement would be in the comfort and function of a dog with arthritis.
Overall, this is a well-done study that provides an encouraging tidbit of evidence for this particular treatment. The authors’ conclusion is supported by the data, and they do not oversell the results. Larger studies will certainly need to be done to confirm the findings, and studies of more typical patients with multiple arthritis joints and other concurrent medical conditions will be needed before we can confidently predict the results of such a therapy in the general population. As with stem cell therapy, autologous platelet therapy seems promising, but hopefully the scientific research will lead the way forward rather than the commercialization and marketing efforts for this therapy.