What is Platelet Therapy
Platelet therapy falls under the umbrella of Regenerative Medicine. Regenerative Medicine is a broad term for innovative medical therapies that will enable the body to repair, replace, restore, and regenerate damaged or diseased tissues. In essence, platelet therapy stimulates the body’s natural cells to help promote healing. The most common term for platelet therapy is “platelet-rich plasma” or PRP. This term has been used loosely to describe solutions where the platelet concentration is higher than that found in whole blood. Platelet therapy has long been used in both human and veterinary medicine however only in the last decade have there been randomized controlled studies (1). Platelets are a component of blood and have been identified as a major source of growth factors. These growth factors can aid in healing and have been studied for the treatment of wounds, osteoarthritis, and pain.
How does Platelet Therapy Work
The process begins with a blood collection. Your veterinarian will collect blood from your dog, cat, or horse, and will utilize a specialized platelet therapy collection kit to concentrate your pet’s platelets. There are two methods to concentrate platelets: centrifuge spinning and gravity filtration. Only one system on the market uses gravity filtration (1): the Pall V-PET™. The rest use some version of centrifugal force. One potential advantage of using a gravity filtration system is more growth factors are left intact in the final platelet concentrate (5).
Once the platelet concentrate is produced, it can be injected directly into an injury site (surface wound or soft tissue injury such as a damaged cruciate ligament) or an arthritic joint. When introduced to the site of injury/inflammation, the platelets activate to release their granular contents which include anabolic growth factors. These growth factors help attract progenitor cells to the injury site and play a key role in stimulating tissue repair through fibroblast expansion and cellular matrix production. In other, less technical terms, when the concentrated platelets are exposed to the damaged tissue, the platelets signal additional healing cells to migrate to the affected area to begin the process of tissue repair.
Common Platelet Therapy Applications
Wound healing
Complicated wound healing is a common problem seen in veterinary medicine. Occasionally, wounds can become chronic and non-healing. Often, these wounds do not respond to traditional therapies and require routine and potentially expensive medical management. Platelet therapy, when administered directly into a wound site, functions as a tissue sealant. The platelets initiate wound repair by releasing the aforementioned growth factors (2). Platelet therapy can be utilized for surgical wounds such as surgical incisions as well as for traumatic wounds. Below is a picture of a chronic, non-healing wound on the amputated stump of a dog named Pearl. Pearl had a prosthetic leg that was rubbing excessively and caused this wound. On the left is a picture before treatment with platelet therapy. On the right is a picture 10 weeks after treatment utilizing the V-PET™ platelet therapy kit.
Osteoarthritis
Platelet therapy has also been studied in the treatment of osteoarthritis. When the platelet concentrate is delivered via intra-articular injection (directly into the joint), the platelets are exposed to inflamed joint tissue. This causes them to release their growth factors which may promote healing (3). In a randomized blinded study evaluating the use of V-PET™ as intra-articular therapy in chronic canine OA, results suggested that a single intra-articular injection of platelet concentrate resulted in significant improvement.
Soft Tissue Injury/Cruciate Ligament Tear
In the same way platelets aid the healing of joint tissues, they can promote healing when exposed to injured soft tissue such as torn cruciate ligaments. In two case reports utilizing the V-PET™ platelet therapy kit, two dogs with injured cruciate ligaments received injections of platelet concentrate into their injured knee. Both dogs went from non-weight bearing on the injured leg to walking on all fours and resuming their normal activities. This same therapy can be used with medial shoulder injuries as well.
Pain
In a recent human study, platelet therapy appeared to be more effective in controlling pain in patients with knee OA compared with other injections including saline placebo, hyaluronic acid, ozone, and steroids(4).
Summary
Platelets can be obtained and concentrated relatively quickly in your veterinarian’s office. These concentrated platelets can be administered locally where needed to aid in wound healing and to encourage regeneration of damaged tissues. Platelet therapy can serve as an alternative to potentially harmful medications, surgery, and complicated medical management.
References
1. Fahie M, Girolamo A, Guercio V, Schaffer J, Johnston G, Au J, et al. A randomized controlled trial of the efficacy of autologous platelet therapy for the treatment of osteoarthritis in dogs. J Am Vet Med Assoc (2013) 243(9):1291-7.
2. Lacci KM, Dardik A. Platelet-rich plasma: support for its use in wound healing. The Yale journal of biology and medicine (2010) 83(1):1-9. PubMed PMID: 20351977; PubMed Central PMCID: PMC2844688.
3. Fortier LA, Barker JU, Strauss EJ, McCarrel TM, Cole BJ. The role of growth factors in cartilage repair. Clinical orthopaedics and related research (2011) 469(10):2706-15. doi: 10.1007/s11999-011-1857-3. PubMed PMID: 21403984; PubMed Central PMCID: PMC3171543.
4. Shen L, Yuan T, Chen S, Xie X, Zhang C. The temporal effect of platelet-rich plasma on pain and physical function in the treatment of knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials. Journal of orthopaedic surgery and research (2017) 12(1):16. doi: 10.1186/s13018-017-0521-3. PubMed PMID: 28115016; PubMed Central PMCID: PMC5260061.
5. Hessel LN1, Bosh G, van Weeren PR, Ionita JC. Equine autologous platelet concentrates: A comparative study between different available systems. Equine Vet J. 2015 May;47(3):319-25. doi: 10.1111/evj.12288. Epub 2014 Jun 11.