The Appeal of Mixed Cell Therapies
What makes minimally manipulated autologous cell therapies so appealing is that they are readily available. Furthermore, for specific indications and using very precise techniques, researchers are finding evidence of anti-inflammatory benefits.
One 2017, level 1, randomized control study of 111 patients with painful knee osteoarthritis (OA) found that a mixed cell therapy of leukocyte-poor platelet rich plasma (PRP) injections tamped down OA inflammation.
The level 1 study compared PRP to hyaluronic acid injections.
The investigators, led by Brian J. Cole[1], Vasilli Karas[2]and Kristen Hussy[3]reported that while there was no difference between HA and PRP at any time point in terms of the primary outcome measure—the patient-reported WOMAC pain score—there were significant improvements in other patient-reported outcome measures, with results favoring PRP over HA.
The investigators specifically measured a decrease in two proinflammatory cytokines, which suggest that the anti-inflammatory properties of PRP may contribute to an improvement of symptoms.
Other studies using leukocyte-rich platelet plasma also reported measurable anti-inflammatory effects in knee OA patients.
Leukocyte-poor or leukocyte-rich?
AAOS Jumps In
In February 2018, key academic and clinical thought leaders convened at Stanford University to tackle the toughest issues swirling around these biologic therapies. The two-day event supported by AAOS and Stanford Orthopedic Surgery was awarded an NIH U13 grant. Symposium Chair Dr. Constance R. Chu explains that “we brought together full-time clinicians with stem cell and clinical trials scientists, as well as government leaders in regulatory and funding agencies into an engaged and cohesive work group to provide consensus recommendations concerning the use of biologics to treat musculoskeletal conditions.”
From February 15 – 17, 2018, symposium participants confronted the biggest issues in commercializing biologic therapies.
For example, regarding “stem-cell” marketing and PRP-type therapies they wrote:
“The use of centrifuge-like devices and other mechanical methods to prepare minimally manipulated autologous cell preparations has been extended to fat, placenta, and many other tissues. These uncharacterized cell products have been marketed as stem cells and used to treat a long list of clinical conditions ranging from hair loss to retinopathy and, most commonly, orthopaedic applications.”
“The high prevalence of painful and disabling orthopaedic conditions such as knee OA [osteoarthritis] has also resulted in an exponential increase in the marketing of unproven biologics to relieve chronic pain.”
“Concerns over misinformation from direct-to-consumer marketing of unproven treatments have led to recent calls to action from professional organizations including the National Academy of Sciences, the International Society for Cellular Therapy (ISCT), the American Association for the Advancement of Science, and the AAOS.”
The symposium’s resulting paper; “Optimizing Clinical Use of Biologics in Orthopaedic Surgery” is available here:
Authors and symposium participants were academic and private practitioners, basic and clinical scientists from academia, patients, representatives from the AAOS, the National Institutes of Health (NIH), the American Orthopaedic Society for Sports Medicine, the Arthroscopy Association of North America, the International Cartilage Regeneration and Joint Preservation Society, young investigator selected through a competitive process and keynote speakers from the National Institutes of Standards and Technology, the Stanford Center for Innovative Study Design, and the FDA.
