Platelet-rich plasma (PRP) is blood plasma that has been enriched with platelets. As a concentrated source of autologous platelets, PRP contains (and releases through degranulation) several different growth factors (cytokines) that stimulate healing of bone and soft tissue. In humans, PRP has been investigated and used as clinical tool for several types of medical treatments, including nerve injury, tendonitis, myocardial injury, bone repair and regeneration, cosmetic procedures, and dental health. PRP has received popular attention due to its use in treating sports injuries in professional athletes.
In early 2010, McGowan Institute for Regenerative Medicine faculty member Johnny Huard, PhD, the Henry J. Mankin Professor of Orthopaedic Surgery Research and director of the Stem Cell Research Center at the University of Pittsburgh, met with fellow members of the International Olympic Committee in Lausanne, Switzerland, to discuss the ethics of PRP use in athletic medicine. The committee released a consensus paper with their recommendations in late 2010.
The paper addressed several issues: The basic science of PRP, the standard procedures for administering it, its uses in tissue repair, and its potential adverse effects. And then the big questions: Could PRP be used to enhance athletic performance, and if so, would that be considered cheating? Also, how do we regulate against that—or even test for it—since these would be [one's] own cells? The authors said much larger, better-controlled studies are needed to know whether PRP truly speeds healing and whether it is effective in the long-term.
"If we understand why it works, then we can understand why sometimes it doesn't work," said Dr. Huard, as reported by Kay Lazar, The Boston Globe.
Dr. Huard's research focuses on ways to repair diseased and damaged muscles and cartilage, including those weakened by injuries and by aging. In particular, he is working on muscle injuries, which are one of the most frequent types of sports-related injuries. Scar tissue formed after an injury often slows healing and can lead to high re-injury rates and muscle weakness.
Dr. Huard has been testing several substances to determine whether they can reduce the amount of scar tissue and improve healing. His studies have suggested that the medication, Losartan, can block the formation of scar tissue in mice. Dr. Huard is planning a larger study to see whether the substance would work equally well in men and women, as well as older athletes. If it continues to show promise, he would also need to pinpoint the optimum timing for treatment.
"If you get an injury today, should I start it today, tomorrow?,'' Dr. Huard said. "Timing . . . is very important.''
Dr. Huard believes substances that block scar-tissue formation could be ready for widespread use in 2 to 5 years.
Dr. Huard is also a professor in the Departments of Orthopaedic Surgery, Molecular Genetics, Biochemistry, Bioengineering, and Pathology. Dr. Huard is deputy director for cellular therapy at the McGowan Institute for Regenerative Medicine and an associate director of the Pittsburgh Tissue Engineering Initiative. Dr. Huard is co-founder of Cook MyoSite, Inc., a biotechnology company.
Illustration: Stem Cell Research Center.
Extract (IOC consensus paper on the use of platelet-rich plasma in sports medicine. J. Huard, et al. British Journal of Sports Medicine; 2010;44:1072-1081)