A call for a standard classification system for future biologic research: the rationale for new PRP nomenclature.

Autologous cell therapies including platelet-rich plasma (PRP) and bone marrow concentrate (BMC) are increasingly popular options for soft tissue and joint-related diseases. Despite increased clinical application, conflicting research has been published regarding the efficacy of PRP, and few clinical publications pertaining to BMC are available. Preparations of PRP (and BMC) can vary in many areas, including platelet concentration, number of white blood cells, presence or absence of red blood cells, and activation status of the preparation. The potential effect of PRP characteristics on PRP efficacy is often not well understood by the treating clinician, and PRP characteristics, as well as the volume of PRP delivered, are unfortunately not included in the methods of many published research articles. It is essential to establish a standard reporting system for PRP that facilitates communication and the interpretation and synthesis of scientific investigations. Herein, the authors propose a new PRP classification system reflecting important PRP characteristics based on contemporary literature and recommend adoption of minimal standards for PRP reporting in scientific investigations. Widespread adoption of these recommendations will facilitate interpretation and comparison of clinical studies and promote scientifically based progress in the field of regenerative medicine.

Technical issues in harvesting and concentrating stem cells (bone marrow and adipose).

The area of regenerative medicine, through the use of cell-based or biologic therapies, affords various options even with the choice of autologous stem cells and requires the clinician to use the currently evolving science along with the art of medicine. Potential sources for stem cells are embryos, fetuses, and adults (adipose tissue or adult cells, usually from skin [induced pluripotent], amniotic fluid, cartilage, bone marrow, menstrual blood, peripheral blood, placenta, skin, teeth, synovium, or umbilical cord blood). Issues regarding the source of stem cells include ethical and political/regulatory concerns, cell frequency, ease/difficulty of extraction, ease/difficulty of graft preparation, and host reaction to the implant. The most common sources of stem cells for orthopedic conditions are adipose tissue and bone marrow. Various opinions are expressed within the medical literature for and against both of these stem cell sources. This article will review patient concerns and preparation for obtaining cells; equipment, supplies, and staffing for the procedures; techniques, pearls, pitfalls, and risks of the procedures; and the manner of/options for processing the cells.