INTRODUCTION
Platelet-rich plasma (PRP) is a blood-derived product containing a higher concentration of platelets in plasma relative to whole blood, which supports its rejuvenating effects. The use of PRP from a patient's own blood (autologous) to promote tissue regeneration began in the 1980s as a technique to hasten recovery from surgery, but in the last 20 years, its use has expanded into numerous applications including wound care, aesthetics, and androgenetic alopecia.1-3 With the increased utility of platelet isolates, the quality of PRP and platelet-poor plasma (PPP) is being evaluated with more rigor as it relates to platelet concentration, growth factor release, and clinical outcome.
The rejuvenating effect of PRP owes to the many growth factors, hormones, nutrients, and protein stabilizers (such as albumin), that naturally elicit cellular and tissue regeneration.4 The required concentration and relative proportion of each differs according to the intended procedure.5 The various PRP systems currently produce biologic matrices with a range of platelet counts and differing degrees of leukocytes and erythrocytes. It is necessary to standardize preparations to ensure reproducibility and create targeted biologic matrices that are specific to the therapeutic niche.
PRP innovations have a longstanding history of continued safe use. Commercially available kits for the production of PRP are now more specific to their intended application. Thus, great caution should be taken by any PRP or PPP therapist when it comes to using tubes or devices that are not cleared by the US Food and Drug Administration (FDA) for the preparation of platelet plasma at the patient’s point of care. The FDA has provided guidelines on its collection and the appropriate types of medical devices.6
To suit the needs of the procedure, it is important to differentiate between PRP and PPP. The technician may also include or exclude an anti-coagulant, to differentiate between platelet plasma and platelet fibrin.7 Furthermore, calcium chloride might be added to convert fibrinogen to fibrin in a procedure known as platelet-rich fibrin or "platelet gel."8 Considering the wide range of procedures that benefit from platelets in plasma, the production technique needs to remain versatile while maintaining high reproducibility. The precision of the technique needs to be qualified with repetitions from the same patient, because of variability of platelet count across patients, ranging from 150k to 450k platelets/μL.9 When normalized for inter-patient variability, there are many methodological factors that account for a lack of precision. In this regard, steps to optimize PRP collection, to capture platelets in the final isolate, are not widely known or practiced.
For example, a recent letter to the editor in the Journal of the American Academy of Dermatology highlights a significant lack of consistency with various technologies for PRP production, demonstrating lower platelet counts than promised by the manufacturers, including platelet concentrations lower than whole blood in many instances.10 Some solutions to these challenges were proposed in response,11 to which the original
