Platelet-Rich Plasma (PRP): Current Applications in Dermatology

Jason Emer, MD

Disclosures

Skin Therapy Letter. 2019;24(5):1-6. 

In This Article

Harvesting Platelet-rich Plasma

There are many commercially available PRP systems and kits, and protocols vary according to brand name and treatment indication (Table 2). Traditionally accepted preparations involve initial venipuncture to obtain 10 to 22 mL of whole blood, which is combined with an anticoagulant agent. Centrifugation then separates the whole blood sample into three layers: red blood cells (RBCs), platelet-poor plasma (PPP), and the of-interest PRP layer. Subsequent centrifugations isolate and harvest the PRP layer, while discarding the RBCs and PPP. The now concentrated PRP pellet may be treated with calcium chloride or thrombin to activate the platelets (many harvesting systems do not require activation), releasing alpha granules and growth factors. For the most common dermatological uses, activation is not required, as a more viscous substance (once activated) is better suited for wound healing, post-surgical healing, and orthopedic uses. Activation of growth factors occurs within 10 minutes, with nearly 100% activation occurring within 1 hour.[5] Some cosmeceutical brands have started to create "customized" skin care products that allow patients' PRP to be added to a base formulation to complete a bespoke growth factor anti-aging skin care product. However, it is not yet known for how long the activated growth factors remain viable. It is thought that changes in pH and temperature may affect the viability of PRP within a few hours after collection. Current US Food and Drug Administration (FDA) guidelines also indicate that platelets should not be used beyond 5 days after collection, due to bacterial contamination during venipuncture. Nevertheless, patient demand for such autologous customized skin care products remains high.

Platelet-rich Plasma Subtype Families

Platelet concentrations vary per harvest protocol; a platelet count of 1 million/mL is widely accepted as the necessary PRP platelet concentration for therapeutic efficacy.[6] Moreover, PRP contains plasma at concentrations 2 to 8 times greater than unaltered whole blood.[2] PRP preparations have been classified into four subtypes: pure platelet-rich plasma (P-PRP), leukocyte platelet-rich plasma (L-PRP), pure platelet-rich fibrin matrix (P-PRFM), and Leukocyte and platelet-rich fibrin matrix (L-PRFM). Aesthetic dermatology indications predominantly use the pure PRP preparation with minimal leukocyte collection.[3] The P-PRFM preparation has a lower platelet concentration and includes fibrin. The fibrin matrix created in P-PRFM binds and traps growth factors, releasing them more slowly over several days. This preparation may be used for fat grafting procedures, as it allows for sustained, prolonged release of growth factors within the grafted tissues.[7]

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