Efficacy of subcutaneous injection of platelet-rich plasma in alopecia: A clinical and histological pilot study on a rat model with a six-month long-term follow-up experience.

PURPOSE: To assess the potential of platelet-rich plasma (PRP) subcutaneous injection of to treat alopecia and to evaluate local toxicity.

MATERIALS-METHODS: Twelve Hairless rats were used. At D0, we performed systematic clinical examination and divided the rat back into four quadrants (Q). We initiated subcutaneous injection using either PRP in PRPQ+, platelet-poor plasma (PPP) in PPPQ+, physiological serum (PS) in PSQ+, or no treatment (Q4). At D7, D14, D21, and D28 but also second month (M2), M3, M4, M5, rats had exactly the same injection procedure. Follow-up with PRP efficacy and toxicity at D28 and M6 using clinical and histological evaluation was performed.

RESULTS: Hair density was significantly improved at D28 and at M6 for PRPQ+ vs PSQ+ (respectively, P = .0156 and P = .0313), PPPQ+ (respectively, P = .042 and P = .046). Significant histological improvement was observed between D28 and M6, for PRPQ+ vs PPPQ+ and PSQ+ for vessels (respectively, P = .0160 and P = .021), collagen (respectively, P = .0036 and P = .032), and epithelium (respectively, P = .0138 and P = .022) with no local toxicity.

CONCLUSION: Our study suggests that subcutaneous PRP injections using controlled concentration of platelets and leukocytes improve hair growth.