Evaluation of Platelet-Rich Plasma on Hair Regrowth and Lesional T-Cell Cytokine Expression in Alopecia Areata: A Randomized Observer-Blinded, Placebo-Controlled, Split-Head Pilot Study

The randomized, placebo-controlled, split-head study involved 27 patients with alopecia areata and aimed to evaluate the effect of platelet-rich plasma (PRP) on hair regrowth and lesional T-cell cytokine expression. The study found that PRP had limited efficacy in treating alopecia areata, with the mean Severity of Alopecia Tool score not changing significantly compared to the baseline with either PRP or placebo injections. However, the mean percentage reduction in the score in the PRP arm was more than in the placebo arm (9.05% ± 36.48% vs 4.99% ± 33.88%; P = .049) at the final assessment. Additionally, the mean interferon gamma and interleukin 17 cytokine messenger RNA expression decreased, while the mean interleukin 10 and FOXP3 messenger RNA expression increased significantly after PRP treatment. The study concluded that PRP may play a role in restoring immune balance in the alopecic patches.