Treatment with intradermal injections of autologous compared with placebo, according to a meta-analysis of seven studies.
In the report of the results, published in the Journal of Cosmetic Dermatology, Gezim Dervishi, from University Hospital Cologne (Germany), and coauthors noted that autologous PRP contains cytokines and growth factors – including platelet‐derived growth factor, vascular endothelial growth factor, and insulinlike growth factor–1 – that are believed to play a role in new hair growth. While the evidence to support the clinical efficacy of this approach is currently limited and PRP is not approved for hair-loss treatment, it is being used in clinical trials and off label for hair restoration in Europe and the United States.
The authors reviewed 13 randomized, controlled trials involving 343 people with pattern hair loss randomized to PRP control treatment, or placebo in a simple-parallel or half-head design, and assessed at 3-6 months after starting treatment. The studies were conducted in countries that included the United States, Brazil, Spain, and Italy.
The meta-analysis included seven studies that used change in hair density as the primary outcome. Six of these studies compared PRP with placebo and one compared PRP plus minoxidil or finasteride versus placebo plus minoxidil or finasteride. Five evaluated outcomes 6 months after the intervention, and two studies evaluated outcomes 3 months afterwards.
Of these seven studies, five reported statistically significant increases in hair density in favor of PRP over placebo, while the remaining two did not find any significant treatment effect. In the seven studies, the pooled mean difference in increasing hair density between treatment and placebo was 30.35 (95% confidence interval, 1.77-58.93; P less than .00001).
The 13 studies involved applications of platelet-rich plasma one to eight times over treatment periods of 1-5 months. Three studies compared PRP in conjunction with either minoxidil, finasteride, or polydeoxyribonucleotide, compared with those same therapies without PRP, and 10 studies compared PRP with either normal saline or distilled water. Five studies were judged to be at high risk of bias for at least one item, but none of these studies were included in the meta-analysis.
None of the studies identified any significant short-term treatment-related adverse effects, but the authors suggested that future studies look at potential long-term adverse effects of treatment.
“We recommend further [randomized, controlled trials] that should ensure adequate random sequence generation, adequate allocation concealment, blinding of performance and detection, and that should prevent incomplete data and selective reporting,” they wrote.
Funding and conflicts of interest statements were not available.
SOURCE: Dervishi G et al. J Cosmet Dermatol. 2019 Aug 12. doi: 10.1111/jocd.13113.