Effect of use of Platelet-Rich Plasma (PRP) in skin with intrinsic aging process

Background: In previous papers, we demonstrated that the treatment of human photoaged skin with stromal-vascular fraction-enriched fat or expanded adipose-derived stem cells showed a decrease of elastosis and the appearance of new oxytalan elastic fibers in dermis and an increase in the vascular network. The utilization of fat plus platelet-rich plasma (PRP) led to an increase in the vascular permeability and reactivity of the nervous component. Objectives: The purpose of this study was to analyze the histologic and ultrastructural changes of human skin after the injection of only PRP in the retroauricular area that was not exposed to sun and did not present the photoaging process, in comparison with our previous results. Methods: This study was performed in 13 patients who were candidates for facelift and whose ages ranged between 45 and 65 years. The PRP injection was performed in the mastoidea area. Fragments of skin were removed before and 3 months after treatment and analyzed by optical and electron microscopy. Results: After the injection of PRP, we observed an increase of reticular dermis thickness because of the deposition of elastic fibers and collagen, with a fibrotic aspect. A modified pattern of adipose tissue was also found at the dermohypodermal junction. Significative regenerative aspects were not found at histologic and ultrastructural analysis. The presence of foci of moderate inflammation and microangiopathy were observed. Conclusions: Treatment with PRP increased reticular dermis thickness with a fibrotic aspect. In the long term, the presence of inflammation and microangiopathy caused by PRP injection could lead to trophic alteration of the skin and the precocious aging process.