Effects of leukocyte- and platelet-rich plasma on tendon disorders based on in vitro and in vivo studies (Review)

Tendon-related disorders are common musculoskeletal system disorders in clinical practice, accounting for 30-50% of all sports-related injuries, and they are difficult to treat due to the hypovascular structure of the tendons. Platelet-rich plasma (PRP), including pure PRP and leukocyte- and platelet-rich plasma (L-PRP), has been attracting increasing attention, as it may stimulate tissue regeneration through the release of growth factors and cytokines. The aim of the present review was to provide a summary of the effects of L-PRP on tendon disorders and the underlying mechanisms through a comprehensive examination of the published literature, including in vitro, animal and clinical studies. It has been demonstrated that L-PRP results in comparatively greater pain relief and improved function in patients suffering from tendon disorders. Furthermore, L-PRP may exert its effects through a diverse range of mechanisms, such as neovascularization, cell proliferation and differentiation of tendon/progenitor stem cells into tenocytes, as well as extracellular matrix reorganization by transforming type III to type I collagen fibers. It has also been indicated that the effects of leukocytes in L-PRP depend on the biological state of the injured tissue and its surrounding microenvironment. L-PRP is beneficial and promotes tendon healing at the early stage, whereas it is likely detrimental to the repair of tendon at a later stage because of the risk of excessive catabolic and inflammatory responses. Overall, the application of L-PRP in tendon disorders appears to be a promising field that is worthy of further research.

Automated summary

Platelet-rich plasma (PRP) has shown promising effects in treating tendon disorders by reducing pain, improving function, and promoting tendon healing. However, the role of leukocytes in PRP depends on the biological state of the injured tissue, leading to varying effects at different stages of tendon repair.