Leukocyte depletion does not affect the in�vitro healing ability of platelet rich plasma

Abstract

The clinical use of platelet-rich plasma (PRP) containing or deprived of leukocytes remains a subject of debate and a controversial issue. It is not yet clear whether leukocyte content has a positive or negative effect on tissue healing processes. Several studies, conducted mainly in the orthopedic field, support the use of leukocyte-poor (LP) PRP, whereas other studies have not identified any significant differences between the use of LP and leukocyte-rich PRP. In the present study, the role of leukocytes contained in PRP was assessed to verify their effect on fibroblasts and endothelial cells, which have a leading role in the biological processes associated with wound healing (including angiogenesis and matrix remodeling). The original sample of PRP was divided into two aliquots, one of which remained unaltered, while the other was deprived of leukocytes. The two aliquots were used in tests in order to verify the effects of leukocytes on proliferation, wound healing and tube formation, and in molecular analyses of growth factor and enzyme content. The present results highlighted a substantial overlap between the two formulations. This may be explained by similar levels of growth factors (vascular endothelial growth factor, thrombospondin-1, interferon-γ, platelet-derived growth factor-BB, -AA and -B, tumor growth factor-β1, fibroblast growth factor 7 and tumor necrosis factor-α) and enzymes (gelatinases and plasminogen activators) in the two formulations. These results support the hypothesis that the ability of the PRP to affect the biological response of endothelial cells and fibroblasts does not rely on the presence of leukocytes.

Allogeneic platelet‐rich plasma (PRP) is superior to platelets or plasma alone in stimulating fibroblast proliferation and migration, angiogenesis, and chemotaxis as relevant processes for wound healing

“…The proliferation of fibroblasts is concentration dependent, and both platelet‐derived factors and plasma act synergistically. Previous research also found positive effects of PRP on fibroblast proliferation . Superior induction of proliferation with human platelet lysate compared to FCS has previously been described for different cell types such as mesenchymal stromal cells .…”

The Use of Platelet-Rich Plasma in Symptomatic Knee Osteoarthritis

“…In vitro, it has been shown that there is not a significant difference between the effect of LR-PRP and LP-PRP on wound healing, suggesting that the major benefits of PRP stem from growth factors rather than leukocytes. 53 Raeissadat et al studied LR-PRP injections in patients with knee OA and found significant improvement in pain, stiffness, functional capacity, and quality of life 6 months post-injection. 54 However, when comparing LR-PRP and LP-RPR, Braun et al reported that LR-PRP led to significantly increased cell death and expression of multiple proinflammatory markers such as IL-1β, IL-6, interferon gamma, and tumor necrosis factorα (TNF-α).…”

Effects of platelet-rich plasma and platelet-poor plasma on human dermal fibroblasts

“…The following two studies investigated the effects of MMPs within their PRP experiments. The first study examined fibroblast proliferation, MMP expressions and GF release after the treatment of LR-or LP-PRP within the dose ranges of 0.3 -3 x 10 6 plt/μl [44]. The outcomes demonstrated fibroblast proliferation increased 2.5-fold for both samples compared to the untreated cells; however, no significant differences occurred between the PRP groups.…”