Prp with or without leukocytes: any difference on chondrocytes and synoviocytes culture?

Objectives: Platelet Rich Plasma (PRP) is a biological compound rich
of growth factors able to support healing processes, and it represents a
fascinating tool for clinicians. However results on its potentiality as
intra-articular treatment for cartilage degenerative lesions in osteoarthritis
(OA) are still controversial, due to the lack of well designed
studies and the differences in the preparation procedures. The aim of
this study was to analyze the modifications induced by two different
PRP preparations on chondrocytes and sinoviocytes in culture, by
documenting changes in proliferations, gene expression, and extracellular
matrix components deposition.
Methods: Blood collected from 10 volunteers was used to obtain two
PRP preparations derived respectively from a ‘‘one-spinning procedure’’,
to obtain a pure platelet concentrate without leukocytes but
with a limited number of platelets (P-PRP), and by a ‘‘two-spinning
approach’’, producing a product characterized by a higher platelet
concentration and the presence of leukocytes (L-PRP).
Results: Our data showed that L-PRP contains higher levels of growth
factors and cytokines compared to P-PRP. Both PRPs stimulate
chondrocytes proliferation during all the culture period evaluated; a
significant enhancement in cell growth was induced by P-PRP respect
to L-PRP only at day 7. Moreover, P-PRP stimulates chondrocyte
anabolism as demonstrated by the expression of collagen type II and aggrecan, while L-PRP promotes catabolic pathways in which some
different cytokines are involved. Interesting, L-PRP induces a higher
expression of hyaluronic acid synthase-2 and hyaluronan compared to
P-PRP. On sinoviocytes, L-PRP is able to sustain the up-regulation of
proinflammatory factors, such as IL-1beta, IL-8 and FGF-2, together
with a down modulation of HGF and TIMP-4 expression, two factors
that have been recognized as anti-catabolic mediators in cartilage,
whereas P-PRP was not able to exert a differential pattern of biological
effect compared to PPP.
Conclusions: Our study highlights that the two PRPs induce distinct
effects on cultured human chondrocytes and sinoviocytes. This is due
to the different content in PRP of platelets, leukocytes, growth factors
and molecules that act synergically to regulate several biological
processes which could influence the regeneration of a functional
tissue.