Leukocyte-platelet-rich plasma (L-PRP) impairs the osteoconductive capacity of the autograft associated to changes in the immunolocalization of TGF-β1 and its co-expression with Wnt10b and CD34 cells

Background: This study evaluated the osteoconductive effect of an autograft, in the presence or absence of the L-PRP, using histomorphometric analysis of the bone formed, and we compared the results in the presence of TGF-b1, Wnt10b and CD34 detected by immunohistochemistry. Materials and methods: Two bone defects were produced in the calvaria of 20 rabbits. The defects were treated with autograft and autograft combined with L-PRP. The animals were euthanized at 15 and 40 days post-surgery. Data were analyzed by Student-NewmaneKeuls (p � 0.05) test for histomorphometric and immunohistochemical interpretation. Results: The results revealed that the presence of bone matrix was significantly less in the defects treated with L-PRP. These results coincided with changes of the immunolocalization of the TGF-b1. In the L-PRPfree groups the TGF-b1 was restricted to bone matrix while the CD34 was scarce and the Wnt10b occurred in peritrabecular cells. In contrast, in defects that received L-PRP the presence of TGF-b1 occurred in cells, which occupied whole area of defect. These TGF-b1þ cells also were co-expressed to Wnt10b and CD34. Conclusion: These results suggest that L-PRP induces a cross-reaction between TGF-b1 and Wnt10b, which stimulates the self-renewal and maintenance of CD34þ stem cells immunophenotype, impairing the osteoconductivity properties of the autograft.