title: Thrombocytes are effectors of the innate immune system releasing human beta defensin-3.
abstract: BACKGROUND
  Thrombocyte concentrate i.e. platelet-rich plasma (PRP) has become a popular adjunct for many surgical procedures. It is believed to improve bone and soft tissue healing. Recently antimicrobial effects of the autologous preparation were reported by several groups. In this study we investigated the antimicrobial effect of PRP against gram-negative microbes which frequently cause severe complications in orthopaedic trauma surgery.
  
  
  METHODS
  Platelet-rich plasma was produced from liquid preserved thrombocyte concentrates. ELISA, Western blot and immunohistochemistry were preformed to investigate the release and content of platelet concentrates. A radial diffusion assay was used to detect antimicrobial effects of PRP.
  
  
  RESULTS
  We detected the human beta defensin-3 in bactericidal concentrations in platelet preparations by ELISA, Western blot and immunohistochemistry. In antimicrobial testing we demonstrated effective inhibition of Escherichia coli (ATCC 11303), Bacterium megaterium (ATCC 14581), Klebsiella pneumoniae (ATCC 13883), Enterococcus faecalis (ATCC 29212) and Proteus mirabilis (ATCC21100).
  
  
  CONCLUSIONS
  With this study we demonstrate antimicrobial action of a popular adjunct for orthopaedic and trauma surgery against gram-positive and gram-negative bacteria. We have identified a possible mechanism of action via the secretion of HBD-3 as a first line defence in contaminated wounds and in elective application of PRP. This finding supports a broader spectrum of clinical indications for an autologous platelet preparation.
authors.affiliation: Department of Anatomy and Cell Biology, RWTH Aachen University, Germany. mtohidnezhad@ukaachen.de
authors.forename: Mersedeh
authors.initials: M
authors.lastname: Tohidnezhad
authors.forename: Deike
authors.initials: D
authors.lastname: Varoga
authors.forename: Rainer
authors.initials: R
authors.lastname: Podschun
authors.forename: Christoph Jan
authors.initials: CJ
authors.lastname: Wruck
authors.forename: Andreas
authors.initials: A
authors.lastname: Seekamp
authors.forename: Lars-Ove
authors.initials: LO
authors.lastname: Brandenburg
authors.forename: Thomas
authors.initials: T
authors.lastname: Pufe
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lippross
mesh_terms: D001792:Blood Platelets / Q000276:immunology / Q000378:metabolism*; D017102:Fracture Healing / Q000502:physiology*; D005597:Fractures, Open / Q000628:therapy*; D006090:Gram-Negative Bacteria; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000628:therapy*; D006801:Humans; D007150:Immunohistochemistry; D019637:Orthopedic Procedures; D053657:Platelet-Rich Plasma / Q000502:physiology*; D014947:Wounds and Injuries / Q000628:therapy*; D023083:beta-Defensins / Q000378:metabolism*
chemical_list: C422950:DEFB103A protein, human; D023083:beta-Defensins