title: Intraarticular injection of platelet-rich plasma reduces inflammation in a pig model of rheumatoid arthritis of the knee joint.
abstract: OBJECTIVE
  Treatment options for rheumatoid arthritis range from symptomatic approaches to modern molecular interventions such as inhibition of inflammatory mediators. Inhibition of inflammation by platelet-rich plasma (PRP) has been proposed as a treatment for tendinitis and osteoarthritis. The present study was undertaken to investigate the effect of PRP on antigen-induced arthritis (AIA) of the knee joint in a large animal model.
  
  
  METHODS
  Six-month-old pigs (n = 10) were systemically immunized by bovine serum albumin (BSA) injection, and arthritis was induced by intraarticular BSA injection. PRP was injected into the knee joints of 5 of the animals after 2 weeks. An additional 5 animals received no systemic immunization (controls). Signs of arthritis were documented by plain histologic analysis, Safranin O staining, and immunohistochemistry analysis for type II collagen (CII), interleukin-6 (IL-6), and vascular endothelial growth factor (VEGF). Interleukin-1β (IL-1β), IL-6, tumor necrosis factor α (TNFα), VEGF, and insulin-like growth factor 1 (IGF-1) protein content was measured by Luminex assay.
  
  
  RESULTS
  In the pigs with AIA, plain histologic analysis revealed severe arthritic changes in the synovium. Safranin O and CII staining showed decreased proteoglycan and CII content in cartilage. Immunohistochemistry analysis revealed increased levels of IL-6 and VEGF in synovium and cartilage, and protein concentrations of IL-6, VEGF, IL-1β, and IGF-1 in synovium and cartilage were elevated as well; in addition, TNFα protein was increased in cartilage. Treatment with PRP led to attenuation of these arthritic changes in the synovium and cartilage.
  
  
  CONCLUSIONS
  We have described a porcine model of AIA. Experiments using this model demonstrated that PRP can attenuate arthritic changes as assessed histologically and based on protein synthesis of typical inflammatory mediators in the synovial membrane and cartilage.
authors.affiliation: University Medical Center Schleswig Holstein, Kiel Campus, Kiel, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lippross
authors.forename: Bjoern
authors.initials: B
authors.lastname: Moeller
authors.forename: Holger
authors.initials: H
authors.lastname: Haas
authors.forename: Mersedeh
authors.initials: M
authors.lastname: Tohidnezhad
authors.forename: Nadine
authors.initials: N
authors.lastname: Steubesand
authors.forename: Christoph Jan
authors.initials: CJ
authors.lastname: Wruck
authors.forename: Bodo
authors.initials: B
authors.lastname: Kurz
authors.forename: Andreas
authors.initials: A
authors.lastname: Seekamp
authors.forename: Thomas
authors.initials: T
authors.lastname: Pufe
authors.forename: Deike
authors.initials: D
authors.lastname: Varoga
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D024043:Collagen Type II / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D007249:Inflammation / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D007719:Knee Joint / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D053657:Platelet-Rich Plasma; D013552:Swine; D013583:Synovial Membrane / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
chemical_list: D024043:Collagen Type II; D016207:Cytokines