title: Clinical Trial and In Vitro Study for the Role of Cartilage and Synovia in Acute Articular Infection.
abstract: OBJECTIVE
  Osteoarthritis is a long-term complication of acute articular infections. However, the roles of cartilage and synovia in this process are not yet fully understood.
  
  
  METHODS
  Patients with acute joint infections were enrolled in a prospective clinical trial and the cytokine composition of effusions compared in patients with arthroplasty (n = 8) or with intact joints (n = 67). Cytokines and cell function were also analyzed using a human in vitro model of joint infection.
  
  
  RESULTS
  Synovial IL-1β levels were significantly higher in patients with arthroplasty (p = 0.004). Higher IL-1β concentrations were also found in the in vitro model without chondrocytes (p < 0.05). The anti-inflammatory cytokines IL-4 and IL-10 were consistently expressed in vivo and in vitro, showing no association with the presence of cartilage or chondrocytes. In contrast, FasL levels increased steadily in vitro, reaching higher levels without chondrocytes (p < 0.05). Likewise, the viability of synovial fibroblasts (SFB) during infection was higher in the presence of chondrocytes. The cartilage-metabolism markers aggrecan and bFGF were at higher concentrations in intact joints, but also synthesized by SFB.
  
  
  CONCLUSIONS
  Our data suggest an anti-inflammatory effect of cartilage associated with the SFBs' increased resistance to infections, which displayed the ability to effectively synthesize cartilage metabolites.The trial is registered with DRKS 00003536, MISSinG.
authors.affiliation: Department of Orthopedics and Trauma Surgery, Albert-Ludwigs University Medical Center Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany.
authors.forename: Elia R
authors.initials: ER
authors.lastname: Langenmair
authors.affiliation: Department of Orthopedics and Trauma Surgery, Albert-Ludwigs University Medical Center Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany.
authors.forename: Eva J
authors.initials: EJ
authors.lastname: Kubosch
authors.affiliation: Department of Orthopedics and Trauma Surgery, Albert-Ludwigs University Medical Center Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany ; Schulthess Clinic, Zurich, Lenghalde 2, 8008 Zurich, Switzerland.
authors.forename: Gian M
authors.initials: GM
authors.lastname: Salzmann
authors.affiliation: Department of Orthopedics and Trauma Surgery, Albert-Ludwigs University Medical Center Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany.
authors.forename: Samuel
authors.initials: S
authors.lastname: Beck
authors.affiliation: Department of Orthopedics and Trauma Surgery, Albert-Ludwigs University Medical Center Freiburg, Hugstetter Street 55, 79106 Freiburg, Germany ; Department of Orthopaedics and Traumatology, Odense University Hospital and Department of Clinical Research, University of Southern Denmark, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: Hagen
authors.initials: H
authors.lastname: Schmal
mesh_terms: D000208:Acute Disease; D000368:Aged; D053674:Aggrecans / Q000032:analysis; D002356:Cartilage / Q000502:physiology*; D019902:Chondrocytes / Q000502:physiology; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000032:analysis; D006801:Humans; D053583:Interleukin-1beta / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000209:etiology*; D011446:Prospective Studies; D013582:Synovial Fluid / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000032:analysis
chemical_list: D053674:Aggrecans; D053583:Interleukin-1beta; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2