title: Identification of candidate serum biomarkers for intervertebral disk degeneration in an animal model.
abstract: OBJECTIVE
  To examine serum markers of matrix turnover in an animal model of disk degeneration.
  
  
  METHODS
  Randomized prospective in vivo study.
  
  
  METHODS
  Laboratory for Orthopaedic and Spine Research and Department of Large Animal Research.
  
  
  METHODS
  Twenty-one New Zealand White rabbits.
  
  
  METHODS
  Rabbits were randomly grouped into control (n = 8), sham surgery (n = 5), or stab surgery (n = 8). The stab surgical group underwent annulotomy of L2-3, L3-4, and L4-5 to induce intervertebral disk degeneration. The sham surgical group underwent surgical exposure without annulotomy, and the control group received no intervention.
  
  
  METHODS
  Lumbar spine magnetic resonance imaging (MRI) and serum samples were obtained before intervention and at 0, 3, 6, and 12 weeks thereafter. MRIs were analyzed for evidence of intervertebral disk degeneration via measurement of MRI index. The serum was assayed at 0, 3, 6, and 12 weeks for the aggrecan biosynthesis marker CS846 and the C-telopeptide of collagen II (CTX-II).
  
  
  RESULTS
  The stabbed disks demonstrate degeneration apparent by MRI criteria. CTX-II increased with time in the stabbed group compared to the control and sham surgery groups regardless of baseline levels. Aggrecan showed no statistically significant difference among groups.
  
  
  CONCLUSIONS
  CTX-II shows promise as a useful serum biomarker for intervertebral disk degeneration.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Pittsburgh, USA. sowaga@upmc.edu
authors.forename: Gwendolyn
authors.initials: G
authors.lastname: Sowa
authors.forename: Ed
authors.initials: E
authors.lastname: Westrick
authors.forename: Arun G
authors.initials: AG
authors.lastname: Rajasekhar
authors.forename: Barrett
authors.initials: B
authors.lastname: Woods
authors.forename: Steven
authors.initials: S
authors.lastname: Leckie
authors.forename: Paulo
authors.initials: P
authors.lastname: Coelho
authors.forename: Nam
authors.initials: N
authors.lastname: Vo
authors.forename: Rebecca
authors.initials: R
authors.lastname: Studer
authors.forename: James
authors.initials: J
authors.lastname: Kang
mesh_terms: D053674:Aggrecans / Q000096:biosynthesis; D000818:Animals; D015415:Biomarkers / Q000097:blood; D024043:Collagen Type II / Q000097:blood*; D004195:Disease Models, Animal; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D011817:Rabbits; D013122:Spinal Diseases / Q000097:blood* / Q000175:diagnosis* / Q000473:pathology
chemical_list: D053674:Aggrecans; D015415:Biomarkers; D024043:Collagen Type II