title: Lactic acid and proteoglycans as metabolic markers for discogenic back pain.
abstract: METHODS
  Disc tissue was removed at surgery from 9 patients with discogenic pain and 9 deformity patients with scoliosis undergoing anterior and posterior spinal fusion. These samples were then analyzed using ex vivo proton high resolution magic angle spinning (HR-MAS) NMR spectroscopy to produce metabolic profiles for comparison between the 2 patient groups.
  
  
  OBJECTIVE
  The goal of this study was to use quantitative ex vivo HR-MAS NMR spectroscopy to identify biochemical markers associated with discogenic back pain.
  
  
  BACKGROUND
  Biomarkers of disc degeneration have been previously described using NMR spectroscopy, but the link between discogenic back pain and biomarkers has not been completely understood.
  
  
  METHODS
  HR-MAS NMR spectroscopy was performed on snap frozen samples taken from 9 patients who underwent discectomies for painful disc degeneration. The resulting proton NMR spectrums were compared with those from discs harvested from a reference population consisting of 9 scoliosis patients.
  
  
  RESULTS
  Spectral analyses demonstrated significantly lower proteoglycan (PG)/collagen (0.31 +/- 0.22 vs. 0.77 +/- 0.48) and PG/lactate (0.46 +/- 0.24 vs. 2.24 +/- 1.11) ratios, and a higher lactate/collagen (0.77 +/- 0.49 vs. 0.40 +/- 0.21) ratio in specimens obtained from discogenic pain patients when compared with scoliosis patients.
  
  
  CONCLUSIONS
  Our results suggest that spectroscopic markers of proteoglycan, collagen, and lactate may serve as metabolic markers of discogenic back pain. These results provide a further basis of the potential to develop in vivo MR spectroscopy for the investigation of discogenic back pain.
authors.affiliation: Department of Radiology, University of California, San Francisco, CA 94158-2330, USA. kayvan.keshari@radiology.ucsf.edu
authors.forename: Kayvan R
authors.initials: KR
authors.lastname: Keshari
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Lotz
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Link
authors.forename: Serena
authors.initials: S
authors.lastname: Hu
authors.forename: Sharmila
authors.initials: S
authors.lastname: Majumdar
authors.forename: John
authors.initials: J
authors.lastname: Kurhanewicz
mesh_terms: D000293:Adolescent; D000328:Adult; D001416:Back Pain / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D006801:Humans; D007403:Intervertebral Disc / Q000378:metabolism / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000378:metabolism* / Q000473:pathology; D019344:Lactic Acid / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008875:Middle Aged; D011509:Proteoglycans / Q000378:metabolism*; D012600:Scoliosis / Q000378:metabolism / Q000473:pathology
chemical_list: D015415:Biomarkers; D011509:Proteoglycans; D019344:Lactic Acid; D003094:Collagen