Lactic acid and proteoglycans as metabolic markers for discogenic back pain.

STUDY
DESIGN: 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. SUMMARY OF BACKGROUND DATA: 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.
CONCLUSION: 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.