Magnetic Resonance Spectroscopy Lipids Peak May Serve as a Potential Biomarker for Back Pain in Intervertebral Disc Degeneration: An Integrative Metabolomics and Proteomics Study Investigating the Role of the Lipid Droplets-Interleukin-17 Inflammatory Axis.

Abstract

Objective: To explore and validate clinical magnetic resonance spectroscopy (MRS) biomarkers associated with patient-reported symptoms in intervertebral disc degeneration, and to further elucidate the pathogenic mechanisms linking these symptoms to MRS biomarkers via an integrative multiomics approach.

Methods: Patients categorized into the predominant lipids peak (pLP) group and the non-pLP group based on MRS spectrum lipids peak. Nucleus pulposus cells underwent lipidomics, proteomics and functional experiments. Outcome measures compared, and Pearson correlation coefficient evaluated relationships between symptoms, interleukin (IL)-17 immune-positive cells, and lipid contents. Multivariate linear analysis was employed to analyze the contributions of various variables to patient-reported symptoms.

Results: The pLP group exhibited significantly higher preoperative visual analogue scale (VAS)-back scores (6.5 vs. 4.7, p<0.01) and Oswestry Disability Index (ODI) scores (63.3% vs. 51.2%, p<0.01) compared to the non-pLP group. The multiomics analysis revealed the pLP group was characterized by lipid droplets accumulation in nucleus pulposus cells, and the activation of interleukin-17 (IL-17) inflammatory pathway. Preoperative VAS-back and ODI scores showed positive correlations with the expressions of IL-17 (r=0.555, p<0.001; r=0.566, p<0.001) and the relative lipid contents (r=0.567, p<0.001; r=0.561, p<0.001). Multivariate linear analysis revealed that percentage of IL-17 positive cells and the relative triglyceride contents were associated with preoperative VAS-back pain (p=0.021, p=0.046).

Conclusion: Patients with the MRS pLP spectrum showed reduced quality of life and upregulation of the lipid droplets-IL-17 inflammatory pathway in nucleus pulposus cells. Inflammatory factors contribute significantly to chronic low back pain development and progression, affecting patient-reported symptoms. The MRS lipids peak may serve as a potential biomarker for diagnosing and monitoring low back pain.