Asian Spine J.  2017 Jun;11(3):472-477. 10.4184/asj.2017.11.3.472.

Correlation among Inflammatory Cytokine Expression Levels, Degree of Disk Degeneration, and Predominant Clinical Symptoms in Patients with Degenerated Intervertebral Discs

• Sainoh T
• Inage K
• Orita S
• Koda M
• Furuya T
• Yamauchi K
• Suzuki M
• Sakuma Y
• Kubota G
• Oikawa Y
• Sato J
• Fujimoto K
• Shiga Y
• Abe K
• Kanamoto H
• Inoue M
• Kinoshita
• Norimoto M
• Umimura T
• Takahashi
• Ohtori S

• KMID: 2382566
• DOI: http://doi.org/10.4184/asj.2017.11.3.472

Abstract

STUDY DESIGN: Observational study. PURPOSE: To assess the correlation among inflammatory cytokine expression levels, degree of intervertebral disk (IVD) degeneration, and predominant clinical symptoms observed in degenerative disk disease (DDD). OVERVIEW OF LITERATURE: Low back pain (LBP) is associated with inflammatory cytokine expression levels, including those of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and nerve growth factor (NGF). However, the association between cytokine expression levels and the physiological mechanisms of disk degeneration and clinical pain remain controversial.
METHODS
Using the enzyme-linked immunosorbent assay, TNF-α, IL-6, and NGF expression levels were analyzed in 58 IVD samples that were harvested from patients with lumbar DDD. Patient samples were grouped according to the degree of IVD degeneration using the Pfirrmann grading system and magnetic resonance imaging, and the correlations between the disease groups and each cytokine expression level were assessed. In addition, on the basis of their predominant preoperative symptoms, the patients were assigned to either an LBP or leg pain group to determine the correlation among these disease manifestations and individual cytokine expression levels.
RESULTS
A gradual increase in TNF-α (R=0.391) and IL-6 (R=0.388) expression levels correlated with the degree of IVD degeneration, whereas NGF (R=0.164) expression levels exhibited a minimal decrease with disease progression. Regarding the predominant clinical manifestation, only the LBP group exhibited a significant increase in TNF-α expression levels (p=0.002).
CONCLUSIONS
These results suggested that TNF-α and IL-6 play an important role in the pathophysiology of IVD degeneration at any stage, whereas NGF plays an important role during the early disease stages. Moreover, because TNF-α expression levels were significantly high in the LBP group, we propose that they are involved in LBP onset or progression.

Keyword

Intervertebral disk; Intervertebral disk degeneration; Low back pain

MeSH Terms

Dichlorodiphenyldichloroethane
Disease Progression
Enzyme-Linked Immunosorbent Assay
Humans
Interleukin-6
Intervertebral Disc Degeneration*
Intervertebral Disc*
Leg
Low Back Pain
Magnetic Resonance Imaging
Nerve Growth Factor
Observational Study
Tumor Necrosis Factor-alpha
Dichlorodiphenyldichloroethane
Interleukin-6
Nerve Growth Factor
Tumor Necrosis Factor-alpha