Abstract
Introduction
Low back pain (LBP) disease is reportedly associated with inflammatory cytokines such as tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), as well as with nerve growth factor (NGF) that is expressed in increased amounts within degenerative intervertebral discs (IVDs). In the present study, we aimed to assess the correlation between the local expression of TNF-α, IL-6, and NGF within degenerative human lumbar IVDs and the degree of degeneration, as well as the correlation between the expression of these mediators and the prominent symptoms.
Materials and Methods
In total, 58 IVD samples of patients who underwent surgery for various lumbar disorders were examined. The expression level of these mediators in each sample was determined using enzyme-linked immunosorbent assay. The samples were grouped according to the degree of IVD degeneration using Pfirrmann grading on magnetic resonance imaging, and the grades were correlated with the individual expression levels. The chief complaints of the patients were then recorded and assigned to the LBP group and the leg pain group, and were compared with the individual expression levels.
Results
A gradual increase in TNF-α (R: 0.391) and IL-6 (R: 0.388) expression levels were observed with a progression in the degree of degeneration, but NGF (R: − 0.164) exhibited a minimal decrease in the expression level. With regard to the chief complaints, the LBP group only exhibited a significant increase in the TNF-α expression level.
Conclusion
We noted a trend of increasing expression levels of TNF-α and IL-6 with the progression of IVD degeneration, which indicates that these cytokines may have an important role in the degenerative process of IVD at any stage. Moreover, NGF may have an important effect during the early stage of the progression of degeneration. With regard to the symptoms, TNF-α expression was significantly greater in the LBP group. Thus, we propose that TNF-α may be significantly involved in LBP.
None declared