Expression of Growth Factors and Cytokines in Patients withDegenerated Disc Disease and Herniated Nucleus Pulposus

ABSTRACT

OBJECTIVE: To investigate the expression of cytokines and growth factors in disc specimens obtained from small numbers of patients with herniated nucleus pulposus (HNP) and degenerated disc disease (DDD). METHOD: A total of ten human intervertebral disc samples consisted of five painful degenerative discs and five herniated intervertebal discs were obtained from surgery. MRI and Western blot analyses on these disc samples were performed to determine the levels of disc degeneration and the expression levels of cytokines and growth factors. RESULTS: The levels of IL-6 were significantly greater in the DDD patients than in the HNP patients, but no statistical differences were observed in the expression of IL-1beta, IL-8 and TNF-alpha between the HNP and DDD patients. In addition, the expression of TGF beta was significantly higher in the DDD patients than in the HNP patients. CONCLUSION: The higher levels of cytokine and growth factor expression in the DDD than in the HNP show why discogenic patients usually have more severe back pain than patients with herniated discs.