The purpose of this study is to:

• evaluate if there is an association between elevated levels of cytokines and chronic pain due to herniated disk disease
• measured cytokines levels in chronic low back pain and in healthy subjects.

23 patients with at least three months of back pain due to herniated disk disease were selected Diagnosis was confirmed by magnetic resonance imaging (MRI) or computerized tomography (CT) imaging of the spine for all patients. In addition, pain severity had to be ³ 5 points on the Numerical Rating Scale (NRS) ranging from zero (no pain) to 10 (worst imaginable pain).

The exclusion criteria were defined as one or more of the following: psychiatric disorders, systemic or inflammatory disease, history of allergy, presence of motor deficits, history of blood dyscrasia, pregnancy, active infection, tumor, use of analgesic drugs in the week before or inability to come to the hospital for evaluation.

Inclusion Criteria:

• 23 patients

  • least three months of back pain due to herniated disk disease
  • pain severity had to be 5 points on the Numerical Rating Scale (NRS)

• 10 healthy volunteers:

  • without previous history of back pain

Exclusion Criteria:

• One or more of the following:

  • psychiatric disorders
  • systemic or inflammatory disease
  • history of allergy
  • presence of motor deficits
  • history of blood dyscrasia
  • pregnancy
  • active infection, tumor
  • use of analgesic drugs in the week before
  • inability to come to the hospital for evaluation.