title: Serum Levels of the Inflammatory Cytokines in Patients with Lumbar Radicular Pain Due to Disc Herniation.
abstract: METHODS
  Cohort study.
  
  
  OBJECTIVE
  This study primarily aimed to evaluate the serum levels of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-4 in patients with lumbar radiculopathy 1 and 12 months after microdiscectomy.
  
  
  BACKGROUND
  Lumbar radiculopathy is possibly caused by inflammatory changes in the nerve root. The intraneural application of pro-inflammatory cytokines induces behavioral signs associated with pain. Anti-inflammatory cytokine treatment effectively reduces hyperalgesia.
  
  
  METHODS
  The role of TNF-α and IL-4 in long-lasting lumbar radiculopathy was addressed. A total of 262 patients were recruited from Anqing Hospital, Anhui Medical University. During inclusion at 1 and 12 months, serum concentrations of TNF-α and IL-4 were analyzed by enzyme-linked immunosorbent assay, and pain intensity was reported on a 0-10 cm visual analog scale (VAS).
  
  
  RESULTS
  Sixty six patients had VAS <3 and 196 patients had VAS ≥3. Serum concentrations of pro-inflammatory TNF-α and anti-inflammatory IL-4 in patients with lumbar radiculopathy related to disc herniation were measured at 1- and 12-month follow-up. TNF-α decreased in both VAS groups with time. In contrast, IL-4 increased in both groups at 1 month and then decreased gradually until month 12. The changes in serum levels of TNF-α and IL-4 over time between the VAS ≥3 and VAS <3 groups were significantly different.
  
  
  CONCLUSIONS
  Chronic lumbar radiculopathy may be associated with high level of pro-inflammatory substances, such as TNF-α, in serum after disc herniation, and elevated anti-inflammatory cytokine in patients with lumbar radiculopathy may indicate a favorable outcome.
authors: Department of Orthopaedics, Anhui Medical University, Hefei, China.; Department of Orthopaedics, Anqing Hospital, Anhui Medical University, Anqing, China.
authors: Bo
authors: B
authors: Zu
authors: Department of Orthopaedics, Anqing Hospital, Anhui Medical University, Anqing, China.
authors: Hong
authors: H
authors: Pan
authors: Department of Orthopaedics, Anqing Hospital, Anhui Medical University, Anqing, China.
authors: Xiao-Jun
authors: XJ
authors: Zhang
authors: Department of Orthopaedics, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
authors: Zong-Sheng
authors: ZS
authors: Yin
keywords: Cytokines; Interleukins; Pain; Tumor necrosis factor-α