title: Serum cytokine levels in patients with chronic low back pain due to herniated disc: analytical cross-sectional study.
abstract: OBJECTIVE
  the role of immune response and proinflammatory cytokines in the pathogenesis of chronic pain has been of growing interest. In order to evaluate whether there is any association between disc herniation and elevated cytokine levels, we measured cytokine levels in patients with chronic low back pain and in healthy subjects.
  
  
  METHODS
  analytical cross-sectional study at the Pain Clinic of Universidade Federal da Bahia (UFBA).
  
  
  METHODS
  cytokine levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique on 23 patients with low back pain (G1) and on 10 healthy subjects (G2).
  
  
  RESULTS
  the levels of tumor necrosis factor-alpha [TNF-alpha] (G1 = 5.6 ± 2.3 pg/ml; G2 = 1.6 ± 0.5 pg/ml; P = 0.01) and interleukin-6 [IL-6] (G1 = 4.1 ± 3.0 pg/ml; G2 = 0.9 ± 0.4 pg/ml; P = 0.01) were higher in G1. There were no statistically significant differences in relation to interleukin-1 [IL-1] (G1 = 0.5 ± 0.3 pg/ml; G2 = 0.5 ± 0.1 pg/ml; P = 1) or soluble tumor necrosis factor receptor [sTNF-R] (G1 = 572 pg/ml ± 36; G2 = 581 ± 50 pg/ml; P = 0.87).
  
  
  CONCLUSIONS
  The patients with chronic low back pain due to disc herniation presented higher levels of TNF-alpha and IL-6, but not of IL-1 or sTNF-R.
authors.affiliation: Universidade Federal da Bahia, Salvador, Bahia, Brazil.
authors.forename: Durval Campos
authors.initials: DC
authors.lastname: Kraychete
authors.forename: Rioko Kimiko
authors.initials: RK
authors.lastname: Sakata
authors.forename: Adriana Machado
authors.initials: AM
authors.lastname: Issy
authors.forename: Olívia
authors.initials: O
authors.lastname: Bacellar
authors.forename: Rogério
authors.initials: R
authors.lastname: Santos-Jesus
authors.forename: Edgar Marcelino
authors.initials: EM
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D016207:Cytokines / Q000097:blood*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007405:Intervertebral Disc Displacement / Q000150:complications*; D017116:Low Back Pain / Q000097:blood* / Q000209:etiology; D008159:Lumbar Vertebrae; D008297:Male; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha