title: The interleukin-1α gene C>T polymorphism rs1800587 is associated with increased pain intensity and decreased pressure pain thresholds in patients with lumbar radicular pain.
abstract: OBJECTIVE
  Previous studies have suggested that many inflammatory cytokines, including interleukin (IL)-1α, may be associated with lumbar radicular pain after disk herniation. In the present study, we examined how variability of the IL-1α gene affects pain intensity and the pressure pain threshold (PPT) in patients with symptomatic disk herniation.
  
  
  METHODS
  A total of 121 patients with lumbar radicular pain due to disk herniation were recruited from Oslo University Hospital, Norway, and followed up at 6 weeks and 12 months. The primary outcome measures were pain intensity scores for the lower back and legs using a visual analog pain scale (VAS) and PPT for the gluteal muscles. Genotyping was carried out using a predesigned TaqMan assay for IL-1α rs1800587. The effect of the IL-1α genotype on the VAS and PPT was analyzed by repeated measure analyses of variance.
  
  
  RESULTS
  The IL-1α gene C>T polymorphism rs1800587 affected VAS and PPT scores in patients with symptomatic disk herniation. Patients with the CT/TT genotype reported a higher VAS leg pain intensity (P=0.002) and also a lower PPT in the gluteal muscles (left P=0.016; right P=0.016) compared with patients with the CC genotype during 1 year of follow-up.
  
  
  CONCLUSIONS
  The present data show that the IL-1α CT/TT genotype rs1800587 may be associated with increased pain intensity and corresponding reduced PPT during the first year after disk herniation.
authors.affiliation: *Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Ullevaal †Faculty of Medicine §Department of Molecular Biosciences, University of Oslo ‡National Institute of Occupational Health, Oslo, Norway.
authors.forename: Elina I
authors.initials: EI
authors.lastname: Schistad
authors.forename: Line M
authors.initials: LM
authors.lastname: Jacobsen
authors.forename: Cecilie
authors.initials: C
authors.lastname: Røe
authors.forename: Johannes
authors.initials: J
authors.lastname: Gjerstad
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D053582:Interleukin-1alpha / Q000235:genetics*; D007405:Intervertebral Disc Displacement / Q000150:complications* / Q000235:genetics* / Q000601:surgery; D007866:Leg / Q000294:innervation; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010146:Pain / Q000209:etiology* / Q000235:genetics; D017288:Pain Threshold / Q000502:physiology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011312:Pressure / Q000009:adverse effects; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D053582:Interleukin-1alpha