title: Systemic inflammatory profiles and their relationships with demographic, behavioural and clinical features in acute low back pain.
abstract: Systemic inflammation is linked with development and persistence of many pathological pain states. Although chronic phase inflammatory responses are well reported, the acute phase has received limited attention. Here we investigated circulating pro-inflammatory cytokines and C-reactive protein (CRP), and explored their relationships with symptom severity and other factors in acute low back pain (LBP). Ninety-nine individuals within two weeks of onset of acute LBP and 55 pain-free controls completed questionnaires related to their pain (visual analogue scale, VAS) and disability, behaviour, sleep quality and psychological status. CRP, interleukin-6 (IL-6), tumor necrosis factor (TNF) and interleukin-1β (IL-1β) were measured from serum samples. Biomarkers were compared between LBP and control participants, and in a separate analysis, for those with "high-pain" (VAS ⩾4) and "low-pain" (VAS <4). The relationships between biomarkers and all other variables, including other cytokines/CRP were assessed. CRP was higher in LBP than controls and in those with high- than low-pain (p<0.01). IL-6 was higher in those with high- than low-pain (p<0.05), but not controls. Various pain and non-pain factors were associated with each biomarker differently. These findings suggest systemic CRP and IL-6 are important contributors to inflammation in the early post-onset phase of LBP and that various factors can shape these responses.
authors.affiliation: The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, Brisbane, Australia.
authors.forename: David M
authors.initials: DM
authors.lastname: Klyne
authors.affiliation: Temple University, Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, United States.
authors.forename: Mary F
authors.initials: MF
authors.lastname: Barbe
authors.affiliation: The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, Brisbane, Australia. Electronic address: p.hodges@uq.edu.au.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Hodges
mesh_terms: D000208:Acute Disease; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D018836:Inflammation Mediators / Q000097:blood*; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D017116:Low Back Pain / Q000097:blood* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: C-reactive protein (CRP); Interleukin-1β (IL-1β); Interleukin-6 (IL-6); Low back pain (LBP); Pro-inflammatory cytokines; Tumor necrosis factor (TNF)