title: Basal inflammation and innate immune response in chronic multisite musculoskeletal pain.
abstract: Dysregulation of the immune system may play a role in chronic pain, although study findings are inconsistent. This cross-sectional study examined whether basal inflammatory markers and the innate immune response are associated with the presence and severity of chronic multisite musculoskeletal pain. Data were used on 1632 subjects of the Netherlands Study of Depression and Anxiety. The Chronic Pain Grade questionnaire was used to determine the presence and severity of chronic multisite musculoskeletal pain. Subjects were categorized in a chronic multisite musculoskeletal pain group (n=754) and a control group (n=878). Blood levels of the basal inflammatory markers C-reactive protein, interleukin-6, and tumor necrosis factor-alpha were determined. To obtain a measure of the innate immune response, 13 inflammatory markers were assessed after lipopolysaccharide (LPS) stimulation in a subsample (n=707). Subjects with chronic multisite musculoskeletal pain showed elevated levels of basal inflammatory markers compared with controls, but statistical significance was lost after adjustment for lifestyle and disease variables. For some LPS-stimulated inflammatory markers, we did find elevated levels in subjects with chronic multisite musculoskeletal pain both before and after adjustment for covariates. Pain severity was not associated with inflammation within chronic pain subjects. An enhanced innate immune response in chronic multisite musculoskeletal pain may be examined as a potential biomarker for the onset or perpetuation of chronic pain.
authors.affiliation: Department of Psychiatry and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands Musculoskeletal Research Collaboration (Epidemiology Group), University of Aberdeen, Aberdeen, UK Department of Clinical and Health Psychology, Utrecht University, Utrecht, The Netherlands Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Ellen
authors.initials: E
authors.lastname: Generaal
authors.forename: Nicole
authors.initials: N
authors.lastname: Vogelzangs
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Macfarlane
authors.forename: Rinie
authors.initials: R
authors.lastname: Geenen
authors.forename: Johannes H
authors.initials: JH
authors.lastname: Smit
authors.forename: Joost
authors.initials: J
authors.lastname: Dekker
authors.forename: Brenda W J H
authors.initials: BWJH
authors.lastname: Penninx
mesh_terms: D000328:Adult; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D059350:Chronic Pain / Q000097:blood / Q000276:immunology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology*; D007249:Inflammation / Q000097:blood / Q000276:immunology*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000097:blood / Q000276:immunology*; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: C-reactive protein; Central sensitization; Chronic pain; Cytokines; Immune system; Innate immune response; Lipopolysaccharide