title: IL-6, but not TNF-α, increases plasma YKL-40 in human subjects.
abstract: Plasma levels of YKL-40 are elevated in patients with systemic infection, inflammatory disorders and cancer. Both monocytes/macrophages, neutrophils, and cancer cells have the capacity to produce YKL-40, but the regulation during the inflammatory response is unknown. To study the possible role of interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α in the regulation of YKL-40 plasma levels, we included healthy men, who received either recombinant human (rh)IL-6 (n=6), rhTNF-α (n=8) or vehicle (n=7) for 3h. The plasma levels of IL-6 and TNF-α reached ∼ 150 and ∼ 18 pg/ml, respectively, during the infusions. Following the IL-6 infusion, the plasma level of YKL-40 increased from ∼ 30 to ∼ 57 ng/ml (p<0.05) at 24h, and returned to normal values after 48 h. The plasma level of YKL-40 did not change during TNF-α infusion or infusion of vehicle. These data demonstrate that IL-6, but not TNF-α, has a key-role in the regulation of plasma YKL-40 levels during inflammation.
authors.affiliation: The Centre of Inflammation and Metabolism, Department of Infectious Diseases and CMRC, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Denmark. rinnov@rh.dk
authors.forename: Anders R
authors.initials: AR
authors.lastname: Nielsen
authors.forename: Peter
authors.initials: P
authors.lastname: Plomgaard
authors.forename: Karen S
authors.initials: KS
authors.lastname: Krabbe
authors.forename: Julia S
authors.initials: JS
authors.lastname: Johansen
authors.forename: Bente K
authors.initials: BK
authors.lastname: Pedersen
mesh_terms: D054392:Adipokines; D000328:Adult; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007262:Infusions, Intravenous; D015850:Interleukin-6 / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D037102:Lectins / Q000097:blood*; D008297:Male; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D015850:Interleukin-6; D037102:Lectins; D014409:Tumor Necrosis Factor-alpha