title: High serum YKL-40 concentration is associated with severe bone disease in newly diagnosed multiple myeloma patients.
abstract: OBJECTIVE
  In multiple myeloma (MM) YKL-40 is present in the bone marrow microenvironment and is suggested to play a role in remodelling of the extracellular matrix. Here, the association between serum YKL-40 and severity of bone disease in MM is investigated.
  
  
  METHODS
  Serum YKL-40 was measured in 34 MM patients at diagnosis. Bone disease was assessed by radiography and biochemical markers of bone metabolism. Patients were treated with conventional chemotherapy and followed for up to 30 months.
  
  
  RESULTS
  Patients with a serum YKL-40 elevated above the age specific reference range (56%) had a higher total X-ray score (P = 0.003) and higher levels of the markers of bone resorption serum C-terminal telopeptide of collagen type I (P = 0.003), urine pyridinoline (P = 0.04) and urine deoxypyridinoline (P = 0.002), while the levels of urine N-terminal telopeptide of collagen type I (NTX-1) and the markers of bone formation equalled those seen in patients with a normal serum YKL-40. Serum YKL-40 level (beta = 7.6; P = 0.002) and urine NTX-1 (log(2)) (beta = 3.5; P = 0.006) were independent predictors of total X-ray score at diagnosis. Patients with elevated serum YKL-40 at diagnosis had shorter time to first osteolytic event compared to patients with normal serum YKL-40 (12 months vs. not reached; Log rank test: P = 0.03).
  
  
  CONCLUSIONS
  Newly diagnosed MM patients with elevated serum concentrations of YKL-40 have more severe bone destruction including increased bone resorptive activity and shorter time to progression of bone disease. At this point, a potential role for YKL-40 in myeloma-related bone disease must be considered.
authors.affiliation: Department of Haematology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark. anne.k.mylin@dadlnet.dk
authors.forename: Anne K
authors.initials: AK
authors.lastname: Mylin
authors.forename: Niels
authors.initials: N
authors.lastname: Abildgaard
authors.forename: Julia S
authors.initials: JS
authors.lastname: Johansen
authors.forename: Niels F
authors.initials: NF
authors.lastname: Andersen
authors.forename: Lene
authors.initials: L
authors.lastname: Heickendorff
authors.forename: Therese
authors.initials: T
authors.lastname: Standal
authors.forename: Peter
authors.initials: P
authors.lastname: Gimsing
authors.forename: Lene M
authors.initials: LM
authors.lastname: Knudsen
mesh_terms: D054392:Adipokines; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001847:Bone Diseases / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D000071451:Chitinase-3-Like Protein 1; D018450:Disease Progression; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D037102:Lectins; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D011859:Radiography; D044967:Serum / Q000378:metabolism*; D015996:Survival Rate
chemical_list: D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins