title: High serum concentration of YKL-40 is associated with short survival in patients with acute myeloid leukemia.
abstract: OBJECTIVE
  YKL-40 is secreted by cancer cells, macrophages, and neutrophils. It may be a growth or differentiation factor, play a role in angiogenesis, or protect against apoptosis. High serum YKL-40 is associated with poor prognosis in solid carcinomas. The aim was to examine serum YKL-40 in patients with acute myeloid leukemia (AML).
  
  
  METHODS
  YKL-40 was measured by ELISA in serum from 77 patients recently diagnosed with AML before and during the first month of chemotherapy.
  
  
  RESULTS
  Forty (52%) of the AML patients had elevated serum YKL-40 (compared with age-matched healthy subjects) and their survival was shorter than in patients with normal serum YKL-40 (median, 128 days; interquartile range, 18-629 days versus 386 days; interquartile range, 180-901; P=0.018 Mann-Whitney test). Univariate analysis of serum YKL-40 (logarithmically transformed and treated as a continuous covariate) showed significant association with survival within the first month after start of chemotherapy [hazard ratio (HR), 1.7; 95% confidence interval (CI), 1.2-2.4; P=0.002], first 12 months (HR, 1.6; 95% CI, 1.2-2.0; P=0.0002), and overall survival (HR, 1.3; 95% CI, 1.1-1.6; P=0.003). Multivariate Cox analysis showed that serum YKL-40 was an independent prognostic variable for survival (first month: HR, 1.7; P=0.011; 12 months: HR, 1.6; P=0.0002; overall survival: HR, 1.4; P=0.002). High serum YKL-40 at start of chemotherapy was a risk factor for pneumonia within the first month, and serum YKL-40 increased (P=0.002) at time of pneumonia and was unchanged in patients without infections.
  
  
  CONCLUSIONS
  Serum YKL-40 is a prognostic biomarker of survival in AML patients. Its role in AML and infections needs to be determined.
authors.affiliation: Research Laboratory, Department of Hematology, Herlev University Hospital, Copenhagen, Denmark. ojb@ribeamt.dk
authors.forename: Olav J
authors.initials: OJ
authors.lastname: Bergmann
authors.forename: Julia S
authors.initials: JS
authors.lastname: Johansen
authors.forename: Tobias W
authors.initials: TW
authors.lastname: Klausen
authors.forename: Anne K
authors.initials: AK
authors.lastname: Mylin
authors.forename: Jørgen S
authors.initials: JS
authors.lastname: Kristensen
authors.forename: Eigil
authors.initials: E
authors.lastname: Kjeldsen
authors.forename: Hans E
authors.initials: HE
authors.lastname: Johnsen
mesh_terms: D000208:Acute Disease; D054392:Adipokines; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D037102:Lectins; D007951:Leukemia, Myeloid / Q000188:drug therapy / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000097:blood / Q000175:diagnosis / Q000382:microbiology; D011379:Prognosis
chemical_list: D054392:Adipokines; D014408:Biomarkers, Tumor; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins