title: Serum YKL-40 levels correlate with infarct volume, stroke severity, and functional outcome in acute ischemic stroke patients.
abstract: OBJECTIVE
  YKL-40 is associated with various neurological disorders. However, circulatory YKL-40 levels early after onset of acute ischemic stroke (AIS) have not been systematically assessed. We aimed to identify the temporal changes and clinical usefulness of measuring serum YKL-40 immediately following AIS.
  
  
  METHODS
  Serum YKL-40 and C-reactive protein (CRP) levels were monitored over time in AIS patients (n = 105) and compared with those of stroke-free controls (n = 34). Infarct volume and stroke severity (National Institutes of Health Stroke Scale; NIHSS) were measured within 48 hours of symptom onset, and functional outcome (modified Rankin Scale; mRS) was measured 3 months after AIS.
  
  
  RESULTS
  Within 12 hours of symptom onset, levels of YKL-40 (251 vs. 41 ng/mL) and CRP (1.50 vs. 0.96 µg/mL) were elevated in AIS patients compared to controls. The power of YKL-40 for discriminating AIS patients from controls was superior to that of CRP (area under the curve 0.84 vs. 0.64) and YKL-40 (r = 0.26, P<0.001) but not CRP levels were correlated with mRS. On day 2 of admission (D2), YKL-40 levels correlated with infarct volume and NIHSS. High YKL-40 levels predicted poor functional outcome (odds ratio 5.73, P = 0.03). YKL-40 levels peaked on D2 and declined on D3, whereas CRP levels were highest on D3.
  
  
  CONCLUSIONS
  Our results demonstrate serial changes in serum YKL-40 levels immediately following AIS and provide the first evidence that it is a valid indicator of AIS extent and an early predictor of functional outcome.
authors.affiliation: Department of Neurology, School of Medicine, Wonkwang University, Iksan, Korea.
authors.forename: Hyun Young
authors.initials: HY
authors.lastname: Park
authors.forename: Chang-Duk
authors.initials: CD
authors.lastname: Jun
authors.forename: Se-Jeong
authors.initials: SJ
authors.lastname: Jeon
authors.forename: See-Sung
authors.initials: SS
authors.lastname: Choi
authors.forename: Hak-Ryul
authors.initials: HR
authors.lastname: Kim
authors.forename: Dan-Bee
authors.initials: DB
authors.lastname: Choi
authors.forename: Seongae
authors.initials: S
authors.lastname: Kwak
authors.forename: Hak-Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Jin Sung
authors.initials: JS
authors.lastname: Cheong
authors.forename: Hong-Seob
authors.initials: HS
authors.lastname: So
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Lee
authors.forename: Do-Sim
authors.initials: DS
authors.lastname: Park
mesh_terms: D054392:Adipokines / Q000097:blood*; D000368:Aged; D020520:Brain Infarction / Q000097:blood / Q000175:diagnosis; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D006801:Humans; D037102:Lectins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D020521:Stroke / Q000097:blood* / Q000175:diagnosis*; D013997:Time Factors
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins; D002097:C-Reactive Protein