Serum YKL-40 is increased in patients with hepatic fibrosis.
OBJECTIVE
YKL-40, a mammalian member of the chitinase family, is a lectin that binds heparin and chitin. The function of YKL-40 is unknown, but it may function in tissue remodelling. The aims of this study were to assess the level of circulating YKL-40 in patients with various kinds and degree of chronic liver disease and its possible relation to liver fibrosis.


METHODS
Serum YKL-40 levels were determined by radioimmunoassay in 129 patients with suspected liver disease and related to histological findings and immunohistochemical staining of YKL-40 in a liver biopsy taken simultaneously with the blood sample.


RESULTS
The median serum YKL-40 was highest in patients with alcoholic cirrhosis (532 microg/l), in particular in patients with additional alcoholic hepatitis (740 microg/l). Patients with alcoholic cirrhosis, post-hepatitic cirrhosis (425 microg/l) and non-cirrhotic fibrosis (330 microg/l) had significantly higher serum YKL-40 than normal subjects (102 microg/l), patients with fatty liver (195 microg/l) or patients with viral hepatitis without fibrosis (174 microg/l). Serum YKL-40 was significantly (p<0.001) related to the degree of liver fibrosis with the highest levels in patients with moderate (466 microg/l) to severe (676 microg/l) fibrosis. Serum YKL-40 was also increased (p=0.018) in patients with slight fibrosis (270 microg/l) compared to patients without fibrosis. Immunohistochemical analysis demonstrated positive staining for YKL-40 antigen in areas with fibrosis, particularly areas with active fibrogenesis. YKL-40 staining was never found in hepatocytes.


CONCLUSIONS
Our study indicates that the increased serum YKL-40 in patients with liver disease of various degree and aetiology seems to reflect fibrosis and fibrogenesis.
Johansen
J S
JS
Department of Medicine, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark. julia.johansen@post3.tele.dk
Christoffersen
P
P
Møller
S
S
Price
P A
PA
Henriksen
J H
JH
Garbarsch
C
C
Bendtsen
F
F
D054392:Adipokines; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D006820:Hyaluronic Acid / Q000097:blood; D007150:Immunohistochemistry / Q000379:methods; D037102:Lectins; D008103:Liver Cirrhosis / Q000097:blood* / Q000473:pathology; D008107:Liver Diseases / Q000097:blood / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood; D012016:Reference Values; D013194:Staining and Labeling
D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins; D010446:Peptide Fragments; D011347:Procollagen; C041876:procollagen Type III-N-terminal peptide; D006820:Hyaluronic Acid