title: Immunohistochemical expression of YKL-40 in peritoneal endometriosis.
abstract: OBJECTIVE
  To evaluate the relationship between the immunohistochemical expression of YKL-40 and peritoneal endometriosis by using paraffinized peritoneal tissue blocks.
  
  
  METHODS
  We retrospectively collected data from 27 patients whose pathologic reports indicated invasion of the peritoneum by endometriosis. A conventional peroxidase staining technique was performed using rabbit polyclonal antibody (Quidel corporation, Santa Clara, CA) on peritoneal tissue blocks; their histology was then reviewed by a pathologist, and data were analyzed by nonparametric and Mann-Whitney tests.
  
  
  RESULTS
  YKL-40 was detected immunohistochemically in 17 (63%) of 27 cases. The number of biopsies which were invaded by endometriosis (P = 0.015), with a score based on the revised classification of endometriosis (American Society for Reproductive Medicine) had statistical significance (P = 0.001). The obstetric history, age, body mass index, severity, and occurrence of dysmenorrhea, menstrual phase, preoperative CA 125, erythrocyte sedimentation rate, and white blood cell count had no statistical significance. YKL-40 immunoreactivity was recognized as brown staining, localized to the cytoplasm of epithelial cells of endometrial gland in peritoneal endometriosis. There was no positive staining on endometrial stromal cells or smooth muscle cells.
  
  
  CONCLUSIONS
  YKL-40 is related to severity of peritoneal endometriosis. However why a different expression level of immunohistochemical staining should occur is not known and needs further investigation.
authors.affiliation: Department of Obstetrics and Gynecology, Kyungpook National University, Graduate School Of Medicine, Daegu, Korea.
authors.forename: Pan Jo
authors.initials: PJ
authors.lastname: Kim
authors.forename: Dae Gy
authors.initials: DG
authors.lastname: Hong
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Park
authors.forename: Young Lae
authors.initials: YL
authors.lastname: Cho
authors.forename: Il Soo
authors.initials: IS
authors.lastname: Park
authors.forename: Yoon Soon
authors.initials: YS
authors.lastname: Lee
mesh_terms: D054392:Adipokines; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D000071451:Chitinase-3-Like Protein 1; D004715:Endometriosis / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D037102:Lectins / Q000378:metabolism*; D008875:Middle Aged; D010532:Peritoneal Diseases / Q000378:metabolism*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014018:Tissue Distribution
chemical_list: D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins