title: Diagnostic utility of a soluble cytokeratin 18 assay for gastrointestinal graft-vs.-host disease detection.
abstract: BACKGROUND
  Gastrointestinal/liver graft-vs.-host disease is a frequent complication after allogeneic hematopoietic cell transplantation. Endoscopic biopsies are needed to confirm clinical diagnosis, but this is not always feasible due to concurrent complications after transplantation. Cytokeratin 18 is expressed in epithelial colon cells and hepatocytes. Apoptosis, a hallmark of graft-vs.-host disease, results in the cleavage of cytokeratin 18 and the resulting fragments are released into the circulation.
  
  
  METHODS
  The aim of the present study was to assess the general performance and usefulness of a serologic test for soluble cytokeratin 18 for gastrointestinal/liver graft-vs.-host disease detection. Plasmatic concentration of soluble cytokeratin 18 was measured in 38 individuals undergoing hematopoietic cell transplantation. A two-fold increase of sCK18 above the pre-transplant concentration was used as a threshold value.
  
  
  RESULTS
  Plasmatic concentration of soluble cytokeratin 18 was significantly elevated in patients with gastrointestinal/liver graft-vs.-host disease. Soluble cytokeratin 18 concentration raised before the onset of clinical symptoms in 69% of the patients with gastrointestinal/liver graft-vs.-host disease. The threshold value used in our study resulted in a high sensitivity and a low false negative rate for gastrointestinal/liver graft-vs.-host disease detection.
  
  
  CONCLUSIONS
  Soluble cytokeratin 18 seems to be a suitable biomarker for gastrointestinal/liver graft-vs.-host disease detection, particularly when a biopsy is not feasible.
authors.affiliation: Department of Hematology/Oncology, Freiburg University Medical Center, Freiburg, Germany. miguel.waterhouse@uniklinik-freiburg.de
authors.forename: Miguel
authors.initials: M
authors.lastname: Waterhouse
authors.forename: Ewa
authors.initials: E
authors.lastname: Samek
authors.forename: Marta
authors.initials: M
authors.lastname: Torres
authors.forename: Hartmut
authors.initials: H
authors.lastname: Bertz
authors.forename: Jürgen
authors.initials: J
authors.lastname: Finke
mesh_terms: D005767:Gastrointestinal Diseases / Q000473:pathology*; D006086:Graft vs Host Disease / Q000175:diagnosis*; D006801:Humans; D053538:Keratin-18 / Q000097:blood*; D012372:ROC Curve; D012015:Reference Standards; D012995:Solubility
chemical_list: D053538:Keratin-18