title: Ki67 and p53 immunohistochemistry reduces interobserver variation in assessment of Barrett's oesophagus.
abstract: OBJECTIVE
  To devise clinically applicable methods for assessing p53 and Ki67 immunohistochemical (IHC) reactivity in Barrett's oesophagus (BE) and to compare the interobserver agreement between these methods and routine haematoxylin and eosin (H&E) evaluation.
  
  
  RESULTS
  One hundred and fifteen biopsies diagnosed as BE, selected from the files of the University Hospital MAS, Malmo, were re-evaluated for dysplasia by three pathologists. For IHC analysis areas with the most prominent positivity were evaluated. The mean of p53+ epithelial nuclei/high-power field (HPF) was obtained by counting between 1 and 5 HPFs/biopsy. A proliferation quotient (PQ) was obtained by dividing the number of Ki67+ epithelial nuclei in the upper half by the lower half of the mucosa, using two HPFs. Mean kappa values were 0.24, 0.71 and 0.52 for H&E, p53 and Ki67 evaluations, respectively. There was a correlation between increasing severity of dysplasia, IHC measurable overexpression of p53 and shift of the mucosal proliferation zone towards the surface, measured as PQ.
  
  
  CONCLUSIONS
  The described methods for p53 and Ki67 evaluation are more reproducible than routine H&E evaluation of BE. Furthermore, the IHC methods correlate with the severity of dysplasia and are useful supplementary prognostic markers.
authors.affiliation: Division of Pathology, Department of Clinical Pathology and Cytology, University Hospital MAS, Malmö, Sweden. ester.lorinc@skane.se
authors.forename: E
authors.initials: E
authors.lastname: Lörinc
authors.forename: B
authors.initials: B
authors.lastname: Jakobsson
authors.forename: G
authors.initials: G
authors.lastname: Landberg
authors.forename: B
authors.initials: B
authors.lastname: Veress
mesh_terms: D001471:Barrett Esophagus / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods* / Q000706:statistics & numerical data; D019394:Ki-67 Antigen / Q000032:analysis*; D015588:Observer Variation; D015203:Reproducibility of Results; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53