title: Expression of proliferating cell nuclear antigen (PCNA) and Ki-67 in dysplasia in inflammatory bowel disease.
abstract: OBJECTIVE
  Previous studies have revealed large variations in the interobserver agreement of dysplasia grading in inflammatory bowel disease. Therefore, we investigated the diagnostic value of two novel monoclonal antibodies (MIB 1 against Ki-67 and PC 10 against PCNA) in the detection of dysplasia.
  
  
  METHODS
  A total of 62 biopsies were investigated and histologically classified as follows: 13 probably positive for dysplasia; 15 low-grade dysplasia; five high-grade dysplasia; and 15 inflammation without dysplasia and 14 normal controls. The percentage of positive Ki-67- or PCNA-stained nuclei (= labelling index) was determined in relation to the distribution throughout the mucosa.
  
  
  RESULTS
  In all biopsies PCNA-labelling index exceeded that of Ki-67-labelling index. In the superficial half of the crypt PCNA- and Ki-67-labelling indices in the biopsies with 'indefinite for dysplasia, probably positive' or low-grade dysplasia exceeded that of normal tissue (P < 0.001). However, an unequivocal discrimination between biopsies with 'indefinite for dysplasia, probably positive' or low-grade dysplasia and inflammation was not possible. PCNA- and Ki-67-labelling indices were significantly higher in high-grade than in low-grade dysplasia (PCNA 81.4% vs. 44.3%, Ki-67 54.8% vs 30.9%, P < 0.001). Most interestingly, labelling indices of both markers were significantly (P < 0.0001) higher in biopsies with high-grade dysplasia than with active inflammation in the superficial half of the crypt.
  
  
  CONCLUSIONS
  PCNA and Ki-67 are useful adjuncts in the diagnosis of high-grade dysplasia, because high-grade dysplasia can easily be distinguished from low-grade dysplasia or active inflammation if the distribution of the positive-stained cells within the mucosa is taken into account. Lower unspecific binding and lower influence on proliferation activity by inflammation prompts us to prefer Ki-67 (MIB 1).
authors.affiliation: Department of Internal Medicine I, University of Regensburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Kullmann
authors.forename: M
authors.initials: M
authors.lastname: Fadaie
authors.forename: V
authors.initials: V
authors.lastname: Gross
authors.forename: R
authors.initials: R
authors.lastname: Knüchel
authors.forename: T
authors.initials: T
authors.lastname: Bocker
authors.forename: P
authors.initials: P
authors.lastname: Steinbach
authors.forename: J
authors.initials: J
authors.lastname: Schölmerich
authors.forename: J
authors.initials: J
authors.lastname: Rüschoff
mesh_terms: D001706:Biopsy; D003093:Colitis, Ulcerative / Q000175:diagnosis* / Q000473:pathology; D003106:Colon / Q000473:pathology; D003424:Crohn Disease / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000737:chemistry / Q000473:pathology; D019394:Ki-67 Antigen / Q000032:analysis*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis*; D012007:Rectum / Q000473:pathology
chemical_list: D019394:Ki-67 Antigen; D018809:Proliferating Cell Nuclear Antigen