title: Hepatocyte paraffin 1 immunoexpression in esophageal brush samples.
abstract: BACKGROUND
  Intestinal metaplasia (IM) is often a component of Barrett esophagus (BE) and is characterized by a distinctive type of epithelium. Because IM has the potential to progress to dysplasia or adenocarcinoma, an accurate identification of its presence is important clinically. A cytopathologic diagnosis of IM on esophageal brushings by morphology alone can be difficult. The authors investigated the role of hepatocyte paraffin 1 (Heppar-1) immunostaining as a possible marker of IM in cytologic samples of BE.
  
  
  METHODS
  Eleven samples each of BE with and without IM diagnosed on esophageal brushings were retrieved from the cytopathology files of The Johns Hopkins Hospital over an 8-year period (1993-2001). All 22 specimens were confirmed histologically on subsequent tissue biopsies. Slides initially were prepared by cytospin and stained with Papanicolaou stain. After destaining, the slides were immunostained with hepatocyte paraffin 1 (Heppar-1) antibody at 1:100 dilution employing conventional methodology.
  
  
  RESULTS
  Among the samples of BE with IM, 9 of 11 samples (82%) were immunoreactive for Heppar-1, compared with 0 of 11 specimens of BE with only cardiac-type metaplasia. The immunoexpression was cytoplasmic and granular and was seen only focally in the glandular fragments.
  
  
  CONCLUSIONS
  Heppar-1 was a moderately sensitive (82%) and highly specific (100%) immunomarker for IM in BE. It was easy to use in limited cytologic samples that originally were stained with Papanicolaou stain and is recommended for inclusion in morphologically difficult samples of BE with questionable IM. The immunostaining pattern predominantly was focal, necessitating a careful evaluation of positive reactions on cytologic samples.
authors.affiliation: Department of Pathology, The Johns Hopkins Hospital, Baltimore, Maryland 21287, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Anil V
authors.initials: AV
authors.lastname: Parwani
authors.forename: Syed Z
authors.initials: SZ
authors.lastname: Ali
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000941:Antigens / Q000032:analysis / Q000096:biosynthesis*; D001471:Barrett Esophagus / Q000175:diagnosis* / Q000473:pathology*; D015415:Biomarkers / Q000032:analysis; D003584:Cytological Techniques; D004938:Esophageal Neoplasms / Q000209:etiology; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D007118:Immunoassay; D008679:Metaplasia; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000941:Antigens; D015415:Biomarkers; C493846:veltuzumab