title: T-bet expression patterns in coeliac disease, cryptic and overt enteropathy-type T-cell lymphoma.
abstract: OBJECTIVE
  To clarify the distribution and lineage allocation of T-bet-expressing cells in coeliac disease (CD) and in enteropathy-type T-cell lymphoma (ETTCL). The detection of elevated levels of interferon-gamma, interleukin-18 and the key regulator of Th1 helper immune response T-bet in CD biopsies led to the view that CD is the result of a Th1 response to gluten. It remains unknown whether T-bet is expressed in cryptic and overt ETTCL.
  
  
  METHODS
  Specimens from 20 patients with CD, five patients with cryptic and 10 patients with overt ETTCL were analysed by immunohistology employing single and double labellings for T-bet and CD4 or CD8 antigens.
  
  
  RESULTS
  In CD specimens nearly all intraepithelial CD8 cells and many CD4 cells in the lamina propria expressed T-bet. Cryptic ETTCL showed T-bet expression in the intraepithelial neoplastic cells while T-bet+ CD4 cells in the lamina propria were rare. Overt ETTCL showed T-bet expression in cases with non-anaplastic morphology. In addition, a proportion of bystander T cells expressed T-bet.
  
  
  CONCLUSIONS
  Morphological evidence proves that while T-bet orchestrates a CD4- and CD8-based Th1 reaction in CD, its expression shifts to the neoplastic intraepithelial compartment of cryptic ETTCL and becomes absent or lost in anaplastic overt ETTCL.
authors.affiliation: Institute of Pathology, Consultation and Reference Centre for Lymph Node Pathology and Haematopathology, Charité, Campus Benjamin Franklin, Medical University Berlin, Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Jöhrens
authors.forename: I
authors.initials: I
authors.lastname: Anagnostopoulos
authors.forename: H
authors.initials: H
authors.lastname: Stein
mesh_terms: D015704:CD4 Antigens / Q000096:biosynthesis; D016827:CD8 Antigens / Q000096:biosynthesis; D002446:Celiac Disease / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007414:Intestinal Neoplasms / Q000378:metabolism* / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000378:metabolism* / Q000473:pathology; D016133:Polymerase Chain Reaction; D020825:T-Box Domain Proteins; D014157:Transcription Factors / Q000096:biosynthesis*; D000098815:T-bet Transcription Factor
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D014157:Transcription Factors