title: Intra-epithelial CD8+ T cells and basement membrane disruption in oral lichen planus.
abstract: BACKGROUND
  We investigated basement membrane (BM) disruption and the distribution of mast cells (MCs) and T cell subsets, in oral lichen planus (OLP) and normal buccal mucosa (NBM) using immunohistochemistry. In OLP, there were increased numbers of tryptase+ MCs in areas of BM disruption (P < 0.05).
  
  
  METHODS
  We identified clusters of intraepithelial CD8+ T cells in OLP, specifically in regions of BM disruption. The number of intraepithelial CD8+ T cells in regions of BM disruption was significantly greater than in regions of BM continuity (P < 0.05).
  
  
  RESULTS
  There were comparable numbers of lamina propria CD8+ T cells in regions of BM disruption and BM continuity. The number of CD4+ T cells in the epithelium and lamina propria of OLP lesions did not vary between regions of BM disruption and BM continuity.
  
  
  CONCLUSIONS
  These data suggest a role for MCs in epithelial BM disruption in OLP. CD8+ T cells may migrate through BM breaks to enter the OLP epithelium.
authors.affiliation: Oral Biology & Pathology, School of Dentistry, The University of Queensland, Brisbane, Australia.
authors.forename: Xijing J
authors.initials: XJ
authors.lastname: Zhou
authors.forename: Philip B
authors.initials: PB
authors.lastname: Sugerman
authors.forename: Neil W
authors.initials: NW
authors.lastname: Savage
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Walsh
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Seymour
mesh_terms: D000704:Analysis of Variance; D001485:Basement Membrane / Q000473:pathology; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000473:pathology; D016827:CD8 Antigens / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000473:pathology*; D016022:Case-Control Studies; D002465:Cell Movement; D004848:Epithelium / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D017676:Lichen Planus, Oral / Q000473:pathology*; D018655:Lymphocyte Count; D008407:Mast Cells / Q000473:pathology; D009061:Mouth Mucosa / Q000473:pathology*; D012697:Serine Endopeptidases / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000473:pathology; D053802:Tryptases
chemical_list: D016827:CD8 Antigens; D012697:Serine Endopeptidases; D053802:Tryptases