title: Oral lichen planus and dermal dendrocytes.
abstract: BACKGROUND
  Oral lichen planus (OLP) is a relatively common inflammatory disease with a wide range of clinical forms. Its pathogenesis has not been fully elucidated although it is known to be mediated by lymphocytes with the participation of cytokines and other inflammatory cells, including type I and type II dermal dendrocytes (DD) (factor XIIIa+ DD and CD34+ DD, respectively).
  
  
  OBJECTIVE
  To describe the presence and tissue distribution of these cells, through immunohistochemistry, in 23 specimens from patients with clinical and histopathological criteria of OLP.
  
  
  RESULTS
  Factor XIIIa+ DD were mainly located in the superficial dermis (p < 0.0001) as opposed to the deep submucosa. These cells were abundant throughout the dermal-epidermal junction and closely related to lymphocyte infiltration. Moreover, factor XIIIa+ DD were also found in the epithelium and deep dermis. CD34+ DD were distributed mostly to the deep dermis directly below the lymphocyte infiltrate with few cells in the subepithelial region.
  
  
  CONCLUSIONS
  DD were present in OLP, with distinct tissue distributions. Factor XIIIa+ DD were predominant in the superficial dermis while CD34+ DD could be found mostly in the deep dermis. These findings suggest that DD, and those positive for factor XIIIa+ in particular in view of their ability to express intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor alpha (TNF-alpha), may play an important role in pathogenesis of OLP.
authors.affiliation: Sector of Dermatology and Post Graduation Course, HUCFF/UFRJ and School of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: A L
authors.initials: AL
authors.lastname: Cardozo
authors.forename: C
authors.initials: C
authors.lastname: Moura-Castro
authors.forename: M
authors.initials: M
authors.lastname: Figueiredo
authors.forename: T
authors.initials: T
authors.lastname: Cuzzi
authors.forename: M
authors.initials: M
authors.lastname: Ramos-e-Silva
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis; D000943:Antigens, Differentiation / Q000032:analysis; D001706:Biopsy; D001854:Bone Marrow Cells / Q000166:cytology; D019070:Cell Lineage; D026122:Factor XIIIa / Q000032:analysis; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D017676:Lichen Planus, Oral / Q000276:immunology / Q000473:pathology*; D012157:Mononuclear Phagocyte System / Q000737:chemistry / Q000276:immunology / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D018952:Antigens, CD34; D000943:Antigens, Differentiation; D006684:HLA-DR Antigens; D026122:Factor XIIIa