title: Regulatory function of factor-XIIIa-positive dendrocytes in incipient toxic epidermal necrolysis and graft-versus-host reaction. A hypothesis.
abstract: BACKGROUND
  Lymphocyte-poor graft-versus-host-reaction (GVHR) and toxic epidermal necrolysis (TEN) share some histological resemblance. In both diseases, factor-XIIIa-positive dendrocytes show some morphological changes, probably as a response to altered cytokine environment.
  
  
  OBJECTIVE
  To study the ultrastructural aspect of boosted dendrocytes in GVHR and TEN.
  
  
  METHODS
  Sixty GVHR and 25 TEN lesions were examined using immunohistochemistry. Among them, 6 dendrocyte-rich cases of each disease were studied by electron microscopy.
  
  
  RESULTS
  Dendrocyte activation with enlarged endoplasmic reticulum, and collagen fiber and mast cell granule phagocytosis were evidenced in both diseases. Depletion in dendrocytes was only encountered in a few GVHR cases exhibiting specifically a sclerotic aspect in the superficial dermis.
  
  
  CONCLUSIONS
  Factor-XIIIa-positive dendrocytes probably play a role in the regulation of the connective tissue remodeling that may accompany epidermal destruction.
mesh_terms: D003713:Dendritic Cells / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D006087:Graft vs Host Reaction / Q000502:physiology*; D006801:Humans; D012867:Skin / Q000473:pathology; D013262:Stevens-Johnson Syndrome / Q000473:pathology / Q000503:physiopathology*; D011503:Transglutaminases / Q000032:analysis*