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.
Conclusion: Factor-XIIIa-positive dendrocytes probably play a role in the regulation of the connective tissue remodeling that may accompany epidermal destruction.