Ultrastructural findings in bullous pemphigoid

Area of Science:

• Dermatology
• Immunodermatology
• Electron Microscopy

Background:

• Bullous pemphigoid (BP) is an autoimmune blistering disease of the skin.
• Understanding the ultrastructural and immunopathological changes in BP is crucial for diagnosis and treatment.
• The precise mechanism of blister formation and the role of perilesional skin changes require further investigation.

Purpose of the Study:

• To investigate the ultrastructural and immunofluorescence characteristics of blister formation in bullous pemphigoid.
• To compare changes in perilesional skin, distant normal skin, and artificially induced lesions.
• To elucidate the cellular and molecular events underlying blister formation in BP.

Main Methods:

• Electron microscopy and direct immunofluorescence examinations were performed.
• Skin samples included blister borders, perilesional normal skin, distant normal skin, and skin subjected to xenon lamp irradiation.
• Analysis focused on cellular morphology, intercellular spaces, and the presence of immunoglobulins and complement.

Main Results:

• Bullous pemphigoid blisters result from cleavage of basal cells from an intact basal lamina.
• Perilesional skin exhibits widened intercellular spaces and a reduced number of half-desmosomes.
• Xenon lamp irradiation induced similar ultrastructural changes to perilesional skin, but without in vivo immunoglobulin and complement deposition.

Conclusions:

• The findings elucidate the specific cleavage plane in bullous pemphigoid blisters.
• Perilesional skin changes in BP are characterized by alterations in cell adhesion structures.
• Xenon lamp irradiation can mimic some ultrastructural features of perilesional skin in BP, suggesting a role for external stimuli in disease pathogenesis.