Research Techniques Made Simple: Immunofluorescence Antigen Mapping in Epidermolysis Bullosa

Abstract

Inherited epidermolysis bullosa is a group of genetic blistering diseases with a broad spectrum of clinical severity and molecular defects. Epidermolysis bullosa results from mutations in genes encoding proteins involved in cell-cell and cell-matrix adhesion in the epidermis. Immunofluorescence antigen mapping makes use of monoclonal antibodies against proteins of the dermal-epidermal junction zone to determine the layer of skin where cleavage occurs and the relative protein abundance. It allows the diagnosis of the type and subtype of inherited epidermolysis bullosa and sheds light on molecular mechanisms underlying the disease. Immunofluorescence mapping steps include obtaining a skin biopsy sample, processing the biopsy material, antigen-antibody interaction on tissue, washing, incubation with fluorescently conjugated secondary antibodies, mounting, observation under a fluorescence microscope, and interpretation. A minimal antibody panel allows discrimination of the main epidermolysis bullosa subtypes. Extended panels can be used depending on the diagnostic or scientific question to be addressed. Immunofluorescence mapping contributed to significant progress in understanding epidermolysis bullosa, including identification of new underlying genetic mutations, mutation mechanisms, and the presence of revertant mosaicism. It is also an important tool in the assessment of the efficacy of experimental therapeutic approaches.