Background and design: Diagnosis of autoimmune pemphigus is based on the immunodetection of IgG deposits in the epidermal intercellular spaces. Desmoglein is a desmosomal component that has been assumed to be the antigen of pemphigus foliaceus. We investigated the use of one monoclonal antibody (32-2B) to desmoglein 1 on paraffin sections. Twenty-nine pemphigus samples were studied (22 pemphigus vulgaris, seven pemphigus foliaceus).
Results: In 29 patients suffering from autoimmune pemphigus, the staining for desmoglein was represented by coarse granules along the cytoplasmic borders of epithelial cells in lesional and perilesional skin and in mucous membranes. This peculiar staining is different from the fine dots along the cytoplasmic membrane observed in normal skin. This abnormal staining seems to be specific for pemphigus. Hereditary acantholytic diseases and other diseases such as bullous pemphigoid, intraepidermal IgA dermatosis, eczema, herpes, and transient acantholytic dermatosis show a similar pattern to normal skin.
Conclusion: The use of 32-2B on biopsy specimens in cases of autoimmune pemphigus demonstrated a specific staining pattern. It could be used on paraffin sections as a diagnostic test of autoimmune pemphigus. It can even be done retrospectively.