Epithelial Antibody-Associated Immunobullous Diseases Testing
Immunobullous diseases are caused by or associated with specific autoantibodies that bind to epithelium. The autoantibodies are directed to components in skin and mucous membranes that are critical for cell-cell and cell-matrix adhesion, resulting directly or indirectly in tissue separation/blistering within and beneath the epithelium. Immunobullous diseases include pemphigus, pemphigoid, pemphigoid gestationis, epidermolysis bullosa acquisita (EBA), linear IgA disease, dermatitis herpetiformis, and bullous lupus erythematosus. Although the various diseases have characteristic clinical and histopathologic features, presentation may be atypical and often demonstrates overlap with other immunobullous diseases or with more common skin diseases such as eczema and urticaria. Accurate diagnosis depends on clinical assessment plus the detection of autoantibodies (tissue bound and/or circulating). Direct immunofluorescence (DIF) microscopy of a perilesional biopsy is used to detect patterns of immunoglobulins and complement component 3 (C3) that characterize the diseases. DIF is sensitive and is considered a diagnostic standard. Serum antibody testing using indirect fluorescent antibody (IFA) testing and enzyme-linked immunosorbent assays (ELISAs) can be used to distinguish the various disorders more precisely based on autoantibody reactions to specific epithelial antigenic targets. Although DIF testing of a biopsy specimen may be more sensitive than serum testing for diagnosing immunobullous diseases, either may be positive when the other is negative, and together they offer the most sensitivity. Precise diagnosis is important for prognosis, treatment decisions, and, importantly, because some immunobullous skin diseases are associated with malignancies. Monitoring serum autoantibody profiles and levels may be useful to follow disease expression and activity, including response to therapy.
Last Update: August 2019