Pemphigoid nodularis with IgA autoantibodies against the intracellular domain of desmoglein 1

• Published in: British journal of dermatology (1951) Vol. 142; no. 1; pp. 143 - 147
• Main Authors: Fujisawa, H., Ishii, Y., Tateishi, T., Kawachi, Y., Otsuka, F., Amagai, M., Komai, A., Hashimoto, T.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-01-2000; Blackwell; Oxford University Press
• Subjects: Anti-Inflammatory Agents - administration & dosage; Antibodies, Anti-Idiotypic - immunology; Biological and medical sciences; Bullous diseases of the skin; Cytoskeletal Proteins - immunology; Dermatology; Desmoglein 1; Desmogleins; Desmoplakins; Humans; IgA autoantibody; Immunoglobulin A - immunology; Male; Medical sciences; pemphigoid nodularis; Pemphigoid, Bullous - immunology; Prednisolone - administration & dosage; Bullous dermatosis; Case study; Human; Immunopathology; Skin disease; IgA; Antibody; Bullous pemphigoid; Nodular prurigo; Autoantibody; Autoimmune disease; Japanese
• ISSN: 0007-0963; 1365-2133
• DOI: 10.1046/j.1365-2133.2000.03257.x

Pemphigoid nodularis is a rare variant of bullous pemphigoid. We report a 49‐year‐old Japanese male with clinical and histopathological features of pemphigoid nodularis including circulating and in vivo‐bound IgG antibasement membrane zone antibodies and IgA anti‐intercellular antibodies. Although the precise molecular target of the IgG autoantibodies could not be determined, intriguingly, immunoblotting showed that the IgA in the patient’s serum reacted with the intracellular domain of desmoglein 1, the target antigen in cases of pemphigus foliaceus. However, the IgA did not react with the extracellular domain of desmoglein 1 in sensitive enzyme‐linked immunosorbent assay studies using a baculovirus system. These results suggest therefore that these IgA antibodies may possibly not be pathogenic. The mechanism for the production of different autoantibodies is unknown, but this case provides further illustration of the atypical skin immunoreactants often seen in this unusual subtype of bullous pemphigoid.