A Case of Bullous Pemphigoid Patient Suggesting the Importance of Anti-BP180 Measurement

Bullous pemphigoid (BP) is an autoimmune blistering skin disease characterized by subepidermal bullae and circulating autoantibodies that bind to components of the hemidesmosome adhesion complex. The diagnosis of BP is based on clinical criteria and laboratory examinations, including direct and indirect immunofluorescence and the enzyme-linked immunosorbent assay (ELISA). Direct immunofluorescence and serological classic indirect immunofluorescence by using human salt-split skin sections and/or monkey esophagus sections have been mainly tested for BP. Antibodies targeting the structural hemidesmosomal proteins BP180 and BP230 have been shown to play a crucial role in the development of BP, and the detection of anti-BP180 antibodies by using an immunoassay ELISA or a chemiluminescent enzyme immunoassay (CLEIA) is routinely performed in Japan. We report on an 82-year-old man who was diagnosed with BP and followed up by testing anti-BP180 antibody. The patient responded well to the treatment, exhibiting a decreased anti-BP180 antibody that fluctuates in parallel with disease activity until a negative result, whereas the IIF test result was still positive. This discrepancy may be related to the fact that the IIF test detects the reaction of antibodies not only anti-BP180 but also anti-BP230. This study demonstrated that the enzyme immunoassay of anti-BP180 is useful as a part of routine examination for follow-up of disease activity and initial diagnosis of BP.