Diagnostic Usefulness of Immunoblot Assay in Autoimmune Bullous Dermatoses / 대한면역학회지

ABSTRACT

Immunologic or immunopathologic assays are neccesary for the diagnosis of autoimmune bullous dermatoses including pemphigus vulgaris (PV), bullous pemphigoid (BP), and epidermolysis bullosa acquisita (EBA). The objectives of this study is to compare the sensitivity and usefulness of indirect immunofluorescence 0F) with that of immunoblot assay using amplified alkaline phosphatase staining system in the diagnosis of the above diseases; detection of disease-specific IgG autoantibodies. We selected 4 patients in each bullous dermatosis of PV, BP, and EBA, who had serum levels of IgG autoantibodies at a titer of 180 or higher. In each three disease, 2 patients with negative serum antibodies or serum titer lower than 120, were also enrolled. Among the former 4-patient groups the titers of IgG antibodies found on indirect IF were in the range of 180 to 1160, whereas the titers recognized by immunoblot assay were 1 or 2 dilutions higher in most of these patients. In the latter 2-patient groups, 4 out of the 6 cases revealed antibody-positive on immunoblot-staining membrane. The indirect IF can be performed easily and seems favorable in the aspect of cost-effectiveness. However, immunoblot assay with sensitive staining method would be warranted in cases of antibody-negative or atypical clinical variants of autoimmunebullous dermatoses to confirm the diagnosis.