Role of BP180NC16a-enzyme-linked immunosorbent assay (ELISA) in the diagnosis of bullous pemphigoid in China.

BACKGROUND: Autoantibodies of bullous pemphigoid (BP) patients react with two components of the hemidesmosome of stratified epithelia: the BP antigen 230 (BP230) and the BP antigen 180 (BP180). Recently, strong evidence has been provided that autoantibodies to BP180 play a key role in subepidermal blister formation in BP patients, and NC16A contains an important antigen determinant of BP.

OBJECTIVE: To study the role of BP180NC16a enzyme-linked immunosorbent assay (BP180NC16a-ELISA) in the diagnosis of BP in China.

METHODS: Sera from BP patients (n = 42) and control subjects (normal controls, n = 24; pemphigus patients, n = 18) were measured by BP180NC16a-ELISA. All BP sera were obtained at presentation from patients who had not received previous systemic treatment. The values of immunoglobulin G (IgG) antibody levels measured by ELISA were compared with those measured by indirect immunofluorescence (IIF) (gold standard for the diagnosis of BP) on salt-split skin.

RESULTS: Using BP180NC16a-ELISA, 41 of the 42 BP sera were positive, whereas only one of the serum samples from 24 normal controls was positive and all the pemphigus sera showed a negative result. Thus, the sensitivity and specificity of BP180NC16a-ELISA were both 97.62%. There was no correlation between the mean ELISA values and IIF titers. The ELISA and IIF results were further compared and analyzed using a 2 x 2 contingency table, which showed that they were not significantly different.

CONCLUSIONS: It is suggested that BP180NC16a-ELISA is a useful tool for the diagnosis of BP.