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


Suying Feng, md 14 Jiangwangmiao Street Nanjing 210042 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 × 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.