Abstract: Objective To establish a new method for detecting pemphigus antibody (PAb). Methods PI 1 anti idiotype monoclonal antibodies against pemphigus and purified PAb from the serum of a patient with active pemphigus were used to establish an ELISA system for detecting the PAb. Results The result showed the purified PAb was IgG4 subclass, the sensitivity and specificity for the detection of PAb were high in the ELISA system, the sensitivity and specificity were not significantly different among the IIF, indirect ELISA and ABC-ELISA. The standard curve for detecting the concentration of the purified PAb was primarily obtained in the study. Conclusion The ELISA system for the detection of PAb in the sera of patients is a good qualitative method, it might be of value in the clinical diagnosis of pemphigus. It is expected to quantitatively detect PAb of pemphigus patients in the future with the ELISA system established, which is directed to the IgG4 subclass of PAb, so it may be of value in the study of IgG4 subclass in the pathogenesis of pemphigus.

Key words: Pemphigus, Antibodies,anti-idiotypic, Enzyme-linked immunosorbent assay