Sensitivity of immunoblot assay for antibodies to plakin and alpha-2-macroglobulin-like 1 protein 1 (A2ML1) in the diagnosis of paraneoplastic pemphigus

Background: Paraneoplastic pemphigus (PNP) is a rare autoimmune bullous disease associated with underlying malignant neoplasms. Diagnosis of PNP is a challenge for clinicians due to heterogeneous clinical presentation and lack of consensual diagnostic criteria. Studies have reported the pathogenic role of multiple antigenic targets in PNP including plakins and a protease inhibitor, α-2-macroglobulin-like protein 1 (A2ML1). In this study, results of an immunoblot panel comprising of envoplakin, periplakin and alpha-2 macroglobulin-like-1 protein were compared to traditional methods for diagnosis of PNP.