Diagnostic Utility of Full-Length BP180 and Native BP180-α6β4 Integrin Complex ELISAs in Serologically Inconclusive Mucous Membrane Pemphigoid.

Mucous membrane pemphigoid (MMP) is a chronic autoimmune subepithelial blistering disorder of mucosal surfaces that can cause irreversible scarring, blindness, or dysphagia. Early diagnosis is challenging because histopathology is nonspecific and conventional BP180 NC16A ELISAs have limited sensitivity. We evaluated ELISAs using full-length recombinant BP180 and a native BP180-α6β4 integrin complex in six patients with suspected oral or ocular MMP. The conventional NC16A ELISA was negative in four of six patients, and biopsy alone was often insufficient. Both assays provided useful serological support in a subset of cases when interpreted alongside direct immunofluorescence (DIF) and clinical phenotype, whereas in others DIF remained the primary basis for diagnosis. These assays can therefore complement, but not replace, clinicopathological assessment in suspected MMP.