Prospective studies on the routine use of a novel multivariant enzyme-linked immunosorbent assay for the diagnosis of autoimmune bullous diseases.

ABSTRACT

BACKGROUND: Serologic diagnosis of autoimmune blistering disease (AIBD) usually follows a sophisticated multistep algorithm. OBJECTIVE: We sought validation of a multivariant enzyme-linked immunosorbent assay (ELISA) in the routine diagnosis of AIBD. METHODS: The multivariant ELISA comprising 6 recombinant immunodominant forms of major AIBD target antigens, ie, desmoglein 1, desmoglein 3, envoplakin, BP180, BP230, and type VII collagen was applied in (1) a cohort of well-characterized AIBD (n = 173) and control sera (n = 130), (2) a prospective multicenter study with 204 sera from patients with newly diagnosed AIBD with positive direct immunofluorescence microscopy, and (3) a prospective monocenter study with 292 consecutive sera from patients with clinical suspicion of AIBD in comparison with the conventional multistep diagnostic algorithm. RESULTS: Concordant results in the multivariant ELISA compared with direct immunofluorescence microscopy were seen in 94% of patients with pemphigus and 71% of patients with pemphigoid (Cohen κ value, 0.95 and 0.66) and with the conventional multistep diagnostic approach in 91% of patients with pemphigus and 88% of patients with bullous pemphigoid and 93% of autoantibody-negative sera (Cohen κ, 0.95, 0.84, and 0.78). LIMITATIONS: IgA autoantibodies and less common target antigens were not analyzed. CONCLUSIONS: The multivariant ELISA is a practical, highly standardized, and widely available novel diagnostic tool for the routine diagnosis of AIBD.