An extract of cultured A431 cells contains major tissue antigens of autoimmune bullous diseases

Background Autoantibodies that are characteristic of autoimmune bullous dis eases (AIBDs) can be detected by immunoblot assay using epidermal or dermal extracts. However, none of the substrates obtained by ordinary methods see ms to contain a sufficient amount of all of the autoantigens involved in AI BDs, and diagnosis may require the use of several different substrates. Objectives To examine the potential of A431 cell extracts as a substrate fo r immunoblotting. Methods Fourteen sera obtained from patients with major AIBDs (pemphigus vu lgaris, pemphigus foliaceus, paraneoplastic pemphigus, bullous pemphigoid a nd epidermolysis bullosa acquisita) were tested using this substrate. Results Bands corresponding to desmoglein 1 and 3, desmoplakin 1 and 2, per iplakin, BPAG1, BPAG2 and type VII collagen were identified distinctly with these sera. Conclusions This finding suggests that culture extracts of A431 cells provi de an effective substrate for the diagnosis and differential diagnosis of m ajor AIBDs.