A pool of sera from 3 patients with biopsy-proven, acute TEN was used as a reagent in an organ culture. A pool of sera from 3 age- and race-matched healthy individuals was used as a control reagent. Normal human skin (NHS), normal human conjunctiva (NHC), and normal human buccal mucosa (NHBM) were used as substrates in the organ culture. Informed consent was obtained from all patients and healthy individuals. All experiments were approved by an institutional review board.