Identification of the 80-kDa protein recognized by IgG Abs of patients with AA. UT-7 lysates (lanes 1, 4), culture supernatants of UT-7 cells (lanes 2, 5, 7), and recombinant Grp 78 protein (lanes 3, 6) were subjected to Western blotting using sera from a healthy person (lanes 1-3), a patients with PNH⁺ AA (lanes 4-6), and antimoesin monoclonal Ab (lane 7). The arrow indicates 80-kDa protein bands.