Immunogenic hotspots in the spacer domain of ADAMTS13 in immune‐mediated thrombotic thrombocytopenic purpura

International audience; Background Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is caused by anti-ADAMTS13 autoantibodies inducing a severe deficiency of ADAMTS13. Epitope mapping studies on samples obtained during acute iTTP episodes have shown that the iTTP immune response is polyclonal, with almost all patients having autoantibodies targeting the spacer domain of ADAMTS13.Objectives To identify the immunogenic hotspots in the spacer domain of ADAMTS13.Patients/methods A library of 11 full-length ADAMTS13 spacer hybrids was created in which amino acid regions of the spacer domain of ADAMTS13 were exchanged by the corresponding region of the spacer domain of ADAMTS1. Next, th…