ADAMTS13 Antibody Depletion by Bortezomib in Thrombotic Thrombocytopenic Purpura

Abstract

To the Editor: Inhibitory autoantibodies against ADAMTS13, a metalloproteinase enzyme that cleaves von Willebrand factor, are associated with the majority of nonfamilial cases of thrombotic thrombocytopenic purpura (TTP). Therapeutic plasma exchange aims to remove autoantibodies while replenishing levels of ADAMTS13.1 Adjunctive immunosuppression is often required and may include selective B-cell depletion with rituximab.1,2 Here we report a case of acute TTP in which the disease was refractory to plasma exchange and immunosuppression. Subsequent treatment with the proteasome inhibitor bortezomib resulted in a rapid clinical response associated with in vivo depletion of inhibitory autoantibodies against ADAMTS13. A 53-year-old woman presented . . .