Splenectomy relapsing and plasma-refractory acquired thrombotic thrombocytopenic purpura

Background and Objectives. Acquired thrombotic thrombocytopenic purpura (TTP) is often due to autoantibodies inhibiting ADAMTS-13 activity resulting in impaired processing of very large von Willebrand factor multimers. TTP usually presents with an acute onset and a fulminant, sometimes fatal course. With appropriate treatment including plasma exchange, and fresh frozen plasma replacement, often supplemented by immunosuppressive therapy, the acute episode generally resolves within days to weeks. Design and Methods. We describe the clinical course of 3 patients with acquired TTP. One was refractory to PE, the other 2 relapsed after this treatment. All three were treated with splenectomy. ADAMTS-13 activity and inhibitor levels were monitored. Results. ADAMTS-13 activity was initially < 5% in all 3 patients. After splenectomy the inhibitor against ADAMTS-13 disappeared rapidly in 2 patients and there was full recovery of ADAMTS-13 activity in all 3 patients. Interpretation and Conclusions. Splenectomy, by eliminating a source of pathogenic autoantibody production, can be a successful treatment for patients with relapsing or plasma-refractory acquired TTP due to autoantibody-mediated ADAMTS-13 deficiency.