Factors Associated with Mortality in Patients Experiencing First Episodes of Acquired Thrombotic Thrombocytopenic Purpura (aTTP). Results of the Spanish TTP Registry

Introduction: Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare, but life-threatening, hematological disorder characterized by severe thrombocytopenia, hemolytic microangiopathic anemia, and frequent organ damage. The underlying pathophysiology of aTTP is a functional deficiency of plasma ADAMTS13 activity caused by antibodies directed against the ADAMTS13 protease. Despite plasma exchange (PEX) and immunosuppression with corticosteroids, and, more recently, rituximab, which achieve remission in most patients with aTTP, 10-20% of patients are refractory to treatment and die as a result of disease progression. Most of such deaths occur during first episodes of aTTP, as subsequent…