Thrombotic thrombocytopenic purpura is a non-malignant but life-threatening haematological disorder caused by deficiency of ADAMTS13, a metalloproteinase cleaving ultra-large von Willebrand factor multimer. Urgent initiation of therapeutic plasma exchange, in most cases associated with corticosteroids, has dramatically increased outcome of patients presenting with thrombotic thrombocytopenic purpura. Recently a phase II trial with caplacizumab, a humanised nanobody binding to the A1 domain of von Willebrand factor, has shown promising results by reducing the number of plasma exchanges with an acceptable safety profile.

(BELG J HEMATOL 2016;7(2):79–81)