Determinants and Clinical Impact of Time to Plasma Exchange in Patients with Immune Thrombotic Thrombocytopenic Purpura

Background:Immune thrombotic thrombocytopenic purpura (iTTP) is a hematologic emergency characterized by severe acquired deficiency in the von Willebrand factor-cleaving metalloprotease ADAMTS13 and thrombotic microangiopathy, resulting in end organ damage and death if untreated. Plasma exchange (PLEX) is vital to the management of iTTP and has dramatically improved survival in this disorder since the 1980s. Guidelines recommend initiation of PLEX within 4-8 hours of presentation. However, despite the importance of prompt medical intervention, determinants of the total interval between symptom onset and initiation of PLEX (S2P) and time from presentation at the pheresis center to PLEX (door to PLEX, D2P) remain unclear. Further, the impact of S2P and D2P on clinical outcomes in iTTP have not been evaluated.