Venous thrombo-embolism during immune-mediated thrombotic thrombocytopenic purpura is prevalent in patients with a prolonged treatment with therapeutic plasma exchange

Introduction. - Thrombotic thrombocytopenic purpura (TTP) is a devastating disease characterized by disseminated microvascular thrombosis. Despite pro-thrombotic predisposing conditions, the prevalence of macrovascular venous thrombosis event (VTE) in immune-mediated TTP (iTTP) has rarely been assessed. Methods. -We reviewed data of all iTTP patients of the French reference Center for thrombotic microangiopathies registry prospectively enrolled through a 10-year period, between 2008 and 2018. Venous thrombosis included either thrombosis of central venous catheter, symptomatic deep venous thrombosis of the limbs or pulmonary embolism. Results. -Forty-eight (12.7%) VTE were diagnosed. VTE was diagnosed after a median time of 7 [IQR, 3-16] days following the first therapeutic plasma exchange (TPE) and consisted mainly in catheter-related thrombosis (73%), and to a lesser extend symptomatic deep venous thrombosis (16%), proximal pulmonary embolism (8%) and splanchnic vein thrombosis (2%). Caseswith VTE (VTE+ cases), requiredmore TPE to achieve remission (P b 0.01), and the total volume of plasma required to achieve remissionwas larger (P b 0.01) than for VTE-cases. There was also a trend for more rituximab use in the VTE+ cases as compared to the VTE-cases (47% vs 33%; respectively; P= 0.07). Curative anticoagulationwas started in 38 cases (79%), while 6 VTE cases did not receive any antithrombotic agents, and catheter was systematically removed when catheter-related thrombosiswas diagnosed. VTE+ cases had a higher number of inserted central venous catheters than VTE-cases (P < 0.05). Conclusion. -VTE is a frequent condition occurring during iTTP management and is observed when patients require a prolonged treatment with daily TPE and multiple catheter insertions. Therapeutic strategies aimed at reducing the duration of TPE treatment in iTTP should substantially reduce this complication. (C) 2020 Societe Nationale Francaise de Medecine Interne (SNFMI). Published by Elsevier Masson SAS. All rights reserved.