Therapeutic plasma exchange-related complications in patients with immune-mediated thrombotic thrombocytopenic purpura.

BACKGROUND: Daily therapeutic plasma exchange (TPE) is the cornerstone of treatment for immune-mediated thrombotic thrombocytopenic purpura (iTTP). However, TPE is not a risk-free procedure and there is scarce evidence regarding its safety in iTTP. This study aims to describe the TPE-related clinical complications occurred in a cohort of patients hospitalized for an acute iTTP episode. MATERIALS AND METHODS: In this cross-sectional study, patients hospitalized for an acute iTTP episode at the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico (Milan) between January 2016 and April 2022 undergoing a central venous catheter (CVC) placement to start TPE were enrolled. RESULTS: Thirty-three iTTP episodes from 32 patients were included, 20 (61%) first episodes and 2 (6%) complicated with acute exacerbations. Twenty-one episodes (64%) were complicated with at least one major TPE-related complication, 18 (55%) with at least one CVC-related complication, of which 9 (27%) with a major complication. Among major CVC-related complications, 5 were venous thromboses (VTs) requiring heparin treatment and CVC removal, and 3 infections (2 systemic) requiring systemic antibiotic treatment and CVC removal. The 19 CVC-related bleeds (in 16 episodes) were minor bleeds and required only local hemostatic medications. Among the major procedure-related complications, the most common were allergic reactions (present in 16 episodes, 49%), mostly urticarial rashes requiring systemic steroids and antihistamines, and clinical hypocalcemia (in 8 episodes, 24%). The episodes complicated with CVC-related VT or infection required a longer hospitalization and those complicated with CVC-related infection required also a higher number of TPE procedures. DISCUSSION: TPE procedure was well tolerated in our cohort of acute iTTP patients in the majority of cases, with CVC-related minor bleeds and allergic reactions being the most common complications. The occurrence of CVC-related major complications, as VT or infections, was associated with a longer hospitalization (medians: 30 vs 11.5 days).