Characterization of efficacy and safety of pathogen inactivated and quarantine plasma in routine use for treatment of acquired immune thrombotic thrombocytopenic purpura

Background Auto‐immune thrombotic thrombocytopenic purpura ( TTP ) is a morbid multi‐organ disorder. Cardiac involvement not recognized in initial disease descriptions is a major cause of morbidity. Therapeutic plasma exchange ( TPE ) requires exposure to multiple plasma donors with risk of transfusion‐transmitted infection ( TTI ). Pathogen inactivation ( PI ) with amotosalen‐ UVA , the INTERCEPT Blood System for Plasma ( IBSP ) is licensed to reduce TTI risk. Methods An open‐label, retrospective study evaluated the efficacy of quarantine plasma ( QP ) and IBSP in TTP and defined treatment emergent cardiac abnormalities . Medical record review of sequential patient cohorts treated with QP and IBSP characterized efficacy by remission at 30 and 60 days (d) of treatment, time to remission, and volume (L/kg) of plasma required. Safety outcomes focused on cardiac adverse events ( AE ), relapse rates, and mortality. Results Thirty‐one patients (18 IBSP and 13 QP ) met study criteria for auto‐immune TTP . The proportions (%) of patients in remission at 30 d ( IBSP = 61·1, QP = 46·2, P = 0·570) and 60 d ( IBSP = 77·8, QP = 76·9, P = 1·00) were not different. Median days to remission were less for IBSP (15·0 vs. 24·0, P = 0·003). Relapse rates (%) 60 d after remission were not different between cohorts ( IBSP = 7·1, QP = 40·0, P = 0·150). ECG abnormalities before and during TPE were frequent; however, cardiac AE and mortality were not different between treatment cohorts. Conclusions Cardiac and a spectrum of ECG findings are common in TTP . In this study, IBSP and QP had similar therapeutic profiles for TPE .