Amotosalen-inactivated fresh frozen plasma is comparable to solvent-detergent inactivated plasma to treat thrombotic thrombocytopenic purpura

Background: Therapeutic Plasma Exchange (TPE) is the primary therapy of immune-mediated Thrombotic Thrombocytopenic Purpura (iTTP). Efficacy and safety data for TPE of iTTP have been assessed with Quarantine and Solvent-Detergent inactivated (SD) plasma. Here, amotosalen-UVA pathogen inactivated (AI) plasma, also in routine use, was evaluated in iTTP. Methods: We conducted a retrospective review of iTTP cases prospectively reported to the French national registry (2010-2013). Cases reviewed underwent TPE with >= 70% of either AI or SD plasma. The primary endpoint was time to platelet count recovery; secondary endpoints were related to follow-up (sustained remission, relapses, flare-ups and refractoriness). Results: 30 Test patients were identified in the AI group which could be timely matched to 40 Control patients in the SD group. The groups were fairly comparable for clinical presentation. Major findings were: (i) iTTP patients were exposed to lower plasma volumes in the AI group than in the SD group; (ii) Recovery rates were comparable between the groups. Median time to platelet count recovery ( > 150 x 10(9)/L) trended to be shorter in the AI group though non significantly. Tolerance of AI vs SD plasma was of comparable frequency and severity in either group. Conclusion: TPE with Amotosalen-inactivated plasma demonstrated therapeutic efficacy and tolerability for iTTP patients. In view of the retrospective design, confirmation of these results is required in larger prospective studies.