Type of plasma preparation used for plasma exchange and clinical outcome of adult patients with acquired idiopathic thrombotic thrombocytopenic purpura: a French retrospective multicenter cohort study

Plasma exchange (PE) is the first-line therapy of acquired thrombotic thrombocytopenic purpura (TTP). Several plasma preparations have been available; their equivalence in terms of outcome remains uncertain.We performed a retrospective analysis of the cases prospectively reported from 2005 to 2010 to the national registry established by the thrombotic microangiopathies French reference center. We analyzed 108 initial episodes of acquired idiopathic TTP in adults treated with PE, 81 with solvent/detergent (S/D) plasma, and 27 with quarantine fresh-frozen plasma (qFFP). The primary endpoint was the time to platelet (PLT) count recovery.Time to PLT count recovery was not significantly different with S/D plasma versus qFFP (median, 15 days vs. 19 days, respectively; p = 0.126). Complete remission rates, exacerbations, and survival were comparable. By multivariate competitive risk (Fine-Gray) analysis, the only significant association with a shorter time to PLT count recovery was the absence of additional treatment (hazard ratio, 2.06; 95% confidence interval [CI], 1.39-3.05; p 0.001). There was a significant interaction between type of plasma and age, and for patients less than 40 years old, the use of S/D plasma was associated with a shorter time to PLT count recovery versus qFFP (median, 13 [95% CI, 9-16] days vs. 20 [95% CI, 16-64] days, respectively; p = 0.004).The outcomes of acquired TTP treated with S/D plasma or qFFP seem similar and therefore both preparations can be used safely for PE in this indication. The faster response of S/D plasma observed in younger patients warrants confirmation in prospective studies.