Occurs when patients do not have a clinical response after 5 sessions of PEX. Clinical response is defined as sustained platelet count ≥150 × 109/L and LDH <1.5 times ULN and no clinical evidence of new or progressive organ injury.4
A platelet count decrease after a clinical response and before a clinical remission. A clinical exacerbation is defined as platelet count decrease to <150 × 109/L (with other causes of thrombocytopenia excluded), with or without clinical evidence of new or progressive ischemic organ injury, within 30 days of stopping any therapy.4
*Retrospective review of French Reference Centre for TMA registry (N=388).
A new episode of TTP after achieving clinical remission.† A clinical relapse is defined as platelet count decrease to <150 × 109/L (with other causes of thrombocytopenia ruled out), with or without clinical evidence of new ischemic organ injury and a confirmed documentation of severe ADAMTS13 deficiency.4
†Clinical remission is defined as sustained clinical response with no specific treatment for ≥30 days or attainment of ADAMTS13 remission.
ADAMTS13=a disintegrin and metalloproteinase with thrombospondin type 1 motif, 13; aTTP=acquired thrombotic thrombocytopenia purpura; LDH=lactate dehydrogenase; TMA=thrombotic microangiopathy; ULN=upper limit of normal; vWF=von Willebrand factor.
References: 1. Scully M, Cataland SR, Peyvandi F, et al. N Engl J Med. 2019;380(4):335-346. doi:10.1056/NEJMoa1806311 2. Joly BS, Coppo P, Veyradier A. Thrombotic thrombocytopenic purpura. Blood. 2017;129(21):2836-2846. doi:10.1182/blood-2016-10-709857 3. Sayani FA, Abrams CS. How I treat refractory thrombotic thrombocytopenic purpura. Blood. 2015;125(25):3860-3867. doi:10.1182/blood-2014-11-551580 4. Cuker A, Cataland SR, Coppo P, et al; International Working Group for Thrombotic Thrombocytopenic Purpura. Redefining outcomes in immune TTP: an international working group consensus report. Blood. 2021;137(14):1855-1861. doi:10.1182/blood.2020009150 5. Han B, Page EE, Stewart LM, et al. Depression and cognitive impairment following recovery from thrombotic thrombocytopenic purpura. Am J Hematol. 2015;90(8):709-714. doi:10.1002/ ajh.24060 6. Deford CC, Reese JA, Schwartz LH, et al. Multiple major morbidities and increased mortality during long-term follow-up after recovery from thrombotic thrombocytopenic purpura. Blood. 2013;122(12):2023-2029. doi:10.1182/ blood-2013-04-496752 7. Thejeel B, Garg AX, Clark WF, et al. Long-term outcomes of thrombotic microangiopathy treated with plasma exchange: a systematic review. Am J Hematol. 2016;91(6):626-630. doi:10.1002/ajh.24339 8. Goel R, King KE, Takemoto CM, Ness PM, Tobian AAR. Prognostic risk-stratified score for predicting mortality in hospitalized patients with thrombotic thrombocytopenic purpura: nationally representative data from 2007 to 2012. Transfusion. 2016;56(6):1451-1458. doi:10.1111/trf.13586 9. Kremer Hovinga JA, Vesely SK, Terrell DR, Lämmle B, George JN. Survival and relapse in patients with thrombotic thrombocytopenic purpura. Blood. 2010;115(8):1500-1511. doi:10.1182/ blood-2009-09-243790 10. Peyvandi F, Scully M, Kremer Hovinga JA, et al. J Thromb Haemost. 2017;15(7):1448-1452. doi:10.1111/jth.13716 11. Grall M, Azoulay E, Galicier L, et al. Thrombotic thrombocytopenic purpura misdiagnosed as autoimmune cytopenia: causes of diagnostic errors and consequence on outcome. Experience of the French Thrombotic Microangiopathies Reference Centre. Am J Hematol. 2017;92(4):381-387. doi:10.1002/ajh.24665