Redefining outcomes in immune TTP: an international working group consensus report. Blood 2021 Apr 08;137(14):1855-1861
Date
02/03/2021Pubmed ID
33529333DOI
10.1182/blood.2020009150Scopus ID
2-s2.0-85103778501 (requires institutional sign-in at Scopus site) 102 CitationsAbstract
Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a potentially fatal thrombotic microangiopathy caused by autoantibody-mediated severe deficiency of ADAMTS13. Standardized definitions of response, exacerbation, remission, and relapse were initially proposed in 2003 and modified by the International Working Group for TTP in 2017. These definitions, which have been widely used in clinical practice and research, are based primarily on the platelet count and are benchmarked against the timing of discontinuation of therapeutic plasma exchange (TPE). They do not incorporate ADAMTS13 activity or the temporizing effects on the platelet count of caplacizumab, a novel anti-von Willebrand factor (VWF) nanobody. In light of these limitations, the IWG aimed to develop revised consensus outcome definitions that incorporate ADAMTS13 activity and the effects of anti-VWF therapy, by using an estimate-talk-estimate approach. The updated definitions distinguish clinical remission and clinical relapse (defined primarily by platelet count) from ADAMTS13 remission and ADAMTS13 relapse (defined by ADAMTS13 activity). The revised definitions of exacerbation and remission are benchmarked against not only the timing of discontinuation of TPE but also that of anti-VWF therapy. Retrospective validation of the revised definitions is described, although they have yet to be prospectively validated. Clinical implications of the updated outcome definitions are also discussed and an example of their application to clinical practice is provided to highlight their clinical relevance.
Author List
Cuker A, Cataland SR, Coppo P, de la Rubia J, Friedman KD, George JN, Knoebl PN, Kremer Hovinga JA, Lämmle B, Matsumoto M, Pavenski K, Peyvandi F, Sakai K, Sarode R, Thomas MR, Tomiyama Y, Veyradier A, Westwood JP, Scully MAuthor
Kenneth D. Friedman MD Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ADAMTS13 ProteinAdult
Consensus
Disease Management
Female
Fibrinolytic Agents
Humans
Plasma Exchange
Platelet Count
Purpura, Thrombotic Thrombocytopenic
Recurrence
Single-Domain Antibodies
Treatment Outcome
von Willebrand Factor
