Relapsing Thrombotic Thrombocytopenic Purpura: A Single Center Experience

• Published in: Blood 2016-12, Vol.128 (22), p.3732-3732
• Main Authors: Heeke, Arielle L, Kessler, Craig M., Broome, Catherine
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V128.22.3732.3732

Thrombotic thrombocytopenic purpura (TTP) is due to a severe deficiency of the von Willebrand factor (vWF) cleaving serine metalloprotease ADAMTS13 and is most commonly diagnosed in adults due to autoantibodies against ADAMTS13. Standard therapy includes plasma exchange (PEX) until platelet counts normalize plus concurrent high dose corticosteroids. In refractory cases, weekly pulse Rituximab for 4 doses is often added. Successful long-term management of relapsing patients beyond these treatments is unclear, in part because the mechanisms for relapsing TTP are unknown. Dysfunctional immunoregulatory systems likely play a role in relapsing disease. Several case series have described disease control following bortezomib therapy (Patriquin 2016). Other immunomodulators including complement pathway and tyrosine kinase inhibitors may prove to offer benefit. Further, supplementing PEX with N-acetylcysteine (Rottenstreich 2016) & Caplacizumab (anti-vWF humanized immunoglobulin) (Peyvandi 2016) has shown promising preliminary clinical results when used to treat an acute episode. Effects on relapse rates with these treatments have not been fully evaluated. Eight cases of relapsing TTP were identified at MedStar Georgetown University Hospital May 2004 to July 2016. Relapsing TTP was defined as recurrent episode(s) of thrombocytopenia, microangiopathic hemolysis, and confirmed ADAMTS13 activity levels 8) at the time of relapse(s). Normalization of ADAMTS13 activity was confirmed in most following treatment (n=6), with a mean ADAMTS13 activity level between relapses of 50.5% (range 32-88%). At