What is TTP? A rare, life-threatening medical emergency
Early diagnosis and treatment of Thrombotic thrombocytopenic purpura (TTP) can help prevent the high risk of early deaths.
TTP is an extremely rare and potentially fatal thrombotic microangiopathy manifested by the presence of microvascular occlusions and subsequent thrombocytopenia, hemolytic anemia, and organ ischemia. It has a reported annual incidence of 4 to 5 cases per million in the US. TTP primarily affects young, healthy adults, with a median age of 40 years.1,2
Purpura:
spots of variable size on the skin or in the mucous membranes, due to small hemorrhages; they can be dark red and as small as a pinhead (petechiae) or purplish and 2 to 3 cm in diameter (ecchymosis).
Thrombocytopenic:
a lower-than-normal platelet count (below 30x10^9/L) due to the consumption of platelets during microthrombi formation, which causes occlusion of microvasculature.
Thrombotic:
characterized by the formation of microthrombi (blood clots) within a blood vessel, which clog the vessel.
Types of TTP
aTTP can be divided according to whether there is a confirmed triggering cause of not. However, all causes require immediate treatment.6
Without treatment, the fatal outcome of TTP is rapid, with a mortality rate of 90%7-9

Signs and symptoms of aTTP include7-10
These symptoms, along with the rarity of TTP, may cause confusion with other thrombotic microangiopathies (TMA), making the diagnosis of TTP challenging.1,11,12
Références
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Terrell DR, et al. The incidence of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome: all patients, idiopathic patients, and patients with severe ADAMTS-13 deficiency. J Thromb Haemost. 2005 Jul;3(7):1432-6
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Miller DP, et al. Incidence of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome. Epidemiology. 2004 Mar;15(2):208-15
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Scully M, et al. Caplacizumab Treatment for Acquired Thrombotic Thrombocytopenic Purpura. N Engl J Med. 2019 Jan 24;380(4):335-346
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Zheng XL, et al. ISTH guidelines for the diagnosis of thrombotic thrombocytopenic purpura. J Thromb Haemost. 2020 Oct;18(10):2486-2495
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National Institutes of Health. Congenital thrombotic thrombocytopenic purpura. Updated July 12, 2018. Accessed March 16, 2022. https://rarediseases.info.nih.gov/diseases/9430/congenital-thrombotic-thrombocytopenic-purpura
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Scully M, et al. Consensus on the standardization of terminology in thrombotic thrombocytopenic purpura and related thrombotic microangiopathies. J Thromb Haemost. 2017;15(2):312–22.
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Scully M, et al. Guidelines on the diagnosis and management of thrombotic thrombocytopenic purpura and other thrombotic microangiopathies. Br J Haematol. 2012 Aug;158(3):323-35
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Sayani FA, Abrams CS. How I treat refractory thrombotic thrombocytopenic purpura. Blood. 2015;125(25):3860–7.
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Kremer Hovinga JA, et al. Survival and relapse in patients with thrombotic thrombocytopenic purpura. Blood. 2010; 115(8):1500–11.
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Azoulay E, et al. Expert statement on the ICU management of patients with thrombotic thrombocytopenic purpura. Intensive Care Med. 2019;45(11):1518-1539.
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Gallan AJ, Chang A. A new paradigm for renal thrombotic microangiopathy. Semin Diagn Pathol. 2020;37(3):121-126.
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Tsai H-M. Pathophysiology of thrombotic thrombocytopenic purpura. Int J Hematol. 2010;91(1):1-19.