TTP Diagnosis
79 min
This external medical education webinar is part of the ESICM TTP Centenary Series
Commemorating a hundred years of TTP advancements, this webinar on September 9, 2024, focuses on diagnostic challenges and advancements:
- Understanding the Challenge by Shruti Chaturvedi: Delves into the complexities of diagnosing TTP.
- From Thrombotic Microangiopathies to TTP: The Devil is in the Details by Katerina Pavenski: Highlights the subtle distinctions between various thrombotic microangiopathies and TTP.
- Clinical Algorithms for TTP Diagnosis by Spero Cataland: Presents comprehensive clinical algorithms to enhance the accuracy of TTP diagnosis.
- Inherited ADAMTS13 Mutations Associated with Thrombotic Thrombocytopenic Purpura by Nathalie Biebuyck: Investigates the genetic mutations in ADAMTS13 that contribute to inherited TTP.
Speakers: Shruti Chaturvedi, Katerina Pavenski, Spero Cataland, Nathalie Biebuyck
Abbreviations, Glossary and References
Abbreviation
ADAMTS13; A disintegrin and metalloproteinase with a thrombospondin motifs 13
cTTP; Congenital TTP
TTP; Thrombotic thrombocytopenic purpura
Glossary
ADAMTS13; ADAMTS13 (A Disintegrin And Metalloprotease with ThromboSpondin motifs 13) is a constitutively active enzyme (plasma metalloprotease) that catalyzes the breakdown of ultra large and high molecular weight von Willebrand factor (VWF) into smaller multimers, reducing their thrombogenic potential, and maintaining hemostasis.1,2
Incidence; The rate of new cases or events over a specified period for the population at risk for a certain event.
Microangiopathic hemolytic anemia (MAHA); Process of red blood cell destruction within the microvasculature accompanied by thrombocytopenia due to platelet activation and consumption. Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are primary forms of thrombotic microangiopathies.3
Prevalence; The proportion of a particular population found to be affected by a medical condition at a specific time.
Schistocyte; Circulating fragments of red blood cells commonly seen in blood smears from patients with thrombotic microangiopathies including TTP.4
Thrombocytopenia; Refers to a state of reduced peripheral platelets below normal levels (150x109/L) and can be caused by a wide variety of aetiologies that either decrease platelet production or increase platelet consumption.5
Thrombotic microangiopathy (TMA); TMA includes a diverse set of syndromes that can be hereditary or acquired, which can occur in children and adults with sudden or gradual onset.
TMA syndromes, despite being diverse, have a common set of clinical and pathological features: MAHA, thrombocytopenia, organ injury, vascular damage manifested by arteriolar and capillary thrombosis with characteristic abnormalities in the endothelium and vessel wall.6
Thrombotic thrombocytopenic purpura (TTP); TTP is a type of MAHA presenting with moderate or severe thrombocytopenia. There is associated organ dysfunction, including neurologic, cardiac, gastrointestinal and renal involvement; oliguria or anuric renal failure requiring renal replacement therapy is not typically a feature. TTP is confirmed by a severe deficiency (<10%) of ADAMTS13 activity.7
von Willebrand factor (VWF); VWF plays two key roles in hemostasis: 1) in primary (platelet-mediated) hemostasis, VWF binds to collagen and platelets thus promoting platelet activation and aggregation, and 2) in secondary (coagulation factor mediated) hemostasis VWF binds factor VIII (FVIII) protecting FVIII from rapid clearance. When VWF binds to collagen following vascular injury, it releases FVIII, leading to FVIII activation and initiation of the coagulation cascade.8,9
References
- Markham-Lee, Z., N.V. Morgan, and J. Emsley, Inherited ADAMTS13 mutations associated with Thrombotic Thrombocytopenic Purpura: a short review and update. Platelets, 2023. 34(1): p. 2138306.
- Kremer Hovinga, J.A., et al., Thrombotic thrombocytopenic purpura. Nat Rev Dis Primers, 2017. 3: p. 17020.
- Arnold, D.M., C.J. Patriquin, and I. Nazy, Thrombotic microangiopathies: a general approach to diagnosis and management. CMAJ, 2017. 189(4): p. E153-E159.
- Zini, G., et al., ICSH recommendations for identification, diagnostic value, and quantitation of schistocytes. Int J Lab Hematol, 2012. 34(2): p. 107-116.
- Gauer, R.L. and M.M. Braun, Thrombocytopenia. Am Fam Physician, 2012. 85(6): p. 612-622.
- George, J.N. and C.M. Nester, Syndromes of thrombotic microangiopathy. N Engl J Med, 2014. 371(7): p. 654-666.
- Scully, M., et al., Consensus on the standardization of terminology in thrombotic thrombocytopenic purpura and related thrombotic microangiopathies. J Thromb Haemost, 2017. 15(2): p. 312-322.
- Rauch, A., et al., On the versatility of von Willebrand factor. Mediterr J Hematol Infect Dis, 2013. 5(1): p. e2013046.
- Stockschlaeder, M., R. Schneppenheim, and U. Budde, Update on von Willebrand factor multimers: focus on high-molecular-weight multimers and their role in hemostasis. Blood Coagul Fibrinolysis, 2014. 25(3): p. 206-216.