TTP and ADAMTS13: When Is Testing Appropriate?

Hematology ◽  
2007 ◽  
Vol 2007 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Pier Mannuccio Mannucci ◽  
Flora Peyvandi
Keyword(s):  
Platelet Adhesion ◽  
Multiorgan Failure ◽  
Microangiopathic Hemolytic Anemia ◽  
Thrombocytopenic Purpura ◽  
Life Threatening ◽  
Adamts13 Deficiency ◽  
A Disintegrin And Metalloproteinase ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The last 10 years witnessed the publication of many studies on the pathophysiology of thrombotic thrombocytopenic purpura (TTP), a life-threatening disease characterized by microangiopathic hemolytic anemia, thrombocytopenia and multiorgan failure. The most important finding was the identification of a novel metalloprotease, named ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motives), that is involved in the regulation of the size of von Willebrand factor (VWF), a major modulator of platelet adhesion and aggregation in the microcirculation. Inherited or acquired deficiencies of ADAMTS13 impair VWF cleavage, leading in turn to the disseminated formation of platelet-rich thrombi in the micro-circulation and to symptoms of end-organ ischemia. By measuring ADAMTS13 in plasma, it has been clearly shown that patients with inherited TTP have severe ADAMTS13 deficiency. However, patients with acquired TTP present with clinical and laboratory heterogeneity, and there are unequivocal cases of acquired TTP with measurable plasma levels of ADAMTS13. This heterogeneity poses a challenge for understanding the pathogenesis of TTP and selecting appropriate therapies.

scholarly journals THROMBOTIC THROMBOCYTOPENIC PURPURA (TTP) AND MODERN APPROACH TO ITS INVESTIGATION AND TREATMENT

2019 ◽  
pp. 12-13
Author(s):  
K. Ukleba ◽  
L. Gvetadze
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Severe Thrombocytopenia ◽  
Thrombocytopenic Purpura ◽  
Modern Approach ◽  
Severe Deficiency ◽  
Life Threatening ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor

Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening thrombotic microangiopathy characterized by microangiopathic hemolytic anemia, severe thrombocytopenia, and organ ischemia linked to disseminated microvascular platelet rich-thrombi. TTP is specifically related to a severe deficiency in ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13), the specific von Willebrand factor-cleaving protease. ADAMTS13 deficiency is most frequently acquired via ADAMTS13 autoantibodies, but rarely, it is inherited via mutations of the ADAMTS13 gane. The first acute episode of TTP usually occurs during adulthood, with a predominant anti – ADAMTS13 autoimmune etiology. In rare cases, however, TTP begins as soon as childhood, with frequent inherited forms. TTP is 2 – fold more frequent in women, and its outcome is characterized by a relapsing tendency.

scholarly journals Pathophysiology of thrombotic thrombocytopenic purpura

Blood ◽  
2017 ◽  
Vol 130 (10) ◽  
pp. 1181-1188 ◽  
Author(s):  
J. Evan Sadler
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Tissue Injury ◽  
Preventive Therapy ◽  
Neurological Deficits ◽  
Autoantibody Production ◽  
Thrombocytopenic Purpura ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The discovery of a disintegrin-like and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS13) revolutionized our approach to thrombotic thrombocytopenic purpura (TTP). Inherited or acquired ADAMTS13 deficiency allows the unrestrained growth of microthrombi that are composed of von Willebrand factor and platelets, which account for the thrombocytopenia, hemolytic anemia, schistocytes, and tissue injury that characterize TTP. Most patients with acquired TTP respond to a combination of plasma exchange and rituximab, but some die or acquire irreversible neurological deficits before they can respond, and relapses can occur unpredictably. However, knowledge of the pathophysiology of TTP has inspired new ways to prevent early deaths by targeting autoantibody production, replenishing ADAMTS13, and blocking microvascular thrombosis despite persistent ADAMTS13 deficiency. In addition, monitoring ADAMTS13 has the potential to identify patients who are at risk of relapse in time for preventive therapy.

scholarly journals Systemic antithrombotic effects of ADAMTS13

2006 ◽  
Vol 203 (3) ◽  
pp. 767-776 ◽  
Author(s):  
Anil K. Chauhan ◽  
David G. Motto ◽  
Colin B. Lamb ◽  
Wolfgang Bergmeier ◽  
Michael Dockal ◽  
...  
Keyword(s):  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Type I ◽  
Inhibitory Antibody ◽  
Antithrombotic Agent ◽  
Antithrombotic Effects ◽  
Life Threatening ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor

The metalloprotease ADAMTS13 (a disintegrin-like and metalloprotease with thrombospondin type I repeats 13) cleaves highly adhesive large von Willebrand factor (VWF) multimers after their release from the endothelium. ADAMTS13 deficiency is linked to a life-threatening disorder, thrombotic thrombocytopenic purpura (TTP), characterized by platelet-rich thrombi in the microvasculature. Here, we show spontaneous thrombus formation in activated microvenules of Adamts13−/− mice by intravital microscopy. Strikingly, we found that ADAMTS13 down-regulates both platelet adhesion to exposed subendothelium and thrombus formation in injured arterioles. An inhibitory antibody to ADAMTS13 infused in wild-type mice prolonged adhesion of platelets to endothelium and induced thrombi formation with embolization in the activated microvenules. Absence of ADAMTS13 did not promote thrombi formation in αIIbβ3 integrin-inhibited blood. Recombinant ADAMTS13 reduced platelet adhesion and aggregation in histamine-activated venules and promoted thrombus dissolution in injured arterioles. Our findings reveal that ADAMTS13 has a powerful natural antithrombotic activity and recombinant ADAMTS13 could be used as an antithrombotic agent.

scholarly journals How I treat refractory thrombotic thrombocytopenic purpura

Blood ◽  
2015 ◽  
Vol 125 (25) ◽  
pp. 3860-3867 ◽  
Author(s):  
Farzana A. Sayani ◽  
Charles S. Abrams
Keyword(s):  
Plasma Exchange ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Clinical Symptoms ◽  
Thrombocytopenic Purpura ◽  
New Therapeutic Approaches ◽  
Number Of Patients ◽  
A Disintegrin And Metalloproteinase ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Acquired thrombotic thrombocytopenic purpura (TTP) is characterized by thrombocytopenia and microangiopathic hemolytic anemia (MAHA) without an obvious cause, and may include fever, mild renal failure, and neurologic deficits. It is characterized by a deficiency of the von Willebrand factor (VWF) cleaving enzyme, ADAMTS13 (a disintegrin and metalloproteinase, with a thrombospondin type 1 motif, member 13), resulting in formation of microthrombi in the high sheer environment of the microvasculature. This causes microvascular occlusion, MAHA, and organ ischemia. Diagnosis is based on the presence of clinical symptoms, laboratory aberrations consistent with MAHA, decreased ADAMTS13 activity, and possibly presence of anti-ADAMTS13 autoantibodies. Upfront treatment of acute TTP includes plasma exchange and corticosteroids. A significant number of patients are refractory to this treatment and will require further interventions. There are limited data and consensus on the management of the refractory TTP patient. Management involves simultaneously ruling out other causes of thrombocytopenia and MAHA, while also considering other treatments. In this article, we describe our management of the patient with refractory TTP, and discuss use of rituximab, increased plasma exchange, splenectomy, and immunosuppressive options, including cyclophosphamide, vincristine, and cyclosporine. We also review recent evidence for the potential roles of bortezomib and N-acetylcysteine, and explore new therapeutic approaches, including recombinant ADAMTS13 and anti-VWF therapy.

ADAMTS13 turns 3

Blood ◽  
2005 ◽  
Vol 106 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Gallia G. Levy ◽  
David G. Motto ◽  
David Ginsburg
Keyword(s):  
Research Effort ◽  
Adamts13 Activity ◽  
Hematologic Disease ◽  
Thrombocytopenic Purpura ◽  
Adamts13 Deficiency ◽  
Normal Hemostasis ◽  
Von Willebrand ◽  
Willebrand Factor

It has now been 3 years since the von Willebrand factor (VWF)–cleaving protease implicated in thrombocytopenic purpura (TTP) pathogenesis was identified as ADAMTS13 (adisintegrin-like and metalloprotease with thrombospondin type 1 motif 13). More than 50 ADAMTS13 mutations resulting in familial TTP have been reported. Considerable progress has also been realized toward understanding the role of ADAMTS13 in normal hemostasis, as well as the mechanisms by which ADAMTS13 deficiency contributes to TTP pathogenesis. Measurement of ADAMTS13 activity in TTP and other pathologic conditions also remains a focus of a substantial clinical research effort. Building on these studies, continued investigation of ADAMTS13 and VWF holds considerable promise for advancing the understanding of TTP pathogenesis and should lead to improved diagnosis and treatment for this important hematologic disease.

Epitope mapping of ADAMTS13 autoantibodies in acquired thrombotic thrombocytopenic purpura

Blood ◽  
2004 ◽  
Vol 103 (12) ◽  
pp. 4514-4519 ◽  
Author(s):  
Christoph Klaus ◽  
Barbara Plaimauer ◽  
Jan-Dirk Studt ◽  
Friedrich Dorner ◽  
Bernhard Lämmle ◽  
...  
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Thrombocytopenic Purpura ◽  
Severe Deficiency ◽  
Adamts13 Deficiency ◽  
Multiple Domains ◽  
Von Willebrand ◽  
Recombinant Fragments ◽  
Willebrand Factor

Abstract Severe deficiency of the von Willebrand factor (VWF)-cleaving protease ADAMTS13 can lead to thrombotic thrombocytopenic purpura (TTP), a disease associated with the widespread formation of platelet-rich thrombi in many organs. Autoantibodies that inactivate ADAMTS13 are the most frequent cause of acquired TTP. Little is known about epitope specificity and reactivity of anti-ADAMTS13 antibodies. In this study, a series of ADAMTS13 domains were expressed in Escherichia coli, and the reactivity of purified recombinant fragments with anti-ADAMTS13 auto-antibodies from 25 patients with severe ADAMTS13 deficiency was evaluated in vitro. All TTP plasmas contained antibodies directed against the cysteine-rich spacer (cys-rich/spacer) domain of ADAMTS13. In the plasma of 3 patients, antibodies were detected that reacted exclusively with the cys-rich/spacer domain, underscoring the importance of this region for functional activity of ADAMTS13. In 64% of the plasmas, antibodies reacted with the 2 CUB domains, and in 56% they reacted with the isolated first thrombospondin type 1 (TSP-1) repeat and with the compound fragment consisting of the catalytic, the disintegrin-like, and the TSP1-1 domain. Less frequently, in 28% of the plasmas, antibodies reacted with the TSP1 repeats 2 to 8. Unexpectedly, antibodies reacted with the propeptide region in 20% of the plasmas. In conclusion, this study shows that even though anti-ADAMTS13 autoantibodies react with multiple domains of the protease, the cys-rich/spacer domain is consistently involved in antibody reactivity. (Blood. 2004;103:4514-4519)

scholarly journals Diagnosis of thrombotic thrombocytopenic purpura

2020 ◽  
Vol 92 (12) ◽  
pp. 207-217
Author(s):  
G. M. Galstyan ◽  
E. E. Klebanova
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Inhibitory Effect ◽  
Plasma Samples ◽  
Adamts13 Activity ◽  
Microangiopathic Hemolytic Anemia ◽  
Inhibitory Effects ◽  
Thrombocytopenic Purpura ◽  
Life Threatening ◽  
Von Willebrand ◽  
Willebrand Factor

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening disease, disease, characterised by microangiopathic hemolytic anaemia, consumption thrombocytopenia, and organ dysfunction. The pathogenesis of TTP is attributed to the deficiency in the activity of the metalloproteinase ADAMTS13, specific von Willebrand factor cleaving protease. TTP is suspected when detecting microangiopathic hemolytic anemia, thrombocytopenia, damage to various organs. Diagnosis of TTP is confirmed by the detection of ADAMTS13 activity in plasma less than 10%. Plasma samples for the study of ADAMTS13 activity should be taken before the start of plasma transfusions or plasma exchange. In patients with severe ADAMTS-13 deficiency autoantibodies anti-ADAMTS13 and inhibitor ADAMTS13 should be investigated. Anti-ADAMTS13 antibodies belonging to IgG not always have inhibitory effects. The inhibitory effect of anti-ADAMTS13 antibodies is confirmed by mixing test. All patients with the first established diagnosis of TTP should be examined for mutations of the ADAMTS13 gene.

scholarly journals Assessment of the Dual Role of Clumping Factor A in S. Aureus Adhesion to Endothelium in Absence and Presence of Plasma

2018 ◽  
Vol 118 (07) ◽  
pp. 1230-1241 ◽  
Author(s):  
Jorien Claes ◽  
Bartosz Ditkowski ◽  
Laurens Liesenborghs ◽  
Tiago Veloso ◽  
Jose Entenza ◽  
...  
Keyword(s):  
Infective Endocarditis ◽  
Binding Protein ◽  
Protein A ◽  
Bacterial Proteins ◽  
Fibronectin Binding Protein ◽  
A Disintegrin And Metalloproteinase ◽  
Von Willebrand ◽  
Willebrand Factor

AbstractAdhesion of Staphylococcus aureus to endothelial cells (ECs) is paramount in infective endocarditis. Bacterial proteins such as clumping factor A (ClfA) and fibronectin binding protein A (FnbpA) mediate adhesion to EC surface molecules and (sub)endothelial matrix proteins including fibrinogen (Fg), fibrin, fibronectin (Fn) and von Willebrand factor (vWF). We studied the influence of shear flow and plasma on the binding of ClfA and FnbpA (including its sub-domains A, A16+, ABC, CD) to coverslip-coated vWF, Fg/fibrin, Fn or confluent ECs, making use of Lactococcus lactis, expressing these adhesins heterologously. Global adherence profiles were similar in static and flow conditions. In the absence of plasma, L. lactis-clfA binding to Fg increased with shear forces, whereas binding to fibrin did not. The degree of adhesion of L. lactis-fnbpA to EC-bound Fn and of L. lactis-clfA to EC-bound Fg, furthermore, was similar to that of L. lactis-clfA to coated vWF domain A1, in the presence of vWF-binding protein (vWbp). Yet, in plasma, L. lactis-clfA adherence to activated EC-vWF/vWbp dropped over 10 minutes by 80% due to vWF-hydrolysis by a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13 and that of L. lactis-fnbpA likewise by > 70% compared to the adhesion in absence of plasma. In contrast, plasma Fg supported high L. lactis-clfA binding to resting and activated ECs. Or, in plasma S. aureus adhesion to active endothelium occurs mainly via two complementary pathways: a rapid but short-lived vWF/vWbp pathway and a stable integrin-coupled Fg-pathway. Hence, the pharmacological inhibition of ClfA-Fg interactions may constitute a valuable additive treatment in infective endocarditis.

scholarly journals The role of ADAMTS13 testing in the diagnosis and management of thrombotic microangiopathies and thrombosis

Blood ◽  
2018 ◽  
Vol 132 (9) ◽  
pp. 903-910 ◽  
Author(s):  
Camila Masias ◽  
Spero R. Cataland
Keyword(s):  
Thrombotic Microangiopathies ◽  
Acute Setting ◽  
Artery Disease ◽  
A Disintegrin And Metalloproteinase ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Deficient Activity

Abstract ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, 13) is a metalloprotease responsible for cleavage of ultra-large von Willebrand factor (VWF) multimers. Severely deficient activity of the protease can trigger an acute episode of thrombotic thrombocytopenic purpura (TTP). Our understanding of the pathophysiology of TTP has allowed us to grasp the important role of ADAMTS13 in other thrombotic microangiopathies (TMAs) and thrombotic disorders, such as ischemic stroke and coronary artery disease. Through its action on VWF, ADAMTS13 can have prothrombotic and proinflammatory properties, not only when its activity is severely deficient, but also when it is only moderately low. Here, we will discuss the biology of ADAMTS13 and the different assays developed to evaluate its function in the context of TTP, in the acute setting and during follow-up. We will also discuss the latest evidence regarding the role of ADAMTS13 in other TMAs, stroke, and cardiovascular disease. This information will be useful for clinicians not only when evaluating patients who present with microangiopathic hemolytic anemia and thrombocytopenia, but also when making clinical decisions regarding the follow-up of patients with TTP.

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