scholarly journals Application of SELDI-TOF mass spectrometry in clinical evaluation of thrombotic thrombocytopenic purpura

2006 ◽  
Vol 20 (5-6) ◽  
pp. 219-227
Author(s):  
Haifeng M. Wu ◽  
Spero R. Cataland ◽  
Michael Bissell ◽  
Ming Jin
Keyword(s):  
Mass Spectrometry ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Rapid Determination ◽  
Correct Diagnosis ◽  
Thrombocytopenic Purpura ◽  
Autoimmune Antibodies ◽  
Adamts13 Deficiency ◽  
Rapid Purification ◽  
Von Willebrand

Surface Enhanced Laser Desorption/Ionization Time Of Flight (SELDI-TOF) mass spectrometry is characterized by integration of mass spectrometry with surface chemistry, which gives rise to rapid purification and subsequent determination of protein/peptide analytes. There are several surface matrices, named proteinChips, available for analyzing a particular analyte or a subset of biomolecules in biological samples. Each proteinChip has a unique surface property suitable for fractionation of a specific group of molecules. This article demonstrates the application of SELDI-TOF for the analysis of a cleaved peptide (Mr7739 daltons) from von Willebrand Factor by a metalloproteinase, ADAMTS13. Deficiency of ADAMTS13 is a known primary risk factor for the devastating hematological disorder, Thrombotic thrombocytopenic purpura (TTP). Rapid determination of ADAMTS13 activity helps clinicians tremendously in making the correct diagnosis and initiating timely therapy. Most patients with TTP are acquired cases who exhibit a production of autoimmune antibodies against ADAMTS13 protease. TTP's clinical course is critically controlled by the autoantibody's ability to inhibit ADAMTS13 function. Thus, a second SELDI-TOF based test has been devised to measure ADAMTS13 autoantibody activity for the evaluation of TTP disease activity. In conclusion, the unique features of SELDI-TOF which allow for the examination of the role of key proteases in disease processes have opened up new doors for the clinical application of mass spectrometer based techniques.

scholarly journals Beyond plasma exchange: novel therapies for thrombotic thrombocytopenic purpura

Hematology ◽  
2018 ◽  
Vol 2018 (1) ◽  
pp. 539-547 ◽  
Author(s):  
Kathryn Dane ◽  
Shruti Chaturvedi
Keyword(s):  
Plasma Exchange ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Relapse Prevention ◽  
Tissue Injury ◽  
Novel Therapies ◽  
Thrombocytopenic Purpura ◽  
Platelet Recovery ◽  
Adamts13 Deficiency ◽  
Prophylactic Use ◽  
Von Willebrand

Abstract The advent of plasma exchange has dramatically changed the prognosis of acute thrombotic thrombocytopenic purpura (TTP). Recent insights into TTP pathogenesis have led to the development of novel therapies targeting pathogenic anti-ADAMTS13 antibody production, von Willebrand factor (VWF)–platelet interactions, and ADAMTS13 replacement. Retrospective and prospective studies have established the efficacy of rituximab as an adjunct to plasma exchange for patients with acute TTP, either upfront or for refractory disease. Relapse prevention is a major concern for survivors of acute TTP, and emerging data support the prophylactic use of rituximab in patients with persistent or recurrent ADAMTS13 deficiency in clinical remission. Capalcizumab, a nanobody directed against domain A1 of VWF that prevents the formation of VWF–platelet aggregates, recently completed phase 2 (TITAN) and 3 (HERCULES) trials with encouraging results. Compared with placebo, caplacizumab shortened the time to platelet recovery and may protect against microthrombotic tissue injury in the acute phase of TTP, though it does not modify the underlying immune response. Other promising therapies including plasma cell inhibitors (bortezomib), recombinant ADAMTS13, N-acetyl cysteine, and inhibitors of the VWF–glycoprotein Ib/IX interaction (anfibatide) are in development, and several of these agents are in prospective clinical studies to evaluate their efficacy and role in TTP. In the coming years, we are optimistic that novel therapies and international collaborative efforts will usher in even more effective, evidence-based approaches to address refractory acute TTP and relapse prevention.

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.

FRETS-VWF73 rather than CBA assay reflects ADAMTS13 proteolytic activity in acquired thrombotic thrombocytopenic purpura patients

2014 ◽  
Vol 112 (08) ◽  
pp. 297-303 ◽  
Author(s):  
Ilaria Mancini ◽  
Carla Valsecchi ◽  
Luca Lotta ◽  
Louis Deforche ◽  
Silvia Pontiggia ◽  
...  
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Proteolytic Activity ◽  
Binding Activity ◽  
Adamts13 Activity ◽  
Flow Conditions ◽  
Thrombocytopenic Purpura ◽  
Severe Deficiency ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryCollagen-binding activity (CBA) and FRETS-VWF73 assays are widely adopted methods for the measurement of the plasmatic activity of ADAMTS13, the von Willebrand factor (VWF) cleaving-protease. Accurately assessing the severe deficiency of ADAMTS13 is important in the management of thrombotic thrombocytopenic purpura (TTP). However, non-concordant results between the two assays have been reported in a small but relevant percentage of TTP cases. We investigated whether CBA or FRETS-VWF73 assay reflects ADAMTS13 proteolytic activity in acquired TTP patients with non-concordant measurements. Twenty plasma samples with non-concordant ADAMTS13 activity results, <10% using FRETS-VWF73 and ≥20% using CBA, and 11 samples with concordant results, <10% using either FRETS-VWF73 and CBA assays, were analysed. FRETS-VWF73 was performed in the presence of 1.5 M urea. ADAMTS13 activities were also measured under flow conditions and the VWF multimer pattern was defined in order to verify the presence of ultra-large VWF due to ADAMTS13 deficiency. In FRETS-VWF73 assay with 1.5 M urea, ADAMTS13 activity significantly increased in roughly 50% of the samples with non-concordant results, whereas it remained undetectable in all samples with concordant measurements. Under flow conditions, all tested samples showed reduced ADAMTS13 activity. Finally, samples with non-concordant results showed a ratio of high molecular weight VWF multimers higher than normal. Our results support the use of FRETS-VWF73 over CBA assay for the assessment of ADAMTS13 severe deficiency and indicate urea as one cause of the observed differences.

von Willebrand factor cleaving protease (ADAMTS13) is deficient in recurrent and familial thrombotic thrombocytopenic purpura and hemolytic uremic syndrome

Blood ◽  
2002 ◽  
Vol 100 (3) ◽  
pp. 778-785 ◽  
Author(s):  
Giuseppe Remuzzi ◽  
Miriam Galbusera ◽  
Marina Noris ◽  
Maria Teresa Canciani ◽  
Erica Daina ◽  
...  
Keyword(s):  
Hemolytic Uremic Syndrome ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Acute Phase ◽  
Von Willebrand Factor ◽  
Adamts13 Activity ◽  
Thrombocytopenic Purpura ◽  
Uremic Syndrome ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Whether measurement of ADAMTS13 activity may enable physicians to distinguish thrombotic thrombocytopenic purpura (TTP) from hemolytic uremic syndrome (HUS) is still a controversial issue. Our aim was to clarify whether patients with normal or deficient ADAMTS13 activity could be distinguished in terms of disease manifestations and multimeric patterns of plasma von Willebrand factor (VWF). ADAMTS13 activity, VWF antigen, and multimeric pattern were evaluated in patients with recurrent and familial TTP (n = 20) and HUS (n = 29). Results of the collagen-binding assay of ADAMTS13 activity were confirmed in selected samples by testing the capacity of plasma to cleave recombinant VWF A1-A2-A3. Most patients with TTP had complete or partial deficiency of ADAMTS13 activity during the acute phase, and in some the defect persisted at remission. However, complete ADAMTS13 deficiency was also found in 5 of 9 patients with HUS during the acute phase and in 5 patients during remission. HUS patients with ADAMTS13 deficiency could not be distinguished clinically from those with normal ADAMTS13. In a subgroup of patients with TTP or HUS, the ADAMTS13 defect was inherited, as documented by half-normal levels of ADAMTS13 in their asymptomatic parents, consistent with the heterozygous carrier state. In patients with TTP and HUS there was indirect evidence of increased VWF fragmentation, and this occurred also in patients with ADAMTS13 deficiency. In conclusion, deficient ADAMTS13 activity does not distinguish TTP from HUS, at least in the recurrent and familial forms, and it is not the only determinant of VWF abnormalities in these conditions.

scholarly journals Von Willebrand factor, ADAMTS13, and thrombotic thrombocytopenic purpura

Blood ◽  
2008 ◽  
Vol 112 (1) ◽  
pp. 11-18 ◽  
Author(s):  
J. Evan Sadler
Keyword(s):  
Plasma Exchange ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Von Willebrand Factor ◽  
Unanswered Question ◽  
Thrombocytopenic Purpura ◽  
The Past ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Intensive Immunosuppressive Therapy

Abstract Discoveries during the past decade have revolutionized our understanding of idiopathic thrombotic thrombocytopenic purpura (TTP). Most cases in adults are caused by acquired autoantibodies that inhibit ADAMTS13, a metalloprotease that cleaves von Willebrand factor within nascent platelet-rich thrombi to prevent hemolysis, thrombocytopenia, and tissue infarction. Although approximately 80% of patients respond to plasma exchange, which removes autoantibody and replenishes ADAMTS13, one third to one half of survivors develop refractory or relapsing disease. Intensive immunosuppressive therapy with rituximab appears to be effective as salvage therapy, and ongoing clinical trials should determine whether adjuvant rituximab with plasma exchange also is beneficial at first diagnosis. A major unanswered question is whether plasma exchange is effective for the subset of patients with idiopathic TTP who do not have severe ADAMTS13 deficiency.

Thrombotic Thrombocytopenic Purpura: A Moving Target

Hematology ◽  
2006 ◽  
Vol 2006 (1) ◽  
pp. 415-420 ◽  
Author(s):  
J. Evan Sadler
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
High Titer ◽  
Early Death ◽  
Thrombocytopenic Purpura ◽  
Asymptomatic Patients ◽  
Potential Biomarker ◽  
Increased Risk ◽  
Inhibitor Level ◽  
Adamts13 Deficiency ◽  
Von Willebrand

Abstract Almost 80 years after Eli Moschcowitz published the first description of the disease, most patients with idiopathic thrombotic thrombocytopenic purpura (TTP) were found to have acquired autoantibody inhibitors of the ADAMTS13 metalloprotease. Plasma ADAMTS13 normally cleaves von Willebrand factor within nascent platelet-rich thrombi, and ADAMTS13 deficiency allows unchecked thrombus growth to cause microangiopathic hemolysis, thrombocytopenia, and tissue infarction. At present, ADAMTS13 deficiency with a high-titer inhibitor level appears to be associated with an increased risk of early death and subsequent relapse. Thus, acquired ADAMTS13 deficiency identifies a specific mechanism of TTP and is a potential biomarker of disease activity or risk. At present, two major clinical questions in the field may be summarized as follows. First, by emphasizing TTP caused by ADAMTS13 deficiency, are we in danger of neglecting other causes that should be treated with plasma exchange? Second, should we treat asymptomatic patients who have severe ADAMTS13 deficiency to prevent future disease, and if so, how?

Complete deficiency in ADAMTS13 is prothrombotic, but it alone is not sufficient to cause thrombotic thrombocytopenic purpura

Blood ◽  
2006 ◽  
Vol 107 (8) ◽  
pp. 3161-3166 ◽  
Author(s):  
Fumiaki Banno ◽  
Koichi Kokame ◽  
Tomohiko Okuda ◽  
Shigenori Honda ◽  
Shigeki Miyata ◽  
...  
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Hemolytic Anemia ◽  
Thrombus Formation ◽  
Wild Type ◽  
Thrombocytopenic Purpura ◽  
Phenotypic Differences ◽  
System Functioning ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract ADAMTS13 is a plasma metalloproteinase that regulates platelet adhesion and aggregation through cleavage of von Willebrand factor (VWF) multimers. In humans, genetic or acquired deficiency in ADAMTS13 causes thrombotic thrombocytopenic purpura (TTP), a condition characterized by thrombocytopenia and hemolytic anemia with microvascular platelet thrombi. In this study, we report characterization of mice bearing a targeted disruption of the Adamts13 gene. ADAMTS13-deficient mice were born in the expected mendelian distribution; homozygous mice were viable and fertile. Hematologic and histologic analyses failed to detect any evidence of thrombocytopenia, hemolytic anemia, or microvascular thrombosis. However, unusually large VWF multimers were observed in plasma of homozygotes. Thrombus formation on immobilized collagen under flow was significantly elevated in homozygotes in comparison with wild-type mice. Thrombocytopenia was more severely induced in homozygotes than in wild-type mice after intravenous injection of a mixture of collagen and epinephrine. Thus, a complete lack of ADAMTS13 in mice was a prothrombotic state, but it alone was not sufficient to cause TTP-like symptoms. The phenotypic differences of ADAMTS13 deficiencies between humans and mice may reflect differences in hemostatic system functioning in these species. Alternatively, factors in addition to ADAMTS13 deficiency may be necessary for development of TTP.

scholarly journals A case of severe ADAMTS 13 deficiency presenting as thrombotic thrombocytopenic purpura in pregnancy

2012 ◽  
Vol 65 (9-10) ◽  
pp. 436-439 ◽  
Author(s):  
Marinos Nikolaou ◽  
Marina Karakantza ◽  
George Adonakis ◽  
George Theodorou ◽  
Nikolaos Zoumbos ◽  
...  
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Prophylactic Treatment ◽  
Thrombocytopenic Purpura ◽  
Treatment And Prevention ◽  
Severe Deficiency ◽  
History Of ◽  
Adamts13 Deficiency ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Plasma Infusions

Introduction. Thrombotic thrombocytopenic purpura is a rare lifethreatening disorder characterized by thrombocytopenia and microangiopathic hemolytic anemia. It is caused by the absent or severe deficiency of the von Willebrand Factor-cleaving protease named ADAMTS13. Pregnancy is a well recognized factor precipitating the appearance of the disease both in women that had reduced levels of ADAMTS13 activity prior to gestation and in those with other inherited or acquired thrombophilic syndromes. Case Report. We report a 25-year old woman with severe ADAMTS13 deficiency presented early in her 1st pregnancy and relapsed in two subsequent gestations. This presentation is uncommon for thrombotic thrombocytopenic purpura is associated with pregnancy (ADAMTS13 deficiency <5%, without an inhibitor). In the first pregnancy she started with daily plasma exchange 1.5xvolume, corticosteroids and IV immunoglobulin and finally entered remission after 23 sessions and termination of pregnancy. In the second pregnancy she did not receive prophylactic treatment and relapsed in the 3rd trimester. Prophylactic treatment during the third pregnancy with plasma infusions proved also ineffective to prevent relapse. Discussion. Many issues regarding treatment and prevention of thrombotic thrombocytopenic purpura relapses in subsequent pregnancies are unclear. Proposed guidelines recommend that the same treatment should be performed on pregnant and non pregnant patients without modification of plasma replacement dose according to ADAMTS13 levels. In addition, many authors suggest that pregnant patients with history of thrombotic thrombocytopenic purpura and severe deficiency of ADAMTS13 levels should received prophylactic treatment for prevention of relapses in the subsequent pregnancies. Conclusion. Severe ADAMTS 13 deficiency may present as thrombotic thrombocytopenic purpura of pregnancy. Pregnant women with thrombotic thrombocytopenic purpura and especially with severe deficiency of ADAMTS13 levels require specific consideration regarding treatment and prophylaxis in subsequent pregnancies.

scholarly journals Insights into 3D Structure of ADAMTS13: A Stepping Stone towards Novel Therapeutic Treatment of Thrombotic Thrombocytopenic Purpura

2018 ◽  
Vol 118 (01) ◽  
pp. 028-041 ◽  
Author(s):  
Bogac Ercig ◽  
Kanin Wichapong ◽  
Chris Reutelingsperger ◽  
Karen Vanhoorelbeke ◽  
Jan Voorberg ◽  
...  
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Platelet Adhesion ◽  
3D Structure ◽  
Thrombocytopenic Purpura ◽  
Adamts13 Deficiency ◽  
Uncommon Condition ◽  
Circulating Autoantibodies ◽  
Function Relationship ◽  
Von Willebrand ◽  
Relationship Of

AbstractADAMTS13 (a disintegrin and metalloprotease with a thrombospondin type-1 motif, member 13) and von Willebrand factor (VWF) can be considered as scale weights which control platelet adhesion during primary haemostasis. In a very uncommon condition designated thrombotic thrombocytopenic purpura (TTP), functional absence of ADAMTS13 tips the balance toward VWF-mediated platelet adhesion in the microcirculation. TTP is associated with a high mortality and arises from either a congenital or acquired autoimmune deficiency of the plasma enzyme ADAMTS13. In case of acquired ADAMTS13 deficiency, autoantibodies bind to and inhibit the function of ADAMTS13. Currently available treatments of TTP aim to supply ADAMTS13 through plasma exchange or are aimed at B-cell depletion with rituximab. None of the available therapeutics, however, aims at protection of ADAMTS13 from circulating autoantibodies. In this review, our aim is to describe the structure–function relationship of ADAMTS13 employing homology models and previously published crystal structures. Structural bioinformatics investigation of ADAMTS13 reveals many insights and explains how mutations and autoantibodies may lead to the pathophysiology of TTP. The results of these studies provide a roadmap for the further development of rationally designed therapeutics for the treatment of patients with acquired TTP. In addition, we share our opinion on the state of the art of the open–closed conformations of ADAMTS13 which regulate the activity of this highly specific VWF cleaving protease.

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