Thrombotic Thrombocytopenic Purpura and the Hemolytic Uremic Syndrome

2002 ◽  
Vol 126 (11) ◽  
pp. 1430-1433
Author(s):  
Joel L. Moake
Keyword(s):  
Platelet Aggregation ◽  
Hemolytic Uremic Syndrome ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Data Extraction ◽  
Fresh Frozen Plasma ◽  
Thrombocytopenic Purpura ◽  
Fresh Frozen ◽  
Uremic Syndrome ◽  
Metalloprotease Activity ◽  
Von Willebrand

Abstract Objective.—To evaluate the usefulness and feasibility of measuring plasma von Willebrand factor (vWF)-cleaving metalloprotease activity (ADAMTS 13) in the differential diagnosis of thrombotic thrombocytopenic purpura (TTP), the hemolytic uremic syndrome, and other thrombotic microangiopathies. Data Sources.—Articles published in the medical literature. Data Extraction and Synthesis.—In TTP, a multimeric form of vWF that is larger than that ordinarily found in the plasma may cause systemic platelet aggregation under the high-shear conditions of the microcirculation. ADAMTS 13 is a divalent cation-activated, vWF-cleaving metalloprotease that converts unusually large vWF multimers derived from endothelial cells into smaller vWF forms in normal plasma. ADAMTS 13 is severely reduced or absent in most patients with TTP. The vWF-cleaving metalloprotease is present in fresh-frozen plasma, cryoprecipitate-depleted plasma (cryosupernatant), and in plasma that has been treated with solvent and detergent. The enzyme is defective in children with chronic relapsing TTP. Infusion of any of the plasma products that contain the vWF-cleaving metalloprotease stops or prevents (for about 3 weeks) TTP episodes in these patients. An immunoglobulin (Ig) G autoantibody to the vWF-cleaving metalloprotease is found transiently in many adult patients with acquired acute idiopathic, recurrent, and ticlopidine/clopidogrel-associated TTP. Patients with acquired TTP require plasma exchange, that is, both infusion of a plasma product containing vWF-cleaving metalloprotease and removal of autoantibody and/or unusually large vWF multimers by plasmapheresis. The pathophysiology of platelet aggregation in bone marrow transplantation/chemotherapy-associated thrombotic microangiopathy, as well as in hemolytic uremic syndrome, is not established. In neither condition is there a severe decrease in plasma vWF-cleaving metalloprotease activity, as there is in TTP. Conclusions.—The presently available lengthy and complicated procedure for estimation of plasma vWF-cleaving metalloprotease activity is not yet practical for rapid diagnostic use. This test has supplanted the equally lengthy and difficult, less specific analysis of plasma vWF multimeric pattern. If the clinical distinction between TTP and hemolytic uremic syndrome is uncertain, it is appropriate to acquire (before therapy) a citrate-plasma sample for the ultimate determination of vWF-cleaving metalloprotease activity.

Rituximab in Chronic Relapsing Acquired Thrombotic Thrombocytopenic Purpura.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3997-3997
Author(s):  
Gaetano Giuffrida ◽  
Amalia Figuera ◽  
Rocca Cingari ◽  
Santo Maccarone ◽  
Ernesto Di Francesco ◽  
...  
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Intravenous Immunoglobulins ◽  
Fresh Frozen Plasma ◽  
Additional Treatment ◽  
Treatment Modalities ◽  
First Episode ◽  
Thrombocytopenic Purpura ◽  
Fresh Frozen ◽  
Platelet Aggregates ◽  
Von Willebrand

Abstract Thrombotic thrombocytopenic purpura (TTP) is a rare syndrome characterized by microangiopathic hemolytic anemia, thrombocytopenia, fever, renal failure and neurological manifestation. It is caused by a severe decreased of Von Willebrand factor cleaving protease activity (ADAMTS-13), leading to persistence of unusually ultra-large Von Willebrand multimers (ULVWF) in the circulation that bind to platelets, causing platelet aggregates, microangiopathic hemolysis and thrombocytopenia. A lack of ADAMTS-13 activity can be caused by autoimmune inhibitors or may be due to a constitutional deficiency of this protein. Recently, the ADAMTS-13 gene that encodes for the ADAMTS-13 protein was found. It was mapped to chromosome 9q34 and consists of 29 exons. Several mutations has been identified in the ADAMTS gene in patient with the congenital form of TTP. Although TTP usually occurs as an acquired form due to autoantibodies against ADAMTS-13. The determination of the activity of ADAMTS-13 and of antibodies against ADAMTS-13 are important part in the workup of patients with TTP. Plasma exchange (PE) with fresh frozen plasma replacement is the standard treatment in the acquired TTP. The efficacy of PE is likely due to the removal of both antibodies and ULVWF and the infution of ADAMTS-13. Additional treatment modalities include glucocorticoids, splenectomy, vincristine, cyclophosphamide, azathioprine, cyclosporin A, combination chemotherapy, intravenous immunoglobulins and, recently, rituximab, a monoclonal antibody against CD20 present on B-limphoid cells. We report a case of chronic relapsing acquired idiopathic TTP successfully treated with rituximab. The patient, an 50-year old woman, developed her first episode of TTP in May 2001. Remission was achieved after 12 sessions of PE, four dose of vincristine at dose of 0,02 mg/kg/die, corticosteroids at dose of 1 mg/kg/die and increased dose of prociclide from 10 to 60 mg /kg/die. From 2001 to 2004, she had six relapses responding to treatment with PE, vincristine, and corticosteroids. The relapse in 2004 was followed by a protracted course despite the addition of cyclosporine A and she become dependent on PE. On May 2004 she was treated with splenectomy. The postoperative course was uneventful. The inhibitors against ADAMTS-13 disappared, but after 8 months the patient relapsed and received six PE and corticosteroids, and then rituximab therapy (four doses of 375 mg/mq weekly). ADAMTS-13 activity and inhibitor levels were monitored. ADAMTS-13 activity was initially, pre-rituximab,<6% (n.v. 46–160%) and inhibitor’s titre against ADAMTS-13 was 12 U/ml (n.v. <1 U/ml). After rituximab, the inhibitor against ADAMTS-13 disappeared rapidly after one month, while ADAMTS-13 activity has remained very low (<6%). After six months from rituximab therapy, there wasn’t full recovery of ADAMTS-13 activity. Follow up is now 6 months, responses are manteined, ADAMTS-13 activity has remained <6% and inhibitors have not reappeared. Our experience suggests that rituximab, by eliminating an important source of B-lymphocytes producing inhibitory ADAMTS-13 autoantibodies, may be a useful immunomodulating adjunct in the treatment of refractory chronic relapsing acquired TTP, before than others immunosoppressors and/or splenectomy.

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 Enhanced proteolysis of plasma von Willebrand factor in thrombotic thrombocytopenic purpura and the hemolytic uremic syndrome

Blood ◽  
1989 ◽  
Vol 74 (3) ◽  
pp. 978-983 ◽  
Author(s):  
PM Mannucci ◽  
R Lombardi ◽  
A Lattuada ◽  
P Ruggenenti ◽  
GL Vigano ◽  
...  
Keyword(s):  
Hemolytic Uremic Syndrome ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Von Willebrand Factor ◽  
Relative Increase ◽  
Thrombocytopenic Purpura ◽  
Uremic Syndrome ◽  
Von Willebrand ◽  
Willebrand Factor

To examine whether enhanced in vivo proteolysis of von Willebrand factor (vWF) would account for the reported loss of larger multimers in acute thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), we studied eight patients with acute TTP/HUS whose blood samples were collected into an anticoagulant containing a cocktail of protease inhibitors to impede in vitro proteolysis. In all, enhanced proteolytic degradation of vWF was expressed as a relative decrease in the intact 225-Kd subunit of vWF and a relative increase in the 176-Kd fragment. However, instead of the loss of larger forms of normal multimers reported by other investigators, the plasma of all but one of our patients (whether they had TTP or HUS) contained a set of larger than normal (supranormal) multimers. Hence, although proteolytic fragmentation of vWF was enhanced during acute TTP/HUS, this phenomenon was not associated with the loss of larger multimers. In the five patients who survived the acute disease and underwent plasma exchange (three with HUS and two with chronic relapsing TTP), subunits and fragments returned to normal values, and supranormal multimers were no longer detected in plasma. In conclusion, even though vWF proteolysis is enhanced in acute TTP/HUS, it does not lead to loss of larger multimers.

Increased Fragmentation of von Willebrand Factor, Due to Abnormal Cleavage of the Subunit, Parallels Disease Activity in Recurrent Hemolytic Uremic Syndrome and Thrombotic Thrombocytopenic Purpura and Discloses Predisposition in Families

Blood ◽  
1999 ◽  
Vol 94 (2) ◽  
pp. 610-620 ◽  
Author(s):  
Miriam Galbusera ◽  
Marina Noris ◽  
Chiara Rossi ◽  
Silvia Orisio ◽  
Jessica Caprioli ◽  
...  
Keyword(s):  
Hemolytic Uremic Syndrome ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Acute Phase ◽  
Von Willebrand Factor ◽  
Thrombocytopenic Purpura ◽  
Uremic Syndrome ◽  
Sporadic Cases ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract We investigated here the changes in von Willebrand factor (vWF) multimers in recurrent, sporadic and familial forms of hemolytic uremic syndrome (HUS)/thrombotic thrombocytopenic purpura (TTP) to see whether they are actually proteolyzed in vivo in these patients. Molecular determinants of fragments in vWF were also characterized to identify possible sites of cleavage of the subunit. Unusually large vWF multimers were found in blood of 8 of 10 patients with recurrent HUS/TTP, both in the acute phase and in remission, but never in familial and sporadic cases. Instead, all of the groups showed evidence of enhanced fragmentation of vWF multimers during the acute phase. Increased fragmentation was also shown by decrease in native 225-kD vWF subunit. In recurrent and sporadic HUS/TTP, enhanced fragmentation normalized at remission, but the abnormality persisted in familial HUS/TTP patients. The latter findings suggest that patients with familial HUS/TTP may have a congenital abnormality in vWF processing. Analysis with specific monoclonal antibodies showed the presence of the normal vWF fragments with apparent molecular mass of 189, 176, and 140 kD in all patients; however, in 6 recurrent and in 5 familial cases, novel fragments that differed in size from normal ones were found. The size of these abnormal fragments differed from one patient to another and none of them was ever found in normal plasma. These results documented, for the first time in HUS/TTP, an abnormal cleavage of the vWF subunit that might account for the increased fragmentation observed in these patients.

Increased Fragmentation of von Willebrand Factor, Due to Abnormal Cleavage of the Subunit, Parallels Disease Activity in Recurrent Hemolytic Uremic Syndrome and Thrombotic Thrombocytopenic Purpura and Discloses Predisposition in Families

Blood ◽  
1999 ◽  
Vol 94 (2) ◽  
pp. 610-620 ◽  
Author(s):  
Miriam Galbusera ◽  
Marina Noris ◽  
Chiara Rossi ◽  
Silvia Orisio ◽  
Jessica Caprioli ◽  
...  
Keyword(s):  
Hemolytic Uremic Syndrome ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Acute Phase ◽  
Von Willebrand Factor ◽  
Thrombocytopenic Purpura ◽  
Uremic Syndrome ◽  
Sporadic Cases ◽  
Von Willebrand ◽  
Willebrand Factor

We investigated here the changes in von Willebrand factor (vWF) multimers in recurrent, sporadic and familial forms of hemolytic uremic syndrome (HUS)/thrombotic thrombocytopenic purpura (TTP) to see whether they are actually proteolyzed in vivo in these patients. Molecular determinants of fragments in vWF were also characterized to identify possible sites of cleavage of the subunit. Unusually large vWF multimers were found in blood of 8 of 10 patients with recurrent HUS/TTP, both in the acute phase and in remission, but never in familial and sporadic cases. Instead, all of the groups showed evidence of enhanced fragmentation of vWF multimers during the acute phase. Increased fragmentation was also shown by decrease in native 225-kD vWF subunit. In recurrent and sporadic HUS/TTP, enhanced fragmentation normalized at remission, but the abnormality persisted in familial HUS/TTP patients. The latter findings suggest that patients with familial HUS/TTP may have a congenital abnormality in vWF processing. Analysis with specific monoclonal antibodies showed the presence of the normal vWF fragments with apparent molecular mass of 189, 176, and 140 kD in all patients; however, in 6 recurrent and in 5 familial cases, novel fragments that differed in size from normal ones were found. The size of these abnormal fragments differed from one patient to another and none of them was ever found in normal plasma. These results documented, for the first time in HUS/TTP, an abnormal cleavage of the vWF subunit that might account for the increased fragmentation observed in these patients.

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