scholarly journals Targeting raised von Willebrand factor levels and macrophage activation in severe COVID-19: Consider low volume plasma exchange and low dose steroid

2020 ◽  
Vol 192 ◽  
pp. 2 ◽  
Author(s):  
U. Zachariah ◽  
S.C. Nair ◽  
A. Goel ◽  
K.A. Balasubramanian ◽  
I. Mackie ◽  
...  
Keyword(s):  
Plasma Exchange ◽  
Von Willebrand Factor ◽  
Macrophage Activation ◽  
Low Dose ◽  
Low Volume ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals Recurrent Arterial Thrombosis Linked to Autoimmune Antibodies Enhancing von Willebrand Factor Binding to Platelets and Inducing FcγRII Receptor-Mediated Platelet Activation

Blood ◽  
1998 ◽  
Vol 91 (8) ◽  
pp. 2810-2817 ◽  
Author(s):  
Marc F. Hoylaerts ◽  
Chantal Thys ◽  
Jef Arnout ◽  
Jos Vermylen
Keyword(s):  
Platelet Activation ◽  
Von Willebrand Factor ◽  
Low Dose ◽  
Antithyroid Drug ◽  
Fetal Loss ◽  
Thyroid Peroxidase ◽  
Spontaneous Aggregation ◽  
Von Willebrand ◽  
Induced Aggregation ◽  
Willebrand Factor

A patient with a history of recurrent late fetal loss associated with multiple placental infarcts and cerebrovascular ischemia at the age of 36, followed a year later by a myocardial infarction, was referred for further investigation. Coronary angiography was normal. Antinuclear factor, lupus anticoagulant, anticardiolipin antibodies, and other thrombophilia parameters were negative, but there was moderate hyperthyroidism with positive thyroid peroxidase antibodies. Platelet numbers and von Willebrand factor (vWF) were normal. Her platelets showed spontaneous aggregation that disappeared with aspirin intake. However, aggregation still was induced by low levels of ristocetin (0.3 to 0.5 mg/mL). The low-dose ristocetin aggregation in patient platelet-rich plasma (PRP) was completely blocked by neutralizing antiglycoprotein Ib (GPIb) and anti-vWF antibodies. The monoclonal anti-FcγRII receptor antibody IV.3 inhibited partly, which suggests that PRP aggregation by low-dose ristocetin was elicited by vWF-immunoglobulin (Ig) complexes. Upon addition to washed human platelets, with vWF (10 μg/mL), purified patient Igs dose-dependently enhanced ristocetin (0.15 mg/mL)-induced aggregation between 0 and 500 μg/mL, an effect that disappeared again above 1 mg/mL. Aggregation was dependent on the vWF concentration and was blocked by IV.3 or neutralizing anti-GPIb or anti-vWF antibodies. The spontaneous aggregation of normal platelets resuspended in patient plasma could be inhibited totally by IV.3 and partially by neutralizing anti-GPIb or anti-vWF antibodies. Perfusion with normal anticoagulated blood, enriched with 10% of control or patient plasma, over surfaces coated with vWF showed increased platelet adhesion and activation in the presence of patient antibodies. Treatment of the patient with the antithyroid drug thiamazol and temporary corticosteroids, aspirin, and ticlopidine did not correct the platelet hypersensitivity to ristocetin. These observations suggest that some autoantibodies to vWF may both enhance vWF binding to platelets and cause platelet activation through binding to the FcγRII receptor, and thereby may be responsible for a new form of antibody-mediated thrombosis.

Recovery and Half-Life of von Willebrand Factor-Cleaving Protease after Plasma Therapy in Patients with Thrombotic Thrombocytopenic Purpura

1999 ◽  
Vol 81 (01) ◽  
pp. 8-13 ◽  
Author(s):  
Rodolfo Robles ◽  
Beat Morselli ◽  
Pierre Sandoz ◽  
Bernhard Lämmle ◽  
Miha Furlan
Keyword(s):  
Plasma Exchange ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Von Willebrand Factor ◽  
Half Life ◽  
Protease Activity ◽  
Plasma Therapy ◽  
Thrombocytopenic Purpura ◽  
Plasma Infusion ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryPlasma exchange using fresh-frozen plasma (FFP) for replacement was given to two brothers during a relapse of thrombotic thrombocytopenic purpura (TTP). A constitutional deficiency of von Willebrand factor(vWF)-cleaving protease had been previously established in both patients. No inhibitor of vWF-cleaving protease was present in patients’ plasmas. They received plasma exchange for four and three consecutive days, respectively. In both patients, the activity of vWF-cleaving protease after the first plasmapheresis session was evaluated and was found to be virtually identical to anticipated activity calculated from predicted patient plasma volume and volume of exchanged plasma. Pathologic platelet counts and lactate dehydrogenase levels were normalized in both patients within 4-6 days. The biologic half-life of vWF-cleaving protease was determined in these patients following the last plasma exchange. The respective half-lives of 3.3 and 2.1 days represent the lowest known clearance rates of proteases in circulating human plasma.Another patient with relapsing TTP was treated with plasma exchange and/or plasma infusion for 10 consecutive days during the first relapse, 221-231 days after the initial TTP event. Pharmacokinetic studies of vWF-cleaving protease were performed after plasma exchange on day 221 and after plasma infusion on day 231. High level of an IgG in patient plasma, capable of completely inhibiting protease activity in an equal volume of normal plasma, had been established prior to first plasmapheresis. There was no measurable protease activity at any time during plasma therapy. Following plasma exchange, the level of the inhibitor was transiently slightly depressed. After 10 days of plasma therapy, the concentration of the inhibitor in patient plasma was increased about 5-fold. We suggest that, in contrast to protease deficient patients without circulating inhibitor, complementary therapy including immunosuppressive treatment, vincristine and/or splenectomy is indicated in patients with acquired inhibitors of vWF-cleaving protease. Testing for vWF-cleaving protease inhibitor may be useful in predicting the response to plasma exchange in patients with TTP.

scholarly journals Acquired Deficiency of von Willebrand Factor-Cleaving Protease in a Patient With Thrombotic Thrombocytopenic Purpura

Blood ◽  
1998 ◽  
Vol 91 (8) ◽  
pp. 2839-2846 ◽  
Author(s):  
Miha Furlan ◽  
Rodolfo Robles ◽  
Max Solenthaler ◽  
Bernhard Lämmle
Keyword(s):  
Platelet Count ◽  
Plasma Exchange ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Von Willebrand Factor ◽  
Protease Activity ◽  
Temporary Increase ◽  
Severe Thrombocytopenia ◽  
Thrombocytopenic Purpura ◽  
Von Willebrand ◽  
Willebrand Factor

Plasma of patients with thrombotic thrombocytopenic purpura (TTP) has been shown to contain unusually large von Willebrand factor (vWF) multimers that may cause platelet agglutination in vivo. Fresh frozen plasma infusions and plasma exchange represent the most efficient therapy of acute TTP. A specific protease responsible for cleavage of vWF multimers has been recently isolated from normal human plasma and was found to be deficient in four patients with chronic relapsing TTP. We examined the activity of the vWF-cleaving protease in plasma samples collected over a period of 400 days from a further patient with recurrent episodes of TTP who was treated by plasma exchange, plasma infusion, vincristine, corticosteroid therapy, and splenectomy. Complete deficiency of the vWF-cleaving protease was established during the first episode of TTP. The ensuing normalization of the platelet count was associated with the appearance of the protease activity. Three months after remission from the initial TTP event, the vWF-cleaving protease again disappeared and the platelet count gradually decreased. Relapses of severe thrombocytopenia occurred 7 and 11 months after the first acute episode of TTP. Deficient protease activity was associated with the presence in the patient plasma of an inhibitor that was found to be an IgG. Plasma exchange/infusion was followed by a temporary increase in the antibody titer, whereas treatment with vincristine led to a recovery of the platelet count without affecting the inhibitor concentration. Splenectomy and corticosteroid treatment resulted in disappearance of the autoantibody and normalization of the protease activity and of the platelet count. Our data suggest that the thrombocytopenia in this patient with TTP was associated with a lack of the vWF-cleaving protease activity depleted by an autoimmune mechanism. This case, together with our previously reported patients, leads us to conclude that acquired as well as constitutional deficiency of the vWF-cleaving protease may predispose to TTP.

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.

Caplacizumab: an anti–von Willebrand factor antibody for the treatment of thrombotic thrombocytopenic purpura

2020 ◽  
Vol 77 (15) ◽  
pp. 1201-1207
Author(s):  
Alyssa L Hollifield ◽  
Justin R Arnall ◽  
Donald C Moore
Keyword(s):  
Adverse Events ◽  
Plasma Exchange ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Von Willebrand Factor ◽  
Antibody Fragment ◽  
Self Administration ◽  
Phase 3 ◽  
Thrombocytopenic Purpura ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Purpose The pharmacology, pharmacokinetics, efficacy, safety, dosing and administration, and place in therapy of caplacizumab, a novel antibody fragment that inhibits von Willebrand factor, for the treatment of acquired thrombotic thrombocytopenic purpura (TTP) are summarized. Summary Caplacizumab is a humanized anti–von Willebrand factor monoclonal antibody fragment that inhibits the interaction between ultralarge von Willebrand factor multimers and platelets. Caplacizumab is indicated for use in combination with standard-of-care modalities such as plasma exchange and immunosuppressive therapy for the treatment of adults with acquired TTP. By inhibiting von Willebrand factor, caplacizumab offers a new approach to the management of TTP by preventing the development of potentially life-threatening microvascular thrombosis that can occur in the disease process. In a randomized, placebo-controlled phase 3 trial, patients with acquired TTP treated with caplacizumab had more rapid platelet level normalization than placebo users; caplacizumab use also resulted in lower rates of disease recurrence and TTP-related death. The most common adverse events associated with caplacizumab use are bleeding-related events. In a phase 3 trial, serious bleeding-related adverse events were reported in 8 patients (11%) in the caplacizumab group and 1 patient (1%) in the placebo group. Caplacizumab is administered as an 11-mg intravenous loading dose 15 minutes prior to plasma exchange, followed by administration of 11 mg subcutaneously daily after plasma exchange. Once-daily caplacizumab administration can be continued for 30 days after the last plasma exchange. The medication and supplies for administration are provided as a single-use kit; patients should be trained on proper reconstitution and self-administration technique prior to the use of caplacizumab in the ambulatory setting. Conclusion Caplacizumab is a first-in-class von Willebrand factor inhibitor approved for the treatment of adults with acquired TTP.

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