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1.
Expert Rev Hematol ; 13(6): 599-606, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32286895

RESUMO

INTRODUCTION: Rare acquired bleeding disorders include a wide spectrum of coagulopathies characterized by spontaneous or post-trauma and post-surgery hemorrhages in patients without a previous personal or family history of bleeding. AREAS COVERED: This review, based on a Medline/PubMed search during the last 20 years, will focus mainly on rare acquired bleeding disorders caused by autoantibodies against coagulation factors, including autoantibodies against factor VIII (acquired hemophilia A), von Willebrand factor (acquired von Willebrand syndrome) and other coagulation factors (factors V, X, XI, and XIII). The pathogenic, laboratory, and clinical features of these rare hemorrhagic conditions will be discussed, with particular attention to their management. EXPERT OPINION: The treatment of rare acquired bleeding disorders includes the control of bleeding and the elimination of the autoantibody and of the underlying disease, when present. As the bleeding clinical phenotype is often severe, the management of affected patients is particularly challenging. Thus, while an early diagnosis of the acquired coagulopathy is essential to start the most appropriate treatment and to improve patients' outcomes, the support of specialized centers is equally important to provide a correct management of such complicated cases.


Assuntos
Autoanticorpos , Inibidores dos Fatores de Coagulação Sanguínea , Fatores de Coagulação Sanguínea , Hemofilia A , Doenças Raras , Doenças de von Willebrand , Autoanticorpos/sangue , Autoanticorpos/imunologia , Inibidores dos Fatores de Coagulação Sanguínea/sangue , Inibidores dos Fatores de Coagulação Sanguínea/imunologia , Fatores de Coagulação Sanguínea/imunologia , Fatores de Coagulação Sanguínea/metabolismo , Hemofilia A/sangue , Hemofilia A/imunologia , Humanos , Doenças Raras/sangue , Doenças Raras/imunologia , Doenças de von Willebrand/sangue , Doenças de von Willebrand/imunologia
2.
Transfus Clin Biol ; 26(4): 356-358, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31262628

RESUMO

We report the case of a French woman with acquired von Willebrand syndrome who presents recurrent subarachnoid and intra-cerebral hemorrhage since 2012. She had no family or personal bleeding history. In the biologic explorations, APTT was abnormally high with no anticoagulant drugs (it was normal, historically). Two monoclonal IgG and IgM kappa proteins were detected without any lymphoproliferative disorder. Intravenous infusion of immunoglobulin is very effective in AVWS with immunoglobulin G monoclonal gammapathie of undetermined significance. We had a satisfactory correction of coagulation factors for about 30 days. The exploration of APTT is surely essential for the diagnosis and treatment.


Assuntos
Hemorragia Cerebral/etiologia , Gamopatia Monoclonal de Significância Indeterminada/imunologia , Doenças de von Willebrand/diagnóstico , Idoso , Autoanticorpos/imunologia , Testes de Coagulação Sanguínea , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/prevenção & controle , Epistaxe/etiologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Cadeias kappa de Imunoglobulina/sangue , Imunoglobulinas Intravenosas/uso terapêutico , Imageamento por Ressonância Magnética , Gamopatia Monoclonal de Significância Indeterminada/complicações , Neuroimagem , Paraproteínas/análise , Recidiva , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/etiologia , Doenças de von Willebrand/etiologia , Doenças de von Willebrand/imunologia , Doenças de von Willebrand/terapia , Fator de von Willebrand/uso terapêutico
4.
PLoS One ; 12(2): e0171029, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28234916

RESUMO

OBJECTIVES: Acquired von Willebrand syndrome (AvWS) is associated with postoperative bleeding complications in patients with continuous flow left ventricular assist devices (CF-LVADs). The aim of this study is to analyze the perioperative vWF profile comparing an axial pump (HMII) to a centrifugal pump (HVAD) regarding the correlation between perioperative occurrence of AvWS, early- and late-postoperative bleeding events. METHODS: From July 2013 until March 2015 blood samples of 33 patients (12 HMII/ 8 HVAD/ 13 controls) were prospectively collected at 12 different time points and analyzed for the vWF antigen (vWF:Ag), its activity (vWF:Ac) and the vWF:Ac/vWF:Ag-ratio (vWF:ratio). The follow up period for postoperative bleeding events was from July 2013 until July 2016. RESULTS: Postoperatively, there was no difference in the vWF-profile between HVAD and HMII groups. However, a subgroup of patients already had significantly lower vWF:ratios preoperatively. Postoperatively, both CF-LVAD groups presented significantly lower vWF:ratios compared to the control group. Bleeding events per patient-year did not differ between the two groups (HMII vs. HVAD: 0.67 vs. 0.85, p = 0.685). We detected a correlation between vWF:ratio <0.7at LVAD-start (r = -0.583, p = 0.006) or at the end of surgery (r = -0.461, p = 0.035) and the occurrence of pericardial tamponade. In the control group, the drop in both vWF:Ag and vWF:Ac recovered immediately postoperatively above preoperative values. CONCLUSION: A subgroup of patients with end-stage heart failure already suffers AvWS preoperatively. In both CF-LVAD groups, AvWS begins immediately after surgery. Intraoperative vWF:ratios <0.7 correlate with higher incidences of pericardial tamponade and re-operation. The presumably dilutive effect of the heart lung machine on vWF vanishes immediately at the end of surgery, possibly as part of an acute-phase response.


Assuntos
Ponte de Artéria Coronária/efeitos adversos , Insuficiência Cardíaca/sangue , Hemorragia Pós-Operatória/sangue , Doenças de von Willebrand/sangue , Fator de von Willebrand/metabolismo , Idoso , Antígenos/sangue , Antígenos/imunologia , Feminino , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/cirurgia , Coração Auxiliar/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Período Perioperatório/efeitos adversos , Hemorragia Pós-Operatória/etiologia , Hemorragia Pós-Operatória/fisiopatologia , Doenças de von Willebrand/etiologia , Doenças de von Willebrand/imunologia , Doenças de von Willebrand/fisiopatologia , Fator de von Willebrand/imunologia
5.
Rinsho Ketsueki ; 56(7): 901-4, 2015 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-26256928

RESUMO

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder similar to inherited von Willebrand disease. We describe a 78-year-old woman with coexistent idiopathic thrombocytopenic purpura (ITP) and AVWS. The patient had once been admitted to our hospital because of cerebral infarction. Her platelet count had been normal at that time. Ten years later, she showed a severe bleeding tendency (platelet count 3.2×10(4)/µl). Analysis of hemostatic parameters showed very low (<6%) von Willebrand factor ristocetin cofactor (vWF: Rco), and low VIII: C (22%), but elevated (276%) von Willebrand antigen. Electrophoretic analysis of plasma showed low levels of the high-molecular weight VWF multimer. The presence of antibodies (IgG1 and IgG4) to VWF was detected by enzyme linked immunosorbent assay (ELISA). Factor XIII activity was 42%. Treatment with corticosteroids did not improve the thrombocytopenia, but did correct the bleeding diathesis. Also, VWF: Rco and VIII: C showed normalization. These findings indicated that the patient had ITP associated with AVWS. All reported cases of AVWS associated with systemic lupus erythematosus were cured by appropriate treatment of the underlying autoimmune disease with prednisone or immunosuppression. This bleeding disorder occurs mainly in patients with lymphoproliferative, myeloproliferative, cardiovascular and immunologic disorders, but no patients with ITP have previously been reported. This patient had the rare presentation of AVWS complicated by ITP and factor XIII deficiency.


Assuntos
Púrpura Trombocitopênica Idiopática/complicações , Doenças de von Willebrand/imunologia , Idoso , Anticorpos/imunologia , Evolução Fatal , Feminino , Humanos , Doenças Pulmonares Intersticiais/complicações , Doenças de von Willebrand/tratamento farmacológico , Fator de von Willebrand/imunologia
6.
Thromb Res ; 134(6): 1316-22, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25300810

RESUMO

BACKGROUND: Acquired von Willebrand Syndrome is a rare bleeding disorder, which arises in individuals with no personal or family history of bleeding, associated with lymphoproliferative and myeloproliferative disorders or other diseases. AIM: To develop a two-step approach assay to detect autoantibodies against VWF and to verify their prevalence in AVWS. METHODS: AVWS definition: negative personal or family history of bleeding diathesis, VWF below normal range and recent history of bleeding manifestations. Twenty-three consecutive patients affected by AVWS were enrolled. An ELISA assay (first step) using recombinant VWF protein immobilized on plates and sheep/goat polyclonal anti-human IgG or IgM labelled with peroxidase was developed. A group of 40 healthy subjects was tested to calculate the floating cut point value. A confirmation assay (with addition of purified VWF vs buffer) was performed (second step). RESULTS: Twenty-one patients (93%) had an associated disease, two patients had idiopathic AVWS. Anti-VWF autoantibodies were detected in 9 patients (39%). Of these, eight (89%) had VWF:RCo levels <10%, but none of them resulted positive using Bethesda assay (neutralizing antibodies). The confirmation test confirmed the positive results obtained with ELISA and resulted negative in those patients with negative results and in the controls. CONCLUSION: With the present two-step approach assay nine out of 23 (39%) patients affected with AVWS resulted positive for anti-VWF autoantibodies. This ELISA assay might be used as an additional confirmation tool in the diagnostic procedure in patients affected by AVWS or in the follow-up of congenital and acquired patients exposed to replacement therapy.


Assuntos
Autoanticorpos/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/imunologia , Fator de von Willebrand/imunologia , Idoso , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Haemophilia ; 20(4): e304-10, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24758424

RESUMO

Haemostatic management of surgery in patients with von Willebrand disease (VWD) includes DDAVP or von Willebrand factor (VWF)-containing concentrates. Although the recommendations are for monitoring by VWF activity assays, it is quite common for clinicians to use factor VIII due usually to longer turnaround times required for VWF ristocetin cofactor assay (VWF:RCo) measurements. The aim of this study was to evaluate use of the rapid HaemosIL VWF activity (VWF:Act) latex immuno assay (LIA) on an automated coagulometer (ACL TOP(™) 700; Instrumentation Laboratory, Bedford, MA, USA) compared to platelet-based VWF:RCo assays in this setting. One hundred and sixty-seven plasma samples from 42 patients [Type 1 (n = 22), Type 2A (n = 2), Type 2B (n = 3), Type 2M (n = 10), Type 3 (n = 3)] and acquired von Willebrand syndrome (n = 2) with VWD treated with DDAVP or VWF-containing concentrates were included in the study. Method comparison and method bias were evaluated by Bland-Altman analysis (BA) and Passing and Bablok regression modelling respectively. BA of baseline samples (n = 39) showed a mean difference of -3.0 (±1.96 SD -25.2 to +19.4). Post (treatment) samples (n = 120) were separated into two groups. Group 1 contained samples with VWF:RCo levels 10 to ≤175 IU dL(-1) (n = 97) and group 2, samples with VWF:RCo levels >175 IU dL(-1) (n = 23). BA of group 1 postsamples showed a mean difference of +3.4 (±1.96 SD -44.6 to +51.5), and the BA of Group 2 samples was -23.9 (±1.96 SD -136.1 to +88.3). In conclusion, use of HaemosIL VWF:Act LIA test on an automated coagulometer is a reproducible and rapid assay that can be used as an alternative test for monitoring VWF replacement therapy, facilitating dose adjustments on a real-time basis.


Assuntos
Desamino Arginina Vasopressina/uso terapêutico , Imunoensaio/métodos , Látex , Doenças de von Willebrand/tratamento farmacológico , Doenças de von Willebrand/imunologia , Fator de von Willebrand/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Plaquetas/efeitos dos fármacos , Plaquetas/imunologia , Criança , Pré-Escolar , Feminino , Liofilização , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem , Doenças de von Willebrand/sangue
8.
Intern Med ; 52(23): 2661-3, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24292759

RESUMO

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder with laboratory findings similar to those of congenital von Willebrand disease. We herein report a case of AVWS associated with Hashimoto's thyroiditis and subcutaneous mucosa-associated lymphoid tissue lymphoma. An IgG autoantibody against von Willebrand factor (VWF) was detected. The antibody bound to VWF but did not inhibit VWF activity. Rapid clearance of VWF seemed to be the cause of AVWS in the present case. VWF-containing concentrates stopped the bleeding. Even if such a complication is rare, for AVWS patients, prompt recognition of the underlying mechanism can save lives.


Assuntos
Doença de Hashimoto/complicações , Linfoma de Zona Marginal Tipo Células B/complicações , Doenças de von Willebrand/etiologia , Autoanticorpos/sangue , Feminino , Doença de Hashimoto/imunologia , Humanos , Imunoglobulina G/sangue , Pessoa de Meia-Idade , Doenças de von Willebrand/imunologia , Doenças de von Willebrand/terapia , Fator de von Willebrand/administração & dosagem , Fator de von Willebrand/imunologia , Fator de von Willebrand/metabolismo
9.
J Thromb Haemost ; 10(11): 2315-23, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23006049

RESUMO

BACKGROUND: Polyphosphate, a phosphate polymer released by activated platelets, has recently been described as a potent modulator of blood coagulation and fibrinolysis. In blood plasma, polyphosphate binds to and alters the biological functions of factor XII, fibrin(ogen), thrombin and factor VII activating protease. OBJECTIVES: The aim of the present study is to investigate whether polyphosphate also binds to von Willebrand factor (VWF) and alters some of its activities. METHODS/RESULTS: When studying patients with type 1 von Willebrand disease (VWD) and their healthy relatives, we discovered a significant correlation between von Willebrand factor (VWF) and platelet polyphosphate levels. We have also found polyphosphate in preparations of VWF isolated from normal platelets and plasma. Surface plasmon resonance and electrophoretic mobility assays indicated that polyphosphate interacts with VWF in a dose- and time-dependent manner. Treatment of normal plasma with active exopolyphosphatase decreased the VWF ristocetin cofactor (VWF:RCo) activity, a functional measure of VWF binding to platelet glycoprotein receptor Ib. VWF collagen binding and multimerization were unaltered after polyphosphate depletion. Moreover, addition of polyphosphate increased the deficient VWF:RCo activity presented by plasma from patients with type 1 VWD. CONCLUSIONS: Our results reveal that a new role is played by polyphosphate in hemostasis by its interaction with VWF, and suggest that this polymer may be effective in the treatment of some types of VWD.


Assuntos
Complexo Glicoproteico GPIb-IX de Plaquetas/química , Polifosfatos/química , Doenças de von Willebrand/sangue , Fator de von Willebrand/química , Hidrolases Anidrido Ácido/química , Coagulação Sanguínea , Plaquetas/citologia , Colágeno/química , Fator XII/química , Fibrinogênio/química , Fibrinólise , Humanos , Microscopia Confocal , Polímeros/química , Ligação Proteica , Serina Endopeptidases/química , Ressonância de Plasmônio de Superfície , Trombina/química , Doenças de von Willebrand/imunologia
10.
Rinsho Shinkeigaku ; 51(5): 334-7, 2011 May.
Artigo em Japonês | MEDLINE | ID: mdl-21706830

RESUMO

We report a case of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) concomitant with acquired von Willebrand syndrome. A 33-year-old man developed motor and sensory polyneuropathy with electrophysiological conduction slowing. At this time, M-protein was absent He was diagnosed with CIDP and received intravenous immunoglobulin and subsequent oral corticosteroids, which resulted in almost complete remission for over 10 years. At the age of 44, he presented with chronic anemia. Laboratory tests and colonoscopy revealed that he had acquired von Willebrand syndrome with monoclonal gammopathy of undetermined significance (IgG lambda type) and colon cancer. Bleeding symptoms were.resolved with intravenous immunoglobulin, but not with supplementation of factor VIII. Shortly after successful excision of the cancer, CIDP and acquired von Willebrand syndrome simultaneously recurred. Intravenous immunoglobulin produced rapid improvement of both neurological and hematological abnormalities. Concurring CIDP and acquired von Willebrand syndrome in the present case may indicate that the conditions have a partly common immunological background including monoclonal gammopathy and a potential common autoantibody-mediated mechanism. Alternatively, dysfunction of von Willebrand factor may increase blood-nerve barrier permeability, inducing the recurrence of CIDP.


Assuntos
Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/complicações , Doenças de von Willebrand/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/complicações , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/imunologia , Doenças de von Willebrand/imunologia
11.
Eur J Haematol ; 87(2): 99-106, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21535159

RESUMO

Acquired von Willebrand disease (AVWD) is a rare, underdiagnosed hemorrhagic disorder, which is similar to congenital VWD with regard to the clinical and laboratory parameters; however, it is found in individuals with no positive family history and has no genetic basis. The etiology is varied, the commonest being hematoproliferative disorders and cardiovascular disorders. Other disorders associated with AVWD are autoimmune disorders such as systematic lupus erythematosus, hypothyroidism, and neoplasia, or it may also be drug induced. In quite a few cases, the etiology is unknown. The pathogenic mechanisms are different in different underlying disorders or they may be overlapping among these disorders. Some of the proposed mechanisms include the development of autoantibodies, selective absorption of high molecular weight von Willebrand factor (VWF) multimers, non-selective absorption of VWF, mechanical destruction of VWF under high shear stress, and increased proteolysis. This report presents a concise review of the pathophysiological mechanisms of AVWD in these various underlying conditions.


Assuntos
Doenças de von Willebrand/fisiopatologia , Autoanticorpos/biossíntese , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/complicações , Humanos , Hipotireoidismo/sangue , Hipotireoidismo/complicações , Transtornos Linfoproliferativos/complicações , Transtornos Linfoproliferativos/imunologia , Transtornos Mieloproliferativos/sangue , Transtornos Mieloproliferativos/complicações , Neoplasias/sangue , Neoplasias/complicações , Multimerização Proteica , Doenças de von Willebrand/sangue , Doenças de von Willebrand/etiologia , Doenças de von Willebrand/imunologia , Fator de von Willebrand/química , Fator de von Willebrand/imunologia
12.
Acta Haematol ; 121(2-3): 177-82, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19506364

RESUMO

Acquired von Willebrand disease (aVWD) occurs in association with a variety of underlying disorders, most frequently in lymphoproliferative and myeloproliferative disorders, other malignancies, and cardiovascular disease. aVWD is a complex and heterogeneous defect with a multifactorial etiology and the pathophysiologic mechanisms remain unclear in many cases. Assays for anti-factor VIII (FVIII)/von Willebrand factor (VWF) activities often yield negative results although antibodies may be present in autoimmune disease and some lymphoproliferative disorders. Functional assays of VWF in patients' plasma and particularly in heart valve disease, VWF multimer analysis are important for aVWD diagnosis. In patients with normal partial thromboplastin times and normal VWF activity, the diagnosis of aVWD is based on clinical suspicion and a careful bleeding history, which should prompt the clinician to initiate further laboratory investigations. Management of bleeding in aVWD relies mainly on desmopressin, FVIII/VWF concentrates and high-dose intravenous immunoglobulin. The half-life of VWF may be very short, and in bleeding episodes high doses of FVIII/VWF concentrates at short intervals may be necessary even when high-dose intravenous immunoglobulin was applied before. Since the optimal treatment strategy has not yet been defined for aVWD of different etiology, controlled multicenter trials aiming at the development of standardized treatment protocols are urgently needed.


Assuntos
Autoanticorpos/imunologia , Autoantígenos/imunologia , Doenças de von Willebrand/etiologia , Fator de von Willebrand/imunologia , Especificidade de Anticorpos , Autoanticorpos/sangue , Doenças Autoimunes/complicações , Doenças Autoimunes/imunologia , Desamino Arginina Vasopressina/uso terapêutico , Cardiopatias/complicações , Hemorragia/etiologia , Hemorragia/prevenção & controle , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Imunoglobulinas Intravenosas/uso terapêutico , Imunossupressores/uso terapêutico , Transtornos Linfoproliferativos/complicações , Transtornos Linfoproliferativos/imunologia , Neoplasias/complicações , Neoplasias/imunologia , Doenças de von Willebrand/induzido quimicamente , Doenças de von Willebrand/classificação , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/imunologia , Doenças de von Willebrand/terapia , Fator de von Willebrand/metabolismo
13.
J Pediatr ; 155(1): 68-72, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19394040

RESUMO

OBJECTIVE: To review the incidence of postoperative bleeding in children with type 1 von Willebrand disease (VWD) who were treated with a single institution protocol. STUDY DESIGN: We performed a retrospective study to determine the postoperative hemorrhage rate in pediatric patients with type 1 VWD who were treated via the Children's Hospital of Philadelphia institutional protocol. This protocol utilizes intravenous desmopressin (DDAVP), oral aminocaproic acid, and overnight observation. RESULTS: Between the years of 2000 to 2006, 41 children with type 1 VWD underwent an adenotonsillar procedure and were treated with this protocol. Seven patients (17%) experienced delayed (>24 hours after surgery) postoperative hemorrhage requiring intervention. Five of the 7 patients required cautery to control the bleeding, and the remaining 2 patients responded to DDAVP and aminocaproic acid alone. Older age and lower VW antigen levels were associated with postoperative hemorrhage (P = .05). CONCLUSIONS: Despite therapeutic intervention to decrease the risk of postoperative hemorrhage, the incidence of hemorrhage was higher in pretreated patients with type 1 VWD than in children without bleeding disorders. Further prospective studies are necessary to determine the optimal treatment to reduce bleeding complications in these patients.


Assuntos
Adenoidectomia , Hemorragia Pós-Operatória/epidemiologia , Hemorragia Pós-Operatória/prevenção & controle , Tonsilectomia , Doenças de von Willebrand/epidemiologia , Administração Oral , Adolescente , Fatores Etários , Aminocaproatos/uso terapêutico , Cauterização , Criança , Pré-Escolar , Desamino Arginina Vasopressina/uso terapêutico , Feminino , Hemostáticos/uso terapêutico , Humanos , Infusões Intravenosas , Masculino , Náusea e Vômito Pós-Operatórios/epidemiologia , Estudos Retrospectivos , Doenças de von Willebrand/imunologia , Fator de von Willebrand/análise , Fator de von Willebrand/imunologia
15.
16.
Am J Hematol ; 82(5): 363-7, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17205535

RESUMO

Acquired loss of functional von Willebrand factor (VWF) has been termed the acquired von Willebrand syndrome (AVWS). AVWS is a rare adult-onset bleeding diathesis that is clinically similar to congenital von Willebrand disease (VWD), and occurs with a variety of autoimmune, lymphoproliferative, or myeloproliferative disorders. We have identified four patients with AVWS in association with immunoglobulin light chain (AL) amyloidosis. These patients, lacking any pre-existing or family history of abnormal bleeding, developed cutaneous, mucosal, or gastrointestinal bleeding in the course of their disease without deficiency of clotting factor X or other factors; the activated partial thromboplastin time (aPTT) was prolonged in three out of the four cases. Despite normal VWF antigen levels, VWF ristocetin cofactor activity (VWF:RCo) was low. Electrophoresis patterns of high molecular weight (HMW) VWF multimers were abnormal in two of the four cases. Two of the patients were treated with high-dose intravenous melphalan followed by autologous stem cell transplantation (HDM/SCT) and achieved hematologic remission. In these two patients, the bleeding diathesis improved and the coagulation parameters normalized, confirming a causal relationship between the plasma cell dyscrasia and the AVWS. AVWS should be considered in AL amyloidosis patients with hemorrhagic diatheses and normal clotting factor levels.


Assuntos
Amiloidose/complicações , Doenças de von Willebrand/etiologia , Adulto , Amiloidose/sangue , Amiloidose/tratamento farmacológico , Amiloidose/cirurgia , Antígenos/análise , Eletroforese das Proteínas Sanguíneas , Eletroforese em Gel de Ágar , Hemorragia/etiologia , Humanos , Cadeias Leves de Imunoglobulina/análise , Masculino , Melfalan/uso terapêutico , Peso Molecular , Tempo de Tromboplastina Parcial , Transplante de Células-Tronco de Sangue Periférico , Indução de Remissão , Ristocetina/farmacologia , Transplante Autólogo , Doenças de von Willebrand/imunologia , Fator de von Willebrand/imunologia
17.
Am J Hematol ; 82(5): 368-75, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17133419

RESUMO

Acquired von Willebrand syndrome (aVWS) is a rare bleeding disorder with laboratory findings similar to those for congenital von Willebrand disease (VWD). However, unlike congenital VWD, it arises in individuals with no personal or family history of bleeding. aVWS occurs in association with a variety of underlying disorders, most frequently in lymphoproliferative disorders, myeloproliferative disorders, and cardiovascular diseases. Through an analysis of the more recent literature data, the pathophysiology and the clinical, laboratory, and therapeutic aspects of this syndrome are concisely reported in this review.


Assuntos
Doenças de von Willebrand/etiologia , Proteínas ADAM/metabolismo , Proteína ADAMTS13 , Adsorção , Autoanticorpos/imunologia , Doenças Autoimunes/etiologia , Doenças Autoimunes/imunologia , Testes de Coagulação Sanguínea , Doenças Cardiovasculares/complicações , Desamino Arginina Vasopressina/uso terapêutico , Doenças do Sistema Endócrino/complicações , Fator VIII/uso terapêutico , Doenças Hematológicas/complicações , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Doenças de von Willebrand/sangue , Doenças de von Willebrand/induzido quimicamente , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/imunologia , Doenças de von Willebrand/fisiopatologia , Doenças de von Willebrand/terapia , Fator de von Willebrand/química , Fator de von Willebrand/imunologia , Fator de von Willebrand/metabolismo , Fator de von Willebrand/uso terapêutico
18.
Semin Thromb Hemost ; 32(6): 577-88, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16977568

RESUMO

The most common nonimmune etiology of acquired von Willebrand syndrome (AvWS) includes hypothyroidism, Wilms' tumor, thrombocythemia, or congenital heart defects, and the use of various drugs. AvWS type 1 in patients with hypothyroidism is due to decreased Willebrand factor (vWF) synthesis and is reversible by treatment with thyroxin. AvWS type 1 or 3 in children with Wilms' tumor disappears after successful chemotherapy or tumor resection but the mechanism of the vWF deficiency is unknown. The AvWS type 2 in patients with thrombocythemia of various myeloproliferative disorders is caused by increased proteolysis of large vWF multimers at increasing platelet counts to above 1000 x 10 (9)/L. Reduction of platelet counts to normal results in correction of the vWF parameters together with disappearance of the bleeding tendency. Type 2-like AvWS in children with congenital heart valve defects is caused by shear stress-induced proteolysis of large vWF multimers and is reversible after surgical correction. AvWS associated with the use of drugs disappears after discontinuation of the causative agent. Immune-mediated AvWS is associated with either systemic lupus erythematosus (SLE) or immunoglobulin G (IgG) benign monoclonal gammopathy (BMG), and usually shows a type 2 vWF deficiency. Using a simple enzyme-linked immunosorbent assay, an IgG antibody against vWF is detectable in AvWS associated with SLE and IgG BMG. The IgG-autoantibody-factor (F) vWF/VIII complex is rapidly cleared from the circulation, which explains the combined FVIII:coagulant activity (C) and vWF deficiency and the poor responses of FVIII:C and vWF parameters to intravenous desmopressin acetate and vWF/FVIII concentrates. A transient correction of both FVIII:C and vWF parameters to normal for a few weeks after high-dose intravenous immunoglobulin is seen in AvWS associated with SLE and IgG BMG. AvWS associated with SLE uniformly shows a curative response to corticosteroids. AvWS associated with IgG BMG does not respond to corticosteroids, immune suppression, or chemotherapy. AvWS associated with IgM BMG is rare and does not respond to any conventional treatment.


Assuntos
Anticorpos Monoclonais/química , Sistema Imunitário/fisiologia , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/imunologia , Gamopatia Monoclonal de Significância Indeterminada/complicações , Gamopatia Monoclonal de Significância Indeterminada/imunologia , Doenças de von Willebrand/imunologia , Doenças de von Willebrand/terapia , Adolescente , Adulto , Idoso , Plaquetas/metabolismo , Química Clínica/métodos , Fator VIII/química , Humanos , Lúpus Eritematoso Sistêmico/terapia , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/terapia , Mieloma Múltiplo/complicações , Tumor de Wilms/complicações , Tumor de Wilms/diagnóstico
19.
Hum Immunol ; 66(4): 422-30, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15866707

RESUMO

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder with laboratory findings similar to those for congenital von Willebrand disease. Unlike the congenital form, AVWS usually occurs in individuals with no personal or family history of bleeding disorders. According to an international registry, AVWS is mainly associated with lymphomyeloproliferative, immunologic, and cardiovascular disorders, as well as with solid tumors and other miscellaneous conditions; however, the prevalence of AVWS in these underlying disorders is still unknown. von Willebrand factor (VWF) is synthesized normally in most AVWS patients, and the low plasma VWF levels are from its accelerated removal from plasma by five different mechanisms, including autoantibodies. Because of the reduced half-life of endogenous-exogenous plasma VWF, bleeding of AVWS cannot be managed with desmopressin or factor VIII/VWF concentrates. Clinical use of intravenous immunoglobulin (IVIg) in AVWS has been reported since 1988. IVIg is most effective in AVWS with type immunoglobulin (Ig) G monoclonal gammopathies of undetermined significance and in other cases with IgG autoantibodies. IVIg can correct factor VIII and von Willebrand factor complex activities for about 15-20 days, and repeated injections induce remission of AVWS in these patients. Prospective studies are required to evaluate the efficacy and safety of IVIg in AVWS.


Assuntos
Imunoglobulinas Intravenosas/uso terapêutico , Doenças de von Willebrand/terapia , Humanos , Imunoglobulinas Intravenosas/administração & dosagem , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/etiologia , Doenças de von Willebrand/imunologia
20.
Blood ; 103(12): 4424-8, 2004 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-14996701

RESUMO

The activity and safety profile of selective B-cell depletion with rituximab, an anti-CD20 monoclonal antibody, were evaluated in 10 patients with acquired hemophilia. Rituximab was given intravenously at the dose of 375 mg/m(2) once weekly for 4 consecutive weeks. Infusion-related side effects were observed in 3 patients but were of mild intensity and did not require discontinuation of treatment. Eight patients with Factor VIII (FVIII) inhibitor titers between 4 and 96 Bethesda units per milliliter (BU/mL) achieved a complete remission, which was defined as a return to normal FVIII activity and undetectable FVIII inhibitor titers. Two more patients with inhibitor levels greater than 100 BU/mL experienced only a partial transient decrease of the inhibitor after rituximab alone, but they achieved a complete response after being challenged with a combination of rituximab plus pulse intravenous cyclophosphamide. With a median follow-up of 28.5 months (range, 12-41 months), 3 patients have thus far relapsed. Retreatment with the monoclonal antibody at the same dose and schedule resulted in a new sustained response in all these patients. In conclusion, rituximab appears an effective and well-tolerated treatment for patients with acquired hemophilia and low inhibitor titers. A reinforcement of therapy with other agents seems to be required to achieve a full and durable response in those patients with high inhibitor levels.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Doenças de von Willebrand/tratamento farmacológico , Doenças de von Willebrand/imunologia , Adulto , Idoso , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Murinos , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Progressão da Doença , Fator VIII/antagonistas & inibidores , Feminino , Humanos , Depleção Linfocítica , Masculino , Pessoa de Meia-Idade , Monitorização Imunológica , Rituximab , Fatores de Tempo
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