Lack of multimer organization of von Willebrand factor in an acquired von Willebrand syndrome

Cryptic non-canonical splice site activation is part of the mechanism that abolishes multimer organization in the c.2269_2270del von Willebrand factor

We report a new pathogenic mechanism in von Willebrand disease involving the use of a non-canonical splicing site. The proband, carrying the homozygous c.2269_2270del mutation previously classified as a type 3 mutation, showed severely reduced plasma and platelet von Willebrand factor antigen levels and functions, and no factor VIII binding capacity. A particular von Willebrand factor multimer pattern emerged in plasma, characterized by the presence of only two oligomers: the dimer and an unusually large band, with no intermediate components. There were von Willebrand factor multimers in platelets, but each band ran more slowly than the normal counterpart. No anti-von Willebrand factor antibodies were detectable. The proband was classified as having severe type 1 von Willebrand disease. Seeking the relationship between phenotype and genotype, we found the c.2269_2270del mutation associated with three different RNA: r.2269_2270del (RNAI), giving a truncated von Willebrand factor protein; r.[2269_2270del;2282_2288del] (RNAII), resulting from activation of a cryptic “AG” splicing site; and r.[2269_2270del;2281_2282insAG] (RNAIII), where the wild-type “AG” acceptor of exon 18 was retained due to the non-canonical 2279-2280 “CG” acceptor splicing site being used. The aberrant RNAII and RNAIII caused the alteration of the furin cleavage and binding sites, respectively, both resulting in a von Willebrand factor protein characterized by the persistence of von Willebrand factor propeptide, as confirmed by western blot analysis of the recombinant mutated von Willebrand factor molecules produced in vitro. Taken together, these findings explain the residual von Willebrand factor synthesis, slower-running multimers, and absent factor VIII binding capacity. The apparently pure gene null mutation c.2269_2270del profoundly alters von Willebrand factor gene splicing, inducing a complex RNA expression pattern.

Acquired von Willebrand Syndrome Complicating Nephrotic Syndrome: A Case of a Patient With Membranous Nephropathy

Acquired von Willebrand syndrome (AVWS) is a rare clinical entity presenting with heterogeneous hemorrhagic manifestations, although some subsets of patients with AVWS may be asymptomatic until they are exposed to major trauma, an invasive procedure, or surgery. We herein report one such case in a 73-year-old male patient with nephrotic syndrome with a prolonged active partial thromboplastin time. We initially did not deal with this distinct abnormal clotting profile seriously, but persistent bleeding after a retroperitoneoscopic-assisted renal biopsy that allowed us to ascribe his nephrotic syndrome to membranous nephropathy fortuitously led to the discovery of concurrent AVWS. We feel that an accurate and prompt diagnosis as well as awareness of the disease remain a challenge for physicians and therefore strongly recommend the further accumulation of experiences similar to our own in a prospective manner. This report underscores the pitfalls associated with determining the bleeding risk, including an insufficient assessment and improper weighting of an abnormal clotting profile prior to the invasive procedure. Several management concerns that emerged in the current case are also discussed.

Acquired Von Willebrand's Syndrome in Systemic Lupus Erythematosus

Acquired von Willebrand syndrome (AVWS) is an uncommon, underdiagnosed, and heterogeneous disease which is increasingly recognized as a cause of bleeding diatheses. Systemic lupus erythematosus (SLE) is an infrequent cause of AVWS. Herein, we report a case of AVWS diagnosed during the initial presentation of SLE in a previously healthy young man with no family history of bleeding diathesis who presented with worsening epistaxis, gastrointestinal bleeding, and anasarca. He was found to have severe anemia and prolonged activated partial thromboplastin time (aPTT) with severely decreased levels of von Willebrand factor (VWF) measurements in addition to markedly decreased factor VIII levels. Further evaluation revealed nephrotic syndrome and interstitial lung disease due to SLE. He initially received combination therapy with intravenous immunoglobulin (IVIG) and von Willebrand factor/factor VIII concentrates without significant improvement. Treatment with steroids, cyclophosphamide, and rituximab was followed by clinical improvement evidenced by cessation of bleeding. The short follow-up did not allow us to definitely prove the therapeutic effect of immunosuppressive treatment on AVWS in SLE patients. This case adds to the literature supporting the relationship between AVWS and SLE and highlights the importance of combination therapy in the treatment of severe AVWS as well as the role of IVIG, cyclophosphamide, and rituximab in AVWS associated with SLE.

Acquired hemophilia A and von Willebrand syndrome in a patient with late-onset systemic lupus erythematosus

Acquired hemophilia A (AHA) and acquired von Willebrand Syndrome (AVWS) are both rare bleeding disorders that can be associated with lymphoproliferative or autoimmune diseases. AHA is uniformly caused by inhibitory autoantibodies against coagulation factor VIII (FVIII), while the pathophysiology of AVWS comprises several distinct mechanisms, including reduced synthesis, accelerated clearance, or increased proteolysis. In this regard, autoantibodies to von Willebrand factor (VWF) have been described in patients with systemic lupus erythematosus (SLE) or monoclonal gammopathy. Here, we report the case of a 71-year-old patient with a recent onset of spontaneous mucocutaneous and soft-tissue bleeding due to severely decreased FVIII and VWF. While there was no evidence for monoclonal gammopathy, specific IgG antibodies against both FVIII and VWF were detected. Furthermore, VWF multimer analysis revealed the presence of ultralarge plasma multimers and absence of the typical multimeric triplet structure, a finding consistent with decreased proteolytic processing of massively released, but rapidly cleared VWF. Both FVIII and VWF readily responded to immunosuppressive therapy with prednisolone. Interestingly, clinical and laboratory findings established the diagnosis of “late-onset SLE” in our patient. Thus, about 45 years after the first description of AVWS in a 12-year-old boy with SLE, we present another unusual case of concomitant autoimmune-mediated AHA and AVWS in an elderly SLE patient, which, to the best of our knowledge, has not been reported so far.

[Acquired von Willebrand's disease type 2A following arteriovenous fistula for haemodialysis?]

Acquired von Willebrand's disease (aVWD) is considered to be an underestimated cause of unexplained bleeding. Adsorption of von Willebrand factor (VWF) to tumour cells or hydroxyethyl starch and elimination of VWF by autoantibodies as well as shear stress-induced mechanical alteration of VWF with concomitant cleavage by enzymes may lead to an acquired deficiency of VWF and a bleeding disorder. We report a 39-year-old woman who developed spontaneous bleeding five years after surgical creation of an arteriovenous fistula (AVF) for haemodialysis treatment. AVWD type 2A was diagnosed after successful renal transplantation. One year after surgical closure of the AVF, the aVWD could not be verified again. Thus, the aVWD may have developed because of altered blood flow and shear stress inside the arteriovenous fistula.

[Acquired von Willebrand syndrome: from diagnosis to treatment]

Acquired von Willebrand syndrome is a rare bleeding disorder, which has been related in various diseases including lymphoproliferative disorders or autoimmune diseases. Its diagnosis is an important step before treatment of patients and particularly in case of bleeding. We report four cases from Caen Hemophilia Treatment Center, diagnosed and treated from 1999 to 2008. Mucocutaneous bleeds in every case were the same as in hereditary von Willebrand disease. All patients had no personal or family history of bleeding. Phenotype was identified as type 2 von Willebrand disease with a loss of high molecular weight multimers. Anti-von Willebrand factor inhibitor screening was positive for three patients. The etiological diagnosis was one chronic lymphocytic leukaemia, two monoclonal gammapathies of undetermined significance (MGUS) and one undetermined case. The management of patients need two stages: first infusions of factor von Willebrand/factor VIII concentrates to stop bleeds, then treatment of the underlying disease such as chemotherapy, corticotherapy and treatment with high doses of polyvalents immunoglobulins. In every case, treatment was effective and improved patient's quality of life.

Systemic lupus erythematosus complicated by acquired von Willebrand’s syndrome

Haematological abnormalities are common in systemic lupus erythematosus (SLE). In some cases of acquired von Willebrand syndrome (AvWS), von Willebrand disease (vWD) is associated with autoimmune or lymphoproliferative disorders. In this study, we describe a 36-year-old woman with SLE and AvWS. The patient was referred to our hospital because of easy bruisability and recurrent vaginal bleeding. She had no history of bleeding tendency and no family history of bleeding diathesis, but she had a history of recurrent arthralgia, photosensitivity and sicca symptoms. Tests for antinuclear, anti–double stranded DNA, anticardiolipin and anti–β2-glycoprotein I antibodies were all positive. Analysis of haemostatic parameters showed complete absence of von Willebrand factor ristocetin cofactor (vWF:Rco), von Willebrand antigen (vWF:Ag) and ristocetin-induced platelet aggregation (RIPA). Electrophoretic analysis of plasma showed a complete absence of high–molecular weight vWF multimer. The presence of antibody to vWF was detected by enzyme linked immunosorbent assay (ELISA). Treatment with corticosteroids improved SLE symptoms and corrected bleeding diasthesis. Also, the multimeric patterns of vWF became normalised and anti–vWF antibody disappeared. These findings indicated that this patient had SLE associated with AvWS, which was ameliorated by corticosteroid treatment.

Association of acquired von Willebrand syndrome with AL amyloidosis

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.

Acquired von Willebrand syndrome: features and management

Acquired von Willebrand syndrome (AvWS) is not a well-known bleeding disorder among clinicians and is associated with various underlying diseases. The clinical manifestations are similar to congenital von Willebrand disease. Diagnosis is confirmed mainly by a decrease of ristocetin cofactor activity (vWF:RCo) and/or collagen binding activity (vWF:CBA) and by vWF multimeric analysis, usually with a selective loss of large multimers. Plasma von Willebrand factor propeptide (vWF:AgII) is a good marker of vWF synthesis. Various pathogenic mechanisms have been proposed, including development of autoantibodies to the von Willebrand factor (vWF), adsorption of vWF onto tumor cells or activated platelets, increase of vWF proteolysis, and mechanical destruction of vWF under high shear stress. Treatment of the underlying disorder may resolve AvWS. Desmopressin (DDAVP) is a first-line therapeutic option. Factor VIII/vWF concentrates and high-dose immunoglobulin infusions are reserved for patients unresponsive to DDAVP.

Cefotaxime as the potential cause of transient acquired von Willebrand syndrome

Acquired von Willebrand syndrome (AvWS) is a relatively rare bleeding disorder. It has been reported in association with myeloproliferative disorders, autoimmune diseases, plasma cell dyscrasias and certain drugs. Cefotaxime is a third generation cephalosporin widely used for surgical prophylaxis and as empirical treatment of bacterial meningitis. We report a case of a transient AvWS in association with cefotaxime therapy.