How I treat the acquired von Willebrand syndrome

Retrospectively diagnosed autoimmune VWF deficiency in a patient with repeated hemorrhagic events after two common colds

Autoimmune von Willebrand factor (VWF) deficiency (AiVWFD) caused by anti-VWF autoantibodies is a rare bleeding disorder, whereas "non-immune" acquired von Willebrand syndrome (AVWS) caused by other etiologies is more common. Therefore, only 40 patients with AiVWFD have been identified in Japan through an ongoing nationwide survey on autoimmune coagulation factor deficiencies. This may be due to the inability to efficiently detect anti-VWF antibodies, as anti-VWF antibody testing is not routine. An 80-year-old Japanese woman developed AVWS and experienced bleeding after two separate common colds. She took the same cold medicine each time and recovered spontaneously after discontinuation of the medicine. Severe VWF deficiency normalized each time. Initial immunological tests did not detect anti-VWF autoantibodies, and thus a diagnosis of "non-immune" AVWS of unknown origin was made. However, after 6 years, new ELISA assays using purified VWF proteins detected free anti-VWF autoantibodies, which led to a retrospective diagnosis of AiVWFD. It is probable that the cold medicine (and/or cold virus infection) induced the autoantibodies, as the recurrence and normalization of the same coagulation abnormality and the clinical course (including drug administration and discontinuation) were completely synchronized. If AiVWFD is suspected, highly sensitive autoantibody tests should be performed.

Acquired bleeding disorders

Acquired bleeding disorders can develop in previously healthy people irrespective of age or gender but are particularly common in patients with certain underlying conditions. Here, we review recent advances in the management of acquired haemophilia A (AHA), acquired von Willebrand syndrome (AVWS), and patients with hemostatic abnormalities due to chronic liver disease (CLD). Patients with AHA can now benefit from prophylaxis with emicizumab, a therapeutic antibody that mimics the function of activated coagulation factor VIII. The treatment of AVWS remains challenging in many situations and requires careful consideration of the underlying condition. Haemostatic abnormalities in CLD are often compensated by proportional reduction in pro and anti-haemostatic factors resulting in sustained or even increased thrombin generation. Consequently, bleeding in CLD is rarely caused by haemostatic failure and infusion of plasma or coagulation factor concentrates may not be effective.

Acquired von Willebrand Syndrome in a 17-Year-Old With Essential Thrombocythemia: A Case Report With Literature Review

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that is often underdiagnosed. AVWS typically occurs in adults without a family history of bleeding disorders and with associated conditions such as lymphoproliferative, myeloproliferative, and cardiovascular disorders. Here, we present a case of AVWS in a young patient with essential thrombocythemia and a literature review on AVWS in the setting of essential thrombocythemia.

Shear-induced acquired von Willebrand syndrome: an accomplice of bleeding events in adults on extracorporeal membrane oxygenation support

Extracorporeal membrane oxygenation (ECMO) is an increasingly acceptable life-saving mechanical assistance system that provides cardiac and/or respiratory support for several reversible or treatable diseases. Despite important advances in technology and clinical management, bleeding remains a significant and common complication associated with increased morbidity and mortality. Some studies suggest that acquired von Willebrand syndrome (AVWS) is one of the etiologies of bleeding. It is caused by shear-induced deficiency of von Willebrand factor (VWF). VWF is an important glycoprotein for hemostasis that acts as a linker at sites of vascular injury for platelet adhesion and aggregation under high shear stress. AVWS can usually be diagnosed within 24 h after initiation of ECMO and is always reversible after explantation. Nonetheless, the main mechanism for the defect in the VWF multimers under ECMO support and the association between AVWS and bleeding complications remains unknown. In this review, we specifically discuss the loss of VWF caused by shear induction in the context of ECMO support as well as the current diagnostic and management strategies for AVWS.

Gastrointestinal bleeding in von Willebrand patients: special diagnostic and management considerations

INTRODUCTION

Severe and recurrent gastrointestinal (GI) bleeding caused by angiodysplasia is a significant problem in patients with von Willebrand disease (VWD) and in those with acquired von Willebrand syndrome (AVWS). At present, angiodysplasia-related GI bleeding is often refractory to standard treatment including replacement therapy with von Willebrand factor (VWF) concentrates and continues to remain a major challenge and cause of significant morbidity in patients despite advances in diagnostics and therapeutics.

AREAS COVERED

This paper reviews the available literature on GI bleeding in VWD patients, examines the molecular mechanisms implicated in angiodysplasia-related GI bleeding, and summarizes existing strategies in the management of bleeding GI angiodysplasia in patients with VWF abnormalities. Suggestions are made for further research directions.

EXPERT OPINION

Bleeding from angiodysplasia poses a significant challenge for individuals with abnormal VWF. Diagnosis remains a challenge and may require multiple radiologic and endoscopic investigations. Additionally, there is a need for enhanced understanding at a molecular level to identify effective therapies. Future studies of VWF replacement therapies using newer formulations as well as other adjunctive treatments to prevent and treat bleeding will hopefully improve care.

Manifestations rares des gammapathies monoclonales : à propos de 2 cas et revue de la littérature

INTRODUCTION

Monoclonal gammopathies are common over the age of 50. Patients are usually asymptomatic. However, some patients present with secondary clinical manifestations, which are now grouped under the entity « Monoclonal Gammopathy of Clinical Significance » (MGCS).

CASE REPORT

Here, we report two rare cases of MGCS: an acquired von Willebrand syndrome (AvWS) and an acquired angioedema (AAE).

CONCLUSION

The discovery of a decrease in von Willebrand activity (vWF:RCo) or angioedema in a patient over 50 years of age, in the absence of a family history, should prompt a search for a hemopathy and in particular, a monoclonal gammopathy.

The effect of recombinant versus plasma-derived von Willebrand factor on prolonged PFA closure times in ECMO patients with acquired von Willebrand syndrome - an observational study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is applied in patients with respiratory or cardiopulmonary failure, but bleeding is a frequent complication contributing to the high mortality rates in this patient collective. A major factor predisposing patients to bleeding events is an acquired von Willebrand syndrome (aVWS). So far, specific treatment options for this phenomenon are lacking. In hereditary von Willebrand disease (VWD), treatment with recombinant or plasma-derived von Willebrand factor (rVWF or pVWF) is common practice. Closure time measured by the Platelet Function Analyser-200 (PFA-200) is an established assay to detect defects in primary hemostasis and the method is useful to monitor the effect of hemostatic therapy. The aim of this study was to assess the effect of recombinant (rVWF) vs. plasma-derived von Willebrand factor (pVWF) on closure times measured by PFA in blood obtained from ECMO patients with aVWS.

METHODS

Blood was sampled from thirteen patients receiving extracorporeal membrane oxygenation and three patients with hereditary VWD. Diagnosis of aVWS was made by conventional coagulation parameters and by multimeric structure analysis. PFA analysis of blood spiked with rVWF or pVWF was performed.

RESULTS

Thirteen patients receiving ECMO were recruited. Ten patients survived and three patients suffered major bleeding complications. PFA closure times in ECMO patients with aVWS spiked with rVWF were significantly shorter at all concentrations than with pVWF (e.g., rVWF vs. pVWF: 1 U/ml: 150.4 ± 21.7 s vs. 263.8 ± 11.7 s; 4 U/ml: 97.8 ± 9.8 s vs. 195.8 ± 15.4 s, p<0.001). PFA closure times were also significantly shorter in three patients with hereditary VWD treated with rVWF compared to pVWF (e.g., 1 U/ml rVWF vs. pVWF: 73.7±1.33 s vs. 231.3±43.4 s, p<0.01) CONCLUSION: In summary, this study shows that rVWF compared to pVWF more effectively reduced PFA closures times in blood samples of ECMO patients with aVWS. Higher doses of VWF are needed to normalize PFA closure time in blood samples of patients with ECMO-induced aVWS compared to hereditary VWD. These data support the use of PFA-200 to monitor hemostatic effects in a future clinical trial involving ECMO patients with aVWS.

The endogenous thrombin potential in patients with left ventricular assist device or heart transplant

Background

The Heartmate 3 (HM 3) is a left ventricular assist device featuring less shear stress, milder acquired von Willebrand syndrome, and fewer bleeding incidences than its predecessor the Heartmate II (HM II). The novel surface coating of the HM 3 suggests less contact activation of plasmatic coagulation. We hypothesized that patients with HM 3 exhibit fewer aberrations in their thrombin potential than patients with HM II. We compared these results with the thrombin potential of patients with heart transplantation (HTX).

Methods

Thrombin generation in plasma samples of patients with HM II (n = 16), HM 3 (n = 20), and HTX (n = 13) was analyzed 3 days after implantation/transplantation and after long-term support (3-24 months) with HM II (n = 16) or HM 3 (n = 12) using calibrated automated thrombography. Heparin in postoperative samples was antagonized with polybrene.

Results

Three days postoperatively HM II patients exhibited a lower endogenous thrombin potential (ETP) than HM 3 and HTX patients (HM II: 947 ± 291 nM*min; HM 3: 1231 ± 176 nM*min; HTX: 1376 ± 162 nM*min, p < 0.001) and a lower velocity index of thrombin generation (HM II: 18.74 ± 10.90 nM/min; HM 3: 32.41 ± 9.51 nM/min; HTX: 37.65 ± 9.41 nM/min, p < 0.01). Subtle differences in the thrombin generation profiles remained in HM II and HM 3 patients under long-term support (Velocity Index: HM II: 38.70 ± 28.46 nM/min; HM 3: 73.32 ± 32.83 nM/min, p < 0.05). Prothrombin fragments 1 + 2 were higher in HM II than in HM 3 patients (HM II: 377.7 ± 208.4 pM; HM 3: 202.1 ± 87.7 pM, p < 0.05) and correlated inversely with the ETP (r = -0.584, p < 0.05).

Conclusion

We observed a more aberrant thrombin generation in HM II than in HM 3 despite comparable anticoagulation and routine parameters. A trend toward lower values was still observable in HM 3 compared to HTX patients. Calibrated automated thrombography may be a good tool to monitor the coagulation state of these patients and guide anticoagulation in the future.

Acquired von Willebrand Syndrome Secondary to Normally Functioning Mechanical Aortic Valve and High-Output Cardiac State

Acquired von Willebrand syndrome (AVWS) is caused by an acquired deficiency of von Willebrand factor (VWF), a multimeric protein required for primary hemostasis. For patients with heart valve diseases, high gradient across the malfunctioning valves could cause elevated shear stress and damage the most effective large VWF, eventually resulting in AVWS. However, AVWS has not been reported in association with normally functioning mechanical valves. Herein, we reported a 74-year-old female who suffered from recurrent gastrointestinal bleeding with a history of mechanical aortic and mitral valve replacement. This patient's function/antigen ratio of VWF was decreased and gel electrophoresis revealed the loss of large VWF, which confirmed the diagnosis of AVWS. Echocardiogram showed that the function of the prostheses was normal. However, the gradient across aortic valve was increased due to a high cardiac state which is secondary to chronic anemia, resulting in the disruption of large VWF multimers and exacerbation of gastrointestinal (GI) bleeding. After managing the patient's anemia with transfusion, the gradient across the aortic valve had improved, with the resolution of GI bleeding. This is the first case report of AVWS that is associated with a normally functioning mechanical valve. AVWS should be considered one of the differential diagnoses if patients present with unexplained GI bleeding on the background of having prosthetic heart valves. The management of the underlying condition is essential.

Successful and safe response to ibrutinib alone in treating relapsed Waldenström macrogobulinemia and related acquired von Willebrand syndrome: an option to consider

Ibrutinib, a first-class Bruton tyrosine kinase inhibitor, is known to be associated with adverse bleeding events and has been recently approved for the treatment of relapse Waldenström macroglobulinemia (WM). Here, we report the exhaustive clinical and biological follow-up of 2 patients treated by ibrutinib alone in the context of relapsed WM with an acquired von Willebrand syndrome (AVWS) complication. In two cases, ibrutinib has been shown to be quickly efficient and safe for treating both AVWS and its underlying condition the WM, without bleeding complications. Interestingly, ibrutinib treatment brings a rapid and extended over time normalization of von Willebrand factor clearance. These observations show that ibrutinib is a valuable therapeutic option in relapsed WM patients associated with AVWS and highlighting the need for further cohort studies with long-term follow-up of patients to confirm the efficacy and safety of a treatment by ibrutinib for WM patients with AVWS complication.

Practical management of the haemorrhagic complications of myeloproliferative neoplasms

Myeloproliferative neoplasms can be associated with bleeding manifestations which can cause significant morbidities. Although haematologists are aware of the likelihood of this complication in the setting of myeloproliferative neoplasms, it may often be overlooked especially in patients with no extreme elevation of blood counts and those with myelofibrosis. Acquired von Willebrand syndrome and platelet dysfunction are the two common diagnoses to be considered in this regard. In this review article, we discuss the mechanisms for the development of these rare bleeding disorders, their diagnosis and practical management.

[Cancer-associated coagulation disorders]

Diagnosis and treatment of paraneoplastic coagulation disorders are a challenge in daily practice. While prophylactic anticoagulation to prevent venous thromboembolism (VTE) is standard of care in all surgical and acutely ill medical cancer patients, particularly careful evaluation of risks and benefits using validated risk assessment models is required during outpatient chemotherapy. Low-molecular-weight heparin and direct oral factor Xa inhibitors are available to treat established cancer-associated VTE, adhering to algorithms for bleeding risk stratification. In patients with overt disseminated intravascular coagulation, therapeutic measures should strictly follow clinical symptoms. An acquired von Willebrand syndrome may evoke a severe bleeding tendency in patients with myeloproliferative neoplasms or plasma cell dyscrasias. In 15% of cases, acquired hemophilia A, due to the formation of inhibitory autoantibodies against coagulation factor VIII, is associated with malignancy.

Acquired von Willebrand syndrome: Five cases report and literature review

Acquired von Willebrand syndrome is a rare bleeding disorder with laboratory findings similar to those of inherited von Willebrand disease. Principal factors distinguishing acquired von Willebrand syndrome from the latter condition include lack of prior bleeding disorders, diagnosis at older age, negative family history and association with underlying conditions.

METHODS

Retrospective, monocentric descriptive case series of acquired von Willebrand syndrome diagnosed between 2010 and 2020. Diagnostic criteria included a recent history of bleeding, a negative family history and a presence of underlying disorders.

RESULTS

Five men were diagnosed with acquired von Willebrand syndrome. All of them presented with recent mucocutaneous bleeding. The biological phenotype was a type 2 von Willebrand disease in all cases, with decreased VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag ratios (<0.7). Lymphoproliferative, autoimmune and cardiovascular diseases were the main underlying conditions identified. Screening for an anti-von Willebrand factor inhibitor was positive in two patients. Four patients received treatment for the underlying disorder. High-dose intravenous immunoglobulins were the most frequent treatment administrated. Improvement of plasma von Willebrand factor levels was observed in four cases.

CONCLUSION

Acquired von Willebrand syndrome is a rare but potentially serious disease. The diagnostic should be suspected in adults with unusual mucocutaneous bleeding associated with lymphoproliferative, myeloproliferative, autoimmune and cardiovascular disorders.

Acquired von Willebrand syndrome and lymphoid neoplasms: A review of malignancy management, and propositions of practical recommendations

INTRODUCTION

Acquired von Willebrand syndrome (AWS) is a rare and potentially life-threatening bleeding disorder. AWS is primarily associated with lymphocyte-related disorders (AWS-LRD), such as lymphoma and IgM monoclonal gammopathy of undetermined significance (MGUS), and plasmocyte-related disorders (AWS-PRD), such as non-IgM MGUS and myeloma. Symptomatic treatments are important to control and prevent bleeding, but AWS-LRD and AWS-PRD can only be cured by targeting the responsible clonal cell. No reviews exist on this specific subgroup of AWS.

AIM

We performed a literature review to help manage these rare cases.

METHOD

Thirty-two AWS-PRD and 43 AWS-LRD cases with data on malignancy treatment were reported in 56 articles from the Medline database.

RESULTS

LRDs were exclusively indolent and primarily associated with IgM monoclonal compounds. LRDs and PRDs may be treated because of severe bleeding symptoms, but severe VWF deficiency did not necessarily correlate with severe bleeding. Immunosuppressive drugs in AWS-PRD, including rituximab, provided an overall response rate of AWS (AWS-ORR) of 30% (3/10), including short responses. Anti-myeloma drugs provided an AWS-ORR of 71.4% (20/28), with long-lasting remissions. Bortezomib was the most commonly used drug and provided an AWS-ORR of 66.7% (6/9), including therapeutic associations with other anti-myeloma drugs. Autologous and allogeneic stem cell transplantation was performed in eight and two patients, respectively, and some details on the management of AWS during these procedures were provided. Rituximab in AWS-LRD provided an AWS-ORR of 60% (3/5), and a chemotherapy + rituximab regimen increased the AWS-ORR to above 50%. Bleeding syndrome in AWS-PRD and AWS-LRD generally improved prior to AWS biological improvement.

CONCLUSION

Long term remission of AWS due to lymphoid neoplasms is attainable by treating the underlying clonal cell. Some data and recommendations are provided to help answer difficult questions, including treatment timing, choice of drug, and the timing of evaluations and treatment changes.

A Review of Autoimmune Acquired von Willebrand Factor Deficiency in Japan

von Willebrand factor (VWF) forms high-molecular-weight multimers and plays an essential role in hemostasis, and thus its deficiency leads to bleeding symptoms. Acquired von Willebrand syndrome (AVWS) is rare, but potentially underdiagnosed, and develops in various underlying disorders. AVWS caused by anti-VWF autoantibodies is a rare subcategory of AVWS that can also be referred to as autoimmune VWF deficiency (AiVWFD). We performed a search of patients with autoimmune coagulation factor deficiencies in our nationwide survey in Japan. Among these, suspected cases of AiVWFD were extremely few, with only 11 case consultations in the last 10 years. Of these, three and five were respectively positive for anti-VWF autoantibodies (anti-VWF-Ab) and VWF inhibitor (VWF-inh). We also performed an extensive literature search of other cases from Japan, and in total, 40 cases were finally identified to have AiVWFD, with mean age of 55.0 years. Most underlying disorders were lympho- or myeloproliferative diseases, followed by autoimmune diseases. The major bleeding sites were subcutaneous and mucosal, the bleeding severity was moderate, and there were no hemorrhagic deaths. Bleeding time was prolonged; factor VIII activity, VWF antigen, and VWF activity were decreased, and high-molecular-weight VWF multimers were absent or decreased. These are similar to the common abnormal laboratory findings observed among general AVWS cases. Hemostatic therapy often involved VWF concentrates and vasopressin, and antibody eradication therapy often included corticosteroids and achieved remission. Notably, of all cases, 68% had anti-VWF-Abs, and 83% of anti-VWF-Ab-positive patients were also VWF-inh positive. To accumulate precise clinical information on AiVWFD, it is necessary to verify and improve the measurement methods for both anti-VWF-Ab and anti-VWF-inh. These findings from Japan should be confirmed in other geographic localities.

Sixth Åland Island Conference on von Willebrand disease

Introduction

The sixth Åland Islands Conference on von Willebrand disease (VWD) on the Åland Islands, Finland, was held from 20 to 22 September 2018.

Aim

The meeting brought together experts in the field of VWD from around the world to share the latest advances and knowledge in VWD.

Results and discussion

The topics covered both clinical aspects of disease management, and biochemical and laboratory insights into the disease. The clinical topics discussed included epidemiology, diagnosis and treatment of VWD in different countries, management of children with VWD, bleeding control during surgery, specific considerations for the management of type 3 VWD and bleeding control in women with VWD. Current approaches to the management of acquired von Willebrand syndrome were also discussed. Despite significant advances in the understanding and therapeutic options for VWD, there remain many challenges to be overcome in order to optimise patient care. In comparison with haemophilia A, there are very few registries of VWD patients, which would be a valuable source of data on the condition and its management. VWD is still underdiagnosed, and many patients suffer recurrent or severe bleeding that could be prevented. Awareness of VWD among healthcare practitioners, including non‐haematologists, should be improved to allow timely diagnosis and intervention. Diagnosis remains challenging, and the development of fast, simple assays may help to facilitate accurate and rapid diagnosis of VWD.

Hemorrhages in polycythemia vera and essential thrombocythemia: epidemiology, description, and risk factors, learnings from a large cohort

BACKGROUND

The management of myeloproliferative neoplasms (MPN) is based on the reduction of thrombosis risk. The incidence, impact, and risk factors of bleedings have been less studied.

METHOD

All patients with polycythemia vera (n=339) or essential thrombocythemia (n=528) treated in our center are included in OBENE cohort (NCT02897297). Major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) occurring after diagnosis were included, except after leukemic transformation.

RESULTS

With a median follow-up of 8.3 years, incidence of hemorrhages was 1.85% patient/year, with an incidence of MB of 0.95% patient/year. The 10-year bleeding-free survival was 89%. The most frequent locations were digestive tractus, "mouth, nose and throat" and muscular hematoma. The case fatality rate of MB was 25%. The proportion of potentially avoidable iatrogenic bleeding was remarkable (17.6%). In multivariable analysis, eight risk factors of bleeding were identified: leukocytes >20 giga/l at diagnosis (HR=5.13 95%CI [1.77;14.86]), secondary hemopathies (HR=2.99 95%CI [1.27;7.04]), aspirin use at diagnosis (HR=2.11 95%CI [1.24;3.6]), platelet count >1000 giga/l at diagnosis (HR=1.93, 95%CI [1.11;3.36]), history of hemorrhage (HR=1.82 95%CI [1.03;3.24]), secondary cancers (HR=1.71 95%CI [1.01;2.89]), atrial fibrillation (HR=1.66, 95%CI [1.01;2.72]) and male gender (HR=1.54, 95%CI [1.02-2.33]). The majority of patients taking hydroxyurea displayed a non-macrocytic median corpuscular value in the months preceding bleeding (51.4%).

DISCUSSION

The morbidity and mortality of bleedings in MPN should not be underestimated, and some patients could beneficiate from cytoreduction in order to reducing bleeding risk. Iatrogenic bleedings represent a substantial proportion of bleeding and could be better prevented.

Acquired bleeding disorders

Acquired bleeding disorders can accompany hematological, neoplastic, autoimmune, cardiovascular or liver diseases, but can sometimes also arise spontaneously. They can manifest as single factor deficiencies or as complex hemostatic abnormalities. This review addresses (a) acquired hemophilia A, an autoimmune disorder characterized by inhibitory autoantibodies against coagulation factor VIII; (b) acquired von Willebrand syndrome in patients with cardiovascular disorders, where shear stress abnormalities result in destruction of von Willebrand factor; and (c) liver function disorders that comprise complex changes in pro- and anti-hemostatic factors, whose clinical implications are often difficult to predict. The article provides an overview on the pathophysiology, diagnostic tests and state-of-the-art treatment strategies.

Acquired von Willebrand Syndrome in Children

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder caused by various underlying diseases or conditions and should be distinguished from the inherited type of von Willebrand disease. AVWS is associated with underlying diseases such as cardiovascular, autoimmune, malignant, proliferative disorders, or with mechanical circulatory support (MCS). AVWS was first reported in 1968 and most case reports describe AVWS in adults. However, AVWS can appear in pediatric patients occasionally as well. Because bleeding complications are rare in everyday life, AVWS may be underdiagnosed in pediatric patients. Therefore, the diagnosis should be suspected in a pediatric patient who is known for one of these underlying diseases or conditions and who presents with an onset of bleeding symptoms, especially before the child will undergo an invasive procedure. Here, we present an overview of the diagnostic analyses regarding AVWS and of the underlying diseases or conditions in which AVWS should be considered. Importantly, the patient's history should be investigated for bleeding symptoms (mucocutaneous or postoperative bleeding). As no single routine coagulation test can reliably confirm or exclude AVWS, the diagnosis may be challenging. Laboratory investigations should include analysis of von Willebrand factor (VWF):antigen, VWF:collagen-binding capacity, VWF:activity, and VWF multimeric analyses. For treatment, tranexamic acid, 1-desamino-8-D-arginine vasopressin, and VWF-containing concentrate can be used. AVWS disappears after the underlying disease has been successfully treated or the MCS has been explanted.

Successful treatment of acquired von Willebrand syndrome associated with monoclonal gammopathy : Breaking a dangerous bond

Acquired von Willebrand syndrome is exceedingly rare and accounts for only 1-3% of von Willebrand disease cases. In this short report, we present our own cases of acquired von Willebrand syndrome associated with monoclonal gammopathy. Both cases went into complete and sustained remission after intensive antimyeloma treatment. The first patient was not deemed fit for autologous stem cell transplantation and was managed with an extensive multidrug combination including daratumumab, carfilzomib, lenalidomide, cyclophosphamide and dexamethasone. After at least VGPR was achieved the coagulation studies rapidly normalized and remained normal after treatment de-escalation to lenalidomide/dexamethasone maintenance. The second patient successfully underwent ASCT after 5 cycles of induction with daratumumab, bortezomib, cyclophosphamide and dexamethasone and has remained in full hematologic and hemostaseologic remission ever since.The two cases highlight the efficacy of aggressive antimyeloma treatment in monoclonal gammopathy-associated acquired von Willebrand syndrome to achieve normalization of coagulation study, providing a possible way to manage these patients.

The Intriguing Connections between von Willebrand Factor, ADAMTS13 and Cancer

von Willebrand factor (VWF) is a complex and large protein that is cleaved by ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13), and together they serve important roles in normal hemostasis. Malignancy can result in both a deficiency or excess of VWF, leading to aberrant hemostasis with either increased bleeding or thrombotic complications, as respectively seen with acquired von Willebrand syndrome and cancer-associated venous thromboembolism. There is emerging evidence to suggest VWF also plays a role in inflammation, angiogenesis and tumor biology, and it is likely that VWF promotes tumor metastasis. High VWF levels have been documented in a number of malignancies and in some cases correlate with more advanced disease and poor prognosis. Tumor cells can induce endothelial cells to release VWF and certain tumor cells have the capacity for de novo expression of VWF, leading to a proinflammatory microenvironment that is likely conducive to tumor progression, metastasis and micro-thrombosis. VWF can facilitate tumor cell adhesion to endothelial cells and aids with the recruitment of platelets into the tumor microenvironment, where tumor/platelet aggregates are able to form and facilitate hematogenous spread of cancer. As ADAMTS13 moderates VWF level and activity, it too is potentially involved in the pathophysiology of these events. VWF and ADAMTS13 have been explored as tumor biomarkers for the detection and prognostication of certain malignancies; however, the results are underdeveloped and so currently not utilized for clinical use. Further studies addressing the basic science mechanisms and real word epidemiology are required to better appreciate the intriguing connections between VWF, ADAMTS13 and malignancy. A better understanding of the role VWF and ADAMTS13 play in the promotion and inhibition of cancer and its metastasis will help direct further translational studies to aid with the development of novel cancer prognostic tools and treatment modalities.

Case report: A case of acquired von Willebrand syndrome as onset clinical presentation of systemic lupus erythematosus manifested as epistaxis and pulmonary hemorrhage

BACKGROUND

Acquired von Willebrand syndrome (AVWS) is a less common bleeding disorder, primarily manifested as mild to moderate mucocutaneous bleeding and laboratory tests are similar to hereditary von Willebrand disease (VWD). AVWS is secondary to other diseases, and systemic lupus erythematosus (SLE) is a relatively rare cause.

CASE PRESENTATION

We report a case of AVWS as onset clinical presentation of SLE manifested as epistaxis and pulmonary hemorrhage. A 13-year-old male child presented to the hospital with a six-month history of recurrent epistaxis and a one-month history of anemia. Routine blood tests demonstrated severe normocytic anemia and normal platelet count. Von Willebrand test revealed a significantly lower level. High-resolution chest computed tomography (CT) showed patchy ground glass opacities consistent with hemorrhagic changes. After ruling out the family history, the patient was diagnosed with AVWS. Additional tests confirmed positive antinuclear and anti-Sm antibodies. The underlying SLE was diagnosed and treated with methylprednisolone with disease recovery.

CONCLUSION

We recommend screening for bleeding disorders in patients with recurrent epistaxis. AVWS should be considered when laboratory findings suggest hereditary von Willebrand disease without a personal or familial history of bleeding. In addition, the underlying disease should be explored.

Recurrent Gastrointestinal Bleeding in a Middle-Aged Man

Acquired von Willebrand disease (avWD) arises because of mechanisms that destroy, decrease, absorb, or clear von Willebrand factor (vWF). A 59-year-old man presented with a 3-year history of recurrent gastrointestinal bleeding. Laboratory workup revealed a prolonged platelet function assay-100. The vWF antigen was decreased, and a low vWF immunofunctional activity/antigen ratio, low collagen binding/antigen ratio, and decreased intermediate and high molecular weight multimers were noted. The patient had no high-shear stress conditions, and an antibody-mediated process was suspected. A vWF mixing study showed complete correction of vWF activity, suggesting no direct functional inhibitor. The patient was given a bolus of vWF concentrate with serial measurements of vWF; the vWF half-life was 2.5 hours. The vWF propeptide/antigen ratio was 4:1, supporting a diagnosis of aVWD resulting from increased antibody-mediated vWF clearance. This case study emphasizes the laboratory’s role in the diagnosis and treatment of rare, overlooked acquired bleeding disorders.

Cryptogenic oozers and bruisers

Bleeding disorders with normal, borderline, or nondiagnostic coagulation tests represent a diagnostic challenge. Disorders of primary hemostasis can be further evaluated by additional platelet function testing modalities, platelet electron microscopy, repeat von Willebrand disease testing, and specialized von Willebrand factor testing beyond the usual initial panel. Secondary hemostasis is further evaluated by coagulation factor assays, and factor XIII assays are used to diagnose disorders of fibrin clot stabilization. Fibrinolytic disorders are particularly difficult to diagnose with current testing options. A significant number of patients remain unclassified after thorough testing; most unclassified patients have a clinically mild bleeding phenotype, and many may have undiagnosed platelet function disorders. High-throughput genetic testing using large gene panels for bleeding disorders may allow diagnosis of a larger number of these patients in the future, but more study is needed. A logical laboratory workup in the context of the clinical setting and with a high level of expertise regarding test interpretation and limitations facilitates a diagnosis for as many patients as possible.

Von Willebrand Factor Multimeric Assay in Acquired von Willebrand Disease Diagnosis: A Report of Experience from North Estonia Medical Centre

Objectives Acquired von Willebrand syndrome (AVWS) is a rare and frequently underdiagnosed bleeding disorder with an unknown prevalence. The diagnosis of AVWS is made based on laboratory investigations and the presence of clinical symptoms. Evaluation and management of affected patients are complex due to the need for multiple laboratory assays.

Materials and Methods Here, we describe the clinical and laboratory data of seven patients with a diagnosis of AVWS. All patients met the criteria for AVWS based on laboratory findings, bleeding symptoms, and the absence of any previous history of a bleeding disorder.

Results In all cases, the laboratory findings, lack of bleeding anamnesis, and family history suggested the presence of AVWS. Von Willebrand factor multimeric analysis showed decreased high-molecular weight (HMW) multimers in six cases. Patients with lower HMW multimers experienced more severe bleeding complications.

Conclusions The diagnosis of AVWS is complex and requires extensive laboratory evaluation. Interdisciplinary collaboration and complex laboratory evaluations are of paramount importance for the early recognition of AVWS and optimal AVWS diagnosis as well as successful clinical management.

Thrombocytapheresis for acquired von Willebrand syndrome in a patient with essential thrombocythemia and recent multivisceral transplantation

BACKGROUND

Essential thrombocythemia (ET) is associated with increased risk of bleeding secondary to acquired von Willebrand syndrome (AVWS). Bleeding in ET requires urgent platelet reduction by cytoreductive therapy such as hydroxyurea or thrombocytapheresis. We report on the efficacy and safety of thrombocytapheresis in managing AVWS in a patient with ET and multivisceral transplantation.

CASE REPORT

The patient was a 51-year-old female who underwent multivisceral transplantation. Her postoperative course was complicated by bleeding from oral cavity, IV lines, gastrointestinal and upper respiratory tracts as well as vaginal bleeding, which coincided with ET flare with a platelet count of 1512 × 10⁹ /L. Coagulation studies including von Willebrand factor (vWF) antigen and activity, vWF propeptide antigen, and vWF multimer analysis were consistent with AVWS. Hydroxyurea was initiated. However, due to major bleeding, rapidly increasing platelet count, and uncertainty of response to hydroxyurea being given through the enteral tube, thrombocytapheresis was initiated for rapid platelet reduction. The patient tolerated the procedure well. Platelet count was reduced from 1636 × 10⁹ /L to 275 × 10⁹ /L with rapid cessation of bleeding. The patient's condition stabilized over the next few days; however, bleeding recurred with increasing platelet count, which required a second thrombocytapheresis 8 days after the first one. The patient was maintained on hydroxyurea 500 mg twice/day. At 11-month follow-up, she had a normal platelet count and no recurrence of bleeding.

DISCUSSION

Thrombocytapheresis is safe and efficient in managing postoperative bleeding due to ET/AVWS in solid organ transplant patients. The procedure can be an adjunct to bridging therapy before response to hydroxyurea is achieved.

Ibrutinib effect in acquired von Willebrand syndrome secondary to Waldenström macroglobulinemia

The pathological increase of clonal IgM in Waldenström macroglobulinemia can be associated with acquired von Willebrand syndrome and can be a major risk of bleeding symptoms in this subgroup of patients with Waldenström macroglobulinemia. The Bruton tyrosine kinase inhibitor ibrutinib is one of the approved treatments for symptomatic Waldenström macroglobulinemia. However, some controversy exists regarding the use of ibrutinib in these patients with high risk of bleeding because of its antiaggregant effect that could increase the risk of bleeding. Here, we present the case of a patient with Waldenström macroglobulinemia with associated acquired von Willebrand syndrome and progressively significant bleeding symptoms, who experienced a rapid increase in von Willebrand factor with ibrutinib treatment, despite only reaching a partial response in IgM levels similar to those reached with other previous treatments. We suggest that the control over the monoclonal protein is not the only mechanism that explains the good response, improvement in the bleeding symptoms and von Willebrand factor levels. This fact could be explained by the reduced glycoprotein Ib receptor expression induced by ibrutinib and the consequent von Willebrand factor increase in peripheral blood.

Subdural Hemorrhage Due to Acquired Von Willebrand Syndrome in a Patient With Polycythemia Vera

Polycythemia vera (PV) is a chronic myeloproliferative neoplasm associated with thrombosis. A 48-year-old female with PV presented with right eye pain following a low-impact head trauma. She consumed aspirin for analgesia and took preparations of Chinese herbs. CT head revealed right-sided subdural hematoma. She had reduced Von Willebrand activity to 26%. Direct angiographic imaging showed an aneurysm arising from a right middle cerebral atery (MCA) branch. The patient was given 1-deamino-8-D-arginine vasopressin (DDAVP) prior to the craniotomy. Intra-operative examination revealed that the aneurysm-like structure was a small grape-like structure of the fibrinous part of the subdural membrane that had formed from the subdural hematoma. Acquired von Willebrand syndrome (AVWS) is an important risk factor for bleeding in PV. DDAVP may be useful to increase levels of Von Willebrand Factor (VWF) and decrease the risk of bleeding perioperatively. Exogenous substances such as ginseng should be investigated as possible contributors to bleeding tendency and discontinued.

Why is Misdiagnosis of von Willebrand Disease Still Prevalent and How Can We Overcome It? A Focus on Clinical Considerations and Recommendations

Despite von Willebrand disease (VWD) being the most common inherited bleeding disorder, its accurate diagnosis is frequently shrouded by diagnostic pitfalls. VWD is frequently under-diagnosed, over-diagnosed and misdiagnosed, leading to significant avoidable patient morbidity and health care system burden. At the heart of this dilemma lies the heterogeneity and complexity of von Willebrand factor (VWF) and associated defects, and the necessity of coalescing clinical and laboratory features to obtain an accurate diagnosis. Common pitfalls include poor clinical and scientific understanding and familiarity with VWD, incomplete clinical history and lack of routine use of standardised bleeding assessment tools (BAT), difficulty in accessing a comprehensive repertoire of laboratory tests, significant pre-analytical, analytical and post-analytical issues, and lack of expertise in laboratory testing and interpretation. Errors, resulting in under-diagnosis, over-diagnosis, and misdiagnosis of VWD, are presented and discussed. Strategies to minimise errors include better education of clinicians and laboratory staff on VWD, routine use of validated BAT, utilising a comprehensive gamut of laboratory investigations according to a standardised algorithm, and repeating testing to minimise pre-analytical errors. Recommendations on appropriate patient selection for VWD testing, how VWD should be investigated in the laboratory, and how to ensure test results are accurately interpreted in the correct clinical context are detailed.

A Case of Acquired von Willebrand Syndrome Complicated by Acute Myelomonocytic Leukemia

We here report a 21-year-old male who presented with acute myelomonocytic leukemia (AMML) associated with acquired von Willebrand syndrome (AVWS). To our knowledge, this is the first case of AVWS caused by AMML. In our case, following remission-induction chemotherapy combined with idarubicin and cytarabine, the patient showed remarkable improvement of bleeding symptoms due to AVWS. Moreover, after an allogeneic stem cell transplantation from a sibling donor, both AMML and AVWS maintain complete remission.

Acquired von Willebrand Syndrome

Acquired von Willebrand syndrome can occur in the setting of myeloproliferative neoplasms; plasma cell dyscrasias and other lymphoproliferative disorders; autoimmune conditions; and causes of increased shear forces, such as aortic stenosis or other structural heart disease and mechanical circulatory support. The depletion of von Willebrand factor, especially high-molecular-weight multimers, can lead to mucocutaneous bleeding and the formation of arteriovenous malformations, particularly in the gastrointestinal tract. Management focuses on correction of the underlying cause when possible, but may include intravenous immunoglobulins, von Willebrand factor concentrate, rituximab, or antiangiogenic therapy depending on the clinical context.

Continuous-infusion von Willebrand factor concentrate is effective for the management of acquired von Willebrand disease

Acquired von Willebrand disease (aVWD) is a rare disorder associated with a reduction in von Willebrand factor (VWF) activity, leading to increased bleeding risk. Monoclonal gammopathy of undetermined significance (MGUS) is the most common cause of lymphoproliferative disorder-associated aVWD and is caused by accelerated clearance of circulating VWF. Standard VWF replacement protocols for congenital VWD based on intermittent bolus dosing are typically less effective for aVWD because of antibody-mediated clearance. Intermittent bolus dosing of VWF concentrates often leads to inadequate peak response and profoundly shortened VWF half-life in aVWD. Intravenous immune globulin (IVIG) has demonstrated efficacy in aVWD; however, treatment effect is delayed up to 4 days, limiting its efficacy in acutely bleeding patients. We report the successful use of continuous-infusion VWF concentrate (with or without concomitant IVIG) in 3 patients with MGUS-associated aVWD who had demonstrated an inadequate response to bolus dosing. VWF concentrate doses required in this cohort were higher than typical doses for bleeding treatment in congenital VWD. This report illustrates that continuous-infusion VWF concentrate administration with or without intravenous immunoglobulin rapidly achieves target ristocetin cofactor activity and provides adequate hemostasis in aVWD associated with immunoglobulin G MGUS.

Differential diagnostic and treatment difficulties in a patient with acquired von Willebrand syndrome

BACKGROUND

Acquired von Willebrand syndrome (AVWS) is a rare, frequently underdiagnosed and underestimated bleeding disorder. Careful personal and family history and late-onset mucocutaneous bleeding could help clarify the etiology of bleeding deficiency.

CASE PRESENTATION

An 82-year-old male patient was admitted to our clinic with a severe nosebleed on 30.05.2018. Laboratory results revealed thrombocytosis, elevated white blood cell count and high LDH. Basic coagulation parameters were normal. He was referred to our clinic, where a bone marrow biopsy was taken. His personal and family history had no mention of bleeding disorders, nor was he on anticoagulant therapy. We detected elevated VWF antigen and decreased VWF ristocetin cofactor activity. Loss of high molecular weight multimers was detected by using agarose gel electrophoresis. These laboratory results were indicative of AVWS. Hydroxyurea treatment was initiated, leading to a gradual decrease in platelet count. The histological examination revealed essential thrombocytosist while mutation analysis was JAK2/CALR/MPL negative. However, due to severe nosebleeds, the patient was hospitalized and needed blood transfusion. A cardiological check-up revealed the progression of aortic valve stenosis. After, balloon-dilation a transcatheter aortic valve implantation was performed. As a result, VWF activity and activity to antigen ratio returned to normal as did multimeric structure. In July 2019, the follow-up examination showed that the patient was in a satisfactory condition, with normal hematological parameters, and no new nosebleed episode occurred.

CONCLUSIONS

The patient complained of recurring nosebleeds, which stopped completely after the resolution of both underlying conditions successful cytoreductive treatment of triple-negative ET and transcatheteric aortic valve replacement.

New Developments in Diagnosis and Management of Acquired Hemophilia and Acquired von Willebrand Syndrome

Acquired hemophilia A and acquired von Willebrand syndrome are rare, but life-threatening bleeding disorders that require prompt diagnosis and treatment by hematologists. Acquired hemophilia A is defined as an acquired severe bleeding tendency caused by autoantibody formation against coagulation factor VIII. Acquired von Willebrand syndrome is characterized by a new onset bleeding tendency caused by a reduced concentration and/or function of von Willebrand factor. These disorders are associated with a variety of underlying disorders, including various hematological malignancies, for example, plasma cell disorders, lymphoproliferative disorders, monoclonal gammopathy of undetermined significance, and myeloproliferative neoplasms. It is of utmost important to recognize these acquired bleeding disorders in these patients who are at risk for severe bleeding, and to perform additional diagnostic hemostasis laboratory evaluation. This will enable immediate diagnosis of the acquired bleeding disorder and management of both the bleeding episodes and the causative underlying disorder. In recent years, several new etiological factors for acquired hemophilia A, such as treatment with immune checkpoint inhibitors or DPP-4 inhibitors and SARS-CoV2 infection, and for acquired von Willebrand syndrome, for example, left ventricular assist devices, have been identified and also new treatment options have become available. In this concise review, the most recent data on etiology, diagnosis, and treatment of acquired bleeding disorders are presented and discussed.

Anticoagulation and bone marrow biopsy: is it safe to proceed?

BACKGROUND

Bone marrow (BM) biopsy is the most common diagnostic procedure in hematology. Bleeding is an expected complication, and its risk is assumed to be increased in patients on anticoagulants. However, the effect of anticoagulation on BM biopsy safety is unclear and guidelines are lacking robust data in this regard. As such, physicians use their clinical judgement to guide periprocedural management of anticoagulation.

OBJECTIVE

To provide the best available evidence regarding management of anticoagulation in patients who need BM biopsy.

METHODS

We reviewed and summarized available guidelines directing management of periprocedural anticoagulation for BM biopsy, and share our experience and practices with BM biopsy at our institution.

RESULTS

The incidence of significant hemorrhage after BM biopsy is very low (0.007-1.1%). BM biopsy is classified as having a low to moderate bleeding risk. Interrupting anticoagulation is not consistently recommended. Strategies exist to minimize bleeding risk for anticoagulated patients. Patients with myeloproliferative neoplasms can develop an acquired von Willebrand syndrome which increases their risk for bleeding and therefore require extra vigilance to ensure appropriate hemostasis.

CONCLUSION

Withholding anticoagulation prior to BM biopsy is not routinely recommended. Instead, assessment and optimization of bleeding risk factors should be done on a patient by patient basis.

Candidatus Mycoplasma haemohominis in Human, Japan

Hemotropic mycoplasmas are common pathogens in animals, but it remains unclear what role these pathogens play in human infections. We report clinical and biologic characterization of Candidatus Mycoplasma haemohominis infection in a 42-year-old man in Japan. The patient had severe hemophagocytic syndrome 1 month after an accidental needlestick injury. Metagenomic deep sequencing identified Candidatus M. haemohominis and determined its draft genome for an isolate from serum of the patient. A high copy number of the Candidatus M. haemohominis genome was detected in serum and bone marrow samples. Electron microscopy examination showed morphologic characteristics of Candidatus M. haemohominis. Levofloxacin monotherapy induced resistance caused by a gyrase A gene mutation in the quinolone resistance–determining region, but a combination treatment with moxifloxacin and minocycline was effective. We identified Candidatus M. haemohominis in a patient who had life-threatening symptoms related to multiple organ infection. Human infection with this mycoplasma might occur more frequently than has been generally recognized.

Efficacy and Safety of Tranexamic Acid in Emergency Trauma: A Systematic Review and Meta-Analysis

In trauma patients, bleeding can lead to coagulopathy, hemorrhagic shock, and multiorgan failure, and therefore is of fundamental significance in regard to early morbidity. We conducted a meta-analysis to evaluate the efficacy and safety of tranexamic acid (TXA) in civil and military settings and its impact on in-hospital mortality (survival to hospital discharge or 30-day survival), intensive care unit and hospital length of stay, incidence of adverse events (myocardial infarct and neurological complications), and volume of blood product transfusion. The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic review of the literature using PubMed, Scopus, EMBASE, Web of Science, and the Cochrane Central Register and Controlled Trials (CENTRAL) database was conducted from inception to 10 January 2021. In-hospital mortality was reported in 14 studies and was 15.5% for the TXA group as compared with 16.4% for the non-TXA group (OR = 0.81, 95% CI 0.62-1.06, I2 = 83%, p = 0.12). In a civilian TXA application, in-hospital mortality in the TXA and non-TXA groups amounted to 15.0% and 17.1%, respectively (OR = 0.69, 95% CI 0.51-0.93, p = 0.02, I2 = 78%). A subgroup analysis of the randomized control trial (RCT) studies showed a statistically significant reduction in in-hospital mortality in the TXA group (14.3%) as compared with the non-TXA group (15.7%, OR = 0.89, 95% CI 0.83-0.96, p = 0.003, I2 = 0%). To summarize, TXA used in civilian application reduces in-hospital mortality. Application of TXA is beneficial for severely injured patients who undergoing shock and require massive blood transfusions. Patients who undergo treatment with TXA should be monitored for clinical signs of thromboembolism, since TXA is a standalone risk factor of a thromboembolic event and the D-dimers in traumatic patients are almost always elevated.

Acquired von Willebrand syndrome in monoclonal gammopathy - A scoping review on hemostatic management

BACKGROUND

Acquired von Willebrand syndrome (AVWS) has been associated with monoclonal gammopathy of undetermined significance (MGUS), with limited data on its management.

METHODS

We conducted a systematic literature search in Medline (Ovid), Embase, and Scopus up to September 11, 2019, for studies reporting on the management of AVWS associated with MGUS (AVWS-MGUS). Data on patient characteristics, laboratory parameters at presentation, and clinical and laboratory outcomes were extracted.

OBJECTIVES

To describe the clinical presentation and outcomes of different therapeutic approaches.

RESULTS

Seventy-five studies were included in the final review, for a total of 137 patients. Most patients had von Willebrand factor ristocetin cofactor activity <30 IU/dL (86.6%) and factor VIII levels <50 IU/dL (91.8%). Bleeding severity ranged from no bleeding (16.1%) to minor bleeding (46.4%) and major bleeding (37.5%). The overall clinical success rates for 1-deamino-8-D-arginine vasopressin (DDAVP), factor replacement therapy, and intravenous immunoglobulin (IVIG) were 43.8%, 33.3%, and 85.4%, respectively. The laboratory response rates for DDAVP, factor replacement therapy, and IVIG were 39.0%, 62.9%, and 88.6%, respectively. Several other treatments were also reported in small numbers, out of which myeloma-directed therapies, plasma exchange, recombinant factor VIIa, and antifibrinolytics appeared most successful, while immunosuppressive agents were largely ineffective.

CONCLUSION

IVIG appears to be an effective treatment for AVWS-MGUS bleeding, conferring a high clinical success rate with measurable laboratory outcomes; albeit temporary. DDAVP and factor replacement therapy may be partially successful in controlling minor bleeds, but not major bleeds. Other less commonly used agents may be effective in certain cases, although data are limited.