How I treat the acquired von Willebrand syndrome

Differences in von Willebrand factor function in type 2A von Willebrand disease and left ventricular assist device-induced acquired von Willebrand syndrome

BACKGROUND

Patients with von Willebrand disease (VWD) type 2A or acquired von Willebrand syndrome (aVWS) as a consequence of implantation of left ventricular assist devices (LVAD) are both characterized by a loss of von Willebrand factor (VWF) function. Loss of VWF function is however more severe in VWD type 2A than in LVAD patients.

OBJECTIVES

To compare VWF function in patients with VWD type 2A and LVAD-induced aVWS to highlight the differences in VWF activity and to stress the importance of VWF multimer analysis for correct diagnosis of aVWS in LVAD patients.

PATIENTS/METHODS

Plasma samples from nine VWD type 2A, nine LVAD patients, and 20 healthy donors (HD) were analyzed for VWF function (VWF:CB/VWF:Ag and VWF:RCo/VWF:Ag) and loss of high molecular weight (HMW) VWF multimers.

RESULTS

A severely impaired VWF function was indeed confirmed in all VWD 2A patients. HMW VWF multimers were severely reduced compared to HD (0% [0, 12.29] vs 34.19% [31.68, 38.88] for HD, P < 0.001) and this loss was reflected by VWF:CB/VWF:Ag and VWF:RCo/VWF:Ag ratios <0.7. In contrast, VWF function was less affected in LVAD patients. Although HMW VWF multimers were reduced in all patients (20.31% [15.84, 21.71], vs 34.19% [31.68, 38.88] for HD, P < 0.001), six out of nine LVAD patients had normal VWF:CB/VWF:Ag or VWF:RCo/VWF:Ag ratios (>0.7).

CONCLUSIONS

VWF:CB/VWF:Ag or VWF:RCo/VWF:Ag analysis allows detection of impaired VWF function in VWD type 2A but not always in LVAD-induced aVWS patients. In contrast, VWF multimeric analysis allows detection of the loss of HMW VWF multimers in both groups of patients. Hence, performing VWF multimer analysis is crucial to detect aVWS in LVAD patients.

Administration of plasma-derived coagulation factor VIII during the perioperative period of mastectomy for breast cancer with acquired von Willebrand syndrome

Background

Acquired von Willebrand syndrome (aVWS) is a rare bleeding disorder with laboratory findings similar to those of congenital von Willebrand disease (VWD). Patients with aVWS may require prophylactic treatment to prevent excessive bleeding following surgery. To our knowledge, to date, there have been no reports on perioperative management for breast cancer patients with aVWS.

Case presentation

A 60-year-old woman with breast cancer was diagnosed with aVWS due to polycythemia vera. Pre-operative laboratory testing showed a high platelet count and low von Willebrand factor (VWF) activity. The VWF activity did not improve despite an attempt to suppress platelet count with hydroxyurea. Therefore, we decided to perioperatively supplement with plasma-derived factor VIII (FVIII) containing von Willebrand factor (FVIII/VWF concentrates) to perform curative surgery for breast cancer safely. Consequently, the patient did not develop hemorrhage during/after surgery and was discharged on postoperative day 7, as planned, without problems.

Conclusions

For a patient with aVWS, which carries a high risk of hemorrhage during the perioperative period, initiation of appropriate management like supplementation of FVIII/VWF concentrates might enable safe curative surgery for breast cancer, and collaboration with the hematology department is critical.

Management of epistaxis in patients with ventricular assist device: a retrospective review

Background

Patients with a ventricular assist device (VAD) are at risk for epistaxis due to the need for anticoagulation. Additionally, these patients develop acquired von Willebrand syndrome (AvWS) due to these devices. Management is complicated by the risk of thrombosis if anticoagulation is reversed. This study sought to characterize the clinical features and management of epistaxis in this high-risk population.

Methods

Retrospective review of adults with VAD and epistaxis necessitating inpatient consultation with the otolaryngology service were included.

Results

49 patients met inclusion criteria. All patients had a presumed diagnosis of AvWS. An elevated INR (> 2.0) was present in 18 patients (36.7%). Anticoagulation was held in 14 (28.6%) patients, though active correction was not necessary. Multiple encounters were required in 16 (32.7%) patients. Spontaneous epistaxis was associated with multiple encounters (p = 0.02). The use of hemostatic material was associated with a lower likelihood of bleeding recurrence (p = 0.05), whereas cauterization with silver nitrate alone was associated with a higher likelihood of re-intervention (p = 0.05). Surgery or embolization was not required urgently for any patient. Endoscopy under general anesthesia was performed for one patient electively. Mean follow up time was 16.6 months (σ = 6.3). At six months, 18 (36.7%) patients were deceased.

Conclusion

While these patients are at risk for recurrent spontaneous epistaxis, nonsurgical treatment without active correction of INR or AvWS was largely successful. Placement of hemostatic material, as opposed to cautery with silver nitrate, should be considered as a first-line treatment in this group. Multidisciplinary collaboration is critical for successful management.

Evaluation of a new commercial method for von Willebrand factor multimeric analysis

INTRODUCTION

Evaluation of von Willebrand factor (VWF) multimeric distribution is useful for subclassification of von Willebrand disease (VWD). Multimer analysis has historically been a manual, labor-intensive laboratory-developed test. The first commercial method for multimeric analysis was recently developed that utilizes a single instrument for gel electrophoresis, staining, and densitometry. The current study was undertaken to evaluate the performance characteristics of the new commercial method.

METHODS

Studies performed with the commercial method included evaluation of accuracy (method comparison), reference intervals (establishment of normal migration patterns in normal donor specimens), precision (multimer pattern reproducibility), and analytical sensitivity.

RESULTS

In the method comparison studies, concordant interpretations were obtained in 19 of 24 comparisons, including normal and abnormal specimens. The 5 specimens with discordant interpretations all involved slight differences and none were considered clinically significant. Thirty-eight normal donor specimens demonstrated normal multimer patterns. Multimer pattern reproducibility was demonstrated in normal and abnormal controls tested on each gel. In the sensitivity studies, adequate visualization of multimers was determined to require VWF protein concentrations of approximately 5%-10% of normal.

CONCLUSION

The commercial multimer method is a streamlined test that demonstrates comparable performance characteristics to our current laboratory-developed method and that provides the advantage of both electrophoresis gels and densitometry scans to aid interpretation.

Acquired von Willebrand Syndrome due to Aortic Valve Stenosis in a Case with Antiphospholipid Antibody

Acquired von Willebrand syndrome (AVWS) is a bleeding disorder caused by an acquired deficiency of von Willebrand factor (vWF). Some patients with AVWS show a low bleeding tendency and are diagnosed by the presence of a mild prolongation of activated partial thromboplastin time (APTT) preoperatively. Another cause of APTT prolongation is the presence of antiphospholipid antibody (aPL). We experienced a case of AVWS due to aortic valve stenosis in a patient with aPL in whom aortic valve replacement surgery was successful with vWF replacement. In patients with AVWS-associated disorders who are identified based on APTT prolongation at the preoperative examination, both vWF and aPL screening tests must be performed.

Characterizing the HeartMate II Left Ventricular Assist Device Outflow Using Particle Image Velocimetry

Ventricular assist devices (VADs) are implanted in patients with a diseased ventricle to maintain peripheral perfusion as a bridge-to-transplant or as destination therapy. However, some patients with continuous flow VADs (e.g., HeartMate II (HMII)) have experienced gastrointestinal (GI) bleeding, in part caused by the proteolytic cleavage or mechanical destruction of von Willebrand factor (vWF), a clotting glycoprotein. in vitro studies were performed to measure the flow located within the HMII outlet cannula under both steady and physiological conditions using particle image velocimetry (PIV). Under steady flow, a mock flow loop was used with the HMII producing a flow rate of 3.2 L/min. The physiological experiment included a pulsatile pump operated at 105 BPM with a ventricle filling volume of 50 mL and in conjunction with the HMII producing a total flow rate of 5.0 L/min. Velocity fields, Reynolds normal stresses (RNSs), and Reynolds shear stresses (RSSs) were analyzed to quantify the outlet flow's potential contribution to vWF degradation. Under both flow conditions, the HMII generated principal Reynolds stresses that are, at times, orders of magnitude higher than those needed to unfurl vWF, potentially impacting its physiological function. Under steady flow, principal RNSs were calculated to be approximately 500 Pa in the outlet cannula. Elevated Reynolds stresses were observed throughout every phase of the cardiac cycle under physiological flow with principal RNSs approaching 1500 Pa during peak systole. Prolonged exposure to these conditions may lead to acquired von Willebrand syndrome (AvWS), which is accompanied by uncontrollable bleeding episodes.

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 Disease Associated with Mantle Cell Lymphoma

We present a rare case of acquired von Willebrand syndrome (AVWS) caused by a mantle cell lymphoma. A 61-year-old male suffered from recurrent bleeding symptoms since a few months. Initially, physical examination was normal. von Willebrand factor antigen (VWF:Ag) level and factor VIII activity (FVIII:C) were low (0.31 IU/ml and 0.43 IU/ml, resp.). Ristocetin cofactor activity (VWF:RCo) was 0.09 IU/ml, and collagen binding activity (VWF:CB) was 0.10 IU/ml. VWF:RCo/VWF:Ag ratio was 0.29, and RIPA value was normal. Highest molecular weight VWF multimers were absent. A diagnosis of von Willebrand Disease (VWD) type 2A was made. However, no genetic mutation was found. No inhibitory antibodies against VWF or factor VIII were detected. A few months later, cervical, axillary, and inguinal lymphadenopathy was found on physical examination. A CT scan confirmed multiple enlarged lymph nodes, and a clonal B-cell population matching a mantle cell lymphoma was detected in the bone marrow. Chemoimmunotherapy resulted in a very good partial remission and concomitantly in a rapid decrease of bleeding problems and complete normalization of FVIII:C and VWF:Ag. The diagnosis of AVWS cannot be rejected by negative mixing studies due to difficulties in the detection of autoantibodies and because of a highly heterogeneous pathogenesis of AVWS. When the suspicion of AVWS is high, an extensive investigation should be performed to find the underlying cause.

Platelet Secretion Defects and Acquired von Willebrand Syndrome in Patients With Ventricular Assist Devices

Background

The number of implanted ventricular assist devices (VADs) has increased significantly recently. Bleeding, the most frequent complication, cannot be solely attributed to anticoagulation therapy. Acquired von Willebrand syndrome (AVWS) caused by increased shear stress is frequent in VAD patients and can increase the bleeding risk. The HeartMate III (HM III) is a novel left VAD featuring potential improvements over the HeartMate II.

Methods and Results

In this study, we investigated the prevalence and onset of AVWS in 198 VAD patients. To our knowledge, this is the largest cohort of VAD patients whose longitudinal data on AVWS have been collected. We also analyzed whether AVWS is less severe in HM III patients than in HeartMate II patients. Because platelet dysfunction can raise the bleeding risk, we investigated platelet function in a subset of patients. In total, 198 VAD patients and 60 patients with heart transplants as controls were included in this study. The ratio of von Willebrand factor collagen binding capacity to von Willebrand factor:antigen, multimer analyses, and platelet function (especially secretion of α‐ and δ‐granules) were investigated. All 198 VAD patients developed AVWS. As soon as the VAD was explanted, the AVWS disappeared within hours. AVWS was less severe in the HM III patients than in the HeartMate II patients. The HM III patients had fewer bleeding symptoms. In addition, VAD patients exhibited a platelet α‐ and δ‐granule secretion defect.

Conclusions

AVWS develops in VAD patients and may increase the bleeding risk. The HM III device causes less severe AVWS. Platelet secretion defects should be investigated in VAD patients because they also raise the bleeding risk.

Clinical Trial Registration

https://www.drks.de/drks_web. Unique identifier: DRKS00000649.

Acquired von Willebrand Syndrome in an Infant With Coarctation of the Aorta and Williams Syndrome

An infant with coarctation of the aorta and Williams syndrome was noted to have petechiae in cardiology clinic prior to planned surgical intervention. Workup revealed acquired von Willebrand syndrome secondary to the high shear force generated by the aortic coarctation. He was treated with intra- and postoperative Humate P; there were no postoperative bleeding complications. His acquired von Willebrand syndrome resolved postoperatively.

Acquired von Willebrand Syndrome: An Under-Recognized Cause of Major Bleeding in the Cardiac Intensive Care Unit

BACKGROUND

Acquired von Willebrand syndrome (AvWS) in the setting of congenital heart disease is an under-recognized cause of bleeding in the pediatric cardiac critical care unit.

METHODS

Fourteen patients diagnosed with AvWS admitted to the cardiac intensive care unit at the Children's National Health System between December 2009 and September 2015 were identified with subsequent chart review and case analysis.

RESULTS

Of the 14 patients included in this study, 4 patients were on ventricular-assist devices, 6 patients were on extracorporeal membrane oxygenation, and 4 were patients with congenital heart disease not receiving any mechanical circulatory support. All patients identified manifested persistent severe bleeding, despite appropriate management of anticoagulation and blood product administration based on the established protocols. Detailed hemostatic testing including quantitative von Willebrand factor (vWF) multimer analysis revealed decreased high-molecular-weight multimers (HMWMs) and absent ultra-HMWM, consistent with AvWS in all patients. Eight patients received treatment with vWF concentrate, one patient with desmopressin, and five recovered without specific treatment. Bleeding ceased in all but one patient.

CONCLUSIONS

Acquired von Willebrand syndrome is an uncommon but important cause of bleeding in pediatric patients with cardiac disease. A high index of clinical suspicion with knowledge of the characteristic clinical scenario in addition to low levels of vWF multimers is required to manage and diagnose AvWS. Although the optimal management of AvWS in this patient population is unclear, vWF concentrates are available and appear to be efficacious for controlling life-threatening bleeding.

IgM myeloma: A multicenter retrospective study of 134 patients

IgM myeloma is a rare hematologic malignancy for which the clinicopathological features and patient outcomes have not been extensively studied. We carried out a multicenter retrospective study in patients with diagnosis of IgM myeloma defined by >10% marrow involvement by monoclonal plasma cells, presence of an IgM monoclonal paraproteinemia of any size, and anemia, renal dysfunction, hypercalcemia, lytic lesions and/or t(11;14) identified by FISH. A total of 134 patients from 20 centers were included in this analysis. The median age at diagnosis was 65.5 years with a male predominance (68%). Anemia, renal dysfunction, elevated calcium and skeletal lytic lesions were found in 37, 43, 19, and 70%, respectively. The median serum IgM level was 2,895 mg dL^-1 with 19% of patients presenting with levels >6,000 mg dL^-1 . International Staging System (ISS) stages 1, 2, and 3 were seen in 40 (33%), 54 (44%), and 29 (24%) of patients, respectively. The malignant cells expressed CD20 (58%) and cyclin D1 (67%), and t(11;14) was the most common cytogenetic finding (39%). The median overall survival (OS) was 61 months. Higher ISS score was associated with worse survival (P = 0.02). Patients with IgM myeloma present with similar characteristics and outcomes as patients with more common myeloma subtypes.

Acquired von Willebrand Syndrome in IgM Monoclonal Gammopathy as the Presentation of Lymphoplasmacytic Lymphoma

Acquired von Willebrand syndrome (AVWS) is an increasingly recognized entity with numerous potential underlying etiologies. Most commonly implicated are lymphoproliferative, myeloproliferative, cardiovascular, and autoimmune disorders. Unlike inherited von Willebrand disease (vWD), AVWS tends to present at an older age and without a family history of vWD. Treatment is directed at the underlying etiology if one is uncovered, as well as treatment and prevention of bleeding. Here, we present a rare case of AVWS secondary to Waldenström macroglobulinemia which went unrecognized for several years but resolved promptly with treatment. The potential mechanisms of AVWS secondary to monoclonal gammopathies are discussed as well as strategies to treat and prevent bleeding in these patients.

von Willebrand factor disruption and continuous-flow circulatory devices

Bleeding events remain a significant and frequent complication of continuous-flow left ventricular assist devices (VADs). von Willebrand factor (VWF) is critical to hemostasis by acting as a bridging molecule at sites of vascular injury for normal platelet adhesion as well as promoting platelet aggregation under conditions of high shear. Clinical and experimental data support a role for acquired von Willebrand disease in VAD bleeding episodes caused by shear-induced qualitative defects in VWF. Pathologic shear induces VWF unfolding and proteolysis of large multimers into smaller less hemostatic multimers via ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13). This review outlines the pathobiology of VWF disruption in the context of VADs as well as current diagnostic and management strategies of the associated acquired von Willebrand disease.

Pediatric Acquired von Willebrand Disease With Berlin Heart Excor Ventricular Assist Device Support

BACKGROUND

The balance of hemostasis and anticoagulation is a concern for patients dependent upon ventricular assist devices (VADs). Bleeding is a common complication with both short- and long-term use of these devices. A better understanding of the risk factors and etiologies of bleeding associated with these devices is needed and could improve the overall results. We sought to determine the relationship of mechanical circulatory assist device use with acquired von Willebrand disease (avWD) in children.

METHODS

Data were analyzed retrospectively via review of the medical record of 19 consecutive patients who were supported with the Berlin EXCOR VAD for greater than 24 hours. Laboratory testing for avWD was performed at the discretion of the clinical team, often in association with clinical bleeding.

RESULTS

Of 19 pediatric patients, 10 (52.6%) had laboratory testing consistent with avWD. Median time to detection of avWD was 35 days postimplantation of device (range 0-310 days). Both minor mucosal bleeding and bleeding requiring intervention were highly prevalent in patients in whom avWD was identified (10/10 [100%] and 7/10 [70%]). The mean age of all patients was 3.3 years, but patients found to have avWD tended to be older (mean 5.3 years) and supported with larger volume VADs.

CONCLUSIONS

This experience demonstrates a high prevalence of avWD following EXCOR implantation. Bleeding, older age, and larger VAD size may be associated with avWD. These results should stimulate critical evaluation of individualized anticoagulation regimens in pediatric VAD patients.

Observational retrospective study of vascular modulator changes during treatment in essential thrombocythemia

Essential thrombocythemia (ET) patients are at risk of developing thrombotic events. Qualitative platelet (PLT) abnormalities and activation of endothelial cells (ECs) and PLTs are thought to be involved. Microparticles (MPs) can originate from PLTs (PMPs), ECs (EMPs), or red cells (RMPs). Previous studies have indicated that MPs contribute to ET pathophysiology. Endothelial modulators (eg, nitric oxide [NO], adrenomedullin [ADM], and endothelin-1 [ET-1]) are also involved in the pathophysiology of this condition. We hypothesized that treatments for reducing PLT count might also indirectly affect MP generation and endothelial activity by altering endothelial modulator production. The rationale of this study was that hydroxyurea (HU), a cytostatic drug largely used in ET, induces the production of a potent vasoactive agent NO in ECs. An observational retrospective study was designed to investigate the relationship between MPs, NO, ADM, and ET-1 in ET patients on treatment with HU, anagrelide (ANA), aspirin (ASA), and a group of patients before treatment. A total of 63 patients with ET diagnosis: 18 on HU + ASA, 15 on ANA + ASA, 19 on ASA only, and 11 untreated patients, and 18 healthy controls were included in this study. Blood samples were analyzed for MP (absolute total values) and functional markers (percentage values) by flow cytometry. PLT-derived MPs were studied using CD61, CD62P, CD36, and CD63, whereas endothelial-derived MPs were studied using CD105, CD62E, and CD144. Endothelial modulator markers (NO, ADM, and ET-1) were measured by ELISA. Total MP count was higher in the group treated with ANA + ASA (P < 0.01). MP markers modified in ET patients returned to levels of healthy controls following treatment, in particular, in patients on ANA treatment. NO and ADM values were higher in the HU group (P < 0.001). HU and ANA treatment also affected MP production in a cell origin-specific manner. HU and ANA, although acting via different pathways, have similar final effects. For instance, HU causes vasodilatation by increasing NO and ADM levels, whereas ANA impairs vasoconstriction by reducing ET-1. In conclusion, therapy with HU cytostatic drugs and ANA can reduce PLT count in ET, and also affect endothelial modulatory agents, with HU sustaining vasodilation and prothrombotic MP concentration, whereas ANA decreases vasoconstriction.

Multiple myeloma and acquired von Willebrand disease: a combined cause of preanalytical interference causing gel formation?

We report a patient with acquired von Willebrand disease, associated with multiple myeloma. At one stage in his illness, we were unable to analyse a sample sent in a serum separator tube, due to the presence of a gel within the separated serum layer. We suggest this was due to anomalous position of the gel because of the density of the sample caused by its high total protein concentration, exacerbated by fibrin strand formation because of inhibition of appropriate fibrin clot formation secondary to clotting disorder.

Perioperative intravenous immunoglobulin treatment in a patient with severe acquired von Willebrand syndrome: case report and review of the literature

Acquired von Willebrand syndrome may be related to plasma cell dyscrasia and can cause severe bleeding complications. Treatment, for example, with intravenous immunoglobulins may be indicated in selected cases. Physicians treating plasma cell dyscrasia have to be aware of bleeding complications in these patients, and clarification is necessary.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

An 11-year experience of acquired von Willebrand syndrome in children diagnosed with Wilms tumour in a tertiary referral centre

Wilms tumour (WT) is the commonest primary malignant renal tumour of childhood. Acquired von Willebrand syndrome (avWS) is a well-described paraneoplastic phenomenon, but it is uncommon and may not be detected until clinically significant bleeding is encountered during interventional procedures. Previous studies on small cohorts of patients have determined an incidence of between 4 and 8%. We have performed a retrospective study on cases of WT presenting over an 11.5-year period to a paediatric haematology/oncology unit in a tertiary referral centre to review the incidence of avWS, bleeding phenotype, management, and response to treatment of the primary pathology.

Pediatric Acquired von Willebrand Syndrome in Cardiopulmonary Disorders: Do Laboratory Abnormalities Predict Bleeding Risk?

There are conflicting reports on whether or not laboratory abnormalities in pediatric acquired von Willebrand syndrome (AVWS) predict bleeding manifestations in patients with cardiopulmonary disorders (CPD). We retrospectively reviewed charts of patients with AVWS and CPD (n=16) seen at Texas Children's Hospital from 2003 to 2012. The most common CPD were valve stenoses, ventricular septal defects, and pulmonary hypertension. All patients had loss of high molecular weight multimers. Fifteen (94%) patients presented with bleeding symptoms, with menorrhagia and epistaxis being the most common. Von Willebrand ristocetin cofactor activity (VWF:RCo), as well as the use of anticoagulant or antiplatelet medication, did not predict bleeding manifestations (P=0.70 and 0.84, respectively). VWF:RCo/VWF antigen (Ag) ratio of <0.7 was significantly associated with presence of bleeding symptoms. All patients who had complete repair of their cardiac defect experienced normalization of VWF multimers and VWF:RCo/Ag ratio, as well as bleeding symptom resolution. We conclude that increased bleeding risk is associated with low VWF:RCo/Ag ratio in pediatric AVWS due to CPD. However, other laboratory abnormalities such as VWF:RCo level and qualitative multimer analysis, do not appear to predict bleeding. Future studies exploring quantification of multimer loss may be helpful in further assessing bleeding risk associations.

von Willebrand Disease: A Concise Review and Update for the Practicing Physician

von Willebrand disease (vWD) is the most common inherited disorder of hemostasis and comprises a spectrum of heterogeneous subtypes. Significant advances have been made in understanding von Willebrand factor ( vWF) gene mutations, resultant physiologic deficits in the vWF peptide, and their correlation to clinical presentation. Diagnostic tests for this disorder are complex, and interpretation requires a thorough understanding of the underlying pathophysiology by the practicing physician. The objective of this review is to summarize our current understanding of pathophysiology, laboratory investigations, and evolving treatment paradigm of vWD with the availability of recombinant von Willebrand factor.

New treatment approaches to von Willebrand disease

von Willebrand disease (VWD) is the commonest inherited bleeding disorder and results from either a quantitative or qualitative deficiency in the plasma glycoprotein von Willebrand factor (VWF). Recent large cohort studies have significantly enhanced our understanding of the molecular mechanisms involved in the pathogenesis of VWD. In contrast, however, there have been relatively few advances in the therapeutic options available for the treatment of bleeding in patients with VWD. Established treatment options include tranexamic acid, 1-deamino-8-d-arginine vasopressin (DDAVP), and plasma-derived VWF concentrates. In addition, a recombinant VWF has also recently been developed. In this review, we focus on how recent insights into the clinical and molecular aspects underpinning VWD are already beginning to influence treatment in the clinic. For example, a number of different bleeding assessment tools (BATs) have been developed to objectively assess bleeding symptoms in patients with VWD. Interestingly, however, these BAT scores may also have an important role to play in predicting bleeding risk in VWD. Furthermore, recent studies have demonstrated that enhanced VWF clearance plays a critical role in the etiology of both type 1 and type 2 VWD. These findings have direct translational relevance with respect to the use of DDAVP in patients with VWD. As understanding of the mechanisms involved in VWD pathogenesis continues to advance, novel treatment options are likely to emerge. Critically, however, large adequately powered and stratified clinical trials will be required to address the outstanding questions that remain regarding VWD treatment optimization.

[Acquired von Willebrand syndrome in three patients and literature review]

OBJECTIVE

To deepen the understanding of acquired von Willebrand syndrome (AVWS).

METHODS

The clinical data of 3 patients were analyzed and related literature were reviewed.

RESULTS

① Case 1, a 70- year- old male, diagnosed as Waldenstrom macroglobulinemia and AVWS, was presented with spontaneous epitaxis and bruising. The VWF∶Ag level was 16%. Treatment was initiated with VWF concentrates. Two cycles of chemotherapy with Bortezomib, thalidomide and Dexamethasone were followed. Partial remission was achieved. Half- year' follow- up showed no sign of spontaneous hemorrhage. ② Case 2, a 48- year- old female, diagnosed as monoclonal gammopathy of undetermined significance and AVWS, was presented with repeated epitaxis. The VWF∶Ag level was 7%. Because the bleeding was slight and self-relieved, no specific treatment was addressed. She was followed up for one and a half year. ③ Case 3, a 50- year- old man, diagnosed as monoclonal gammopathy of undetermined significance and AVWS, was referred to our hospital for presentation with significant hematomas. VWF∶ Ag was reduced to 12%. VWF- containing cryoprecipitate, plasma, intravenous immunoglobulin and rituximab were used to control his bleeding symptom. During the follow-up, spontaneous hemorrhage still occurred occasionally.

CONCLUSIONS

Acquired von Willebrand syndrome presented with heterogeneous symptoms. The level of VWF∶Ag and VWF∶Rco for patients with bleeding disorder should be performed. Abnormal bleeding symptoms in elderly patients without personal or family history of bleeding should prompt consideration of the underlying disorders. Treatment included controlling acute bleeding, curing the underlying diseases and preventing bleeding in high- risk situations. The prognosis of acquired von Willebrand syndrome is mainly related to the underlying diseases.

Lenalidomide as a novel treatment for refractory acquired von Willebrand syndrome associated with monoclonal gammopathy

Essentials Treatment options are limited for refractory bleeding in acquired von Willebrand Syndrome (AVWS). Lenalidomide therapy was studied in two patients with AVWS due to monoclonal gammopathy (MG). Lenalidomide increased von Willebrand factor (VWF), lowered VWF clearance and resolved bleeding. Lenalidomide is a potential treatment option for refractory bleeding in AVWS secondary to MG.

SUMMARY

Background Acquired von Willebrand syndrome (AVWS) is associated with lymphoproliferative disorders, including monoclonal gammopathy (MG) of undetermined significance (MGUS) and multiple myeloma. Patients commonly present with significant bleeding complications that are difficult to manage, owing to a markedly reduced von Willebrand factor (VWF) half-life. Objectives To investigate the use of the immunomodulatory drug lenalidomide in two patients with severe refractory bleeding caused by AVWS associated with MGs. Results In both patients, lenalidomide treatment resulted in significant clinical improvement, and marked increases in plasma VWF antigen (VWF:Ag) and VWF ristocetin cofactor levels. This normalization in plasma VWF levels was sustained for > 2 years in both patients. Furthermore, in one patient, plasma VWF levels remain normal for at least 14 months following discontinuation of lenalidomide treatment. To investigate the molecular mechanisms underlying these observations, VWF propeptide (VWFpp)/VWF:Ag ratios were analyzed to assess VWF clearance. At enrolment, plasma VWFpp/VWF:Ag ratios were significantly elevated in both patients. Importantly, lenalidomide treatment resulted in normalization of VWFpp/VWF:Ag ratios in both patients. These novel data suggest that lenalidomide functions to attenuate enhanced VWF clearance in AVWS. Interestingly, in a patient with MGUS, lenalidomide treatment was associated with a significant increase in plasma VWF levels, despite no major change in paraprotein level. Conclusions Collectively, our findings suggest that lenalidomide constitutes a novel therapeutic option for the management of AVWS associated with MG. The biological mechanism(s) through which lenalidomide causes a sustained increase in plasma VWF levels in AVWS independently of paraprotein level requires further study, but is in part modulated through inhibition of enhanced VWF clearance.

Diagnosis, prevention, and management of bleeding episodes in Philadelphia-negative myeloproliferative neoplasms: recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO) and the Society of Thrombosis and Hemostasis Research (GTH)

Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPN) comprise a heterogeneous group of chronic hematologic malignancies. The quality of life, morbidity, and mortality of patients with MPN are primarily affected by disease-related symptoms, thromboembolic and hemorrhagic complications, and progression to myelofibrosis and acute leukemia. Major bleeding represents a common and important complication in MPN, and the incidence of such bleeding events will become even more relevant in the future due to the increasing disease prevalence and survival of MPN patients. This review discusses the causes, differential diagnoses, prevention, and management of bleeding episodes in patients with MPN, aiming at defining updated standards of care in these often challenging situations.

Monoclonal gammopathy: The good, the bad and the ugly

Monoclonal gammopathy of undetermined significance (MGUS) is a condition characterized by the presence of a monoclonal gammopathy (MG) in which the clonal mass has not reached a predefined state in which the condition is considered malignant. It is a precursor to conditions such as multiple myeloma or lymphoma at a rate of ~1%/year. Thus, from a hematologic standpoint, MGUS is a fairly benign condition. However, it is now recognized that organ damage resulting from just the MG without the need MM or lymphoma can occur. One of the most recognized is nephropathy secondary to monoclonal gammopathy of renal significance (MGRS). Other well-recognized conditions include neuropathies, oculopathies and dermopathies. Some conditions such as autoimmune diseases and coagulopathies are less common and recognized. Finally, systemic involvement of multiple organs is well described in several entities. In all of these conditions, the role of the MG is no longer insignificant. Thus, the term MGUS should be avoided when describing these entities.

Guidelines for the management of myeloproliferative neoplasms

Polycythemia vera, essential thrombocythemia, and primary myelofibrosis are collectively known as 'Philadelphia-negative classical myeloproliferative neoplasms (MPNs).' The discovery of new genetic aberrations such as Janus kinase 2 (JAK2) have enhanced our understanding of the pathophysiology of MPNs. Currently, the JAK2 mutation is not only a standard criterion for diagnosis but is also a new target for drug development. The JAK1/2 inhibitor, ruxolitinib, was the first JAK inhibitor approved for patients with intermediate- to high-risk myelofibrosis and its effects in improving symptoms and survival benefits were demonstrated by randomized controlled trials. In 2011, the Korean Society of Hematology MPN Working Party devised diagnostic and therapeutic guidelines for Korean MPN patients. Subsequently, other genetic mutations have been discovered and many kinds of new drugs are now under clinical investigation. In view of recent developments, we have revised the guidelines for the diagnosis and management of MPN based on published evidence and the experiences of the expert panel. Here we describe the epidemiology, new genetic mutations, and novel therapeutic options as well as diagnostic criteria and standard treatment strategies for MPN patients in Korea.

Thalidomide for treatment of gastrointestinal bleedings due to angiodysplasia: a case report in acquired von Willebrand syndrome and review of the literature

INTRODUCTION

Acquired von Willebrand syndrome is a rare bleeding disorder and treatment of the associated gastrointestinal (GI) bleeding due to angiodysplasia is challenging.

AIM

The aim of this study was to present a new case on the successful use of thalidomide in a patient with acquired von Willebrand syndrome and recurrent angiodysplasia-related GI bleedings, and to conduct a literature review on the use of thalidomide in patients with GI angiodysplasia.

METHODS

A literature review was conducted, searching the electronic databases PubMed, Embase and Cochrane.

RESULTS

We present a 75-year-old woman with IgG MGUS-associated acquired von Willebrand syndrome (AVWS) who suffered from recurrent gastrointestinal (GI) bleedings and epistaxis. Treatment with immunoglobulins, desmopressin, Haemate-P and blood transfusions failed to achieve long-term haemostasis. Eventually, after these bleedings relapsed for almost a decade at 1- to 3-month intervals, thalidomide was prescribed. Since then, only one single nose bleed and one single melaena episode had occurred. She currently remains in remission of GI bleeds after 3 years and 3 months follow-up. The literature review revealed a beneficial effect of thalidomide in reducing GI bleeding due to angiodysplasia, including four case reports on inherited von Willebrand disease.

CONCLUSION

In conclusion, thalidomide can be a reasonable option for the treatment of recurrent GI bleeding due to angiodysplasia in AVWS and we report for the first time that refractory or relapsing GI bleeding in patients with AVWS can successfully be controlled with thalidomide.

Treatment of Acquired von Willebrand Syndrome and Prevention of Bleeding Postautologous Stem Cell Transplant during Severe Pancytopenia with IVIG

The use of high dose chemotherapy followed by autologous hematopoietic stem cell transplantation for remission consolidation after initial induction represents standard of care for patients with multiple myeloma. Patients with myeloma and Acquired von Willebrand Syndrome (AVWS) undergoing autologous stem cell transplant (ASCT) are at significant risk of bleeding due to the profound thrombocytopenia, low Factor VIII levels, fever, and toxicities associated with the preparative regimen. We report a patient with AVWS associated with multiple myeloma who underwent autologous stem cell transplants as consolidation after initial induction and again at relapse. He was successfully treated with high dose intravenous immunoglobulin (IVIG) prior to each transplant with rapid resolution of AVWS.

Acquired von Willebrand syndrome in a child following Berlin Heart EXCOR Pediatric Ventricular Assist Device implantation: case report and concise literature review

The development of acquired von Willebrand syndrome (AVWS) after placement of a pulsatile-flow left ventricular assist device (LVAD) is rare and only recently recognized. We report the case of a young infant who was diagnosed with ventricular assist device (VAD)-related AVWS following implantation of a Berlin Heart EXCOR Pediatric Ventricular Assist Device (Berlin Heart Inc., The Woodlands, Texas, USA) for treatment of severe heart failure. Despite significant bleeding, the patient was successfully managed with von Willebrand factor-containing concentrate until VAD explantation led to definitive resolution of the AVWS. This case demonstrates that the possibility of this diagnosis should be considered in pediatric patients when extensive, nonsurgical bleeding is encountered after pulsatile-flow VAD implantation.

IgG kappa monoclonal gammopathy of undetermined significance presenting as acquired type III Von Willebrand syndrome

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder associated with hematoproliferative disorders, autoimmune conditions, neoplasia and cardiovascular disorders that often present a diagnostic challenge. Monoclonal gammopathy of undetermined significance (MGUS) is one of the most common causes of AVWS that typically presents later in life with mucocutaneous or postsurgical bleeding and multimers consistent with type I or II von Willebrand disease (VWD). Here, we present the case of a patient with a 32-year history of type III VWD that was ultimately found to be AVWS related to an IgG MGUS. In this case report, we highlight the diagnostic challenges of AVWS to ensure proper identification and potentially lifesaving treatment of this rare disorder.

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.

Extracorporeal membrane oxygenation-hemostatic complications

The use of extracorporeal membrane oxygenation (ECMO) support for cardiac and respiratory failure has increased in recent years. Improvements in ECMO oxygenator and pump technologies have aided this increase in utilization. Additionally, reports of successful outcomes in supporting patients with respiratory failure during the 2009 H1N1 pandemic and reports of ECMO during cardiopulmonary resuscitation have led to increased uptake of ECMO. Patients requiring ECMO are a heterogenous group of critically ill patients with cardiac and respiratory failure. Bleeding and thrombotic complications remain a leading cause of morbidity and mortality in patients on ECMO. In this review, we describe the mechanisms and management of hemostatic, thrombotic and hemolytic complications during ECMO support.