The 80th anniversary of von Willebrand's disease: history, management and research

Phenotypic and genetic characterizations of the Milan cohort of von Willebrand disease type 2

von Willebrand disease (VWD) type 2 is caused by qualitative abnormalities of von Willebrand factor (VWF). This study aimed to determine the genotypic and phenotypic characterizations of a large VWD type 2 cohort from Milan. We included 321 patients (54% female) within 148 unrelated families from 1995 to 2021. Patients were fully characterized using laboratory phenotypic tests, and the genotypic diagnosis was confirmed by target genetic analysis using Sanger sequencing. Patients were diagnosed with type 2A (n = 98; 48 families), 2B (n = 85; 38 families), 2M (n = 112; 50 families), or 2N (n = 26; 12 families). Eighty-two unique VWF variants, including 8 novel variants, were found. The potential pathogenic effect of novel variants was assessed by in silico analysis. Most patients were heterozygous for a single variant (n = 259; 81%), whereas 37 cases (11%) had 2 variants (4 homozygous, 9 in trans, and 24 in cis). Twenty-five patients (8%) had ≥3 variants, mainly as a result of gene conversions. Among the 82 distinct variants identified, 5 different types, including missense (n = 64), gene conversion (n = 10), synonymous (n = 1), deletion (n = 4), and splice (n = 3), were observed. The results from this large cohort showed that VWD type 2 is invariably due to variants that do not prevent the synthesis of the protein, and a vast majority of patients (88%) had missense variants. Given the complexity of type 2 diagnosis and the necessity of performing several phenotypic tests, genetic analysis for patients suspected of having type 2 is beneficial to establish the correct diagnosis.

Directed Donation: Special Considerations and Review for Contemporary Clinical Practices

Background: Directed blood donation is defined as the donation of blood or its components for the purpose of transfusion into a specified individual. Directed blood donation holds historic significance, and although practices as of 2021 encourage voluntary, nonrenumerated blood donations, public interest in directed donation remains. Requests to discuss the risks and benefits of directed donations are a common inquiry for transfusion medicine, transplant, and hematology/oncology professionals. This narrative review discusses the history of directed donation and summarizes directed donation considerations in the context of modern transfusion practices. Methods: We conducted a systematic search of PubMed for published literature on the topic of directed blood donation and gathered information about its benefits and potential harms with respect to the variety of products used in transfusion medicine. Results: The drawbacks of directed donation include transfusion-transmitted infection risk, alloimmunization risk, increased transfusion-associated graft vs host disease risk, decreased expediency in treatment, and increased administrative burdens. However, a role remains for directed blood donation in specific patient populations, such as individuals with rare blood types or immunoglobulin A deficiencies, because of the difficulties in finding compatible blood for transfusion. Conclusion: Clinicians should consider the risks and benefits when discussing directed blood donations with patients and family members.

Translating the success of prophylaxis in haemophilia to von Willebrand disease

INTRODUCTION

There is limited awareness of von Willebrand disease (VWD), leading to challenges in both diagnosis and defining the optimal treatment approach for these patients. Patients with VWD are typically treated on-demand, with short-term prophylaxis used during surgery. In contrast, early initiation, and long-term use of prophylaxis is the standard of care in patients with severe haemophilia and can be successfully used to prevent joint bleeding and reduce chronic arthropathy.

AIM

To provide an understanding of the current evidence for the prophylactic treatment of patients with VWD and compare this to the management of patients with haemophilia.

METHODS

Review of published literature using a non-systematic search of PubMed and reference lists of sourced articles.

RESULTS

The successes seen with prophylaxis in haemophilia provide the rationale for long-term prophylaxis in patients with severe forms of VWD; preventing spontaneous, excessive and sometimes life-threatening bleeding, and reducing chronic joint disease. Currently, there are a few clinical trials assessing the long-term benefits of prophylaxis in VWD, and guidelines for the optimal prophylaxis treatment approach are lacking. Greater attempts to provide comprehensive, long-term care for patients with VWD are needed but still lacking within the community. This review highlights the success of prophylaxis in haemophilia and how this knowledge might be applied and translated to patients with VWD.

CONCLUSIONS

Lessons can be learned from the use of prophylaxis in haemophilia and prophylaxis should be considered the standard of care for a subgroup of patients with severe VWD.

Screening of von Willebrand disease in Iranian women with menorrhagia

Background:

Menorrhagia is a common health problem in women, particularly those with bleeding disorders. Little is known about the course of menorrhagia or other bleeding symptoms in women with the most common congenital bleeding disorder, von Willebrand disease (vWD).

Objectives:

The aim of this study was to estimate the prevalence of vWD in women with diagnosed menorrhagia.

Materials and Methods:

In this cross-sectional study, a total of 460 consecutive patients, presenting menorrhagia, were analyzed. The initial screening and confirmation tests for the diagnosis of vWD included determination of prothrombin time (PT), partial thromboplastin time (PTT), bleeding time (BT), fibrinogen, factor VIII, vWF antigen, and vWF activity. A questionnaire was filled for every patient. The data were then analyzed using the SPSS software.

Results:

Mean age of our patients was 32.5 ± 10.6 years. The level of von Willebrand factor in 22.5% and von Willebrand activity in 19.6% of patients was abnormal. The prevalence of vWD among patients with menorrhagia was 24%.

Conclusions:

The high prevalence of vWD among our patients was the same as other previous reports, suggesting low awareness about this disease and under diagnosis of mild cases.

Historical perspective and future directions in platelet research

Platelets are a remarkable mammalian adaptation that are required for human survival by virtue of their ability to prevent and arrest bleeding. Ironically, however, in the past century, the platelets' hemostatic activity became maladaptive for the increasingly large percentage of individuals who develop age-dependent progressive atherosclerosis. As a result, platelets also make a major contribution to ischemic thrombotic vascular disease, the leading cause of death worldwide. In this brief review, I provide historical descriptions of a highly selected group of topics to provide a framework for understanding our current knowledge and the trends that are likely to continue into the future of platelet research. For convenience, I separate the eras of platelet research into the "Descriptive Period" extending from ~1880-1960 and the "Mechanistic Period" encompassing the past ~50 years since 1960. We currently are reaching yet another inflection point, as there is a major shift from a focus on traditional biochemistry and cell and molecular biology to an era of single molecule biophysics, single cell biology, single cell molecular biology, structural biology, computational simulations, and the high-throughput, data-dense techniques collectively named with the "omics postfix". Given the progress made in understanding, diagnosing, and treating many rare and common platelet disorders during the past 50 years, I think it appropriate to consider it a Golden Age of Platelet Research and to recognize all of the investigators who have made important contributions to this remarkable achievement..

Prophylaxis of bleeding episodes in patients with von Willebrand's disease

Patients with severe forms of von Willebrand's disease (VWD) may have frequent haemarthroses, especially when factor VIII (FVIII) levels are below 10 U/dL, so that some of them develop target joints like patients with severe haemophilia A. Some patients have recurrent gastrointestinal bleeding, often without lesions in the gastrointestinal tract, and need treatment every day or every other day. Finally, there are children who have epistaxis frequently and severely enough to cause anaemia. In these frequent and severe bleeders, the optimal therapy may be secondary long-term prophylaxis with von Willebrand factor (VWF)/FVIII concentrates rather than on-demand treatment on the occasion of bleeding episodes. The largest experience on such prophylaxis in VWD has been in Sweden in 35 patients with severe forms of VWD. Long-term prophylaxis was also implemented in a cohort of Italian patients with VWD: prophylaxis was used in seven patients with types 3 (n = 1 ), 2A (n = 4), 2M (n = 1) and type 1 (n = 1) VWD because of recurrent gastrointestinal bleeds and in four patients with type 3 VWD because of joint bleeds. Prophylaxis prevented bleeding completely in eight patients and largely reduced hospitalisation for blood transfusions in the remaining three. The cost-effectiveness of these prophylaxis regimens versus on-demand therapy will now be investigated in one large international study

Highly purified VWF/FVIII concentrates in the treatment and prophylaxis of von Willebrand disease: the PRO. WILL Study

Two therapeutic approaches are available to manage patients with von Willebrand disease (VWD): (i) the release of endogenous von Willebrand factor (VWF) from endothelial compartments induced by desmopressin (DDAVP); (ii) the transfusion of exogenous VWF contained in VWF/FVIII plasma-derived concentrates. Only a few high-purity VWF/FVIII concentrates have been extensively evaluated in pharmacokinetic (PK) trials as well as in retrospective or prospective efficacy studies in VWD. The Alphanate Study Group published results of PK and clinical efficacy studies in 2002. Efficacy results showed that 75% of bleeding episodes were controlled with one or two infusions, and 71% of patients who received prophylactic treatment for surgeries or invasive procedures had good clinical responses. In another retrospective study, 22 VWD patients in Italy received Fanhdi, a VWF concentrate similar to Alphanate. Excellent-good clinical responses were seen in 92% of bleeding episodes and in 93% of surgical procedures. More recently, the efficacy and safety of Fanhdi have been evaluated retrospectively in a larger cohort of Italian patients (n = 103) with 97% (bleedings) and 99% (surgeries) of excellent/good clinical responses. The largest experience on secondary prophylaxis in VWD has been collected in Sweden in 35 patients with severe forms of VWD. Secondary prophylaxis was also implemented in a cohort of Italian patients with VWD. Prophylaxis was started because of GI bleeds in seven patients with types 3 (n = 1), 2A (n = 4), 2M (n = 1) and type 1 (n = 1) and for joint bleeds in four patients with type 3 VWD (n = 4). Prophylaxis prevented bleeding completely in eight patients and largely reduced hospitalization for blood transfusions in the remaining three. The cost-effectiveness of these prophylaxis regimens versus on demand therapy will be now investigated in one large prospective study (PRO.WILL) organized in Italy.

Management of inherited von Willebrand disease in 2007

Von Willebrand disease (VWD) is the most frequent inherited bleeding disorder and is due to quantitative (types 1 and 3) or qualitative (type 2) defects of von Willebrand factor (VWF). VWD is inherited by autosomal dominant or recessive patterns, but women with mild forms are more symptomatic. VWD is classified in six VWD types (1, 2A, 2B, 2M, 2N, 3) with peculiar phenotype and genotype. The ristocetin cofactor activity (VWF:RCo) is the most useful test for VWD diagnosis, because it can mimic the interactions of VWF with its platelet receptor. Knowledge of the segments of VWF involved in the binding to its receptor and to factor VIII prompted the search for mutations in specific exons of the VWF gene, with mutations causing VWD types 2A, 2B, 2M, 2N localized in exons 18-28. In case of VWD types 1 and 3 the mutations are spread within the entire gene. Desmopressin (DDAVP) is the treatment of choice for type 1 VWD because it can induce release of normal VWF from cellular compartments. In type 3 and in severe forms of types 1 and 2 VWD, DDAVP is not effective and plasma virally inactivated VWF concentrates should be used in bleedings, surgery, and secondary long-term prophylaxis.