Molecular and clinical profile of type 2 von Willebrand disease in Iran: a thirteen-year experience.

Type 2 von Willebrand disease (VWD) is the most common congenital bleeding disorder, with variable bleeding tendency and a complex laboratory phenotype. In the current study, we report the clinical and molecular profile of a large number of Iranian patients with type 2 VWD. All exons, intron-exon boundaries, and untranslated regions were sequenced by Sanger sequencing for direct mutation detection. All identified mutations were confirmed in family members and by relevant bioinformatics studies. A total of 136 patients with type 2 VWD were diagnosed, including 42 (30.9%), 32 (23.6%), 38 (27.9%), and 24 (17.6%) patients with type 2A, type 2B, type 2M, and type 2N, respectively. Epistaxis (49%), gum bleeding (30.2%), ecchymosis (23.2%), and menorrhagia (16.3%) were the most common clinical presentations, while miscarriage (2.3%) and umbilical cord bleeding (0.8%) were the rarest. Thirty mutations were identified within the VWF gene, nine (30%) being novel, with p.Arg1379Cys (n = 20), p.Val1316Met (n = 13), p.Arg1597Trp (n = 13), p.Arg1374Cys (n = 10), p.Ser1506Leu (n = 10), and p.Arg1308Cys (n = 9) the most common. Type 2 VWD is a hemorrhagic disorder with variable bleeding tendency and a heterogeneous molecular basis in patients in Iran.

Relevance of platelet desialylation and thrombocytopenia in type 2B von Willebrand disease: preclinical and clinical evidence.

Patients with type 2B von Willebrand disease (vWD) (caused by gain-of-function mutations in the gene coding for von Willebrand factor) display bleeding to a variable extent and, in some cases, thrombocytopenia. There are several underlying causes of thrombocytopenia in type 2B vWD. It was recently suggested that desialylation-mediated platelet clearance leads to thrombocytopenia in this disease. However, this hypothesis has not been tested in vivo The relationship between platelet desialylation and the platelet count was probed in 36 patients with type 2B von Willebrand disease (p.R1306Q, p.R1341Q, and p.V1316M mutations) and in a mouse model carrying the severe p.V1316M mutation (the 2B mouse). We observed abnormally high elevated levels of platelet desialylation in both patients with the p.V1316M mutation and the 2B mice. In vitro, we demonstrated that 2B p.V1316M/von Willebrand factor induced more desialylation of normal platelets than wild-type von Willebrand factor did. Furthermore, we found that N-glycans were desialylated and we identified αIIb and ß3 as desialylation targets. Treatment of 2B mice with sialidase inhibitors (which correct platelet desialylation) was not associated with the recovery of a normal platelet count. Lastly, we demonstrated that a critical platelet desialylation threshold (not achieved in either 2B patients or 2B mice) was required to induce thrombocytopenia in vivo In conclusion, in type 2B vWD, platelet desialylation has a minor role and is not sufficient to mediate thrombocytopenia.

The course of acquired von Willebrand syndrome during pregnancy among patients with essential thrombocytosis.

To investigate the course of acquired type 2A von Willebrand syndrome (AVWS) in relation to patient management and outcomes among pregnant patients with essential thrombocytosis (ET). A review of pregnant women with ET evaluated for AVWS at the beginning of pregnancy and at the third trimester. Eighteen women with 24 pregnancies were included in this study. A history of bleeding was noted in 8 (44%) patients. In 20 (83%) pregnancies AVWS was evident at the initial testing. Following initial testing, antithrombotic therapy was administered in 22 (92%) pregnancies (aspirin, n = 20 and low-molecular-weight heparin, n = 2). In the remaining two pregnancies, VWF:RCo levels were below 30%; thus, aspirin was given only after repeat testing at 14-16 weeks. At third trimester testing, median VWF:RCo levels were significantly higher than at the initial testing (86 vs. 48%, P < 0.001), with no evidence of AVWS in any of the patients. Significant increases were also observed in the VWF:Ag level (127 vs. 84%, P < 0.001), the VWF:RCo/VWF:Ag ratio (0.75 vs. 0.54, P < 0.001) and the FVIII level (103 vs. 68%, P < 0.001); while platelet count (359 vs. 701 × 109/l, P < 0.001) and hemoglobin level (11.6 vs. 13.4 g/dl, P < 0.001) decreased. Neuraxial anesthesia was safely performed in 17 (71%) pregnancies. No significant bleeding events occurred during pregnancy and delivery. AVWS-related abnormalities in women with ET mostly improved during pregnancy, with favorable maternal and fetal outcomes. VWF parameters should be tested at early pregnancy and repeated at the third trimester, to guide pregnancy and delivery management.

Is gingival bleeding a symptom of type 2 and 3 von Willebrand disease?

BACKGROUND: Von Willebrand disease (VWD) is the most common inherent bleeding disorder. Gingival bleeding is a frequently reported symptom of VWD. However, gingival bleeding is also a leading symptom of plaque-induced gingivitis and untreated periodontal disease. In type 1 VWD gingival bleeding was not increased compared to controls. Thus, this study evaluated whether type 2 and 3 VWD determines an increased susceptibility to gingival bleeding in response to the oral biofilm. METHODS: Twenty-four cases and 24 controls matched for age, sex, periodontal diagnosis, number of teeth and smoking were examined hematologically (VWF antigen, VWF activity, factor VIII activity) and periodontally (Gingival Bleeding Index [GBI]), bleeding on probing [BOP], Plaque Control Record [PCR], periodontal inflamed surface area [PISA], vertical probing attachment level). RESULTS: BOP (VWD: 14.5±10.1%; controls: 12.3±5.3%; p = 0.542) and GBI (VWD: 10.5±9.9%; controls: 8.8±4.8%; p = 0.852) were similar for VWD and controls. Multiple regressions identified female sex, HbA1c, PCR and PISA to be associated with BOP. HbA1c and PCR were associated with GBI. Number of remaining teeth was negatively correlated with BOP and GBI. CONCLUSION: Type 2 and 3 VWD are not associated with a more pronounced inflammatory response to the oral biofilm in terms of BOP and GBI.

Type 2B von Willebrand Disease: An Unusual Cause of Severe Neonatal Thrombocytopenia.

An infant with presumed maternal immune thrombocytopenic purpura had persistent thrombocytopenia with platelet clumping. The patient had no significant bleeding symptoms in the first year of life and von Willebrand antigen and ristocetin cofactor activity were normal. Absent high molecular weight multimers ultimately led to a genetically proven diagnosis of type 2B von Willebrand disease (3964G>A VWF exon 28), highlighting the challenges of establishing this diagnosis in infants.

Use of a thrombopoietin receptor agonist in von Willebrand disease type 2B (p.V1316M) with severe thrombocytopenia and intracranial hemorrhage.

We present here a 63-year old woman with a long history of immune thrombocytopenia. She was hospitalized for a traumatic intracranial hemorrhage with thrombocytopenia. Following inefficient treatment of four platelet transfusions, immunoglobulins, and corticosteroids, we initiated treatment with a thrombopoietin (TPO) receptor agonist (eltrombopag 25 mg/d) with a good efficacy. Her mother and sister also had chronic thrombocytopenia. Clinical history, hemostasis results, and gene analysis revealed von Willebrand disease (VWD) type 2B with the mutation (c.3946G>A; p.V1316M), which combines a von Willebrand factor defect with severe thrombocytopenia, as well as a thrombocytopathy. The efficacy of TPO receptor agonists appears to counterbalance, at least to some extent, the thrombocytopathy associated with this mutation. As such, the use of TPO receptor agonists could represent an alternative therapeutic approach in cases of VWD type 2B with severe thrombocytopenia.

How I treat type 2 variant forms of von Willebrand disease.

Type 2 von Willebrand disease (VWD) includes a wide range of qualitative abnormalities of von Willebrand factor structure and function resulting in a variable bleeding tendency. According to the current classification, 4 different subtypes can be identified, each with distinctive phenotypic and therapeutic characteristics. Current available laboratory methods allow a straightforward approach to VWD subtyping, and although the precise molecular characterization remains complex, it is not required for appropriate treatment of the vast majority of cases. Desmopressin can be useful only in a few type 2 cases compared with patients with actual quantitative deficiency (type 1), most often in variants with a nearly normal multimeric pattern (type 2M). However, since no laboratory test accurately predicts response to desmopressin, a trial test should always be performed in all type 2 VWD patients, with the exception of type 2B ones. Replacement therapy with plasma-derived von Willebrand factor-factor VIII concentrates represents the safe mainstay of treatment of all patients, particularly those not responding to desmopressin or requiring a sustained hemostatic correction because of major surgery or bleeding. A significant patient bleeding history correlates with increased bleeding risk and should be considered in tailoring the optimal antihemorrhagic prophylaxis in the individual patient.

Life-threatening bleeding in a patient with mild hemophilia A and heterozygosity for von Willebrand disease Type 2N.

Hemophilia A and von Willebrand disease (VWD) are distinct bleeding disorders with a spectrum of clinical phenotypes. They are characterized by mutations in either factor VIII (F8) or von Willebrand factor (VWF) genes, respectively. The pattern of inheritance and appropriate laboratory evaluation differentiates these diseases, and treatment strategies for both are different. Here, we report a male patient with hemophilia A and VWD Type 2 Normandy (N) mutations who presented with life-threatening bleeding. We document his medical history, clinical course, management, and diagnostic work up.

Co-inheritance of mild hemophilia A and heterozygosity for type 2N von Willebrand disease: a diagnostic and therapeutic challenge.

Hemophilia A and von Willebrand disease are the two most common inherited bleeding disorders. Despite their frequency, however, there are very few reports of co-inheritance of the two disorders. We present the first report of a patient with mild hemophilia A and heterozygosity for type 2N von Willebrand disease (VWD). We discuss the patient's phenotype and highlight the diagnostic and therapeutic challenges caused by this co-inheritance.

Spectrum of Von Willebrand's disease in Punjab: clinical features and types.

BACKGROUND: Von Willebrand's disease (VWD) is a common inherited bleeding disorder caused by quantitative deficiency (Type-1 & Type-3 VWD) or qualitative defect of Von Willebrand's Factor (Type-2 VWD). Regarding VWD limited studies are available in Pakistan. The current study was aimed to determine the clinical presentation and frequency of types of VWD. METHODS: A cross sectional study was carried out from 16th December 2012 to 15th December 2013 on fifty one patients of VWD. RESULTS: Patients were diagnosed on the basis of prolonged bleeding time, abnormal APTT, reduced level of VWF: Ag, FVIII, VWF: RCo and ratio of VWF: RCo/VWF Ag. Among them 26 (50.98%) were male and 25 (49.02%) were female. Type3 VWD (94.12%) was found to be the commonest type. Two (3.92%) cases of type-2 VWD and only one (1.96%) case of type-1 VWD were identified. Easy bruising was the most commonly observed clinical presentation, 21 (41.18%) patients, followed by epistaxis 7 (13.73%), gum bleed 4(7.84%) menorrhagia 5(9.80%), haemarthosis 2(3.92%), haematoma formation 5 (9.80%), bleeding after circumcision 2 (3.92%), bleeding after surgery 2 (3.92%) and umbilical cord bleeding 3 (5.88%). Consanguineous marriages were reported in parents of 42 (82.4%) patients. Family history of bleeding disorder was reported in 44 (86.27%) of cases. CONCLUSION: Type-3 VWD was found to be the commonest type which can be attributed to the fact that type-3 VWD is transmitted through autosomal recessive pattern of inheritance and consanguineous marriages are highly practiced in our society leading to high frequency of this form of VWD. Easy bruising and epistaxis were concluded to be the most common clinical presentation. Menorrhagia was found to be common in the females of child bearing age.