von Willebrand Factor Antigen

What the laboratory says this test is for

This panel may be used to screen for bleeding disorders in patients with abnormal uterine bleeding (AUB; formerly called menorrhagia). It includes initial laboratory evaluation of the 2 most common bleeding disorders affecting women: von Willebrand disease (VWD) and coagulation factor XI deficiency [1].AUB is classified into 9 categories based on cause per the PALM-COEIN system: polyp, adenomyosis, leiomyoma, malignancy and hyperplasia, coagulopathy, ovulatory dysfunction, endometrial disorders, latrogenic, and not otherwise classified [2]. The International Federation of Gynecology and Obstetrics (FIGO) recommends using systems for nomenclature and symptoms (System 1) and for classification of potential causes of AUB in the reproductive years (System 2) to guide clinical investigation of AUB [2].Screening for coagulopathy in patients with AUB starts with a structured history. Specific coagulopathy tests and consultation with a hematologist are appropriate in patients with a relevant history [2]. Testing for VWF antigen, ristocetin cofactor, and factor VIII activity is recommended for initial diagnosis of VWD [3]. Additional tests may be needed to determine VWD subtypes. A factor XI activity test can identify a congenital factor XI deficiency; when an inhibitor pattern is observed, this test may help identify an acquired factor XI inhibitor. Factor XI specific inhibitors may be quantitated using a Bethesda assay (test code 17854).The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. NORD. Factor XI Deficiency. Accessed April 7, 2023. https://rarediseases.org/rare-diseases/factor-xi-deficiency/2. Munro MG, et al; FIGO Menstrual Disorders Committee. Int J Gynaecol Obstet. 2018;143(3):393-408.3. Higgins RA, et al. Platelets and van Willebrand factor. In: Rifai R, et al, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.

What the laboratory says this test is for

This panel may be used to help diagnose von Willebrand disease (VWD) and categorize disease subtype.von Willebrand factor (VWF) is a blood coagulation protein that has 2 functions: (1) mediating platelet adhesion to the injured endothelium and (2) acting as a protective carrier protein for coagulation factor VIII. Deficiency of VWF causes VWD, the most common inherited bleeding disorder that affects approximately 1 in 1,000 individuals at the primary care level [1]. VWD is classified into type 1 (quantitative deficiency of VWF), type 2 (qualitative deficiency of VWF), and type 3 (total absence of VWF). Different types of VWD are further categorized into subtypes, identification of which is important to inform prognosis and treatment decisions.Three tests are recommended for initial diagnosis of VWD [2]: VWF antigen, platelet-dependent VWF activity (eg, ristocetin cofactor), and factor VIII activity. Additional tests may be needed to further identify the subtype of VWD. VWF multimer analysis is also included in this panel and is useful for discriminating between VWD type 2M from 2A/2B and platelet-type VWD [1].Test results of acquired von Willebrand syndrome (AVWS) may be similar to those of congenital VWD [1, 2]. However, patients with AVWS do not have a family history of bleeding or a personal life-long history of bleeding. Conditions associated with AVWS include lymphoproliferative disorders, monoclonal gammopathy of undetermined significance, Wilms tumor expressing GPIb, myeloproliferative disorders, aortic stenosis, ventricular assist devices, and hypothyroidism.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. James PD, et al. Blood Adv. 2021;5(1):280-300.2. Higgins RA, et al. Platelets and van Willebrand factor. In: Rifai R, et al, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.

What the laboratory says this test is for

This test may be used to help diagnose von Willebrand disease (VWD) and categorize disease subtype.von Willebrand factor (VWF) is a blood coagulation protein that has 2 functions: (1) mediating platelet adhesion to the injured endothelium and (2) acting as a protective carrier protein for coagulation factor VIII. Deficiency of VWF causes VWD, the most common inherited bleeding disorder that affects approximately 1 in 1,000 individuals at the primary care level [1]. VWD is classified into type 1 (quantitative deficiency of VWF), type 2 (qualitative deficiency of VWF), and type 3 (total absence of VWF). Different types of VWD are further categorized into subtypes, identification of which is important to inform prognosis and treatment decisions.Three tests are recommended for initial diagnosis of VWD [2]: VWF antigen, platelet-dependent VWF activity (eg, ristocetin cofactor), and factor VIII activity. Additional tests may be needed to further identify the subtype of VWD. VWF multimer analysis and collagen binding activity are included in this panel and are useful to discriminate between VWD subtype 2A/2B from 2M and rare forms of 2M [1].Test results of acquired von Willebrand syndrome (AVWS) may be similar to those of congenital VWD [1, 2]. However, patients with AVWS do not have a family history of bleeding or a personal life-long history of bleeding. Conditions associated with AVWS include lymphoproliferative disorders, monoclonal gammopathy of undetermined significance, Wilms tumor expressing GPIb, myeloproliferative disorders, aortic stenosis, ventricular assist devices, and hypothyroidism.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. James PD, et al. Blood Adv. 2021;5(1):280-300.2. Higgins RA, et al. Platelets and van Willebrand factor. In: Rifai R, et al, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.

What the laboratory says this test is for

von Willebrand Disease is the most common hereditary bleeding disorder; it may also be acquired. von Willebrand Factor is necessary for platelet adhesion to injured endothelium. von Willebrand Factor Antigen is useful in assessing the quantity of von Willebrand Factor. When combined with other tests, results are useful in categorizing the type of von Willebrand Disease.

What the laboratory says this test is for

This test may be used for initial evaluation of individuals with clinical suspicion of von Willebrand disease (VWD).von Willebrand factor (VWF) is a blood coagulation protein that has 2 functions: (1) mediating platelet adhesion to the injured endothelium and (2) acting as a protective carrier protein for coagulation factor VIII. Deficiency of VWF causes VWD, the most common inherited bleeding disorder that affects approximately 1 in 1,000 individuals at the primary care level [1]. VWD is classified into type 1 (quantitative deficiency of VWF), type 2 (qualitative deficiency of VWF), and type 3 (total absence of VWF). Different types of VWD are further categorized into subtypes, identification of which is important to inform prognosis and treatment decisions.Three tests are recommended for initial diagnosis of VWD [2]: VWF antigen, platelet-dependent VWF activity (eg, ristocetin cofactor), and factor VIII activity. Additional tests may be needed to further identify the subtype of VWD.Test results of acquired von Willebrand syndrome (AVWS) may be similar to those of congenital VWD [1, 2]. However, patients with AVWS do not have a family history of bleeding or a personal life-long history of bleeding. Conditions associated with AVWS include lymphoproliferative disorders, monoclonal gammopathy of undetermined significance, Wilms tumor expressing GPIb, myeloproliferative disorders, aortic stenosis, ventricular assist devices, and hypothyroidism.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. James PD, et al. Blood Adv. 2021;5(1):280-300.2. Higgins RA, et al. Platelets and van Willebrand factor. In: Rifai R, et al, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.