Classification of VWD: major types and subtypes
| Type . | Characteristic . |
|---|---|
| 1 | Quantitative decrease in VWF with preserved ratios between VWF/Ag, VWF/Act, and FVIII; normal multimer distribution |
| 1C | Quantitative decrease in VWF with preserved ratios between VWF/Ag, VWF/Act, and FVIII; increased VWF/pp compared with VWF/Ag |
| 2A | Decreased platelet-dependent VWF activity with loss of high-molecular-weight multimers |
| 2M | Decreased platelet-dependent VWF activity with preserved multimer pattern |
| 2N | Decreased binding of FVIII |
| 2B | Increased binding to GPIbα, often leading to thrombocytopenia |
| 3 | Absence or near absence of VWF |
| Platelet-type VWD | Functional defect of platelet GPIbα, leading to excessive binding of platelets and VWF and subsequent thrombocytopenia and loss of high-molecular-weight multimers |
| Acquired von Willebrand syndrome | Decreased VWF and particularly loss of high-molecular-weight multimers as a result of either shearing from mechanical forces (eg, aortic stenosis resulting in Heyde syndrome), adsorption on tumors (eg, Waldenström macroglobulinemia or Wilms’ tumors), or autoimmune inhibitor formation |
| Type . | Characteristic . |
|---|---|
| 1 | Quantitative decrease in VWF with preserved ratios between VWF/Ag, VWF/Act, and FVIII; normal multimer distribution |
| 1C | Quantitative decrease in VWF with preserved ratios between VWF/Ag, VWF/Act, and FVIII; increased VWF/pp compared with VWF/Ag |
| 2A | Decreased platelet-dependent VWF activity with loss of high-molecular-weight multimers |
| 2M | Decreased platelet-dependent VWF activity with preserved multimer pattern |
| 2N | Decreased binding of FVIII |
| 2B | Increased binding to GPIbα, often leading to thrombocytopenia |
| 3 | Absence or near absence of VWF |
| Platelet-type VWD | Functional defect of platelet GPIbα, leading to excessive binding of platelets and VWF and subsequent thrombocytopenia and loss of high-molecular-weight multimers |
| Acquired von Willebrand syndrome | Decreased VWF and particularly loss of high-molecular-weight multimers as a result of either shearing from mechanical forces (eg, aortic stenosis resulting in Heyde syndrome), adsorption on tumors (eg, Waldenström macroglobulinemia or Wilms’ tumors), or autoimmune inhibitor formation |
Act, activity; Ag, antigen; GPIbα, glycoprotein Ibα; pp, propeptide.