Pathophysiological mechanisms per type of VWD. (A) Scatter plots of FVIII:C/VWF:Ag (x-axis) vs VWFpp/VWF:Ag (y-axis) for type 1, 2A, 2B, 2M, and 2N VWD. Shown are patients with increased clearance (yellow), with reduced synthesis (purple), with a combination of both mechanisms (green), and absence of these pathophysiological mechanisms (white). Because of the FVIII binding defect in type 2N VWD, the FVIII:C/VWF:Ag ratio is low by definition and cannot be assessed reliably with respect to aspects of synthesis in type 2N. For a better presentation of the graphics, one type 1 VWD patient with a very high VWFpp/Ag ratio (33.7) and two type 1 VWD patients with high FVIII:C/VWF:Ag ratios (8.4 and 9.7) were omitted. (B) Proportion of VWD patients with increased clearance (yellow), reduced synthesis (purple), combination of increased clearance and reduced synthesis (green), and none of these mechanisms (white). X, not present.