Testing for von Willebrand Disease Supplemental Data Figure 1. Testing for von Willebrand Disease Less then 10% or absent Factor VIII:C vWF:Ag vWF:RCo <10% vWF:CBA <10% Multimerics: loss of all Type III Normal (?) No further testing Decreased vWF:RCo Decreased Multimerics Analysis Probable Type I Normal vWF:CBA Relative decrease or loss of HWM vWF:CBA Normal Decreased Normal Decreased Multimerics: smeary pattern Multimerics: loss of HWM Probable Type I Probable Type II Likely Type IIM Likely Type IIA or IIB