Diagnostic laboratory criteria for each type of von Willebrand disease
| Type Subtype | VWD type 1 | VWD type 2 | VWD type 3 | ||||
|---|---|---|---|---|---|---|---|
| Classic | 1C | 2A | 2B | 2M | 2N | ||
| Ratio of VWF activity to VWF antigen | Normal (about 1) | < 0.6 | Markedly low or undetectable VWF activity and antigen levels | ||||
| Factor VIII levels | Normal or mildly low | Normal or mildly low | Normal or mildly low | Normal or mildly low | Normal or mildly low | Moderately low relative to VWF antigen | Very low |
| VWF multimer analysis | Full spectrum of multimers, but all at low level | Full spectrum of multimers, but all at low level | Absence of high- and intermediate-molecular-weight multimers | Absence of high-molecular-weight multimers | Normal multimer pattern | Normal multimer pattern | Minimal or complete absence of VWF multimers |
| Specific testing to diagnose subtype | None | Elevated ratio of VWF propeptide to VWF antigen > 30% decrease in VWF 4 hours after infusion of desmopressin | Genetic testing | Increased ristocetin-induced platelet aggregation Sensitivity to low-dose ristocetin Genetic testing | Decreased ristocetin-induced platelet aggregation Low VWF-collagen binding capacity Genetic testing | Decreased binding of VWF to factor VIII Prolonged partial thromboplastin time Genetic testing | None |
VWD = von Willebrand disease; VWF = von Willebrand factor
Data adapted from reference 13.