Types of von Willebrand's Disease Based on Laboratory Test Findings

Description

Von Willebrand's Disease is caused by defects in von Willebrand's factor, which is a large and complex molecule. Different types of von Willebrand's disease have been identified based on the pattern of laboratory test abnormalities.

Laboratory Test Parameters:

(1) Factor 8 antigen in U/mL

(2) von Willebrand factor (vWF) antigen in U/mL

(3) ristocetin cofactor (RC) in U/mL

(4) ratio of ristocetin cofactor to von Willebrand factor antigen

(5) ristocetin-induced platelet aggregation

(6) von Willebrand factor antigen multimer analysis (small, intermediate and large sized multimers)

(7) thrombocytopenia

Major types identified:

(1) 1

(2) 2A

(3) 2B

(4) 2M

(5) 2N

(6) 3

(7) platelet type

(8) acquired

where:

• The half-life of factor 8 is reduced if not bound to von Willebrand's factor.

Test Results	Type 1	Type 2A	Type 2B
Factor 8 antigen	low	low	low or normal
vWF antigen	low	low	low or normal
ristocetin cofactor	low	very low	very low
ratio RC/vWF (mean value)	1	0.3	0.6
ristocetin induced platelet aggregation	low or normal	low	increased
vWF multimers	normal, or all sizes decreased	absent intermediate and large	absent large
thrombocytopenia	absent	normally absent	present

after Table 29-3, van Cott and Laposata (2001)

Test Results	Type 2M	Type 2N	coinherited Types 1 and 2N
Factor 8 antigen	low or normal	very low	low
vWF antigen	low	normal	low
ristocetin cofactor	very low	normal	low
ratio RC/vWF (mean value)	< 1	1	1
ristocetin induced platelet aggregation	low or normal	normal	low
vWF multimers	normal	normal	all sizes decreased
thrombocytopenia	absent	absent	absent
ratio factor 8 antigen to vWF antigen (mean)		0.28

Test Results	Type 3	Platelet Type	Acquired
Factor 8 antigen	very low	low or normal	low or very low
vWF antigen	undetectable	low or normal	low or very low
ristocetin cofactor	undetectable	very low	low or very low
ratio RC/vWF (mean value)	NA	< 1	<= 1
ristocetin induced platelet aggregation	very low	increased	low or very low
vWF multimers	all sizes absent	absent large	any
thrombocytopenia	absent	present	may be associated with underlying disease

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Description

Specialty

ICD-10