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Clinical Question: Does my patient have von Willebrand disease? If so, which type?

Item Value
ID 9
Question Does my patient have von Willebrand disease? If so, which type?
AlgorithmLink Click here for algorithm
AlgorithmDescription vWD
- asymptomatic abnormalities of vWF are present in up to ~1% of people
- prevalence of symptomatic vWD is ~1 in 8000 (between 1 in 3000-10000)
- primary symptom of vWD is mucocutaneous bleeding

vWD classification:
- type 1 = partial quantitative defect in vWF
- type 2 = qualitative defect in vWF
- type 3 = complete quantitative defect in vWF

notes:
- vWF may be elevated in many situations (neonatal period, pregnancy, inflammatory states, post-surgery, among others), which could potentially mask mild type 1 disease; in such settings, repeat testing to exclude vWD may be appropriate
- if initial vWD testing is abnormal, strongly consider repeat testing for confirmation and/or Hematology referral"

Please call the hematology laboratory medicine resident at 353-1614 with any questions about this algorithm.
ICD10 D68.0,D68.9,D69.6,D69.9,R23.3
PubMedID PMID:16634745,11686101,17596142,18805962,20231421,17786534,17408405,16961623,18983516,22431572,19506352,19687512,18315614,16246252,16634760,19214910,16862528,20590859
NLMID:101518625,101539022,101595235

 

Tests associated with this clinical question:

Click on the test name for more information about the use of this test to answer this clinical question

ID Test Code Test Name Comment
44 PT Prothrombin Time - does not detect vWD
- useful as a general screen for disorders of coagulation
- consider other diagnoses if prolonged
45 PTT Activated Partial Thromboplastin Time - prolongation is neither sensitive nor specific for vWD, although prolongation may be a feature of vWD (in particular, severe type 1 as well as types 2N and 3)
- consider other diagnoses in addition to vWD if prolonged
46 CBC Complete Blood Count (includes Platelet Count) - thrombocytopenia is neither sensitive nor specific for vWD, although thrombocytopenia may be a feature of vWD (in particular, type 2B and platelet-type)
- consider other diagnoses in addition to vWD if thrombocytopenic
48 PFA100 Platelet Function Analysis (PFA-100) - insufficiently sensitive/specific for vWD (particularly for mild disease)
- not recommended for vWD screening
49 VWFAG von Willebrand Factor Antigen - measurement of amount of vWF protein in patient plasma
- normal in roughly 20% of people with vWD (particularly in type 2B disease)
- ideally, ordered as part of von Willebrand panel (VWP, 1006)

* sensitivity/specificity depend on cutoff (above values are for 2.5th percentile, roughly 50 IU/dL)
50 RCOF Ristocetin Cofactor Activity - measurement of vWF function in patient plasma
- exon 28 SNPs identified in African-American population may decrease ristocetin cofactor activity but do not contribute to clinical bleeding
- ideally, ordered as part of von Willebrand panel (VWP, 1006)

* sensitivity/specificity depend on cutoff (above values are for 2.5th percentile, roughly 50 IU/dL)
70 F8 Factor 8 Activity - vWF binds to F8 and protects it from degradation in plasma
- F8 activity is decreased in many types of vWD and is complementary to vWF antigen levels
- ideally, ordered as part of von Willebrand panel (VWP, 1006)
71 VWMULT von Willebrand Factor Multimers - vWF circulates in plasma as a series of multimers of variable size
- multimer analysis detects changes in the size distribution of plasma multimers (a qualitative abnormality)
72 RIST Ristocetin Aggregation - aggregation to low-dose ristocetin suggests enhanced interaction between vWF and platelet GP1b receptor
- performance with washed patient platelets and normal plasma may provide phenotypic distinction between vWD type 2B from platelet-type vWD
73 VW2NR von Willebrand Factor - Factor 8 Binding Ratio - decreased vWF-F8 binding ratio suggests defective interaction between vWF and F8
- useful in distinguishing hemophilia A (including carrier states) from vWD type 2N
74 MOLT Misc. Outside Laboratory Test vWF-collagen binding assay, sent to Quest
- detects rare 2M variants with defective vWF-collagen binding (not detected by any other assays)
- does not replace RCOF (vWF-collagen binding assay is insensitive to other 2M mutations)
75 MOLT Misc. Outside Laboratory Test VWF exon 28 gene analysis, sent to Blood Center of Wisconsin
"- in combination with GP1BA sequencing, VWF exon 28 gene analysis accurately distinguishes vWD type 2B from platelet-type vWD
- exon 28 sequencing may also be useful in challenging cases of type 2 disease (detects most 2B and 2M mutations)"
76 MOLT Misc. Outside Laboratory Test GP1BA gene analysis
- in combination with VWF exon 28 sequencing, GP1BA gene analysis accurately distinguishes vWD type 2B from platelet-type vWD
- exon 28 sequencing may also be useful in challenging cases of type 2 disease (detects most 2B and 2M mutations)

 

Clinical Algorithm:

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