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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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Item Value
ClinicalQuestion Does my patient have von Willebrand disease? If so, which type?
TestEntryNumber 1004
TestCode VWFAG
TestName Activated Partial Thromboplastin Time
Synonyms PTT; aPTT; Monitoring Anticoagulation; Monitoring heparin
IsThisScreeningTest Yes
PubMedID PMID:18315614,11686101,17408405
Comment - 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)
Sensitivity 80%*
Specificity 98%*
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