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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 830
TestCode RCOF
TestName Ristocetin Aggregation
Synonyms Ristocetin activity; von Willebrand; RIPA; Ristocetin induced platelet aggregation
IsThisScreeningTest Yes
PubMedID PMID:18315614,11686101,17408405,20231421
NLMID:101518625,101539022
Comment - 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)
Sensitivity 81%*
Specificity 98%*
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