Activated protein C resistance assay detects thrombotic risk factors other than factor V Leiden

作者：Graf LL; Welsh CH; Qamar Z; Marlar RA^*

来源：American Journal of Clinical Pathology, 2003, 119(1): 52-60.

DOI：10.1092/LX9E6Y043P58YVCL

• activated protein C resistance
• case-control study
• factor V Leiden
• factor VIII
• HR2 haplotype
• venous thromboembolism

Activated protein C (APC) resistance is a common risk factor for venous thromboembolism (VTE) attributed to various mechanisms, including factor V Leiden (FVL) polymorphism. FVL is considered responsible for up to 95% of APC resistance; however, other factor V polymorphisms and elevated factor VIII levels also have been implicated.
We assessed whether additional mechanisms contribute to APC resistance in a blinded case-control study of 65 subjects by measuring APC resistance using 3 methods: 2 activated partial thromboplastin time-based methods with and without dilution in factor V-deficient plasma and I Russell viper venom-based assay (RVV). Without factor V-deficient plasma, 24 subjects were APC resistant; with factor V-deficient plasma, the assay identified fewer APC-resistant subjects, as did RVV All assays detected the 7 heterozygous FVL subjects. Thirteen subjects had factor VIII levels above 150% (1.50). After excluding subjects with FVL or elevated factor VIII levels, 4 subjects still had APC resistance. VTE risk trended higher for subjects with APC resistance in the absence of FVL. Measurement of APC resistance without dilution in factor V-deficient plasma is needed to assess for potentially important, thrombotic risk factors other than FVL.

• 出版日期2003-1