| Title | A comparison between two activated protein C resistance methods as routine diagnostic tests for factor V Leiden mutation. | | Author(s) | Aboud MR, Ma DD | | Institution | Department of Haematology, Royal North Shore Hospital, Sydney, N.S.W., Australia. | | Source | Br J Haematol 1997 Jun; 97(4):798-803. | | MeSH | Adult
Comparative Study
Factor V
Female
Humans
Lupus Coagulation Inhibitor
Male
Middle Aged
Mutation
Partial Thromboplastin Time
Protein C
Prothrombin Time
Research Support, Non-U.S. Gov't
Sensitivity and Specificity
Thrombosis
Warfarin
| | Abstract | The most common commercially available test measuring activated protein C (APC) resistance relies on the the anticoagulant response to added APC in an activated partial thromboplastin time (APTT) based method. Another method is a Russell Viper venom time (RVVT) based system. To improve the specificity for factor V Leiden of the APTT based method, pre-dilution of test plasma in FV-deficient plasma has recently been recommended. In this study we tested the relative suitabilities of the APTT-based system, the RVVT-based system and their corresponding assays modified by pre-dilution in FV-deficient plasma, for screening asymptomatic subjects, a group of thrombophilic patients (in particular those with low APC ratios), patients on oral anticoagulants, and patients with lupus anticoagulant (LAC). We found the RVVT-based assay to be superior to the APTT-based method in the separation of normals from those with FV Leiden mutation both in asymptomatic subjects and in the thrombophilic patient group. Both modified assays demonstrated a sensitivity and specificity of 100% for FV Leiden, as verified by genotyping in asymptomatic subjects, thrombophilic patients and patients on oral anticoagulants, with the modified RVVT-based assay giving better separation between normals and FV Leiden. Inhibition of phospholipid-dependent coagulation by LAC antibodies rendered the APTT-based system less suitable than the phospholipid-rich RVVT-based one, and as nine of the 20 LAC-positive patients were on warfarin, we showed only the modified RVVT assay to be a reliable predictor of factor V Leiden in this patient group. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 9217178 |
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