Sensitive detection of factor V Leiden gene

An independent study has concluded that American Diagnostica’s ACTICLOT® Protein C Resistance Assay clearly distinguishes between homozygous, heterozygous and non-carriers of the factor V Leiden (FVL) gene, reducing the need for molecular (PCR) testing. The assay, available from Axis-Shield UK, was evaluated by Dr Roger Luddington from the Department of Haemostasis at Addenbrooke’s Hospital in Cambridge. Samples from 38 patients were tested using the ACTICLOT assay and a second, unnamed assay. The study concluded that the ACTICLOT assay had the sensitivity to differentiate between homozygote and heterozygote carriers of the FVL gene. It showed improved sensitivity and specificity when compared to APTT-based techniques.

Protein C is a naturally occurring inhibitor of factor Va. In FVL, a single point mutation renders factor Va resistant to cleavage by activated protein C, increasing risk of thrombosis. This is the most common inherited form of thrombophilia.

The ACTICLOT protein C resistance assay contains a factor V dependent prothrombin activator, which is not calcium or phospholipid dependent and is therefore not affected by lupus anticoagulants. This is a distinct advantage with the high prevalence of lupus anticoagulant in the thrombophilic population.