Utility of thrombin-generation assay in the screening of factor V G1691A (Leiden) and prothrombin G20210A mutations and protein S deficiency.
BACKGROUND
The thrombin-generation assay has a variety of clinical uses, including diagnosis of thromboembolism-related disease, and particular profiles are associated with thrombophilic risk factors. The aim of this study was to evaluate the use of this assay in screening and identifying patients who require specific thrombophilic testing.


METHODS
We used a 2-step approach to perform specific thrombophilic testing and thrombin-generation assays on 169 consecutive patients. The first step was to identify particular profiles of thrombin generation corresponding to each type of thrombophilic risk factor and to determine the pertinent variables related to thrombin generation. We then performed ROC curve analysis for each predefined variable to determine the relevant cutoffs for identification of patients in need of further testing (negative predictive value, 100%).


RESULTS
Suggestive profiles were seen in factor V Leiden (n = 49) and prothrombin (n = 12) mutations and in protein S deficiency (n = 12). ROC curves showed that factor V Leiden may be excluded when the difference between lag times obtained in the absence and presence of activated protein C (APC) is >1.5 min and that prothrombin G20210A may also be excluded when the peak thrombin concentration is <or=426 nmol/L. In addition, protein S deficiency may be excluded when the percentage of APC-induced endogenous thrombin potential inhibition is >63%.


CONCLUSIONS
The thrombin-generation assay represents a promising tool for screening thrombophilic risk factors, particularly in patients who are carriers of factor V Leiden or prothrombin G20210A mutations and patients with protein S deficiency.
Laboratoire d'Hématologie, Centre Hospitalaire et Régional, CHU, Robert Debré, Reims, France.
Nathalie
N
Hézard
Lobna
L
Bouaziz-Borgi
Marie-Geneviève
MG
Remy
Philippe
P
Nguyen
D000328:Adult; D005165:Factor V / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D018455:Protein S Deficiency / Q000097:blood / Q000175:diagnosis*; D011516:Prothrombin / Q000235:genetics*; D012372:ROC Curve; D012307:Risk Factors; D013917:Thrombin / Q000096:biosynthesis*; D019851:Thrombophilia / Q000175:diagnosis / Q000517:prevention & control
C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D013917:Thrombin