Comparison of Russell viper venom-based and activated partial thromboplastin time-based screening assays for resistance to activated protein C.
Thrombotic disease is a significant cause of mortality and morbidity, with an estimated lifetime risk of greater than 10% in Western populations. One of the most common hereditary thrombophilias is the factor V Leiden mutation, which is identified with a screening assay for activated protein C (APC) resistance and confirmed by DNA analysis. In this study, we compared the commercially available Pefakit (Pentapharm, Basel, Switzerland) and Cryocheck (Precision BioLogic, Dartmouth, Canada) assays, 2 recently developed Russell viper venom (RVV)-based screening tests, with the activated partial thromboplastin time (aPTT)-based screening test currently used in our hospital's clinical laboratory. We found that the aPTT-based assay for resistance to APC had a sensitivity of 100%, a specificity of 70%, and a positive predictive value (PPV) of 70%, whereas both of the RVV-based assays exhibited high sensitivity, specificity, and PPV at 100%. In addition, we found that these new functional assays are more cost-effective relative to the screening algorithm previously used in our clinical laboratory and could potentially eliminate the need for DNA analysis, although further study is required.
Herskovits
Adrianna Z
AZ
Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Lemire
Susan J
SJ
Longtine
Janina
J
Dorfman
David M
DM
D020016:Activated Protein C Resistance / Q000175:diagnosis*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005165:Factor V / Q000235:genetics; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time / Q000191:economics / Q000379:methods*; D011517:Prothrombin Time / Q000191:economics / Q000379:methods*; D012680:Sensitivity and Specificity
C095381:factor V Leiden; D005165:Factor V