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.
Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Adrianna Z
AZ
Herskovits
Susan J
SJ
Lemire
Janina
J
Longtine
David M
DM
Dorfman
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