TY - JOUR
T1 - Effect of fondaparinux on coagulation assays
T2 - Results of College of American pathologists proficiency testing
AU - Smogorzewska, Agata
AU - Brandt, John T.
AU - Chandler, Wayne L.
AU - Cunningham, Mark T.
AU - Hayes, Timothy E.
AU - Olson, John D.
AU - Kottke-Marchant, Kandice
AU - Van Cott, Elizabeth M.
PY - 2006/11
Y1 - 2006/11
N2 - Context.-Fondaparinux, a factor Xa inhibitor, is approved for thromboprophylaxis after orthopedic surgery and for treatment of venous thromboembolism. It may also be efficacious, safe, and cost-effective for other patients; thus, more widespread use of fondaparinux is likely. The effect of fondaparinux on coagulation testing needs to be thoroughly examined. Objective.-To report the effects of fondaparinux on coagulation tests (prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin, factor VIII, thrombin time, anti-factor Xa) across diverse methodologies. Design.-Samples with different concentrations of fondaparinux (0, 0.4, 0.8, and 2.0 μg/ml.) were sent to laboratories participating in the College of American Pathologists Comprehensive Coagulation proficiency survey (N = 898). Laboratory-specific methods were used to assay coagulation parameters. Results.-Prophylactic or therapeutic fondaparinux prolonged the prothrombin time by approximately 1 second and the activated partial thromboplastin time by 4 to 5 seconds, and reduced factor VIII from 119% to 107% and 102%, respectively. Supratherapeutic fondaparinux reduced factor VIII to 85%. The activated partial thromboplastin time was prolonged in 19%, 29%, and 52% of laboratories with prophylactic, therapeutic, and supratherapeutic fondaparinux levels, respectively. Fibrinogen, antithrombin, and thrombin time assays did not show clinically significant changes. When measuring fondaparinux concentration using an anti-factor Xa assay, the most accurate results were obtained when fondaparinux was used as the calibrator. Conclusions.-Fondaparinux, even in prophylactic doses, slightly prolongs the prothrombin time and activated partial thromboplastin time and can interfere with factor VIII assays, but it has no clinically relevant effect on fibrinogen, antithrombin, or thrombin time. A fondaparinux standard curve should be used for reporting fondaparinux levels using an anti-factor Xa assay.
AB - Context.-Fondaparinux, a factor Xa inhibitor, is approved for thromboprophylaxis after orthopedic surgery and for treatment of venous thromboembolism. It may also be efficacious, safe, and cost-effective for other patients; thus, more widespread use of fondaparinux is likely. The effect of fondaparinux on coagulation testing needs to be thoroughly examined. Objective.-To report the effects of fondaparinux on coagulation tests (prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin, factor VIII, thrombin time, anti-factor Xa) across diverse methodologies. Design.-Samples with different concentrations of fondaparinux (0, 0.4, 0.8, and 2.0 μg/ml.) were sent to laboratories participating in the College of American Pathologists Comprehensive Coagulation proficiency survey (N = 898). Laboratory-specific methods were used to assay coagulation parameters. Results.-Prophylactic or therapeutic fondaparinux prolonged the prothrombin time by approximately 1 second and the activated partial thromboplastin time by 4 to 5 seconds, and reduced factor VIII from 119% to 107% and 102%, respectively. Supratherapeutic fondaparinux reduced factor VIII to 85%. The activated partial thromboplastin time was prolonged in 19%, 29%, and 52% of laboratories with prophylactic, therapeutic, and supratherapeutic fondaparinux levels, respectively. Fibrinogen, antithrombin, and thrombin time assays did not show clinically significant changes. When measuring fondaparinux concentration using an anti-factor Xa assay, the most accurate results were obtained when fondaparinux was used as the calibrator. Conclusions.-Fondaparinux, even in prophylactic doses, slightly prolongs the prothrombin time and activated partial thromboplastin time and can interfere with factor VIII assays, but it has no clinically relevant effect on fibrinogen, antithrombin, or thrombin time. A fondaparinux standard curve should be used for reporting fondaparinux levels using an anti-factor Xa assay.
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M3 - Article
C2 - 17076521
AN - SCOPUS:33750599861
VL - 130
SP - 1605
EP - 1611
JO - Archives of Pathology and Laboratory Medicine
JF - Archives of Pathology and Laboratory Medicine
SN - 0003-9985
IS - 11
ER -