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Semin Thromb Hemost 2012; 38(07): 742-752
DOI: 10.1055/s-0032-1326780
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Laboratory Investigations for Bleeding Disorders

Catherine P. M. Hayward
1   Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
,
Karen A. Moffat
2   Hamilton Regional Laboratory Medicine Program, Special Coagulation Laboratory, Hamilton, Ontario, Canada
3   Department of Medicine, McMaster University, Hamilton, Ontario, Canada
,
Yang Liu
3   Department of Medicine, McMaster University, Hamilton, Ontario, Canada
› Author Affiliations
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Publication History

Publication Date:
25 September 2012 (online)

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Abstract

Bleeding disorder panels often include the prothrombin time (PT)/international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen level, and thrombin time (TT). We explored the detection of abnormalities from bleeding disorders by these tests among subjects referred for bleeding disorder assessments, using data from a bleeding disorder study to determine sensitivities and specificities. Among subjects referred to hematologists for bleeding disorder assessment, coagulation defects were uncommon and the APTT and TT detected many nonsignificant abnormalities. While all test and panel specificities were acceptable (88 to 100%), coagulation screening tests were less sensitive to clinically significant abnormalities (1.0 to 2.1%) than von Willebrand disease (VWD) screens (6.7%), and light transmission platelet aggregometry (LTA) (26%). Accordingly, panels comprising PT/INR, APTT, fibrinogen, and TT had lower sensitivity to bleeding disorders (3.7%) than panels expanded to include VWD screens (8.5%), or VWD screens and LTA (30%). These findings have important implications for bleeding disorder diagnosis.

Keywords

bleeding disorders - laboratory testing - factor deficiencies - fibrinogen