38. Thrombophilia: Assays and Interpretation

  1. Kandice Kottke-Marchant MD, PhD4,5,6 and
  2. Bruce H. Davis MD7
  1. Sophia Yohe MD1,2 and
  2. John Olson MD, PhD3

Published Online: 8 AUG 2012

DOI: 10.1002/9781444398595.ch38

Laboratory Hematology Practice

Laboratory Hematology Practice

How to Cite

Yohe, S. and Olson, J. (2012) Thrombophilia: Assays and Interpretation, in Laboratory Hematology Practice (eds K. Kottke-Marchant and B. H. Davis), Wiley-Blackwell, Oxford, UK. doi: 10.1002/9781444398595.ch38

Editor Information

  1. 4

    Pathology & Laboratory Medicine Institute, Cleveland, OH, USA

  2. 5

    Department of Pathology, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA

  3. 6

    Hemostasis and Thrombosis, Department of Clinical Pathology, Cleveland Clinic, Cleveland, OH, USA

  4. 7

    Trillium Diagnostics, LLC, Bangor, ME, USA

Author Information

  1. 1

    Department of Laboratory Medicine and Pathology, MN, USA

  2. 2

    Divisions of Hematopathology and Molecular, Diagnostic Pathology, University of Minnesota Medical Center, Minneapolis, MN, USA

  3. 3

    Department of Pathology, The University of Texas Health Science Center, University Health System, San Antonio, TX, USA

Publication History

  1. Published Online: 8 AUG 2012
  2. Published Print: 10 APR 2012

ISBN Information

Print ISBN: 9781405162180

Online ISBN: 9781444398595

SEARCH

Keywords:

  • thrombophilia, acquired;
  • thrombophilia, inherited;
  • thrombophilia risk factors;
  • thrombophilia testing;
  • factor V Leiden;
  • activated protein C resistance;
  • prothrombin gene mutation 20210;
  • protein C deficiency;
  • protein S deficiency;
  • antithrombin deficiency;
  • hyperhomocysteinemia;
  • elevated factor VIII;
  • thrombophilia and oral contraceptives;
  • thrombophilia and hormone replacement therapy;
  • thrombophilia in pregnancy;
  • thrombophilia and recurrent fetal loss;
  • thrombophilia and gestational complications;
  • thrombophilia in children

Summary

Over the course of the past two to three decades, a remarkable number of conditions have been described that may increase the risk of development of venous and/or arterial thrombosis. These conditions may be inherited or acquired. Usually, the presence of a single risk factor is clinically silent and thrombosis is unusual, with the risk being only slightly higher than for those without such risk factors. However, when combinations of risk factors are seen in the same individual, the risk of thrombosis rises significantly.

This chapter reviews the testing that is available for inherited and acquired thrombophilic risk factors with a discussion of the appropriate application of the tests. There are several types of available tests including molecular methods, immunoassays that quantify the protein, assays that reflect the function of the factor, and clinical conditions that increase the risk such as malignancy. With the exception of the molecular methods described, the quality of the assays available is less than would be desired. In addition, many of these assays may be influenced by medications, particularly anticoagulants, and the condition of the patient, for example a recent thrombotic event or another underlying medical condition. For these reasons, timing of testing and interpretation of the results require consideration of the clinical setting and often require repeat testing for confirmation of results.

During pregnancy, a mother's blood slowly changes over the time, preparing for the hemorrhagic challenge of delivery. These changes and other considerations regarding thrombotic risk in pregnancy are addressed.

Pediatricians often remind other clinicians that children are not small adults. This is quite true as one considers thrombophilia, so pediatric thrombophilia requires special consideration and is also addressed.