Journal of Thrombosis and Thrombolysis

, Volume 40, Issue 4, pp 512–514 | Cite as

Consequences of treating false positive heparin-induced thrombocytopenia

  • Jacob Marler
  • Jessica Unzaga
  • Sundae Stelts
  • Carrie S. OliphantEmail author
Letter to the Editor


Identification of patients with heparin-induced thrombocytopenia is encumbered by false positive enzyme-linked immuno assay (ELISA) antibody results, therefore a serotonin release assay (SRA) is used for confirmation. Recently, several studies have demonstrated that increasing the optical density (OD) threshold (currently at 0.4) of the antibody test enhances the positive predictive value. The purpose of this study was to determine the frequency of patients who were ELISA antibody positive but SRA negative, and the costs and bleeding events associated with alternative anticoagulant treatment. We hypothesized that treating patients with a positive ELISA antibody OD value of <1.0 would result in increased cost and bleeding risk. This retrospective chart review was conducted on adult hospitalized patients from 2011 to 2013. Patients with positive ELISA antibodies (OD of 0.4–1.0) and an SRA result were included. Eighty-five patients were identified with positive antibodies (average OD of 0.66), 100 % of which were found to be SRA negative. A total of 59 patients (69 %) received alternative anticoagulants. The average duration of treatment was 3.1 days, and 4 patients (4.7 %) experienced a bleeding event. The cost of testing and laboratory monitoring was $36,346 and the cost of the alternative anticoagulants totaled $47,179. The total cost was $83,525, with an average total cost per patient of $982. This study adds to the body of literature suggesting treatment should only be initiated if the OD is one or greater. The high false positive rate caused increased cost and some bleeding events.


Heparin Thrombocytopenia Cost False positive Enzyme-linked immunosorbent assay 


Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required.


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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Jacob Marler
    • 1
  • Jessica Unzaga
    • 2
  • Sundae Stelts
    • 3
  • Carrie S. Oliphant
    • 1
    • 4
    Email author
  1. 1.Department of PharmacyMethodist Healthcare-University HospitalMemphisUSA
  2. 2.Memorial Cancer InstituteHollywoodUSA
  3. 3.Roper St. Francis Health SystemCharlestonUSA
  4. 4.Department of Clinical PharmacyThe University of Tennessee College of PharmacyMemphisUSA

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