Abstract
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.
References
Altuntas F, Matevosyan K, Burner J, Shen YM, Sarode R (2008) Higher optical density of an antigen assay predicts thrombosis in patients with heparin-induced thrombocytopenia. Eur J Haematol 80:429–435
Cuker A, Gimotty PA, Crowther MA, Warkentin TE (2012) Predictive value of the 4Ts scoring system for heparin-induced thrombocytopenia: a systematic review and meta-analysis. Blood 120:4160–4167
Linkins LA, Dans AL, Moores LK, Bona R, Davidson BL, Schulman S, Crowther M, American College of Chest Physicians (2012) Treatment and prevention of heparin-induced thrombocytopenia: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 141(2 Suppl):e495S–e530S
Pierce W, Mazur J, Greenburg C, Mueller J, Foster J, Lazarchick J (2013) Evaluation of heparin-induced thrombocytopenia (HIT) laboratory testing and the 4Ts scoring system in the intensive care unit. Ann Clin Lab Sci 43:429–435
Warkentin TE, Sheppard JI, Moore JC, Sigouin CS, Kelton JG (2008) Quantitative interpretation of optical density measurements using PF4-dependent enzyme-immunoassays. J Thromb Haemost 6:1304–1312
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The authors declare that they have no conflict of interest.
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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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Marler, J., Unzaga, J., Stelts, S. et al. Consequences of treating false positive heparin-induced thrombocytopenia. J Thromb Thrombolysis 40, 512–514 (2015). https://doi.org/10.1007/s11239-015-1236-0
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DOI: https://doi.org/10.1007/s11239-015-1236-0