Author ORCID Identifier

Clifford V. Harding

Robert W. Maitta

Document Type


Publication Date



OBJECTIVES: Type II heparin-induced thrombocytopenia (HIT) is mediated by formation of antibodies to platelet factor 4 (PF4)-heparin complexes. We evaluated anti-PF4-heparin-negative samples for the presence of additional anti-platelet and anti-red blood cell (RBC) antibodies using whole-cell platelet/ RBC ELISAs we developed. METHODS: Seventy-three samples tested for anti-PF4-heparin by ELISA were included: 62 tested negative, 9 tested positive, and 2 had equivocal results. Plasma specimens from healthy donors were used as controls. RESULTS: 100% (9/9) anti-PF4-positive samples had anti-platelet antibodies detected by whole-cell platelet ELISA. 42.2% (27/64) anti-PF4-heparin-negative samples were negative for anti-platelet and anti-RBC antibodies. 32.8% (21/64) negative samples showed reactivity to both platelets and RBC; 12.5% (8/64) negative samples were each reactive with either platelet or RBC ELISA, respectively. Additionally, two samples that tested equivocal by anti-PF4-heparin ELISA had antibodies to both platelets and RBC by whole-cell ELISA. CONCLUSIONS: Our study suggests that patients with thrombocytopenia testing negative for anti-PF4-heparin may still harbor antibodies to platelets. However, additional research is needed to determine the significance of these antibodies. Nevertheless, these findings may encourage clinicians to further investigate patients with possible immune-mediated etiologies of thrombocytopenia and anemia.


PF4-heparin, anti, antibodies, heparin-induced thrombocytopenia, platelet, red cells, whole-cell ELISA

Publication Title

European Journal of Haematology





First Page


Last Page



R01 AI034343; P0178


National Institutes of Health (NIH); Office of Diversity and Inclusion, University Hospitals Cleveland Medical Center


© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.


This is the peer reviewed version of the following article: Bashover EM, Stefaniuk CM, Harding CV, Maitta RW. Use of a whole‐cell ELISA to detect additional antibodies in setting of suspected heparin‐induced thrombocytopenia. Eur J Haematol. 2019;103:99–106. h t t p s : //, which has been published in final form at

Included in

Hematology Commons


10.1111/ejh.13263" data-hide-no-mentions="true">
10.1111/ejh.13263" data-hide-zero-citations="true" data-style="small_circle">

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.