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Thromb Haemost 2007; 98(06): 1357-1361
DOI: 10.1160/TH07-06-0401
New Technologies, Diagnostic Tools and Drugs
Schattauer GmbH

Laboratory testing for heparin-induced thrombocytopenia is inconsistent in North America: A survey of North American specialized coagulation laboratories

Elizabeth A. Price
1   Department of Medicine, and
,
Catherine P. M. Hayward
2   Department of Pathology and Molecular Medicine, and
3   Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
,
Karen A. Moffat
3   Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
4   Department of Coagulation, Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada
,
Jane C. Moore
2   Department of Pathology and Molecular Medicine, and
3   Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
,
Theodore E. Warkentin
2   Department of Pathology and Molecular Medicine, and
3   Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
,
James L. Zehnder
1   Department of Medicine, and
5   Department of Pathology, Stanford University, Stanford, California, USA
› Author AffiliationsFinancial support: C.P.M.H is supported by a Career Investigator Award from the Heart and Stroke Foundation of Ontario and a Canada Research Chair in Molecular Hemostasis, T.E.W. is supported by the Heart & Stroke Foundation of Ontario, Operating Grant #T6157.
Further Information

Publication History

Received 11 June 2007

Accepted after resubmission 21 October 2007

Publication Date:
30 November 2017 (online)

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Summary

Heparin-induced thrombocytopenia (HIT) is a serious complication of heparin therapy. As HIT is considered a clinico-pathologic entity, laboratory practices have an important role in diagnosing or excluding HIT. It was the objective of this study to assess the current status of laboratory testing for HIT in North America. An online survey consisting of 67 questions related to laboratory testing for HIT was developed by the North American Specialized Coagulation Laboratory Association (NASCOLA), and distributed to its 59 members. The survey included queries about HIT test ordering practices, HIT immunoassay and activation assays performed, and reporting practices. Data was collected from the 44 NASCOLA laboratories who responded. Of these sites, 88% performed immunoassays for HIT, commonly using commercial assays. However, sites varied in practices related to use of controls, immunoglobulin class of antibody detected, and in result interpretation and reporting. Platelet activation assays for HIT were performed by 36% of sites, commonly using assays of serotonin release (50%) or heparin- induced platelet aggregation (43%). Sites varied in the use of washed platelets versus platelet-rich plasma, controls, and heparin concentrations. This survey is the first comprehensive assessment of patterns of practice in HIT testing among diagnostic coagulation laboratories in North America. We observed sitespecific variability of testing methods encompassing all stages of testing, including pre-analytical handling, testing methodologies, and result interpretation and reporting. The variability in HIT platelet activation assay methods among institutions indicates a need for proficiency testing to assess assay performance,and for consensus guidelines on HIT laboratory testing.

Keywords

Heparin-induced thrombocytopenia - laboratory diagnosis - platelet-factor 4 - thrombocytopenia
 

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