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An international external quality assessment for laboratory diagnosis of heparin-induced thrombocytopenia.
- Source :
-
Journal of thrombosis and haemostasis : JTH [J Thromb Haemost] 2019 Mar; Vol. 17 (3), pp. 525-531. Date of Electronic Publication: 2019 Feb 20. - Publication Year :
- 2019
-
Abstract
- Essentials A pilot study for External Quality Assessment for testing of HIT is described. The qualitative accordance for the PF4/heparin IgG test was 97.6%. The qualitative accordance for functional HIT tests was considerably lower. External Quality Assessment for functional HIT tests is required. SUMMARY: Objective Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening complication of heparin exposure. Diagnosis is most reliable using a combination of an enzyme immunoassay (EIA) that detects antibodies against platelet factor 4 (PF4)/heparin complexes ("antigen" assay) and a "functional" assay that detects platelet-activating properties of the pathogenic HIT antibodies. No External Quality Assessment (EQA) is available for a combination of the tests. Here we report on the results of the first international EQA. Methods The pilot EQA was organized by the Department of Transfusion Medicine, Universitätsmedizin Greifswald, Germany. Six serum samples of patients, which were referred to Greifswald for HIT diagnosis, and one negative control sample were distributed to seven participants in Germany, Canada, and Singapore. Participants were asked to report the optical density (OD) values of their local EIA test for IgG-specific antibodies against the PF4/heparin complexes and the results for a functional assay (HIPA or SRA). Consensus was defined as a minimum 70% agreement, i.e., agreement among at least five of the seven participating laboratories. Results and conclusion Six out of seven participants reported results for EIA, with a high quantitative accordance (97.6%). For the functional assay, consensus was reached for all samples except the negative control, for which some participants reported nonspecific reactivity. All HIT-negative samples were correctly diagnosed by all participants; for HIT-positive samples, consensus of 70% was reached. Although the limited availability of sample material is an obstacle to overcome, an EQA combining both EIA and functional testing is feasible.<br /> (© 2019 International Society on Thrombosis and Haemostasis.)
- Subjects :
- Aged
Anticoagulants immunology
Biomarkers blood
Canada
Female
Germany
Heparin immunology
Humans
Laboratory Proficiency Testing
Male
Middle Aged
Observer Variation
Pilot Projects
Predictive Value of Tests
Reproducibility of Results
Singapore
Thrombocytopenia blood
Thrombocytopenia chemically induced
Thrombocytopenia immunology
Antibodies blood
Anticoagulants adverse effects
Heparin adverse effects
Immunoglobulin G blood
Immunologic Tests standards
Platelet Factor 4 immunology
Thrombocytopenia diagnosis
Subjects
Details
- Language :
- English
- ISSN :
- 1538-7836
- Volume :
- 17
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Journal of thrombosis and haemostasis : JTH
- Publication Type :
- Academic Journal
- Accession number :
- 30640980
- Full Text :
- https://doi.org/10.1111/jth.14383