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ORIGINAL ARTICLE
An international multicentre-laboratory evaluation of a new assay to detect specifically lupus anticoagulants dependent on the presence of anti-beta2-glycoprotein autoantibodies
Article first published online: 7 JAN 2011
DOI: 10.1111/j.1538-7836.2010.04068.x
© 2010 International Society on Thrombosis and Haemostasis
Additional Information
How to Cite
DE LAAT, B., DERKSEN, R. H. W. M., REBER, G., MUSIAL, J., SWADZBA, J., BOZIC, B., CUCNIK, S., REGNAULT, V., FORASTIERO, R., WOODHAMS, B. J. and DE GROOT, PH. G. (2011), An international multicentre-laboratory evaluation of a new assay to detect specifically lupus anticoagulants dependent on the presence of anti-beta2-glycoprotein autoantibodies. Journal of Thrombosis and Haemostasis, 9: 149–153. doi: 10.1111/j.1538-7836.2010.04068.x
Publication History
- Issue published online: 7 JAN 2011
- Article first published online: 7 JAN 2011
- Accepted manuscript online: 27 SEP 2010 01:30PM EST
- Received 21 June 2010, accepted 16 September 2010
- Abstract
- Article
- References
- Cited By
Keywords:
- antiphospholipid;
- beta2-glycoprotein I;
- lupus anticoagulant;
- pregnancy morbidity;
- thrombosis
Summary. Background: Antiphospholipid syndrome (APS) is diagnosed by the simultaneous presence of vascular thrombosis and/or pregnancy morbidity and detection of antiphospholipid antibodies in plasma. Objectives: We have shown that prolongation of clotting time by anti-beta2-glycoprotein I (beta2GPI) antibodies correlates better with thrombosis than a positive classic lupus anticoagulant (LAC) assay in a single center study. To confirm or falsify this finding we have conducted a multicenter study. Methods and results: In 325 LAC-positive samples, we found that the beta2GPI-dependent LAC correlated 2.0 times better with thrombosis than the classic LAC assay. Although significant, this was a minimal improvement compared with the ‘classic’ LAC. It was published that calcium influences the behavior of anti-beta2GPI antibodies in coagulation assays. To investigate whether calcium plays a role in the present study, we divided the patient population into two groups: (i) blood was collected in 0.109 m sodium citrate and (ii) blood was drawn in 0.129 m sodium citrate as anticoagulant. We found that a positive result with the beta2GPI-dependent LAC assay correlated better with thrombosis [odds ratio (OR): 3.3, 95% confidence interval (CI) 1.9–5.8] when 0.109 m sodium citrate was used compared with 0.129 m sodium citrate (OR: 0.4, 95% CI 0.1–1.1). Conclusion: We were able to confirm in an international multicenter study that a positive result in a beta2GPI-dependent LAC assay correlates better with thrombosis than the classic LAC assay, but that the assay needs further study as it is sensitive to external factors such as the sodium citrate concentration used as anticoagulant in the test sample.