Thromb Haemost 2009; 101(01): 185-196
DOI: 10.1160/TH08-06-0393
New Technologies, Diagnostic Tools and Drugs
Schattauer GmbH

Laboratory detection of the antiphospholipid syndrome via calibrated automated thrombography

Katrien Devreese
1   Coagulation Laboratory, Department of Clinical Chemistry, Microbiology and Immunology, Ghent University Hospital, Ghent, Belgium
,
Kathelijne Peerlinck
2   Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
,
Jef Arnout
2   Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
,
Marc F. Hoylaerts
2   Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
› Author Affiliations

Financial support: This work was supported by the Leducq Foundation (Paris, France; LINAT project) and by K.U.Leuven grant GOA/2004/09. The CMVB is supported by the “Excellentie financiering KULeuven” (EF/05/013).
Further Information

Publication History

Received: 20 June 2008

Accepted after major revision: 07 October 2008

Publication Date:
23 November 2017 (online)

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Summary

Lupus anticoagulants (LAC) consist of antiphospholipid antibodies, detected via their anticoagulant properties in vitro. Strong LAC relate to thromboembolic events, a hallmark of the anti-phospholipid syndrome. We have analyzed whether detection of this syndrome would benefit from thrombin generation measurements. Therefore, calibrated automated thrombography was done in normal plasma (n=30) and LAC patient plasma (n=48 non-anticoagulated, n=12 on oral anticoagulants), diluted 1:1 with a normal plasma pool. The anti-β2-glycoprotein I monoclonal antibody 23H9, with known LAC properties, delayed the lag time and reduced the peak height during thrombin generation induction in normal plasma dose-dependently (0–150 μg/ml). At variance, LAC patient 1:1 plasma mixtures manifested variable lag time prolongations and/or peak height reductions. Coupling these two most informative thrombin generation parameters in a peak height/lag time ratio, and upon normalization versus the normal plasma pool, this ratio distributed normally and was reduced in the plasma mixtures, for 59/60 known LAC plasmas. The normalized peak height/lag time ratio correlated well with the normalized dilute prothrombin time, diluted Russell’s viper venom time and silica clotting time, measured in 1:1 plasma mixtures (correlation coefficients 0.59–0.72). The anticoagulant effects of activated protein C (0–7.5 nM) or 23H9 (0–150 μg/ml), spiked in the 1:1 LAC plasma mixtures were reduced for the majority of patients, compatible with functional competition between patient LAC and activated protein C and LAC and 23H9, respectively. Hence, the normalized thrombin generation-derived peak height/lag time ratio identifies LAC in plasma with high sensitivity in a single assay, irrespective of the patient’s treatment with oral anticoagulants.