Thromb Haemost 1991; 66(04): 453-458
DOI: 10.1055/s-0038-1646437
Review Article
Schattauer GmbH Stuttgart

Assays for Phospholipid-Dependent Formation of Thrombin and Xa: A Potential Method for Quantifying Lupus Anticoagulant Activity

John T Brandt
The Department of Pathology, Ohio State University, Columbus, Ohio, USA
› Author Affiliations
Further Information

Publication History

Received 11 December 1990

Accepted 09 April 1991

Publication Date:
25 July 2018 (online)

Summary

Lupus anticoagulants (LAs) are antibodies which interfere with phospholipid-dependent procoagulant reactions. Their clinical importance is due to their apparent association with an increased risk of thrombo-embolic disease. To date there have been few assays for quantifying the specific activity of these antibodies in vitro and this has hampered attempts to purify and characterize these antibodies. Methods for determining phospholipid-dependent generation of thrombin and factor Xa are described. Isolated IgG fractions from 7 of 9 patients with LAs were found to reproducibly inhibit enzyme generation in these assay systems, permitting quantitative expression of inhibitor activity. Different patterns of inhibitory activity, based on the relative inhibition of thrombin and factor Xa generation, were found, further substantiating the known heterogeneity of these antibodies. These systems may prove helpful in further purification and characterization of LAs.