Antiphospholipid syndrome (APS) is an autoimmune acquired thrombophilic disorder which is diagnosed based on clinical and laboratory criteria; of the laboratory criteria, a positive lupus anticoagulant (LA) is one of the best predictors of thrombotic risk in APS.

Laboratory testing for APS, as well as the accurate reporting of the data, is complicated and is governed by multiple guidelines from national and international organizations. Given that LA testing is clot-based, anticoagulants and factor deficiencies can significantly interfere with accurate testing; the choice of LA testing reagents can help limit the impact of these interferences. One laboratory's experience optimizing LA testing and APS reporting will be discussed, with interesting cases reviewed.

Learning Objectives:

• Review international guidelines for antiphospholipid syndrome (APS) laboratory diagnosis and reporting
• Examine lupus anticoagulant biochemistry
• Share our laboratory’s improvements in our APS testing reagents, workflow, and turn-around time of comprehensive APS reports
• Learn from some interesting APS cases showing common and rare LA interferences