Abstract
Lupus anticoagulants (LAs) are antiphospholipid antibodies that interfere with in
vitro phospholipid-dependent clotting tests, but are associated in vivo with significant
clinical manifestations such as recurrent pregnancy loss and venous and arterial thrombosis.
Although their detection is important for the diagnosis of thrombotic disorders such
as the antiphospholipid syndrome, laboratory identification has historically been
fraught with many issues. These have included variability in the sensitivity of assays
and reagents; high false-negative and false-positive detection rates; a lack of consensus
for the use of mixing tests; and, to some extent, lack of compliance with guidelines
published by the Lupus Anticoagulant/Antiphospholipid Antibody Scientific Standardization
Committee of the International Society on Thrombosis and Haemostasis (ISTH). Since
the most recently updated guidelines in 2009, external quality assurance (EQA) programs
have conducted surveys to provide a “snapshot” of laboratory practices related to
the investigation of LA and to identify problems and monitor improvements in testing
for LA. This article will review the impact of the most recently updated ISTH guidelines
for LA testing and discuss the findings of recent EQA surveys.
Keywords
lupus anticoagulant - antiphospholipid antibodies - quality assurance - guidelines
- standardization
