Lupus anticoagulant testing using plasma spiked with monoclonal antibodies: performance in the UK NEQAS proficiency testing programme

• Published in: Journal of thrombosis and haemostasis Vol. 2; no. 12; pp. 2178 - 2184
• Main Authors: JENNINGS, I., MACKIE, I., ARNOUT, J., PRESTON, F. E.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Inc 01-12-2004
• Subjects: Algorithms; Antibodies, Monoclonal - chemistry; beta 2-Glycoprotein I; Blood Coagulation Tests - methods; Glycoproteins - chemistry; Humans; Laboratories - standards; lupus anticoagulant; Lupus Coagulation Inhibitor - analysis; Lupus Coagulation Inhibitor - blood; monoclonal antibodies; Partial Thromboplastin Time; Prothrombin - chemistry; Quality Control; Reproducibility of Results; Thromboplastin - biosynthesis; Time Factors; United Kingdom; Whole Blood Coagulation Time
• ISSN: 1538-7933; 1538-7836; 1538-7836
• DOI: 10.1111/j.1538-7836.2004.01028.x

We report here results from a United Kingdom National Quality Assessment Scheme (UK NEQAS) exercise in which both plasma spiked with monoclonal antibodies and plasma from a patient known to have lupus anticoagulant (LA) were distributed to 245 hemostasis laboratories with a request for them to test for possible LA using their routine screening procedure. In general, good agreement was seen in the diagnosis of samples spiked with monoclonal antibodies against β2‐glycoprotein 1 (β2GP1) and prothrombin, the LA‐positive patient sample, and a normal pooled plasma; over 87% of centers correctly identified each sample. However, methods employing platelet neutralizing procedures were associated with a higher proportion of false‐negative responses with the antiprothrombin‐spiked sample, and it is important to recognize that sensitivity and responsiveness of different methods may vary between artificial plasmas and different LA‐positive patient plasmas.