APTT reagent with ellagic acid as activator shows adequate lupus anticoagulant sensitivity in comparison to silica-based reagent
Article first published online: 30 OCT 2012
© 2012 International Society on Thrombosis and Haemostasis
Journal of Thrombosis and Haemostasis
Volume 10, Issue 11, pages 2338–2343, November 2012
How to Cite
KUMANO, O., IEKO, M., NAITO, S., YOSHIDA, M. and TAKAHASHI, N. (2012), APTT reagent with ellagic acid as activator shows adequate lupus anticoagulant sensitivity in comparison to silica-based reagent. Journal of Thrombosis and Haemostasis, 10: 2338–2343. doi: 10.1111/j.1538-7836.2012.04906.x
- Issue published online: 30 OCT 2012
- Article first published online: 30 OCT 2012
- Accepted manuscript online: 21 AUG 2012 10:40AM EST
- Received 3 April 2012, accepted 14 August 2012
- ellagic acid;
- lupus anticoagulant;
Summary. Background: Lupus anticoagulant (LA) is an antibody that interferes with phospholipid-dependent coagulation reactions. Activated partial thromboplastin time (APTT) is widely used as a test for LA screening. APTT reagents are composed of activators, such as silica or ellagic acid, and phospholipids, and APTT reagents with silica are recommended for LA screening because of greater sensitivity. However, the effects of activators on LA activity have not been adequately investigated.
Objectives: In this study, we examined whether an ellagic acid-based reagent was highly sensitive to LA in a low phospholipid condition and useful for LA screening.
Methods: Silica-based (SL) and ellagic acid-based (EA) reagents were prepared in-house with the same composition and concentration of phospholipids, while the commercial APTT reagents APTT-SLA (SLA), Actin FSL (FSL), APTT-SP (SP) and PTT-LA (PTT) were also included in the study.
Results: The normal reference ranges for SL and EA were 30.1–47.0 and 28.0–40.2 s, respectively, while the cut-off index values for circulating anticoagulant activity (ICA) calculated from the results obtained with SL, EA, SLA, FSL, SP and PTT were 12.9, 11.5, 13.2, 15.6, 14.3 and 14.0, respectively. The sensitivity of those reagents based on those cut-off values was 91%, 96%, 68%, 46%, 91% and 86%, respectively.
Conclusions: Our results showed that the ellagic acid-based reagent was more sensitive to LA than silica-based reagents in a low phospholipid condition and had adequate sensitivity to detect LA. We concluded that the sensitivity of APTT reagents for LA is dependent on phospholipid concentration and not the activator.