Author/Editor     De Laat, B; Derksen, RHWM; Reber, G; Musial, J; Swadzba, J; Božič, B; Čučnik, S; Regnault, V; Forastiero, R; Woodhams, BJ
Title     An international multicentre-laboratory evaluation of a new assay to detect specifically lupus anticoagulants dependent on the presence of anti-beta2-glycoprotein autoantibodies
Type     članek
Source     J Thromb Haemost
Vol. and No.     Letnik 9, št. 1
Publication year     2011
Volume     str. 149-53
Language     eng
Abstract     Background: Antiphospholipid syndrome (APS) is diagnosed by the simultaneous presence of vascular thrombosis and/or pregnancy morbidity and detection of antiphospholipid antibodies in plasma. Objectives: We have shown that prolongation of clotting time by anti-beta2-glycoprotein I (beta2GPI) antibodies correlates better with thrombosis than a positive classic lupus anticoagulant (LAC) assay in a single center study. To confirm or falsify this finding we have conducted a multicenter study. Methods and results: In 325 LAC-positive samples, we found that the beta2GPI-dependent LAC correlated 2.0 times better with thrombosis than the classic LAC assay. Although significant, this was a minimal improvement compared with the 'classic' LAC. It was published that calcium influences the behavior of anti-beta2GPI antibodies in coagulation assays. To investigate whether calcium plays a role in the present study, we divided the patient population into two groups: (i) blood was collected in 0.109 m sodium citrate and (ii) blood was drawn in 0.129 m sodium citrate as anticoagulant. We found that a positive result with the beta2GPI-dependent LAC assay correlated better with thrombosis [odds ratio (OR): 3.3, 95% confidence interval (CI) 1.9-5.8] when 0.109 m sodium citrate was used compared with 0.129 m sodium citrate (OR: 0.4, 95% CI 0.1-1.1). Conclusion: We were able to confirm in an international multicenter study that a positive result in a beta2GPI-dependent LAC assay correlates better with thrombosis than the classic LAC assay, but that the assay needs further study as it is sensitive to external factors such as the sodium citrate concentration used as anticoagulant in the test sample.
Descriptors     BLOOD COAGULATION
ENZYME-LINKED IMMUNOSORBENT ASSAY
REAGENT KITS, DIAGNOSTIC
ADULT
AGED
AGED, 80 AND OVER
ANTICOAGULANTS
ANTIPHOSPHOLIPID SYNDROME
ARGENTINA
AUTOANTIBODIES
BLOOD SPECIMEN COLLECTION
CHILD
CITRATES
EUROPE
LOGISTIC MODELS
LUPUS COAGULATION INHIBITOR
ODDS RATIO
PARTIAL THROMBOPLASTIN TIME
THROMBOSIS