The aim is to assess the effect of injectable anticoagulants (unfractionated heparin (UFH), low molecular weight heparins (LMWH), fondaparinux, danaparoid, argatroban) on lupus anticoagulant testing assays over broad anti-Xa activity ranges and to establish their potential for causing false-positive or false-negative results.
Citrated whole blood was collected from subjects with positive lupus anticoagulant (LA) testing and from subjects with negative LA testing. Injectable anticoagulants were prepared in demineralized water and added to plasma samples LA+ and LA- to obtain broad anti-Xa activity ranges. Anti-Xa measurement and LA testing were performed in neat and spiked plasma samples. LA testing was performed with 4 different analyzer-reagent combinations to represent almost all hemostasis manufacturers currently available. There will be no direct comparison between the LA+ and LA- groups, the objective is to evaluate the effect of increasing concentrations of injectable anticoagulants on these 2 distinct populations.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
188
The patient will have a visit during which a blood sample will be taken, a clinical examination will be performed, and data will be collected.
CHU clermont-ferrand
Clermont-Ferrand, France
Results of lupus anticoagulant testing: positive or negative
Concerning the impact of injectable anticoagulants on the final diagnosis of LA testing (negative or positive), in a population of LA+ and LA- subjects, particular attention will be paid to the study of false negatives and false positives expressed in % and 95% confidence intervals.
Time frame: day 1
Effect of injectable anticoagulants on the clotting times of each of the tests involved in LA testing (detection, mixing and confirmation tests).
comparison of clotting times in the absence and presence of increasing concentrations of anticoagulants will be carried out by Anova or non-parametric Kruskal-Wallis test if the conditions of Anova are not respected. Graphical representations will be associated with these analyses.
Time frame: day 1
Determination of the threshold limits of injectable anticoagulants (anti-Xa activities) allowing a reliable LA diagnosis, for each analytical solution tested (analyzer/reagent combinations).
comparison of clotting times in the absence and presence of increasing concentrations of anticoagulants will be carried out by Anova or non-parametric Kruskal-Wallis test if the conditions of Anova are not respected.
Time frame: day1
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