Effect of Injectable Anticoagulants on Research for a Circulating Lupus-type Anticoagulant

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Effect of Injectable Anticoagulants on Research for a Circulating Lupus-type Anticoagulant

Conditions
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Antiphospholipid Syndrome, Anticoagulant Drugs

Intervention / Treatment
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* Diagnostic Test: Lupus anticoagulant testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For all subjects: Adult male or female subject. In capacity to give informed consent to participate in the research. Affiliated to a Social Security system. For the LA- group: Without a previous thrombosis and considered healthy on the basis of the interview and clinical examination. Without coagulation disease For the LA+ group: - Notion of the presence of lupus anticoagulant (according to ISTH criteria) and whose last test was positive. Exclusion Criteria: For all subjects: Medical history considered by the investigator to be incompatible with the trial Refused participation Recent administration of oral or injectable anticoagulants INR > 1.5 Pregnant women, nursing mothers Guardianship, curatorship, deprived of liberty, safeguard of justice

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: Citrated whole blood was collected from all participants and lupus anticoagulant testing was performed before and after spiking in vitro injectable anticoagulants. No distinction between the groups LA+ and LA-.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Group/Cohort 1 :<br>Notion of the presence of lupus anticoagulant (according to ISTH criteria) and whose last test was positive | Diagnostic Test: Lupus anticoagulant testing<br>* 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.<br>|
| Other: Group/Cohort 2:<br>Without a previous thrombosis and considered healthy on the basis of the interview and clinical examination. Without coagulation disease. | Diagnostic Test: Lupus anticoagulant testing<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. | day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. | 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. | day1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Lupus coagulation inhibitor, Anticoagulant drugs