New Biological Tests in Patients With Antiphospholipid Antibodies
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: blood sample.
- Who it may be relevant to
- Registry conditions: Antiphospholipid Syndrome. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Domain 1 of β2-Glycoprotein 1 Autoantibodies and Thrombin Generation Capacity in Patients With Antiphospholipid Antibodies
Overview
Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thromboembolic events or pregnancy complications associated with circulating antiphospholipid antibodies (aPL-Abs). APS diagnosis needs the presence of both clinical and serological criteria (SAPORRO criteria, updated with Sydney criteria in 2006). However, no correlation between laboratory assays and the clinical thrombosis risk in patients with aPL-Abs was observed as only few patients with aPL-Abs developed clinical manifestations. Thrombin generation assays (TGA) is a global coagulation test that may represent a certain interest to evaluate thrombosis risk as a high thrombin generation capacity seems to be an independent risk factor for recurrent thromboembolic events. Another point of interest to assess the thrombotic risk is the detection of autoantibodies recognizing domain 1 of β2Gp1 (aβ2GP1-dm1). These autoantibodies are strongly related correlated with thrombotic and pregnancy manifestations. Recently, a commercial chemiluminescence immunoassay (CLIA) for detection of aβ2GP1-dm1 became available on Acustar® analyzer (HemosIL Acustar®, Instrument Laboratory, Bedford, USA) to facilitate aβ2GP1-dm1 research. The aim of this study is to evaluate two additional laboratory assays to improve the correlation between laboratory assays and the clinical thrombosis risk in patients with antiphospholipid (APL): thrombin generation assay and aβ2GP1-dm1. Each biological result (Antibodies to Domain 1 (Dm1) of β2-Glycoprotein 1 (aβ2GP1-dm1) and Thrombin Generation Test (TGT) parameters: endogen thrombin potential (ETP), lag time and time to peak) will be compared to the history of clinical thrombosis (venous or arterial thrombosis and/or obstetrical complications such as defined by the Saporro criteria updated with Sydney criteria in 2006) for each patient.
Interventions
- Biological blood sample
A single 15 mL blood draw is planned for this study, as follow: * 10 mL citrated tube (2 tubes) for APTT, PT, D-Dimers, LA, aCL, aβ2GP1, aβ2GP1-dm1 and TGA * 5 mL EDTA tube for blood count During a follow up visit, a 5 ml citrated tube and a 5 mL EDTA tube are collected from each patient for their routine laboratory evaluation. One additional citrated tube will be required to measure thrombin generation and aβ2GP1-dm1.
Primary outcome measures
- aβ2GP1-dm [Time frame: One day]
- Endogenous Thrombin Potential (ETP) [Time frame: One day]
- peak of thrombin [Time frame: One day]
- lag time [Time frame: One day]
- time to peak [Time frame: One day]
Eligibility criteria
Inclusion criteria
- Adult patients with confirmed aPL-Abs (at least two positive determinations at least 12 week apart)
- Subject non opposition
Exclusion criteria
- Age < 18 years
- Patient under the protection of justice, under guardianship or under curatorship
- Patient with anticoagulant treatment, except heparin
- Clinically symptomatic liver disease, supported by e.g. diagnosis of cirrhosis, portal hypertension, ascites, PT superior or egal to 5 seconds above upper normal limit
- Platelet count < 100 G/L (giga/liter)
- Poor venous access
- Non confirmed suspicion of APS
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
France · 4 centers
- Hôpital Cardiologique Louis Pradel — Bron
- CHU de Clermont-Ferrand — Clermont-Ferrand
- Hôpital Edouard Herriot — Lyon
- Centre Hospitalier Lyon Sud — Pierre-Bénite
Identifiers
NCT: NCT03890601 · 69HCL18_0522 · 2018-A03020-55