The primary goal of this study is to determine discrepancies between INR measurements with Coaguchek XS and Coagulometer in APS patients. The secondary objective is to investigate which antiphospholipid antibodies correlate with the observed INR…
ID
Source
Brief title
Condition
- Autoimmune disorders
- Embolism and thrombosis
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The main study parameter is the difference in INR values measured with the
Coaguchek XS and Coagulometer. A difference in INR >0,5 will be considered
clinically significant.
Secondary outcome
Secondary parameter includes:
- The determination of antiphospholipid antibodies: IgG / IgM directed against
cardiolipin, β2-Glycoprotein I, phosphatidic acid, phosphatidyl-choline, -
ethanolamine, -glycerol, -inositol, -serine, annexin V and prothrombin, and
antiphospholipid antibodies that prolong the clotting time in vitro, known as
lupus anticoagulant. Lupus anticoagulant will be determined using a dilute
Russell*s Viper Venom Time (dRVVT) screen and confirm, and an activated partial
tromboplastin time (APTT) screen and confirm.
- The evaluation of differences in INR values between triple positive APS
patients (patients at highest risk for recurrent thrombosis) and non-triple
positive APS patients. Patients are considered as triple positive if they are
tested positive for anti-cardiolipin antibodies, anti-β2GPI antibodies and
lupus anticoagulant.
Background summary
Patients with the antiphospholipid syndrome (APS) often receive anticoagulant
treatment with Vitamin K antagonists (VKA). Treatment with VKA is monitored
with the international normalized ratio (INR), which can be determined in a
diagnostic laboratory and requires a visit to an outpatient clinic, or by the
patients themselves with Point Of Care (POC) devices. INR monitoring is
important as low INR values indicate an increased risk of thrombosis and high
INR values are associated with an increased bleeding risk. However, INR values
measured with POC devices could be falsely elevated due to antiphospholipid
antibodies. Previous research that have compared INR values measured with POC
devices and the standard laboratory test in APS patients showed substantial
methodological variantion, which makes the interpretation of the results
difficult.
In the current study, we will investigate whether INR values in APS patients
measured with the most commonly used POC device (CoaguChek XS) in the
Netherlands are similar to INR values measured with the gold standard test,
i.e. determined with the Owren method using a rabbit brain-derived
thromboplastin, performed in our diagnostic laboratory at the UMC Utrecht.
Study objective
The primary goal of this study is to determine discrepancies between INR
measurements with Coaguchek XS and Coagulometer in APS patients. The secondary
objective is to investigate which antiphospholipid antibodies correlate with
the observed INR discrepancies.
Study design
This is a monocenter, cross-sectional, observational study that will be
performed in the UMC Utrecht at the van Creveldkliniek, Central Diagnostic
Laboratory and the department of Rheumatology & Clinical Immunology. A total of
80 adult patients with previously confirmed APS that use Vitamin K antagonists
will be included in the study. Blood withdrawal will be performed at one time
moment.
Study burden and risks
For this study, patients will endure 1 finger stick procedure and 1
venepuncture (4.5 mL for study, 19 mL for biobank), which both induces a very
low risk and burden to humans. The main risk associated with these procedures
is little local bruising and slight local discomfort. Patients will be asked to
participate during a regular outpatient clinic visit. This study has never been
performed before and will provide important information on the regulation of
anticoagulant treatment in APS patients.
Heidelberglaan 100
Utrecht 3584CX
NL
Heidelberglaan 100
Utrecht 3584CX
NL
Listed location countries
Age
Inclusion criteria
- Age 18 years and older
- Previously confirmed antiphospholipid syndrome, diagnosed in accordance with
the Sydney criteria
- Receiving Vitamin K antagonist during at least 3 months
- Willing and be able to understand the study information and sign the informed
consent form
Exclusion criteria
- None
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL76113.041.21 |