The primary goal of this study is to compare serial paired POC and venous INR measuremtents and to distill an individual conversion factor per patient, enabling the ungoing use of POC-INR measurement also in this patient group.
ID
Source
Brief title
Condition
- Coagulopathies and bleeding diatheses (excl thrombocytopenic)
- 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 and Coagulometer.
Secondary outcome
Secondary parameter includes the determination of antiphospholipid antibodies:
IgG / IgM directed against cardiolipin, β2-Glycoprotein I and prothrombin, and
antiphospholipid antibodies that prolong the clotting time in vitro, known as
lupus anticoagulant.
Background summary
Patients with the antiphospholipid syndrome (APS) on anticoagulant therapy can
be monitored with the international normalized ratio (INR) using Point Of Care
(POC) devices. However, INR values can be falsely elevated due to
antiphospholipid antibodies using POC devices. Previous research from our group
confirmed that POC-INR values in patients with high titers of
anti-B2-glycoprotein IgG and strong lupus anticoagulant specifically give an
overestimation of the true INR. At this moment, these patients are advised not
to use POC-measurements any longer.
In the current study, we will compare serial INR values in APS patients
measured with the most commonly used POC device (CoaguChek) in the Netherlands
with whole blood INR values measured with the Owren method using a rabbit brain
derived thromboplastin in our laboratory in the UMC Utrecht. We aim to distill
an individual conversion factor per patient, enabling the ungoing use of
POC-INR measurement also in this patient group.
Study objective
The primary goal of this study is to compare serial paired POC and venous INR
measuremtents and to distill an individual conversion factor per patient,
enabling the ungoing use of POC-INR measurement also in this patient group.
Study design
Prospective, single center, observational study.
Study burden and risks
For this study, patients will endure 1 finger stick procedure and 1
venapuncture (6 mL blood) at ten monthly timepoints, 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. No alterations to
medication or life style are introduced.
Heidelberglaan 100
Utrecht 3584 CX
NL
Heidelberglaan 100
Utrecht 3584 CX
NL
Listed location countries
Age
Inclusion criteria
- Age 18 years and older
- Previously confirmed APS, diagnosed in accordance with the Sydney criteria
- High titers of anti-B2-glycoprotein-I IgG at screening (titer > 99th
percentile)
- Lupus anticoagulant positive at screening
- Receiving VKA during at least 3 months
- At least one thromboembolic event in the past
- Willing and be able to understand the study information and sign the informed
consent form
Exclusion criteria
Patients with only obstetric complications of antiphospholipid syndrome without
thrombotic events
Design
Recruitment
Medical products/devices used
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 | NL85268.041.23 |