The influence of antiphospholipid antibodies on INR values measured with the CoaguChek XS

Completed

Conditions: Thrombosis in the antiphospholipid syndrome
clot formation in the antiphospholipid syndrome
10003816
10014523

Registration Number: NL-OMON51121

Lead Sponsor: niversitair Medisch Centrum Utrecht

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 80

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

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The main study parameter is the difference in INR values measured with the<br /><br>Coaguchek XS and Coagulometer. A difference in INR >0,5 will be considered<br /><br>clinically significant.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Secondary parameter includes:<br /><br>- The determination of antiphospholipid antibodies: IgG / IgM directed against<br /><br>cardiolipin, β2-Glycoprotein I, phosphatidic acid, phosphatidyl-choline, -<br /><br>ethanolamine, -glycerol, -inositol, -serine, annexin V and prothrombin, and<br /><br>antiphospholipid antibodies that prolong the clotting time in vitro, known as<br /><br>lupus anticoagulant. Lupus anticoagulant will be determined using a dilute<br /><br>Russell*s Viper Venom Time (dRVVT) screen and confirm, and an activated partial<br /><br>tromboplastin time (APTT) screen and confirm.<br /><br><br /><br>- The evaluation of differences in INR values between triple positive APS<br /><br>patients (patients at highest risk for recurrent thrombosis) and non-triple<br /><br>positive APS patients. Patients are considered as triple positive if they are<br /><br>tested positive for anti-cardiolipin antibodies, anti-β2GPI antibodies and<br /><br>lupus anticoagulant. </p><br>