The role of active vWF in physiological platelet adhesion and aggregation

The role of active vWF in physiological platelet adhesion and aggregation - Active vWF and platelets

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

NL-OMON

Registry ID

NL-OMON48403

Enrollment

Registered

2019-02-27

Start date

2019-03-14

Completion date

Unknown

Last updated

2024-04-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

von Willebrand Disease type 2B vWD 2B

Interventions

None listed

Eligibility

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: * 18 years or older

Exclusion criteria

Exclusion criteria: * History of thrombosis or bleeding * Use of anti-coagulants, aspirin or other platelet function inhibitors in the 10 days preceding the blood draw for an experiment * Use of statins and ACE inhibitors * Diagnosis of hepatic and/or renal failure * Chronic inflammatory diseases, such as rheumatoid arthritis, psoriasis, inflammatory bowel diseases, systemic lupus erythematous (SLE), diabetes mellitus (DM) * Malignancies (excluding basal cell carcinoma of the skin)

Design outcomes

Primary

Measure	Time frame
The primary study outcome is active von Willebrand factor levels, normalized to levels in normal pooled plasma (% of NPP), as measured by the immunosorbent assay.	—

Secondary

Measure	Time frame
* Binding of the VHH to different forms of vWF (expressed as OD at 490 nm after addition of substrate OPD to reaction). * Ristocetin-induced vWF-platelet binding, measured by flow cytometric assay, expressed as median fluorescence index (MFI). * Ristocetin-, collagen or ADP-induced vWF-dependent platelet agglutination or aggregation (respectively), measured by LTA, expressed as maximal platelet aggregation. * Aperture occlusion time, as measured by PFA-200, expressed in seconds * Platelet covered area (%), measured from images taken during perfusion experiments * Fluorescence intensity (AU), measured from images taken during perfusion experiments	—

Measure

Time frame

* Binding of the VHH to different forms of vWF (expressed as OD at 490 nm after addition of substrate OPD to reaction). * Ristocetin-induced vWF-platelet binding, measured by flow cytometric assay, expressed as median fluorescence index (MFI). * Ristocetin-, collagen or ADP-induced vWF-dependent platelet agglutination or aggregation (respectively), measured by LTA, expressed as maximal platelet aggregation. * Aperture occlusion time, as measured by PFA-200, expressed in seconds * Platelet covered area (%), measured from images taken during perfusion experiments * Fluorescence intensity (AU), measured from images taken during perfusion experiments

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Countries

Netherlands

Outcome results