Plain English Summary
Background and study aims
Platelets are blood cells that help the blood clot. They are an important first line of defence against bleeding. Platelet numbers may be low if a person doesn’t make enough platelets or if their platelets are broken down too quickly once they are made. People with low platelet counts are more vulnerable to bleeding. If they undergo surgery or start to bleed, a transfusion of platelets taken from blood donors is often needed to stop the bleeding. Platelet transfusions have a number of disadvantages: supplies are limited, they are expensive, there can be side effects such as bacterial infections and allergic reactions, and some patients do not benefit. Von Willebrand factor (vWF) naturally occurs in the body and causes platelets to stick to sites of injury to stop bleeding. Initial tests have been performed on the blood of volunteers with normal platelet counts. Their blood was treated to lower the platelet count. Adding vWF to the blood samples considerably improved the way their platelets worked. This study aims to investigate in the laboratory if adding vWF to blood from people with low platelet counts could improve the way the platelets work so that platelet transfusions are no longer needed.
Who can participate?
Patients aged 18 or over with low platelet counts (e.g., immune thrombocytopenic purpura or a bone marrow failure syndrome such as myelodysplastic syndrome).
What does the study involve?
Patients with low platelet counts will be asked if they will give extra blood for a laboratory investigation when they next have blood taken. The volume of extra blood is equivalent to three teaspoons and will be rapidly remade by the body. Patients will be asked questions about medications and recent food that they have eaten, as these can cause changes in the test results. The blood samples will be analysed in the laboratory. Firstly the patient’s platelet count will be rechecked. If there are more than 50 billion platelets per litre, it will not be analysed further. If there are less than 50 billion per litre then further tests will be performed to see how well the platelets are working. vWF will then be added to the blood samples and the tests will be repeated.
What are the possible benefits and risks of participating?
There are no direct benefits for patients who agree to take part in the study. We hope that this study will allow us to identify new ways to treat bleeding for patients with low platelet counts in the future. The risk of any complication from extra blood being taken is minimal.
Where is the study run from?
Churchill Hospital (UK).
When is the study starting and how long is it expected to run for?
From April to September 2015.
Who is funding the study?
Investigator initiated and funded (UK).
Who is the main contact?
Dr Michael Desborough
Trial website
Contact information
Type
Public
Primary contact
Dr Michael Desborough
ORCID ID
http://orcid.org/0000-0002-1951-5616
Contact details
NHS Blood and Transplant
John Radcliffe Hospital
Oxford
OX3 9DU
United Kingdom
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
N/A
Study information
Scientific title
VWF platelet study: a pilot observational study of von Willebrand factor for moderate or severe thrombocytopenia
Acronym
vWF Platelet Study
Study hypothesis
To determine whether the addition of intermediate purity factor VIII (a source of von Willebrand factor) to the donated blood of thrombocytopenic patients improves their platelet function.
Ethics approval
NRES Committee North West - Haydock, 11/02/2015, ref: 15/NW/0138
Study design
Observational single-centre trial
Primary study design
Observational
Secondary study design
Trial setting
Hospitals
Trial type
Other
Patient information sheet
Condition
Immune thrombocytopenic purpura or thrombocytopenia due to bone marrow failure
Intervention
Platelet function will be tested on blood donated by patients. These tests will be repeated after addition of intermediate purity factor VIII.
Intervention type
Other
Phase
Drug names
Primary outcome measures
Normalisation of platelet function, measured with a platelet function analyser 200 adenosine diphosphate/collagen cartridge after addition of intermediate purity factor VIII
Secondary outcome measures
1. Normalisation of platelet function, measured with microfluidics using collagen as an agonist under arterial shear force conditions after addition of intermediate purity factor VIII
2. Normalisation of platelet function, measured with a platelet function analyser 200 P2Y2 cartridge after addition of intermediate purity factor VIII
Overall trial start date
01/04/2015
Overall trial end date
31/03/2017
Reason abandoned
Eligibility
Participant inclusion criteria
1. Age 18 years or over
2. Confirmed diagnosis of immune thrombocytopenic purpura or a bone marrow failure syndrome such as myelodysplastic syndrome
3. Platelet count less than 50x10^9/l
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
20
Participant exclusion criteria
1. Any inherited platelet disorder or von Willebrand disease
2. Use of an antiplatelet agent (e.g. aspirin or clopidogrel) in the 7 days before blood sampling
Recruitment start date
01/04/2015
Recruitment end date
31/03/2017
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Churchill Hospital
Old Road
Headington
Oxford
OX3 7LE
United Kingdom
Sponsor information
Organisation
NHS Blood and Transplant
Sponsor details
R&D Administration
NHS Blood and Transplant
500 North Bristol Park
Bristol
BS34 7QH
United Kingdom
Sponsor type
Hospital/treatment centre
Website
Funders
Funder type
Other
Funder name
Investigator initiated and funded (UK)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
To be confirmed at a later date
Intention to publish date
Participant level data
Available on request
Results - basic reporting
Publication summary