Brief Title
Platelet Function in Patients With Hemophilia A
Official Title
Decreased Platelet Function as a Cause of Increased Bleeding in Patients With Hemophilia A
Brief Summary
Abnormalities in the gene encoding Factor VIII (FVIII) results in hemophilia A, an X-linked
recessive bleeding disorder with a prevalence of 1 in 5000 males. Hemophilia A patients are
classified into 3 different categories based on residual FVIII activity compared to normal:
mild (6-40%), moderate (1-5%) and severe (<1%). This categorization correlates to some degree
with bleeding phenotype, but does not completely define it. Some patients with hemophilia A
bleed less often than others despite identical plasma FVIII levels. The cause(s) of this
phenotype heterogeneity in hemophilia A remains largely unknown, despite a number of studies
of possible factors.
Activated platelets, in addition to their role in primary hemostasis, play a major role in
secondary hemostasis (coagulation) by providing a phospholipid surface to which coagulation
factors bind. A role for platelets in the hemorrhagic propensity of hemophilia A has been
suggested in the past, but only a small number of studies have been performed with
limitations in assays performed and numbers of patients. The purpose of the present study is
to determine whether platelet reactivity in severe hemophilia A patients is associated with
past bleeding frequency and/or predicts future bleeding frequency.
Study Type
Observational
Primary Outcome
The percentage of coated platelets.
Secondary Outcome
Platelet reactivity.
Condition
Hemophilia A
Publications
* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.
Recruitment Information
Estimated Enrollment
36
Start Date
March 2015
Completion Date
February 1, 2020
Primary Completion Date
June 2018
Eligibility Criteria
Inclusion Criteria:
- Patients with severe hemophilia A who are being prophylactically treated with FVIII.
- Age of at least 2 years.
- Bleeding history of at least 6 months.
- IRB-approved informed consent.
Exclusion Criteria:
- Presence of FVIII inhibitors.
- Greater than 7 days since active bleeding.
Gender
Male
Ages
2 Years - 18 Years
Accepts Healthy Volunteers
No
Contacts
Alan D Michelson, MD, ,
Location Countries
United States
Location Countries
United States
Administrative Informations
NCT ID
NCT02093065
Organization ID
BCH-CPRS-hemophilia A
Responsible Party
Principal Investigator
Study Sponsor
Boston Children's Hospital
Collaborators
Baxter Healthcare Corporation
Study Sponsor
Alan D Michelson, MD, Principal Investigator, Boston Children's Hospital
Verification Date
July 2020