Platelet Function in Patients With Hemophilia A

Completed

• Conditions: Hemophilia A

• Registration Number: NCT02093065
• Lead Sponsor: Boston Children's Hospital

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2014-03-19
• Study First Submitted QC: 2014-03-19
• Study First Posted: 2014-03-20
• Study Start: 2015-03
• Primary Completion: 2018-06
• Study Completion: 2020-02-01
• Status Verified: 2020-07
• Last Update Submitted: 2020-07-10
• Last Update Posted: 2020-07-14

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 36

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.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
The percentage of coated platelets.	2 years

Secondary Outcome Measures

Name	Time	Method
The number of procoagulant platelet-derived microparticles.	2 years
Platelet reactivity.	2 years

Trial Locations

Locations (1)

Boston Children's Hospital, Boston Hemophilia Center; 🇺🇸 Boston, Massachusetts, United States