Platelet Function in Patients With Hemophilia A

This study is ongoing, but not recruiting participants.
Sponsor:
Collaborator:
Baxter Healthcare Corporation
Information provided by (Responsible Party):
Children's Hospital Boston
ClinicalTrials.gov Identifier:
NCT02093065
First received: March 19, 2014
Last updated: March 21, 2014
Last verified: March 2014
  Purpose

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.


Condition
Hemophilia A

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Decreased Platelet Function as a Cause of Increased Bleeding in Patients With Hemophilia A

Resource links provided by NLM:


Further study details as provided by Children's Hospital Boston:

Primary Outcome Measures:
  • The percentage of coated platelets. [ Time Frame: 2 years ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Platelet reactivity. [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  • The number of procoagulant platelet-derived microparticles. [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  • The level of FVIII bound to platelets. [ Time Frame: 2 years ] [ Designated as safety issue: No ]

Biospecimen Retention:   Samples With DNA

whole blood


Estimated Enrollment: 36
Study Start Date: May 2014
Estimated Primary Completion Date: May 2016 (Final data collection date for primary outcome measure)
  Eligibility

Ages Eligible for Study:   2 Years to 18 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Patients with severe hemophilia A who do not have inhibitors against FVIII and who have a bleeding history of at least 6 months.

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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT02093065

Locations
United States, Massachusetts
Boston Children's Hospital, Boston Hemophilia Center
Boston, Massachusetts, United States, 02115
Sponsors and Collaborators
Children's Hospital Boston
Baxter Healthcare Corporation
Investigators
Principal Investigator: Alan D Michelson, MD Children's Hospital Boston
  More Information

No publications provided

Responsible Party: Children's Hospital Boston
ClinicalTrials.gov Identifier: NCT02093065     History of Changes
Other Study ID Numbers: BCH-CPRS-hemophilia A
Study First Received: March 19, 2014
Last Updated: March 21, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Children's Hospital Boston:
severe hemophilia A
coated platelets
bleeding

Additional relevant MeSH terms:
Hemophilia A
Blood Coagulation Disorders, Inherited
Blood Coagulation Disorders
Hematologic Diseases
Coagulation Protein Disorders
Hemorrhagic Disorders
Genetic Diseases, Inborn
Factor VIII
Coagulants
Hematologic Agents
Therapeutic Uses
Pharmacologic Actions

ClinicalTrials.gov processed this record on July 31, 2014