Platelet Function in Patients With Hemophilia A

NCT02093065 | Completed

• 1 other identifier: BCH-CPRS-hemophilia A
• Study Type: observational
• Target: 36
• Locations: 1 country
• Sites: 1

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.

Conditions

Hemophilia A

Keywords

severe hemophilia A; coated platelets; bleeding

Outcome Measures

Primary Outcomes (1)

• The percentage of coated platelets.

  2 years

Secondary Outcomes (2)

• Platelet reactivity.

  2 years

• The number of procoagulant platelet-derived microparticles.

  2 years

Eligibility Criteria

• Age: 2 Years - 18 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)
• 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.

You may qualify if:

• 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.

You may not qualify if:

• Presence of FVIII inhibitors.
• Greater than 7 days since active bleeding.

Sponsors & Collaborators

• Boston Children's Hospital: lead
• Baxter Healthcare Corporation: collaborator

Study Sites (1)

Boston Children's Hospital, Boston Hemophilia Center

Boston, Massachusetts, 02115, United States

Location

Biospecimen

Retention: SAMPLES WITH DNA

whole blood

MeSH Terms

Conditions

Hemophilia A; Hemorrhage

Condition Hierarchy (Ancestors)

Blood Coagulation Disorders, Inherited; Blood Coagulation Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Coagulation Protein Disorders; Hemorrhagic Disorders; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Alan D Michelson, MD

  Boston Children's Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Pediatrics and Professor of Medicine, Harvard Medical School Director, Center for Platelet Research Studies Director, Thrombosis and Anticoagulation Program Boston Children's Hospital / Dana-Farber Cancer Institute

Study Record Dates

• First Submitted: March 19, 2014
• First Posted: March 20, 2014
• Study Start: March 1, 2015
• Primary Completion: June 1, 2018
• Study Completion: February 1, 2020
• Last Updated: July 14, 2020

Record last verified: 2020-07

Locations

US (1)