Identification of Donors of CD36-Deficient Platelets Among Japanese Individuals on the NIH Campus (NCT00015639) | Clinical Trial Compass
CompletedNot Applicable
Identification of Donors of CD36-Deficient Platelets Among Japanese Individuals on the NIH Campus
United States150 participantsStarted 2001-04
Plain-language summary
Plasma histidine-rich glycoprotein (HRG) binds to platelets in the presence of zinc (1). This binding is totally blocked by a monoclonal antibody directed against platelet membrane CD36. Therefore, CD36 is assumed to carry the platelet binding site for HRG (2). Because CD36 also has a variety of other ligands, including polyanionic lipids, it is also possible that it contains the binding site for heparin (also polyanionic) and might be involve in the pathogenesis of heparin-induced thrombocytopenia. Demonstrating absent HRG or heparin binding to platelets lacking CD36 would confirm that the binding sites for either or both of these ligands are located on this membrane protein. Because 3% to 11% of healthy Japanese are reported to lack CD36 on their platelets, this population is a practical source of cells for examining the physiologic role(s) for CD36. Therefore, we will recruit blood donors from the Japanese community on the NIH campus. Their platelets will tested for the presence of CD36. Recruitment will be closed after two individuals have been identified whose platelets lack CD36 and who are willing to donate 30 cc of blood on 4 or 5 subsequent occasions for binding studies with radiolabeled HRG and heparin.
Who can participate
Sex
ALL
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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
INCLUSION CRITERIA:
Phase I:
Full Japanese, African American, and Taiwanese ancestry
At least 18 years of age.
Willingness and ability to participate in Phase II of the study.
Must be able to provide written informed consent.
Phase II:
Less than 1% CD36 present on platelets, compared with controls.
EXCLUSION CRITERIA:
Phase I:
A history of anemia or thrombocytopenia.
Unwillingness or inability to participate in Phase II of the study.
Phase II:
Discovery of anemia (hemoglobin less than 11.1 g/dL for women, less than 12.7 for men) or thrombocytopenia (less than 162,000/microliter for women, less than 154,000/microliter for men) in the blood counts performed during Phase I.
Subjects will not be excluded because of any medications.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Trial details
NCT IDNCT00015639
SponsorNational Institutes of Health Clinical Center (CC)