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Trial to Reduce Alloimmunization to Platelets (TRAP)

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ClinicalTrials.gov Identifier: NCT00000589
Recruitment Status : Completed
First Posted : October 28, 1999
Last Update Posted : November 6, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
To determine the best, clinically useful procedure to prevent or minimize platelet alloimmunization as a cause of refractoriness to platelet transfusion in patients undergoing marrow ablative chemotherapy for acute myelogenous leukemia.

Condition or disease Intervention/treatment Phase
Blood Platelets Hematologic Diseases Immunization Leukemia, Myelocytic, Acute Blood Transfusion Procedure: platelet transfusion Phase 3

Detailed Description:


Between 1971 and 1980, there was a 598 percent increase in the use of platelet concentrates from 0.41 million to more than 2.86 million annually. In contrast, red cell transfusions in the United States rose concurrently from 6.3 million annually to 9.9 million, an increase of 58 percent. Although red cell transfusions have leveled or even decreased slightly in the past several years, the use of platelets has continued to increase at a rate of at least 5 to 10 percent each year. This dramatic and continued increase in the use of platelet concentrates is largely the result of treating thrombocytopenic cancer patients. In addition, open heart surgery patients and others given massive transfusions also receive substantial platelet support. Nevertheless, it is the chronically transfused thrombocytopenic patient who frequently develops platelet alloimmunization and accounts for a large percentage of the increased demand for platelets. A recent survey in a large transfusion service indicated that 8 percent of the patients had received 35 percent of the random-donor pooled platelet concentrates. Although some alloimmunized patients can be supported by HLA-matched, apheresis-donor platelets, suitably matched donors are not available in sufficient numbers for every patient. Thus, platelet transfusion programs that could prevent, or at least delay platelet alloimmunization would be of substantial benefit.

Limited studies have suggested several approaches that may reduce or prevent platelet alloimmunization: reducing the number of foreign antigens to which a recipient is exposed by providing single donor platelet apheresis products; providing leukocyte-poor blood products; inactivating donor antigen presenting cells (APC's), a type of lymphocyte contained within the transfused platelet products, by ultraviolet (UV) irradiation of platelet concentrates.

The initiative was recommended by the Blood Diseases and Resources Advisory Committee in May 1987 and approved by the National Heart, Lung, and Blood Advisory Council in September 1987. The Requests for Applications were released in June 1988.


Randomized, double-blind. There were three treatment arms and one control arm. Patients in the treatment arms received either leukocyte-poor filtered pooled random donor platelets, or ultraviolet irradiated pooled random donor platelets, or leukocyte-poor filtered single donor apheresis platelets. Patients in the control group received routinely pooled, random-donor platelets. Patients remained on their assigned treatments for all transfusions through eight weeks. Assigned transfusions were discontinued only in the event of severe adverse reaction to the platelet transfusions, granulocyte transfusions, bone marrow transplant, withdrawal of informed consent, or death. Pre- and post transfusion counts were obtained for all platelet transfusions. Each patient was followed for one year. Recruitment continued through March 1995. Data analysis ended in July 1997.

The study completion date listed in this record was obtained from the "Completed Date" entered in the Protocol Registration and Results System.

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Study Type : Interventional  (Clinical Trial)
Allocation: Randomized
Masking: Double
Primary Purpose: Prevention
Study Start Date : August 1989
Actual Study Completion Date : July 1997

Information from the National Library of Medicine

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Ages Eligible for Study:   15 Years to 75 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Male and female thrombocytopenic patients, ages 15 and over, newly diagnosed with acute myelogenous leukemia (AML) and undergoing chemotherapy.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00000589

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
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OverallOfficial: Hayden Braine Johns Hopkins University
OverallOfficial: Kuo-Jang Kao University of Florida
OverallOfficial: Jeffrey McCullough University of Minnesota
OverallOfficial: Janice McFarland Blood Center of Southeastern Wisconsin
OverallOfficial: Charles Schiffer University of Maryland
OverallOfficial: Sherrill Schlichter Bloodworks
Study Data/Documents: Individual Participant Data Set  This link exits the ClinicalTrials.gov site
Identifier: TRAP
NHLBI provides controlled access to IPD through BioLINCC. Access requires registration, evidence of local IRB approval or certification of exemption from IRB review, and completion of a data use agreement.

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ClinicalTrials.gov Identifier: NCT00000589    
Other Study ID Numbers: 309
U01HL042824 ( U.S. NIH Grant/Contract )
First Posted: October 28, 1999    Key Record Dates
Last Update Posted: November 6, 2016
Last Verified: May 2000
Additional relevant MeSH terms:
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Leukemia, Myeloid
Leukemia, Myeloid, Acute
Hematologic Diseases
Neoplasms by Histologic Type