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Transfusion-Associated Microchimerism in Individuals Receiving a Blood Transfusion After a Traumatic Injury

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Blood Systems Research Institute Identifier:
First received: November 15, 2006
Last updated: April 11, 2013
Last verified: April 2013
Individuals who experience a traumatic injury often have a significant amount of blood loss and may require a blood transfusion. In some individuals who receive a blood transfusion, white blood cells from the donor's blood may remain in the body for years, a condition known as microchimerism. This study will examine the reasons why microchimerism occurs in some blood transfusion recipients and not others.

Blood Transfusion
Wounds and Injuries

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Prospective Study of the Kinetics and Mechanisms of Transfusion-associated Microchimerism in Injured Patients

Resource links provided by NLM:

Further study details as provided by Blood Systems Research Institute:

Primary Outcome Measures:
  • Prevalence and magnitude of transfusion-associated microchimerism [ Time Frame: 1, 2 and 4 weeks, 3 and 6 months ]

Biospecimen Retention:   Samples With DNA
Whole blood, plasma, peripheral blood mononuclear cells

Enrollment: 451
Study Start Date: November 2006
Study Completion Date: July 2012
Primary Completion Date: August 2010 (Final data collection date for primary outcome measure)
Detailed Description:

Approximately 20% of individuals who suffer a traumatic injury require a blood transfusion; of these, 10% to 15% experience a condition known as transfusion-associated microchimerism. This occurs when white blood cells, or leukocytes, from the donor's blood persist in the recipient long after the transfusion occurs. The genetically distinct donor cells can remain in the individual for decades, and may account for as many as 4% of the white blood cells in the recipient's body. This suggests that the donor cells are tolerated by the recipient's immune system. The purpose of this study is to examine the specific factors that predispose some blood transfusion recipients to develop microchimerism.

In this study, blood samples will be collected from injured individuals who arrive at the University of California at Davis Medical Center. Individuals who receive a blood transfusion, as well as a control group of individuals who do not receive a transfusion, will be approached to enroll in the study. Individuals who agree to participate will have their blood collected at Days 7, 14, and 28 and Months 3 and 6. Study researchers will analyze the blood for evidence of microchimerism. Participants with microchimerism will undergo additional blood collection at Months 12, 18, 24, 30, and 36. Information will be collected from all participants on health status, injury characteristics, hospital care, blood transfusion details, and blood donor characteristics.


Ages Eligible for Study:   12 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Emergency Department

Inclusion Criteria:

  • Hospitalized for a traumatic injury
  • Received at least one unit of transfused red blood cells

Exclusion Criteria:

  • Currently incarcerated
  • Inadequate decision-making capacity of the participant and no available surrogate decision-maker
  • Prior bone marrow or solid organ transplantation
  Contacts and Locations
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Please refer to this study by its identifier: NCT00400192

United States, California
University of California, Davis, Medical Center
Sacramento, California, United States, 95817
Sponsors and Collaborators
Blood Systems Research Institute
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Michael P. Busch, MD, PhD Blood Systems Research Institute