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Detailed Evaluation of Microchimerism

This study has been withdrawn prior to enrollment.
(Investigators could not identify subjects who met all inclusion criteria.)
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Blood Systems Research Institute Identifier:
First received: March 25, 2010
Last updated: April 11, 2013
Last verified: April 2013
Individuals who experience traumatic injury often require blood transfusion. In some individuals who receive blood after an injury, white blood cells from a person who donated blood may remain in the body for years, a condition known as microchimerism. This study is designed to examine a group of people who are known to have long-term microchimerism and, through analysis of their blood, determine whether there is evidence that the microchimerism involves blood stem cells that can become any type of blood cell (red blood cells, white blood cells, or platelets) and that might be a permanent part of the body.

Blood Transfusion
Wounds and Injuries

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Cross-Sectional
Official Title: Evaluation to Determine Whether Transfusion-associated Microchimerism Involves Engraftment With Hematopoietic Progenitor Cells

Resource links provided by NLM:

Further study details as provided by Blood Systems Research Institute:

Biospecimen Retention:   Samples With DNA
Leukapheresis filtrate and/or whole blood samples

Enrollment: 0
Study Start Date: March 2010
Estimated Study Completion Date: November 2011
Estimated Primary Completion Date: November 2011 (Final data collection date for primary outcome measure)
Transfused microchimeric subject
Former trauma patient who underwent blood transfusion and has recent evidence of long-term transfusion-associated microchimerism

Detailed Description:

Transfusion-associated microchimerism, the persistence of donor white blood cells months or years after transfusion in the recipient, has been observed in approximately 10-15% of transfused trauma patients. Previous studies suggest that the microchimeric cells include multiple immunophenotypes of leukocytes (CD4+, CD8+, CD15+, and CD19+) and that they can persist for decades, features suggestive of hematopoietic engraftment.

In this study, ten subjects known to have long-term microchimerism will undergo either leukapheresis (a blood filtering procedure) or collection of a 500 mL whole blood sample (the amount of a standard blood donation). These samples will then be analyzed to determine whether the microchimeric (donor) cells include hematopoietic stem cells (CD34+) and precursor cells in the red blood cell, white blood cell, and platelet lineages.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Previous study participants

Inclusion Criteria:

  • Demonstrated long-term microchimerism following transfusion for traumatic injury

Exclusion Criteria:

  • Prior bone marrow or solid organ transplantation
  • Pregnancy
  • Blood transfusion within the past 12 months
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Please refer to this study by its identifier: NCT01094197

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
  More Information