Transfusion medicine
Transfusion side effects

Topic Completed: 1 September 2011

Minor changes: 5 April 2019

Copyright: 2002-2017,, Inc.

PubMed Search: Microchimerism [title] transfusion

Huy Phu Pham, M.D., M.P.H.
Page views in 2019: 30
Page views in 2020 to date: 7
Cite this page: Pham H. Microchimerism. website. Accessed May 30th, 2020.
Definition / general
  • Chimerism: presence of more than one genetically distinct population of cells in a single organism
  • Microchimerism: stable persistence of an allogeneic cell population, representing < 5% of circulating cells in an individual
  • Due to transplantation, pregnancy or transfusion (Semin Hematol 2007;44:24)
  • Present in 50% of transfused, severely injured patients at hospital discharge (J Trauma 2004;57:702)
  • Injury induces immunosuppressive milieu, leading to persistence of donor WBCs
  • Not affected by leukoreduction (Transfusion 2006;46:1863)
  • No apparent increased risk of transfusion associated graft versus host disease (Blood 2001;98:272)
Clinical features
  • No adverse effects, so not recommended to modify transfusion guidelines or practices
  • Can be prevented by irradiation but microchimerism is NOT an indication for irradiation
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