title: Microchimerism in transfused trauma patients is associated with diminished donor-specific lymphocyte response.
abstract: BACKGROUND
  Blood transfusion can result in long-term survival of donor leukocyte subpopulations, or microchimerism, in the peripheral blood of injured patients. Neither injury severity nor the number of transfusions is associated with its occurrence. We sought to determine whether changes in general or antigen-specific lymphocyte activation may be associated with the subsequent development of microchimerism.
  
  
  METHODS
  We evaluated 63 transfused trauma patients, which we compared with 10 non-transfused trauma patients and 10 healthy control subjects. Of the 63 transfused patients, 31 were known to have evidence of microchimerism at hospital discharge with real-time quantitative PCR for non-recipient HLA DR alleles. We assessed lymphocyte response to phytohemagglutinin (PHA) using blood sampled upon arrival to the hospital (before transfusion) and at discharge. We performed one-way mixed leukocyte cultures (MLC) with pre-transfusion recipient specimens to assess recipient lymphocyte response to mitomycin-C treated donor cells and vice versa.
  
  
  RESULTS
  Lymphocyte response to PHA in microchimeric transfusion recipients was lower at admission (before transfusion) and discharge than in non-microchimeric recipients. Lymphocytes from microchimeric patients had less response to donor cells than did lymphocytes from non-microchimeric patients. Microchimeric patients also more frequently had diminished lymphocyte response to a single blood donor on MLC.
  
  
  CONCLUSIONS
  Transfusion-associated microchimerism is correlated with diminished response to mitogen challenge as well as to specific alloantigenic challenges. This microchimerism is predated by diminished lymphocyte response to a specific blood donor in many instances. The blood donor associated with this diminished alloantigenic lymphocyte response may be the source of microchimeric cells present in the recipient.
authors.affiliation: Department of Surgery, University of California, Davis, Medical Center, Sacramento, California 95817, USA.
authors.forename: Garth H
authors.initials: GH
authors.lastname: Utter
authors.forename: John T
authors.initials: JT
authors.lastname: Owings
authors.forename: Tzong-Hae
authors.initials: TH
authors.lastname: Lee
authors.forename: Teresa G
authors.initials: TG
authors.lastname: Paglieroni
authors.forename: William F
authors.initials: WF
authors.lastname: Reed
authors.forename: Robert C
authors.initials: RC
authors.lastname: Gosselin
authors.forename: Paul V
authors.initials: PV
authors.lastname: Holland
authors.forename: Michael P
authors.initials: MP
authors.lastname: Busch
mesh_terms: D000328:Adult; D001782:Blood Donors; D001803:Blood Transfusion; D046528:Chimerism; D005260:Female; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010835:Phytohemagglutinins; D011446:Prospective Studies; D014947:Wounds and Injuries / Q000097:blood / Q000235:genetics* / Q000276:immunology* / Q000628:therapy
chemical_list: D010835:Phytohemagglutinins