title: Prophylactic red blood cell exchange for ABO-mismatched hematopoietic progenitor cell transplants.
abstract: BACKGROUND
  To enhance donor availability, almost half of hematopoietic progenitor cell transplants (HPCTs) cross ABO blood type boundaries. ABO-incompatible HPCTs are well tolerated; however, there is an increased risk of delayed hemolysis in patients with minor and bidirectional ABO mismatches. Delayed hemolysis generally occurs 1 to 2 weeks after HPCT and is related to production of alloantibodies directed against recipient ABO red blood cell (RBC) antigens by passenger donor lymphocytes. One previous study has suggested that prophylactic RBC exchange in patients with minor and bidirectional ABO-mismatched HPCT reduces the risks of severe immune hemolysis, but this recommendation is controversial.
  
  
  METHODS
  Herein we describe our experience using prophylactic RBC exchange in patients with minor and bidirectional ABO-mismatched HPCTs who were deemed to be at high risk for immune hemolysis. We compare the group of patients that received prophylactic RBC exchange with a historical cohort of ABO-mismatched patients who underwent HPCT without prophylactic RBC exchange.
  
  
  RESULTS
  Our study suggests that prophylactic RBC exchange in minor and bidirectional ABO-mismatched HPCT does not reduce severe immune hemolysis, nor does it improve 1-year survival, the number of RBC units transfused after transplant, or length of hospitalization after HPCT.
  
  
  CONCLUSIONS
  This study failed to identify a clear role for selected prophylactic RBC exchange in patients who were deemed at risk for severe post-HPCT immune hemolysis.
authors.affiliation: Research Service and Division of Nephrology-Hypertension, Veterans Affairs San Diego Healthcare System, Veterans Medical Research Foundation, San Diego, California; Department of Medicine, Pathology and Moore's Cancer Center, University of California at San Diego, La Jolla, California.
authors.forename: Robyn
authors.initials: R
authors.lastname: Cunard
authors.forename: Isagani I
authors.initials: II
authors.lastname: Marquez
authors.forename: Edward D
authors.initials: ED
authors.lastname: Ball
authors.forename: Connie L
authors.initials: CL
authors.lastname: Nelson
authors.forename: Sue
authors.initials: S
authors.lastname: Corringham
authors.forename: Paul
authors.initials: P
authors.lastname: Clopton
authors.forename: Amber P
authors.initials: AP
authors.lastname: Sanchez
authors.forename: Thomas
authors.initials: T
authors.lastname: Lane
authors.forename: David M
authors.initials: DM
authors.lastname: Ward
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000328:Adult; D000368:Aged; D001787:Blood Group Incompatibility / Q000150:complications / Q000276:immunology*; D016022:Case-Control Studies; D015331:Cohort Studies; D017707:Erythrocyte Transfusion / Q000379:methods*; D005260:Female; D006086:Graft vs Host Disease / Q000276:immunology / Q000517:prevention & control*; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006461:Hemolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D019172:Transplantation Conditioning / Q000009:adverse effects / Q000379:methods*
chemical_list: D000017:ABO Blood-Group System