title: Riboflavin-ultraviolet light pathogen reduction treatment does not impact the immunogenicity of murine red blood cells.
abstract: BACKGROUND
  Ultraviolet (UV) illumination/pathogen reduction effectively inactivates white blood cells (WBCs) in whole blood. Given that cotransfused WBCs may impact recipient immune responses, we hypothesized that pathogen reduction of whole blood may alter responses to RBC antigens.
  
  
  METHODS
  Transgenic mice expressing a model (HOD) antigen, authentic human (hGPA or KEL) antigens, or natural fluorescence (uGFP) on their RBCs were utilized as blood donors. Recipients were transfused with fresh whole blood to which riboflavin had been added or fresh whole blood treated by UV illumination/pathogen reduction treatment after the addition of riboflavin. Posttransfusion RBC recovery, survival, and alloimmunization were measured by flow cytometry.
  
  
  RESULTS
  UV illumination/pathogen reduction treatment did not alter RBC antigen expression, and recipients of treated syngeneic RBCs had persistently negative direct antiglobulin tests. Greater than 75% of treated and untreated syngeneic RBCs were recovered 24 hours posttransfusion in all experiments, although alterations in the long-term posttransfusion survival of treated RBCs were observed. Treated and untreated KEL RBCs induced similar recipient alloimmune responses, with all recipients making anti-KEL glycoprotein immunoglobulins (p > 0.05). Alloimmune responses to treated HOD or hGPA RBCs were no different from untreated RBCs (p > 0.05).
  
  
  CONCLUSIONS
  Pathogen inactivation treatment of fresh whole murine blood with riboflavin and UV illumination does not impact the rate or magnitude of RBC alloimmunization to three distinct RBC antigens. Further, UV illumination/pathogen reduction appears safe from an immunohematologic standpoint, with no immunogenic neoantigens detected on treated murine RBCs. Future studies with fresh and stored human RBCs are warranted to confirm these findings.
authors.affiliation: Department of Laboratory Medicine.|VA Connecticut Healthcare System, West Haven, Connecticut.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Tormey
authors.affiliation: Department of Laboratory Medicine.
authors.forename: Manjula
authors.initials: M
authors.lastname: Santhanakrishnan
authors.affiliation: Departments of Pediatrics and Pathology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Nicole H
authors.initials: NH
authors.lastname: Smith
authors.affiliation: Department of Laboratory Medicine.
authors.forename: Jingchun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Terumo BCT, Lakewood, Colorado.
authors.forename: Susanne
authors.initials: S
authors.lastname: Marschner
authors.affiliation: Terumo BCT, Lakewood, Colorado.
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Goodrich
authors.affiliation: Department of Laboratory Medicine.|Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut.|Departments of Pediatrics and Pathology, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Jeanne E
authors.initials: JE
authors.lastname: Hendrickson
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000187:drug effects / Q000528:radiation effects; D001793:Blood Preservation / Q000379:methods; D017848:Blood-Borne Pathogens / Q000187:drug effects / Q000528:radiation effects; D004912:Erythrocytes / Q000187:drug effects / Q000276:immunology* / Q000528:radiation effects; D006801:Humans; D007518:Isoantibodies / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000276:immunology; D008666:Metalloendopeptidases / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D012256:Riboflavin / Q000494:pharmacology*; D013242:Sterilization / Q000379:methods*; D014466:Ultraviolet Rays
chemical_list: D007518:Isoantibodies; D008562:Membrane Glycoproteins; C585978:KEL protein, human; D008666:Metalloendopeptidases; D012256:Riboflavin