title: Effect of red blood cell preservation by droplet freezing with non-permeable cryoprotective agents in blood group antigen reactivity.
abstract: BACKGROUND
  In the last few decades, various red blood cell (RBC) freezing techniques have been developed and improved to enable the preservation of erythrocytes for future use in pre-transfusion tests in reference immunohaematology laboratories. However, not all these techniques have been sufficiently evaluated for the preservation of blood group antigens.
  
  
  OBJECTIVE
  In this study, we evaluated the antigenic pattern of RBCs preserved by droplet freezing in liquid nitrogen in a blood bank context.
  
  
  METHODS
  Blood samples were evaluated for the reactivity of blood group antigens after droplet freezing using the non-permeable cryoprotective agent polyvinylpyrrolidone (PVP) and sucrose-dextrose (S + D) solutions.
  
  
  RESULTS
  No qualitative changes were observed in RBC reactivity after freezing and thawing for the antigens Fyb, Leb, C, E, Cw, Lua, Lub, Kpa, Kpband Dia. However, cryopreservation using PVP resulted in a significant increase in reactivity of Fybantigen on comparing fresh and frozen samples (P < 0·001).
  
  
  CONCLUSIONS
  The establishment of detailed protocols for cryopreservation of RBCs, which take into account the maintenance of antigenic characteristics, is necessary to increase security in pre-transfusion testing using frozen RBCs.
authors.affiliation: Fundação Centro de Hematologia e Hemoterapia de Minas Gerais - Hemominas, Belo Horizonte, MG, Brazil.
authors.forename: M A B
authors.initials: MA
authors.lastname: Chagas
authors.affiliation: Fundação Centro de Hematologia e Hemoterapia de Minas Gerais - Hemominas, Belo Horizonte, MG, Brazil.
authors.forename: D G
authors.initials: DG
authors.lastname: Chaves
authors.affiliation: Centro Regional de Hemoterapia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Hemocentro de Ribeirão Preto, Ribeirão Preto, SP, Brazil.
authors.forename: S K
authors.initials: SK
authors.lastname: Haddad
authors.affiliation: Centro Regional de Hemoterapia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Hemocentro de Ribeirão Preto, Ribeirão Preto, SP, Brazil.
authors.forename: E M A
authors.initials: EM
authors.lastname: Ubiali
authors.affiliation: Fundação Centro de Hematologia e Hemoterapia de Minas Gerais - Hemominas, Belo Horizonte, MG, Brazil.
authors.forename: L C
authors.initials: LC
authors.lastname: Schmidt
authors.affiliation: Fundação Centro de Hematologia e Hemoterapia de Minas Gerais - Hemominas, Belo Horizonte, MG, Brazil.
authors.forename: M C F
authors.initials: MC
authors.lastname: Silva-Malta
mesh_terms: D001771:Blood Banks; D001789:Blood Group Antigens / Q000276:immunology* / Q000378:metabolism; D001793:Blood Preservation / Q000379:methods*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004912:Erythrocytes / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D008297:Male; D011205:Povidone / Q000494:pharmacology; D013395:Sucrose / Q000494:pharmacology
chemical_list: D001789:Blood Group Antigens; D003451:Cryoprotective Agents; D013395:Sucrose; D011205:Povidone; D005947:Glucose
keywords: blood group antigens; cryopreservation; red blood cells