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. OBJECTIVES: 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 , Kpb and Dia . However, cryopreservation using PVP resulted in a significant increase in reactivity of Fyb antigen on comparing fresh and frozen samples (P < 0·001). CONCLUSION: 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.