Effect of red blood cell preservation by droplet freezing with non-permeable cryoprotective agents in blood group antigen reactivity.

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 Fy , Le , C, E, C , Lu , Lu , Kp , Kp and Di . However, cryopreservation using PVP resulted in a significant increase in reactivity of Fy 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.