Development of Cryopreserved Red Blood Cell Panels for Verifying ABO and D Blood Grouping Reagents / 대한수혈학회지

BACKGROUND: ABO blood grouping reagent verification is essential to ascertain safe blood transfusions. However, the research use of donated blood products has been hampered in Korea by the blood transfusion law and management policies. In this study, we developed cryopreserved red blood cell (RBC) panels utilizing the high glycerol method to verify the ABO and D blood grouping reagents. In addition, we evaluated the stability of ABO and D antigenicity. METHODS: Fresh blood was frozen by the high glycerol method, aliquoted and cryopreserved in 2 mL cryotubes. Twenty-four vials of bloods with types A (n=5), B (n=5), AB (n=4) and O (n=10) for ABO RBC panels, and eleven vials of blood types D positive (n=5), D negative (n=5) and D weak (n=1) for D RBC panels were established. Potency, avidity and specificity tests were carried out with four different commercial ABO and D blood grouping reagents. RESULTS: The potency of cryopreserved RBCs after thawing showed no statistical difference compared with pre-freezing RBCs. Avidity time measurements were 5 seconds in ABO blood and 20 seconds in D positive blood. Specificity test uniformly showed 100% specificity. When thawed RBCs were stored at 4degrees C for 7 days, the potency test measured at intervals of 2 days showed no variation. CONCLUSION: Cryopreserved RBC panels produced by the high glycerol method showed excellent results in stability test with reagents produced by manufacturers in Korea. Therefore, these panels can be utilized as a reliable method of verifying blood grouping reagents.

Comparison of Cryopreservation Methods of Rare Red Blood Cells Used for Antibody Identification Tests / 대한수혈학회지

BACKGROUND: When a certain antibody, which is not clearly identified, is detected before transfusion, rare red blood cells (RBCs) should be used for antibody identification. But its rarity make it difficult to identify the antibody. This study compared the high glycerol method with the liquid nitrogen method for the cryopreservation of rare RBCs that are used for antibody identification. METHODS: The frozen RBCs were thawed every 2 months to measure the strength of agglutination. We observed the changes of the strength of agglutination. The Di(a) antigen, which is relatively frequent in Asians, was included in this study. RESULTS: Using the high glycerol method, the decrease of the strength of agglutination was observed with using the k antigen from 4 months and the decrease of the strength of agglutination was observed with using M, N, s, Le(a), Le(b) and Fy(b) antigens from 8 months. With freezing the donor RBCs by the liquid nitrogen method, the decrease of the strength of agglutination was observed with using the C, s, k and Le(b) antigens from 2 months, with using the M and S antigens from 4 months, with using the D, c, e, N and Fy(a) antigens from 6 months and with using the Le(a) antigen from 8 months. Rare RBCs with the Di(a) antigen were successfully cryopreserved for 6 months with using the high glycerol method. For the commercial screening cells, the high glycerol method showed effective cryopreservation with using c, e, M, k, Le(a), Le(b), Jk(a) and Fy(b) antigens for 6 months or longer. CONCLUSION: We were able to preserve most of the important antigens of the RBCs for at least 6 months without a significant decrease of reactivity by employing the high glycerol cryopreservation technique.

Comparison of Cryopreservation Methods of Rare Red Blood Cells Used for Antibody Identification Tests / 대한수혈학회지

BACKGROUND: When a certain antibody, which is not clearly identified, is detected before transfusion, rare red blood cells (RBCs) should be used for antibody identification. But its rarity make it difficult to identify the antibody. This study compared the high glycerol method with the liquid nitrogen method for the cryopreservation of rare RBCs that are used for antibody identification. METHODS: The frozen RBCs were thawed every 2 months to measure the strength of agglutination. We observed the changes of the strength of agglutination. The Di(a) antigen, which is relatively frequent in Asians, was included in this study. RESULTS: Using the high glycerol method, the decrease of the strength of agglutination was observed with using the k antigen from 4 months and the decrease of the strength of agglutination was observed with using M, N, s, Le(a), Le(b) and Fy(b) antigens from 8 months. With freezing the donor RBCs by the liquid nitrogen method, the decrease of the strength of agglutination was observed with using the C, s, k and Le(b) antigens from 2 months, with using the M and S antigens from 4 months, with using the D, c, e, N and Fy(a) antigens from 6 months and with using the Le(a) antigen from 8 months. Rare RBCs with the Di(a) antigen were successfully cryopreserved for 6 months with using the high glycerol method. For the commercial screening cells, the high glycerol method showed effective cryopreservation with using c, e, M, k, Le(a), Le(b), Jk(a) and Fy(b) antigens for 6 months or longer. CONCLUSION: We were able to preserve most of the important antigens of the RBCs for at least 6 months without a significant decrease of reactivity by employing the high glycerol cryopreservation technique.