Preservation of red blood cell antigenicity in a new storage solution in vitro.

INTRODUCTION: Red blood cell (RBC) storage solution is used for suspending and preserving RBCs for later use in in vitro immunohematology testing. Proper RBC preservation is crucial for obtaining accurate results in RBC phenotyping and pretransfusion antibody screening tests. Haemolysis or RBC antigen degradation during storage can result in inaccurate RBC phenotyping, thereby decreasing the sensitivity of pretransfusion antibody screening and identification assays. The conventional RBC storage solutions usually contain adenosine, adenine, and antibiotics. We designed an RBC storage solution and determined whether it could preserve RBC integrity for 70 days. MATERIALS AND METHODS: The new storage solution has a different formula from that of the conventional solution-in particular, it is strengthened with polyethylene glycol (PEG). The extent of haemolysis and hemagglutination reactivity of the RBC antigen systems, Rh, Duffy, Kidd, Lewis, MNS, P1, and the rare antigen Mia (which has a low prevalence antigen in most parts of the world but a higher prevalence in Taiwan), in the new RBC storage solution was compared with that of the conventionally preserved RBC storage solution. RESULTS: The RBCs preserved in the new solution for 70 days retained a similar haemolysis grade as those preserved in the control solution for 28 days. Although both solutions largely preserved RBC antigenicity, the decline in RBC hemagglutination scores in new solution often occurred later than that in the control solution in most antigen phenotyping assays, especially labile antigens such as D, P1, and M. CONCLUSION: The new solution reduces haemolysis more effectively and preserves antigenicity throughout the 70-day storage period. Moreover, Mia antigen is more stable in the experimental group.

Thomsen-Friedenreich activation in infants with necrotizing enterocolitis in Taiwan.

BACKGROUND: Thomsen-Friedenreich (T) activation in infants with neonatal necrotizing enterocolitis (NEC) has in some cases led to severe hemolysis after transfusions of plasma-containing blood components, causing some authors to advise routine screening for T activation in all infants with NEC. However, no data are available on the frequency of T activation in infants with NEC in Taiwan. STUDY DESIGN AND METHODS: We retrospectively reviewed the medical records of 43 infants with NEC managed in our hospital from 2000 to 2007. In all cases, Arachis hypogaea lectin was used to test for T activation. RESULTS: Of the 43 infants, 16 infants (37%) had Stage II and 27 (63%) had Stage III NEC. Four infants had trace T activation, two of whom received transfusions with washed red blood cells (RBCs) and two with unwashed RBCs. None had evidence of hemolysis. The overall mortality in this series was 16% (7/43), but none of the four babies with T activation died. CONCLUSION: In this series of Taiwanese infants with NEC, weak T activation was present in only 9% (4/43) of infants, and RBC transfusion did not result in hemolysis, regardless of whether washed or unwashed cells were administered. We considered routine screening for T activation and provision of prepared blood components in infants with NEC in Taiwan might be unnecessary.