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Background: Blood banking procedures are associated with elevated adherence of red blood cells (RBCs) to blood vessel wall endothelial cells (ECs), which can introduce a circulatory risk to recipients. This study was undertaken to examine the possibility of repairing this damage by a poststorage "rejuvenation" procedure before transfusion., Study Design and Methods: Stored RBCs were treated with rejuvenation solution (Rejuvesol, enCyte Systems, Inc.), and their adhesion to cultured human microvascular ECs was determined as a function of shear stress using a cell flow properties analyzer. The adherence of rejuvenation-treated stored RBCs (stRBCs) was compared to that of untreated stRBCs and of freshly donated RBCs., Results: Strong elevation of stRBC/EC adhesion was induced by cold storage and it correlated with translocation of phosphatidylserine (PS) to the RBC surface, a known mediator of RBC/EC adhesion. The role of RBC surface PS in stRBC/EC interaction was confirmed by the suppression of adhesion after the blocking of the stRBC surface PS with annexin V. Concomitantly, RBC storage elevated intracellular levels of reactive oxygen species (ROS) and Ca(2+), the latter known to facilitate PS externalization. Poststorage rejuvenation treatment of stRBCs reversed all the above changes (ROS, Ca(2+), PS), along with complete suppression of the enhanced RBC/EC adhesion, restoring it to that of normal, freshly collected RBCs., Conclusion: Poststorage RBC rejuvenation treatment is effective in reversing the storage-induced RBC/EC interaction. This provides further documentation for the potential clinical benefit of poststorage rejuvenation.

Background: Blood banking procedures are associated with damage to red blood cell (RBC) membranes, which can impair their flow properties, namely, their deformability, aggregability, and adherence to endothelial cells (ECs) and thus possibly introducing a circulatory risk to recipients. This study was undertaken to comprehensively explore the effect of cold storage and gamma irradiation on RBC flow properties., Study Design and Methods: RBC flow properties were monitored as a function of shear stress with a computerized cell flow properties analyzer. Because we had previously studied storage effect on RBC aggregability (Transfusion 1999;39:277-81), here we determined the storage effect on RBC adherence and deformability, by measuring them before (control) and during storage. Gamma irradiation effect on RBC aggregability, adherence, and deformability was determined before (control) and after irradiation., Results: Cold storage significantly elevated the number of adherent RBCs and the strength of their interaction with ECs, and was marked by decreased RBC deformability as early as 2 weeks into the storage period. The elevation of RBC-EC interaction was well correlated with translocation of phosphatidylserine to the RBC surface. Gamma irradiation induced an immediate and marked increase in the number of rigid cells, but did not affect RBC adherence and aggregability., Conclusion: RBC flow properties appear to be especially sensitive to cold storage and gamma irradiation because they are impaired long before the expiration date. Because impaired RBC flow properties facilitate circulatory disorders, the potential circulatory risk of transfusion RBC with blood banking-impaired rheology should be considered.

Background: Lu6 is a high-incidence antigen of the Lutheran blood group. Examples of anti-Lu6 are rare and are of uncertain clinical significance., Case Report: Three patients were encountered in whom anti-Lu6 was detected on pretransfusion screening. The patients were all Iranian Jews and were not known to be related. In vitro studies to ascertain the potential clinical significance of the antibody using the monocyte monolayer assay (MMA) were negative in two patients. The third patient received a two-unit transfusion of incompatible Lu6 RBCs with no signs of hemolysis. However, after the transfusion, the MMA and a chemiluminescence test were positive, whereas a chromium survival study was normal. Thus, the antibody may have changed in its clinical significance., Conclusion: Although anti-Lu6 does not appear to be a clinically significant RBC antibody in all circumstances, transfusion of Lu6 RBCs in patients with anti-Lu6 should be performed cautiously.

Background: Storage of blood units (for 35-42 days, depending on the preservative solution) has been reported to induce changes (e.g., reduction of sialic acid level) in red cells that are expected to alter their aggregability., Study Design and Methods: The aggregability of stored red cells was monitored in their autologous plasma and compared to that obtained with washed cells in dextran-containing buffer throughout the storage period. Red cell aggregability was determined by using a computerized image analyzer of cell flow properties., Results: Blood storage induced changes in red cells that are associated with continuous increase of their aggregability. At the same time, blood storage was associated with a reduction in the level of plasma fibrinogen, the major aggregating agent in plasma. Accordingly, the increased red cell aggregability was observed in red cells stored in dextran-containing buffer, but not in red cells stored in autologous plasma., Conclusion: Because blood transfusion is routinely given to patients with normal or high fibrinogen level, the transfusion of stored red cells has the potential to induce increased aggregation in vivo, depending on the storage period. This should be taken into account when blood transfusion is considered, particularly for patients with microcirculatory disorders.

A patient with postoperative intravascular hemolysis aggravated by transfusion with fresh whole blood and fresh plasma products had acute renal failure. Screening with Arachis hypogaea and Glycine soja lectins showed that his red cells were T-transformed. Only washed red cells were transfused subsequently, and no further fresh plasma products were given. All hemolysis ceased, the renal function returned to normal, and the T-polyagglutination as measured by lectin tests disappeared 4 months after surgery. Early diagnosis of polyagglutination using lectin screening tests is simple to perform, and will facilitate the immediate choice of the correct transfusion therapy, which in this case may have been life-saving.

The Yta and Ytb allelic frequencies were determined by examining the red cells of 1683 blood samples from Israeli Jews, Arabs, and Druse with anti-Yta and -Ytb. The Ytb allelic frequencies ranged between 0.1005 and 0.1522 in the Jewish communities and were 0.1294 and 0.1429 in the Arab and Druse communities, respectively. These are the highest Ytb allelic frequencies observed so far in any population tested, so the Yt blood group system can be used as a genetic marker in these populations. No factors were recognized that may have influenced the selection for the Ytb allele.