Alteration of red cell aggregability and shape during blood storage

BACKGROUND: Storage of blood units (for 35-42 days, depending on the preser vative solution) has been reported to induce changes (e.g., reduction of si alic acid level) in red cells that are expected to alter their aggregabilit y. STUDY DESIGN AND METHODS: The aggregability of stored red cells was monitor ed in their autologous plasma and compared to that obtained with washed cel ls in dextran-containing buffer throughout the storage period. Red cell agg regability was determined by using a computerized image analyzer of cell fl ow properties. RESULTS: Blood storage induced changes in red cells that are associated wit h continuous increase of their aggregability. At the same time, blood stora ge was associated with a reduction in the level of plasma fibrinogen, the m ajor aggregating agent in plasma. Accordingly, the increased red cell aggre gability 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 n ormal or high fibrinogen level, the transfusion of stored red cells has the potential to induce increased aggregation in vivo, depending on the storag e period. This should be taken into account when blood transfusion is consi dered, particularly for patients with microcirculatory disorders.