[Sialic acid content and IgG binding of the glycocalyx of preserved erythrocytes].

Fractions of light and heavy erythrocytes were separated by centrifugation from blood samples banked in ACD-AG medium at 4 degrees C for periods up to 6 weeks. Both light and heavy erythrocytes have lost about 4,9% of their content of sialic acids during banking for 6 weeks. This reduction is in accord with a 6%-decrease of their agglutination by means of alcian blue. It is, however, a variance with the inhibition of agglutination by anti-IgG sera. The present findings provide evidence for the role alterations of the red cell membrane may play in the process of recognition and phagocytosis of banked erythrocytes. With regard to these alterations we suggest two types of rapid elimination of transfused banked erythrocytes: a) Primary elimination refers to cells primarily loaded with immunoglobulins such as to get recognized and phagocytized by macrophages. b) Secondary elimination accounts for rigid erythrocytes suffering from additional degradation while retained in the spleen prior to their loading with immunoglobulins and ensuing phagocytosis. Secondary elimination is considered a process more relevant to reutilisation of banked blood.