INCREASED SUSCEPTIBILITY OF STORED ERYTHROCYTES TO ANTI-BAND-3 IGG AUTOANTIBODY BINDING

When human blood was stored in a citrate-phosphate-dextrose (CPD) solution at 4-degrees-C, the susceptibility of the erythrocytes to binding of autologous IgG increased. The autologous IgG binding was partially inhibited by purified Band 3 glycoprotein and its oligosaccharides. The susceptibility of the erythrocytes to binding of I-125-labeled anti-band 3 IgG autoantibody similarly increased. The results indicate that the anti-band 3 binding sites composed of Band 3 oligosaccharides were generated on the cell surface. The rate of the increase in the susceptibility of the stored cells to the antibody binding was lowered when blood was stored in a CPD solution containing L-ascorbic acid or erythorbic acid, suggesting involvement of an oxidative mechanism in the generation of the binding sites. The cytoplasmic glutathione level of erythrocytes gradually decreased during the blood storage. Storing blood in a CPD solution containing glutathione monoethylester or glutathione monoisopropylester resulted in partial prevention of the decrease in cytoplasmic glutathione level and of the increase in the IgG-binding ability of the cells. Similar preventive effect of glutathione monoethylester was observed in the binding of I-125-labeled anti-band 3 autoantibody to the stored erythrocytes. Thus, the increase in the susceptibility of the stored erythrocytes to anti-band 3 binding may be caused, at least partially, by an oxidative stress resulting in a decreased cytoplasmic glutathione level.