Accelerated elimination from the circulation of homologous aged red blood cells in rats bearing anti-spectrin antibodies

In order to analyse a possible role of anti-spectrin antibodies in the clea rance of aged red blood cells (RBC), a homologous system was employed, wher eby a population of aged RBC, obtained by hypertransfusion, was injected in to rats bearing a high level of anti-spectrin antibodies, following immuniz ation with spectrin. The aged RBC bound the anti-spectrin antibodies 'in vi tro' and were eliminated from circulation in spectrin-treated rats at a fas ter rate than in control rats with naturally occurring antibodies. The anal ysis of the clearance curves revealed aged RBC of heterogeneous lifespans: two principal populations of short- and longer-living could be identified. In rats with anti-spectrin antibodies, the survival of the short-living pop ulation was further reduced. However, the similar kinetics of elimination o f aged RBC in the two groups (with naturally-occurring and induced antibodi es, respectively) suggest that anti-spectrin antibodies strengthened the in tervention of the naturally-occurring ones. On the basis of these results, we assume that during their aging in circulation, RBC can accumulate surfac e alterations to make spectrin accessible to antibodies so that, in additio n to anti-band 3 antibodies, anti-spectrin antibodies may contribute to the ir elimination. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.