Removal of Incompatible Red Cells by the Spleen

THE survival in vivo of a very small volume (I ml.) of incompatible red cells can be studied after labelling with 51Cr or 32P. Two patterns of red-ccll destruction are commonly observed: firstly, elimination of most or all of the red cells within 10 minutes; secondly, slower elimination with a half-time of approximately 20 minutes, varying little from one subject to another (Mollison and Cutbush, 1955). A constant rate of elimination with a half-time of approximately 20 minutes was observed in two subjects whose sera contained incomplete anti-Rh and in onc subject whose serum contained anti-K. It was suggested that in these subjects red cells were probably being reiiiovcd from the circulation by the spleen, the rate of elimination bcing determincd by the rate of blood flow through the spleen (Mollison and Cutbush, 1955). Confirmation of this hypothesis has now been obtained by using the technique of surface counting and this new evidence forms the subject of the present paper.