THE DESTRUCTION OF RED CELLS BY ANTIBODIES IN MAN. III. QUANTITATIVE FACTORS INFLUENCING THE PATTERNS OF HEMOLYSIS IN VIVO*

Abstract

The influence of antibody/antigen proportions on the kinetics of red cell destruction were studied in man and in rats. The effects of anti-B isoantibody were studied by passively immunizing an agammaglobulinemic patient with various amounts of anti-B serum and observing the pattern of destruction of a given amount of type B red cells. A spectrum of effects was observed, ranging from a slow partial trapping by the spleen with small doses to a brisk hepatic trapping with large doses, while still larger doses caused intravascular hemolysis. The effects of incomplete anti-D isoantibody were studied by passively immunizing each of several D-negative subjects with various amounts of anti-D serum and observing their effect upon given amounts of type D red cells. Although small and moderate amounts of antibody caused a mainly splenic pattern of destruction, large amounts caused a moderate hepatic uptake and were similar in their effects to very small amounts of anti-B antibody. Studies on rats employing a rabbit antibody against rat red cells indicated a spectrum of action similar to that of anti-B in man: a slow, incomplete sequestration by the spleen occurred when small amounts of antibody were employed; a rapid, largely hepatic sequestration occurred with larger amounts; and with still larger amounts, intravascular lysis was seen, with hemoglobin deposition in the liver, spleen and kidney. The lungs and bone marrow did not participate in the sequestration process at any dose of antibody. Although the kinetics of red cell destruction in vivo by complete and by incomplete agglutinins ordinarily differ, the differences are modified by purely quantitative factors.