An explanation of the failure of the direct antiglobulin test to detect erythrocyte sensitization in ABO haemolytic disease of the newborn and observations on pinocytosis of IgG anti-A antibodies by infant (cord) red cells.

ABO Blood-Group System Adult Antibodies Binding Sites Blood Group Antigens Cell Membrane Coombs Test Erythroblastosis, Fetal/diagnosis Erythrocytes/immunology Female Ferritins Humans Immunoglobulin G Infant, Newborn Isoantibodies Microscopy, Electron Pinocytosis Pregnancy Ribosomes Umbilical Cord

ABO Blood-Group System Antibodies Blood Group Antigens Immunoglobulin G Isoantibodies Ferritins