Assessment of complement binding by anti-D and anti-M antibodies employing labelled antiglobulin antibodies.
The presence of small amounts of C3d on freshly obtained normal red blood cells (RBC) was demonstrated by a radio-labelled antiglobulin technique; this increased 1.5-fold after incubation in fresh normal serum. No significant further increase in bound C3d was demonstrated for cDE/cDE, CDe/CDe, -D-/-D- RBC maximally sensitized with any of three potent anti-D antibodies. When anti-c, anti-D and anti-E antibodies were used in combination to sensitize cDE/cDE RBC, bound C3d increased by approximately 22%; however, a similar increase occurred with cde/cde RBC and was therefore considered non-Rh specific. Umbilical cord RBC from four infants severely affected by anti-D haemolytic disease of the newborn did not exhibit more bound C3d than cord RBC from normal controls. One serum containing IgM anti-M bound a small amount of complement in vitro; two IgG anti-M sera did not.
D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D001666:Binding Sites, Antibody; D003176:Complement C3 / Q000276:immunology*; D003181:Complement C4 / Q000276:immunology; D004899:Erythroblastosis, Fetal / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007231:Infant, Newborn; D007518:Isoantibodies / Q000276:immunology*; D008951:MNSs Blood-Group System / Q000276:immunology*; D011247:Pregnancy; D012204:Rh-Hr Blood-Group System / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D003176:Complement C3; D003181:Complement C4; D007074:Immunoglobulin G; D007518:Isoantibodies; D008951:MNSs Blood-Group System; D012204:Rh-Hr Blood-Group System