title: Phagocytosis of erythrocytes sensitized with known amounts of IgG1 and IgG3 anti-Rh antibodies.
abstract: Phagocytosis was investigated using human peripheral monocytes and erythrocytes sensitized with known amounts of subclass-specific IgG anti-Rh antibodies. The erythrocyte-bound IgG was quantitated by a radiometric antiglobulin test. This evaluation revealed the following: (1) there is a relationship between phagocytosis and the number of erythrocyte-bound IgG molecules; (2) phagocytosis is IgG subclass-dependent, since a similar degree of phagocytosis is observed with fewer IgG3 than IgG1 molecules and also the minimum number of IgG3 molecules for phagocytosis is 150-640, whilst for IgG1 the minimum is 1,230-4,020; (3) the minimum levels of sensitization for phagocytosis should be detectable by the serological antiglobulin test; (4) the phagocytosis assay is no more sensitive than the monocyte rosette assay for the detection of anti-Rh alloantibodies, and (5) phagocytosis of adherent erythrocytes observed by video-enhanced microscopy indicated that erythrocytes may adhere to monocytes for a considerable time before phagocytosis, but that phagocytosis itself was rapid.
mesh_terms: D004912:Erythrocytes / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000145:classification / Q000276:immunology*; D066298:In Vitro Techniques; D007518:Isoantibodies / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D010587:Phagocytosis; D012204:Rh-Hr Blood-Group System / Q000276:immunology*; D012397:Rosette Formation
chemical_list: D007074:Immunoglobulin G; D007518:Isoantibodies; D012204:Rh-Hr Blood-Group System