Further evidence for the presence of A antigen on group B erythrocytes through the use of specific exoglycosidases.
Certain antibodies have shown the ability to detect small amounts of A antigenic structures on certain group B cells. These rare cells that reverse group as B, are designated here as B(A) cells. Among the anti-A antibodies capable of detecting these cells are MHO4 (an IgM murine monoclonal antibody) and polyclonal anti-A derived from blood group O donors. The latter (anti-A, B) have been adsorbed exhaustively with normal B cells, to deplete the serum of antibodies to group B antigen. The cell specificity detected by these antibodies can be removed only by an alpha-N-acetylgalactosaminidase (A-zyme) but not by an alpha-galactosidase (B-zyme). Inhibition studies show that these reactions can be inhibited by A secretor saliva and cannot be inhibited by B secretor saliva. Moreover, papain treatment of normal group B cells not previously agglutinable with these antibodies, now causes these cells to become reactive, and this specificity, too, is removed only by A-zyme. These results suggest that low levels of blood group A antigen are being recognized by these antibodies and that these structures can exist not only on B(A) cells but on all group B erythrocytes.
Goldstein
J
J
Cell Biochemistry Laboratory, New York Blood Center, New York.
Lenny
L
L
Davies
D
D
Voak
D
D
D000017:ABO Blood-Group System / Q000276:immunology*; D000911:Antibodies, Monoclonal; D004912:Erythrocytes / Q000276:immunology*; D005696:Galactosidases; D006386:Hemagglutination Tests; D006596:Hexosaminidases; D006801:Humans; D007519:Isoantigens / Q000032:analysis*; D010206:Papain; D012463:Saliva / Q000276:immunology; D000519:alpha-Galactosidase; D048809:alpha-N-Acetylgalactosaminidase
D000017:ABO Blood-Group System; D000911:Antibodies, Monoclonal; D007519:Isoantigens; D005696:Galactosidases; D006596:Hexosaminidases; D000519:alpha-Galactosidase; C482722:NAGA protein, human; D048809:alpha-N-Acetylgalactosaminidase; D010206:Papain