Human milk fat globule membrane glycoproteins express blood group-related determinants primarily on mucin-like epithelial membrane antigens and gp70.

Milk fat globule membranes (MFGM) were prepared from 21 human milks and dot-blotted. MFGM samples were compared with reference to 8 blood group-related antigens reactive with monoclonal antibodies and lectins. All preparations contained epithelial membrane antigen (EMA) and the majority was positive for type 1 Lewis a and b antigens, whereas only trace amounts of sialyl Lewis a were found. For type 2 Lewis antigens, most MFGM reacted intensely for X, but only weakly and infrequently for the Y antigen. Reactivities for H were also infrequent and antigens related to A and/or B (types 1 and 2) were not found. Western blot analyses established that these antigenic determinants were borne mainly by mucin-like components and gp70.