DIFFERENTIAL REACTIVITIES OF FETAL AND ADULT HUMAN ERYTHROCYTES TO ANTISERA DIRECTED AGAINST GLYCOLIPIDS OF HUMAN ERYTHROCYTES

Summary. The immunological reactivities of fetal and adult erythrocytes to antisera which were directed against globoside, hematoside and lactosylceramide were compared. Fetal erythrocytes showed higher reactivity than adult erythrocytes in agglutination, hemolysis and absorption capacity of antibody when tested with anti‐globoside and anti‐hematoside. No differential reactivity was found when tested with anti‐lactosylceramide. Treatment of adult erythrocytes by trypsin or by neuraminidase resulted in an increase in their reactivity to the same level as that of fetal erythrocytes, but the reactivity of fetal erythrocytes was not greatly affected by enzyme treatment. The results indicate that globosidie and hematosidie groupings of fetal cells are directly exposed on the periphery of cells, while those of mature erythrocytes are masked by ‘sialomucopeptidyl’ groupings, and their reactivities are hampered. © 1969 Blackwell Publishing Ltd