Phenotypic conversion of human erythrocytes by H-Y antigen

Human male erythrocytes absorb H-Y antiserum while those of human females do not. Studies on the mode of attachment of H-Y antigen to the erythrocyte membrane reveal: (1) After several washes H-Y antigen can only be removed from male erythrocytes and not from other male cells such as granulocytes. (2) Female erythrocytes absorb exogenous H-Y antigen and thus become H-Y positive. (3) Complement mediated lysis of erythrocytes by H-Y antiserum is not sex specific but is dependent on the ABO blood group type of the red blood cells. It is concluded that H-Y antigen is unspecifically attached to red blood cells and is therefore not an integral part of the erythrocyte membrane.