title: Evidence of platelet complement-fixing and lymphocytotoxic anti-A-1 antibodies.
abstract: 3 human antisera exhibiting non HL-A specific antibody were studied in micro-complement fixation with platelets and micro-lymphocytotoxicity. Screening studies as well as absorption and elution studies with platelets, lymphocytes and erythrocytes revealed an antibody activity associated with blood group A-1. Within blood group A-1, a subpopulation of A-1 donor cells- provisionally called "weak A-1" - was defined, which had a minor ability for complement-fixing and lymphocytotoxic A-1-antibody absorption. Contrary to HL-A specific antibodies, acid eluates from platelets of these 3 sera were always negative whereas heat and ether eluates gave positive results. From neutralization studies and studies on the hemolytic activity against A-1 erythrocytes it was concluded, that the A-1-specific antibodies probably are immune antibodies belonging to the IgG class of immunoglobulins.
mesh_terms: D000042:Absorption; D000906:Antibodies / Q000032:analysis*; D000918:Antibody Specificity; D001789:Blood Group Antigens; D001792:Blood Platelets / Q000276:immunology*; D003168:Complement Fixation Tests; D003165:Complement System Proteins; D003601:Cytotoxicity Tests, Immunologic; D004912:Erythrocytes; D005260:Female; D006680:HLA Antigens; D006801:Humans; D008214:Lymphocytes; D008297:Male; D009500:Neutralization Tests; D011247:Pregnancy
chemical_list: D000906:Antibodies; D001789:Blood Group Antigens; D006680:HLA Antigens; D003165:Complement System Proteins