[Autoantibodies in the ABO-Ii-system (author's transl)].

Abstract

Nine cases of autoantibodies in the ABO-system, found by routine investigations, showed the following specificities by agglutination, absorption, and elution techniques: 5 anti-AI, 2 anti-(not-I)-A, I anti-BI and 1 anti-HI. Neutralization experiments by blood group substances revealed heterogeneity among the 5 anti-AI-cases. This is interpreted by different antibody specificities directed against I-antigen components. The relations between the ABO- and Ii-systems are discussed. The occurrence of these antibodies is attributed to oligosaccharides, which are common to both antigen systems. The etiology remains unknown.