Expression of ABO blood-group antigenic determinants identified by monoclonal antibodies B7H4 and D1E8 in normal human tissues and organs.

: Human blood group antigens are genetically determined structures of undefined nature found not only in red blood cells but also in various tissues. Monoclonal antibodies against A and B human blood group antigens (B7H4 and D1E8) were obtained. Their tissue compatibility was tested in 11 different normal human organs taken from people with A1 and B blood group phenotypes. The antigen-antibody reaction was visualized using the indirect immunoperoxidase technique. The results of the study showed that the antibodies B7H4 and D1E8 react specifically with the tissue blood group antigens in healthy subjects. The findings obtained in most of the tested organs were in accord with those described by other researchers. Differences were found only in the stomach, urothelium, the lungs and the thyroid gland. A possible explanation of the results is the difference in the epitopes recognized by the monoclonal antibodies used by us and the blood group antibodies applied by other researchers. It is suggested that the monoclonal antibodies against the human blood group antigens A and B obtained by us could be used to establish suspected modification of ABH-antigens in the process of oncogenesis.