Аннотация:Abstract ABO incompatibility is a barrier for solid organ transplantation, but not for hematopoietic stem cell transplantation. To investigate tolerance induction, we enrolled patients who had undergone minor ABO ‐incompatible (O into A group, n = 6) and ABO ‐identical (O into O group, n = 4) bone marrow transplantation ( BMT ). None of the six O into A patients were positive for recipient‐specific (anti‐blood group A) isohemagglutinins, whereas all four O into O patients were. Peripheral blood mononuclear cells ( PBMC s) were engrafted into NOD/SCID/gamma(c)(null) ( NOG ) mice, followed by sensitization of blood group A red blood cells. Anti‐blood group A antibodies (Abs) in the sera of the patients and the human PBMC ‐engrafted NOG mice were measured by enzyme‐linked immunosorbent assays. Anti‐blood group A Abs in the patients' sera were significantly correlated with anti‐A isohemagglutinin titers (p < 0.01). In the human PBMC ‐engrafted NOG mice, anti‐blood group A Abs were significantly lower in the O into A group than in the O into O group (p < 0.05), despite ex vivo restimulation of B cells. The results of this study suggest that long after receiving minor ABO ‐incompatible BMT , B cells derived from newly engrafted donor precursor cells were induced tolerance to recipient‐specific antigens.
