[Immunohematologic surveillance of patients treated with ABO incompatible bone marrow allografts].

Direct antiglobulin test (DAT), ABO typing and isoagglutinins titers were regularly performed in 26 patients who received a marrow transplant from a major ABO incompatible donor (M = 10 cases), from a minor ABO incompatible donor (m = 10 cases) or both (B = 6 cases). Erythrocyte or plasma depletion of bone marrow infusate was used in all major or certain minor ABO incompatibilities respectively. A positive DAT was recorded in 19/26 patients at various times, but only a few of them, belonging to groups M or B, exhibited a significant hemolysis. No serious complication was observed after bone marrow infusion. Five patients showed evidence of hemolysis after transplantation, 1 patient died with a graft rejection and 3 patients had a delayed erythropoietic engraftment. In all cases of major ABO incompatibility, the erythrocyte recovery was preceeded by a decrease of antibodies against the donor's blood group. These antibodies finally disappeared in all patients except one who had a persistence of isoagglutinins beyond day + 650. A transient appearance of isoagglutinins against the recipient blood group was sometimes detected in minor ABO incompatibility without any clinical complications.