Exchange transfusion the hard way: Massive hemolysis following transplantation of bone marrow with minor ABO incompatibility

Background: Bone marrow transplantation using donors with minor ABO incompatibility may result in the rapid production of donor-derived red cell isohemagglutinins, causing hemolysis of recipient red cells. Case Report: The transplant of sibling-donor marrow with minor ABO incompatibility (group O donor marrow to group A recipient), using FK-506 as an immunosuppressant to prevent graft-versus-host disease, is reported. Following early myeloid engraftment, the recipient developed hemolysis of her entire A red cell population between Day 8 and Day 11. This brisk hemolytic anemia was due to rapid donor lymphoid engraftment that resulted in the explosive production of donor-derived anti-A. Conclusion: Patients undergoing the transplantation of marrow from donors with minor ABO incompatibility in which the donor cells can produce isohemagglutinins against the recipient's red cells must be kept under vigilant observation for the possible development of severe hemolysis, particularly in the setting of profound T-cell suppression without B-cell suppression.