A 66-year-old woman who was diagnosed with acute myeloid leukemia, myelodysplasia-related underwent allogeneic peripheral blood stem cell transplantation (PBSCT) from her human leukocyte antigen (HLA)-mismatched daughter after primary induction failure. The patient had a high donor-specific antibody (DSA) titer to the mismatched HLA antigen and received multiple desensitization treatments including rituximab, intravenous immunoglobulin, and random platelet concentrate transfusions, which resulted in a slight decrease in the DSA titer. The donor was a poor mobilizer and the patient could have received a limited number of CD34-positive cells in the PBSCT with a relatively high CD34-negative fraction. Although the graft rejection was a great concern, the patient achieved delayed but successful engraftment and complete remission. The extent of the DSA reduction was greatest after transplantation, indicating that a relatively greater number of infused CD34-negative cells had a certain effect on antagonizing the DSAs. The DSAs were detected even after engraftment, suggesting that other factors, such as HLA expression levels and HLA epitopes, might affect the engraftment outcome.
Izumi et al. (Fri,) studied this question.