27-OR

Aim Case: 36 year old female with AML diagnosed in Dec 2011 and persistent disease after 3 rounds of chemotherapy. She received 7 granulocyte transfusions for neutropenic sepsis in Dec 2011. Single antigen bead (SAB) testing in Jan 2012 demonstrated alloimmunization to HLA-DPB1. Patient has one mismatched sibling and unrelated search was initiated. She demonstrated donor specific antibodies (DSA) to all donors. We present here the progression of DSA over a 5 month period and the clinical care based on these DSA. Methods Confirmatory typing of 5 donors found that 2 were 10/10 match with the recipient, while 3 were mismatched at DQB1. Since the recipient demonstrated DP antibodies with MFI >1000, DPB1 typing was performed on the recipient and donors. Results Recipient and donor DPB1 typing and DSA are summarized [ Table 1 ]. Serial SAB demonstrate decreasing MFI with no specific DSA reducing intervention and reflected in B-FXM with donor-2 cells [ Table 2 ]. Based on the high DSA levels, an autologous bone marrow harvest was performed as backup to allotransplant. As the DSA MFI was