A 71year old female was initially diagnosed with myelodysplastic syndrome (del 5q) which progressed to AML one year later. Patient had pancytopenia, experienced bruising, and needed blood transfusions. Allogeneic stem cell transplant was recommended and she presented to the University of Chicago Medicine for allo-stem cell transplant work up. This patient had one potential related donor (sibling), who was a 9/10 match (mismatch at HLA-A). When examining the patient’s HLA antibodies, it was found that she was highly sensitized, and anti-HLA-A24 was a donor specific antibody (DSA). A search for matched unrelated donors was conducted but no suitable donors were found. It was decided to accept her sibling and desensitize the patient prior to transplant. The desensitization protocol consisted of plasmapheresis (PP), with IVIG (100mg/kg) given after each PP. The initial MFI of the DSA was >18,000 and showed evidence of rebound after each PP. As a result, PP was performed daily or every other day, with A24 MFI measurement before and after each PP (Figure). While the strength of A24 decreased over the course, a total of 18 sessions of PP were needed to decrease the strength to <2500, our laboratory’s cutoff for predicting a negative crossmatch. Flow cytometric crossmatch was performed post 19th PP, and the T cell result was negative. The patient received conditioning with a regimen of fludarabine/melphalan/campath and a final PP (20th). The transplant occurred on 11/29/2016 and showed donor engraftment two weeks later. The post-transplant antibody tests indicate that HLA-A24 became undetecTable 8days after transplant (12/7/2016) and remained negative 5days later (12/12/2016). The patient is currently stable and under follow-up. While desensitizing a strong DSA may require a large number of PP, it is nevertheless possible, and can be free of PP-associated complications. The protocol described here may be useful to remove strong DSA in patients with no other option than a DSA-positive donor.