Graft Versus Host Disease (GVHD) occurs in 20–35% of bone marrow transplants. It occurs in less than 6% of solid organ transplants, though it has been reported in liver and small intestine. GVHD occurs when donor cells, transplanted into the recipient, see the recipient cells as foreign and attack. We report two cases of GVHD in sisters who received deceased donor kidney pancreas transplants. MeML, African American (AA), 29 year old, and MiM, AA, 27 year old. Antibody (Ab) analysis on MeML, immediately prior to transplant, indicated the presence of Abs to HLA B7 and B81, not Donor Specific Abs (DSA). No HLA class II Ab was detected. The final crossmatch (XM) was negative T cell by FWA, AHG, DTT FWA and DTT AHG. However, the B cell XM was positive by all methods. Flow XMs had a T cell MCS of 26 and B cell MCS of 36. The positive cutoffs for T Cell = 40 and B Cell = 80. One month post transplant there were no HLA class I Abs but class II Abs were detected to DQB1∗06:09, 06:03 and DQ5, none DSA. MiM had no Abs to HLA class I or II except on 5/24/2014 and 11/11/2013. Antibodies to HLA B81 was identified in 2013, not DSA, and DPB1∗04:01 in 2014, the donor DP was not available. The final XM was negative for HLA class I and class II by all methods. The flow XM was also negative for both T and B cells. GVHD diagnosis was based on Short Tandem Repeat Analysis by the Molecular Diagnostic Laboratory. The HLA laboratory identified the possibility of Chimerism in MiM while performing confirmatory typing as she was being worked up for Living Related Bone Marrow Transplant with her father. MeML recovered from her GVHD and continues to do well. MiM succumbed to her GVHD, 74 days post transplant. These two cases clearly demonstrate the importance of analyzing for GVHD following kidney pancreas transplantation. Download full-size image Download full-size image