Spousal hematopoietic stem cell transplantation

We report a pilot series of five patients who received stem cell transplantation (SCT) from a spouse for post-transplant relapse or rejection. The inclusion criterion regarding HLA disparities was three or fewer antigen mismatches in the graft-versus-host direction at the HLA-A, B, and DR loci. Four patients received spousal SCT as a third transplant attempt after post-transplant relapse and one as rescue for graft rejection. The reduced intensity conditioning (RIC) regimen consisted of fludarabine, melphalan, and anti-thymocyte globulin (ATG) with 3 Gy of total body irradiation (TBI) for relapse cases and ATG plus 4 Gy of TBI for the rejection case. Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus, methylprednisolone, and mycophenolate mofetil. Peripheral blood stem cells were transplanted. Granulocyte engraftment was achieved in all cases between days 9 and 11 (median, 10) with complete spousal chimerism. In three of the five patients, no acute GVHD was observed, while one case developed grade III GVHD and one case grade IV. All four patients evaluable for the anti-leukemic effect achieved complete remission; however, all relapsed between 106 and 334 day post-transplant, and died between days 152 and 548. We suggest that spousal SCT can be performed as a repetitive SCT using a RIC regimen with low-dose ATG and steroid-containing GVHD prophylaxis.