A second unrelated bone marrow transplant: successful quantitative monitoring of mixed chimerism using a highly discriminative PCR-STR system

A second bone marrow transplant (BMT) might be considered as an option in p atients with leukaemia with graft failure after BMT. We report the successf ul treatment of a patient with graft failure by a second stem cell transpla nt from another unrelated donor. We evaluated the usefulness of an unrelate d donor as the source of the second BMT in this clinical setting. In additi on to this, a penta PCR-STR system was tested and shown to be sensitive for monitoring of marrow engraftment. The conditioning regimen for the first t ransplantation consisted of busulfan and cyclophosphamide while anti-thymoc yte globulin and CY were used for the second BMT. The patient successfully engrafted at day + 11 after second BMT.