Early relapse after non myeloablative allogeneic stem cell transplantation in a patient with acute promyelocytic leukemia in complete molecular remission.

We described a 41-year-old patient with acute promyelocytic leukemia (APL) who experienced two successive relapses: one after all-trans retinoic acid (ATRA) treatment and chemotherapy, and another after ATRA treatment and chemotherapy, followed by autologous peripheral blood stem cell transplantation. A third complete remission (CR) was achieved with arsenic trioxide (As2O3) therapy. Mini-transplantation was performed as consolidation therapy. While the patient was in molecular remission at the beginning of conditioning regimen, a new relapse arose after transplantation at time of cell recovery. This raises a potential relationship between relapse and the severe immunosuppression induced by mini-transplantation. To our knowledge, this is the first description of a mini-allograft in an APL patient achieving molecular remission after As2O3 therapy.