OBJECTIVETo evaluate the efficacy of second allogeneic hematopoietic stem cell transplantation (allo-HSCT) for treatment of leukemia relapsed after first allo-HSCT.

METHODSNine patients with relapsed acute leukemia (5 AML, 4 ALL) and one with chronic myelogenous leukemia (CML) who showed cytogenetic relapse after first allo-HSCT received second allo-HSCT. The median relapse time from the first allo-HSCT was 141 days. Conditioning regimens for second allo-HSCT were combination chemotherapy based on moderate-dose Ara-C (n = 5), Bu (n = 3), conventional-dose Ara-C (n = 1) and Flud/Mel (n = 1). Prophylaxis for acute graft-versus-host disease (aGVHD) were CsA alone (n = 2), CsA/MTX (n = 1), FK506 (n = 1), and no prophylaxis in 6. The median number of peripheral blood mononuclear cells transfused was 6.1 x 10(8)/kg.

RESULTSEight cases were evaluable. All of them were engrafted and 7 developed aGVHD (grade I 4, grade II 3). The median time for absolute neutrophil count (ANC) > 0.5 x 10(9)/L and platelets > 20 x 10(9)/L were 11 and 12 days, respectively. Five cases developed localized chronic GVHD. Of all the 10 cases received second allo-HSCT, 8 died from interstitial pneumonia (n = 2), multiple-organ failure (n = 1), sepsis (n = 1), fungous pneumonia (n = 1), and leukemia relapse (n = 3), and 2 survived without leukemia for +986 and +1913 days, respectively. The leukemia free survival, transplantation related mortality and relapse rate at 2 year were 20%, 50% and 30%, respectively.

CONCLUSIONSecond allo-HSCT is a therapeutic alternative for selected patients with relapsed leukemia after first allo-HSCT.