Sequential intensified conditioning followed by prophylactic DLI could reduce relapse of refractory acute leukemia after allo-HSCT

// Li Xuan 1 , Zhiping Fan 1 , Yu Zhang 1 , Hongsheng Zhou 1 , Fen Huang 1 , Min Dai 1 , Danian Nie 2 , Dongjun Lin 3 , Na Xu 1 , Xutao Guo 1 , Qianli Jiang 1 , Jing Sun 1 , Yang Xiao 4 , Qifa Liu 1 1 Department of Hematology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China 2 Department of Hematology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China 3 Department of Hematology, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China 4 Department of Hematology, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou 510010, China Correspondence to: Qifa Liu, email: liuqifa628@163.com Keywords: donor lymphocyte infusion, refractory advanced acute leukemia, relapse, allogeneic hematopoietic stem cell transplantation, sequential intensified conditioning Received: January 26, 2016      Accepted: March 28, 2016      Published: April 11, 2016 ABSTRACT The major obstacle is leukemia relapse for refractory leukemia undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We previously introduced a strategy of sequential intensified conditioning and early rapid immunosupressant withdrawal for refractory leukemia undergoing allo-HSCT, with 5-year overall survival (OS) and 3-year relapse rate of 44.6% and 33.3%. To reduce leukemia relapse, prophylactic donor lymphocyte infusion (DLI) was administered based on our historical strategy. A total of 153 refractory advanced acute leukemia patients were enrolled in this prospective study. According to the availability of donor lymphocytes and the criteria for DLI, 144 patients surviving day +60 were divided into two groups (80 DLI versus 64 non-DLI). The relapse rate was less and OS was better in patients receiving DLI than in those not receiving DLI (22.7% vs 33.9%, P =0.048; 58.1% vs 54.9%, P =0.043). The non-relapse mortality (NRM) was similar between DLI and non-DLI groups ( P =0.104). Overall, the 5-year overall and disease-free survival post-transplantation were 51.1%±5.7% and 49.2%±5.3%. The 5-year relapse rate and NRM were 27.3%±4.4% and 29.7%±5.3%. Multivariate analysis revealed that lower bone marrow blasts on day 0, DLI and chronic graft-versus-host disease were associated with less relapse and better OS. The strategy of sequential intensified conditioning followed by early immunosupressant withdrawal and DLI could reduce relapse of refractory acute leukemia after allo-HSCT and improve survival.