[Analysis of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Hematological Malignancies: A Single-center Study].

Objective: To analyze the survival, prognostic factors, and prevention of relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with hematological malignancies, and explore the relationship between immune reconstruction, loss of human leukocyte antigen (HLA-loss) and relapse after transplantation.
Methods: From July 2012 to June 2020, 47 patients with hematological malignancies who relapsed after allo-HSCT were retrospectively analyzed, including 20 cases undergoing matched-sibling donor transplantation (MSD), 26 cases undergoing haploidentical transplantation (HID), and 1 case undergoing matched-unrelated donor transplantation (MUD). Multivariate analysis was used to analyze the risk factors related to post-relapse overall survival (PROS).
Results: All the 47 patients were implanted successfully. The cumulative incidence of grade Ⅱ-Ⅳ, Ⅲ/Ⅳ acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD) was 40.4%, 10.6%, and 31.9%, respectively. The incidence of grade Ⅱ-Ⅳ and Ⅲ/Ⅳ aGVHD in HID group was 42.3% and 11.5%, while in MD group was 38.1% and 9.5% (P=0.579, P=1.000), and the incidence of cGVHD in the two groups was 34.6% and 28.6% (P=0.659). The PROS of patients with NK cell absolute count > 190 cells/μl 30 days after transplantation was higher than that of patients with NK cell absolute count ≤190 cells/μl (P=0.021). The 1-year and 3-year PROS of all the patients was 68.1% and 28.4%, respectively, while in the HID group was 78.9% and 40.3%, in the MD group was 54.4% and 14% (P=0.048). Multivariate analysis showed that grade Ⅱ-Ⅳ aGVHD and time of relapse < 3 months were independent risk factors of PROS (P<0.05).
Conclusion: The therapeutic effect of haploidentical transplantation in patients with relapsed hematological malignancies after allo-HSCT is better than that of matched donor transplantation. The high absolute count of NK cells 30 days after transplantation can increase PROS. Grade Ⅱ-Ⅳ aGVHD and time of relapse < 3 months have prognostic significance for long-term survival of patients with relapsed hematological malignancies after transplantation.