[A retrospective comparative study of haplotype hematopoietic stem cell transplantation and human leukocyte antigen-matched sibling donor hematopoietic stem cell transplantation in the treatment of acute B-lymphocyte leukemia].

To investigate whether haplotype hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of pre transplant minimal residual disease (Pre-MRD) positive acute B lymphoblastic leukemia (B-ALL) compared with HLA- matched sibling donor transplantation (MSDT) . A total of 998 patients with B-ALL in complete remission pre-HSCT who either received haplo-HSCT (=788) or underwent MSDT (=210) were retrospectively analyzed. The pre-transplantation leukemia burden was evaluated according to Pre-MRD determinedusing multiparameter flow cytometry (MFC) . Of these patients, 997 (99.9% ) achieved sustained, full donor chimerism. The 100-day cumulative incidences of neutrophil engraftment, platelet engraftment, and grades Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) were 99.9% (997/998) , 95.3% (951/998) , and 26.6% (95% 23.8% -29.4% ) , respectively. The 3-year cumulative incidence of total chronic GVHD was 49.1% (95% 45.7% -52.4% ) . The 3-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) of the 998 cases were 17.3% (95% 15.0% -19.7% ) and 13.8% (95% 11.6% -16.0% ) , respectively. The 3-year probabilities of leukemia-free survival (LFS) and overall survival (OS) were 69.1% (95% 66.1% -72.1% ) and 73.0% (95% 70.2% -75.8% ) , respectively. In the total patient group, cases with positive Pre-MRD (=282) experienced significantly higher CIR than that of subjects with negative Pre-MRD [=716, 31.6% (95% 25.8% -37.5% ) 14.3% (95% 11.4% -17.2% ) , <0.001]. For patients in the positive Pre-MRD subgroup, cases treated with haplo-HSCT (=219) had a lower 3-year CIR than that of cases who underwent MSDT [=63, 27.2% (95% 21.0% -33.4% ) 47.0% (95% 33.8% -60.2% ) , =0.002]. The total 998 cases were classified as five subgroups, including cases with negative Pre-MRD group (=716) , cases with Pre-MRD<0.01% group (=46) , cases with Pre-MRD 0.01% -<0.1% group (=117) , cases with Pre-MRD 0.1% -<1% group (=87) , and cases with Pre-MRD≥1% group (=32) . For subjects in the Pre-MRD<0.01% group, haplo-HSCT (=40) had a lower CIR than that of MSDT [=6, 10.0% (95% 0.4% -19.6% ) 32.3% (95% 0% -69.9% ) , =0.017]. For patients in the Pre-MRD 0.01% -<0.1% group, haplo-HSCT (=81) also had a lower 3-year CIR than that of MSDT [=36, 20.4% (95% 10.4% -30.4% ) 47.0% (95% 29.2% -64.8% ) , =0.004]. In the other three subgroups, the 3-year CIR was comparable between patients who underwent haplo-HSCT and those received MSDT. A subgroup analysis of patients with Pre-MRD<0.1% (=163) was performed, the results showed that cases received haplo-HSCT (=121) experienced lower 3-year CIR [16.0% (95% 9.4% -22.7% ) 40.5% (95% 25.2% -55.8% ) , <0.001], better 3-year LFS [78.2% (95% 70.6% -85.8% ) 47.6% (95% 32.2% -63.0% ) , <0.001] and OS [80.5% (95% 73.1% -87.9% ) 54.6% (95% 39.2% -70.0% ) , <0.001] than those of MSDT (=42) , but comparable in 3-year NRM [5.8% (95% 1.6% -10.0% ) 11.9% (95% 2.0% -21.8% ) , =0.188]. Multivariate analysis showed that haplo-HSCT was associated with lower CIR (=0.248, 95% 0.131-0.472, <0.001) , and superior LFS (=0.275, 95% 0.157-0.483, <0.001) and OS (=0.286, 95% 0.159-0.513, <0.001) . Haplo HSCT has a survival advantage over MSDT in the treatment of B-ALL patients with pre MRD<0.1% .