[Effect of minimal residual disease monitoring by multiparameter flow cytometry pre-conditioning on prognosis of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation].

Objective: To investigate the effect of minimal residual disease (MRD) monitoring by multiparameter flow cytometry (MFC) pre-conditioning on prognosis of acute myeloid leukemia in first complete remission (CR(1)-AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) , and to explore the value of MRD monitoring by MFC in the prognosis evaluation on allo-HSCT in CR(1)-AML. Methods: Between April 2012 and March 2015, consecutive 186 patients with CR(1)-AML who underwent allo-HSCT were analyzed retrospectively. MRD in BM before conditioning was detected by eight-color MFC. Any level of residual disease was considered to be MRD positive. Results: ①Of 186 patients, MRD was negative in 151 patients, positive in 35 patients (<1% in 25 patients and 1% to 3% in 10 patients) . ② With the median follow up of 18 (5-41) months, two-year DFS was 80.0% (95% CI 68.5%-92.3%) . Univariate analysis showed that MRD positive patients had lower DFS[62.9% (95% CI 50.6%-75.2%) vs 88.9% (95% CI 76.6%-100.0%) , P <0.001], higher relapse[11.4% (95% CI 4.1%-29.0%) vs 3.3% (95% CI 0.6%-20.9%) , P =0.003] and higher NRM [25.7% (95% CI 8.1%-43.3%) vs 7.9% (95% CI 1.3%-26.5%) , P =0.001] after HSCT compared with that of MRD negative patients. Secondary AML showed lower DFS than primary AML [60.0% (95% CI 42.4%-76.6%) vs 86.0% (95% CI 68.4%-100.0%) , P =0.004]. ③Multivariate analysis indicated that MRD positive pre-HSCT was the independent risk factor on DFS [ HR =4.565 (95% CI 2.918-9.482) , P <0.001], relapse [ HR =5.854 (95% CI 1.538-22.288) , P =0.010] and NRM [ HR =3.379 (95% CI 1.361-8.391) , P =0.009] after allo-HSCT in CR(1)-AML. Conclusion: MRD positive pre-conditioning was the only negative impact factor for patients with CR(1)-AML after allo-HSCT. MRD by MFC can be used to assess the prognosis of CR(1)-AML after allo-HSCT.