MRD abnormal expression predict poor outcomes for refractory or relapsed acute myeloid leukemia after allogeneic...

We retrospectively analyzed data from 197 patients with refractory or relapsed acute myeloid leukemia (r/rAML) who underwent allo-HCT between January 2013 and February 2020 in our center (patients with promyelocytic leukemia were excluded). Of all patients, 86 achieved a complete morphological remission (CR) before transplant, while 111 failed to do so (NR). In the CR group, 32 patients displayed minimal residual disease (MRD-positive). According to their immunophenotype pre-HCT, we divided the MRD-positive group and NR group into three subgroups: MRD 0+ group (without any antigen abnormal expression of CD7+, CD56+, CD38-, or HLA-DR-) 28 patients, MRD 1+ group (with one abnormal antigen expression of CD7+, CD56+, CD38-, or HLA-DR-) 63 patients, MRD 2+ group (with two or more abnormal antigens expression of CD7+, CD56+, CD38-, or HLA-DR-) 52 patients. 3-year estimates of disease-free survival (DFS) for MRD 0+, MRD 1+ and MRD 2+ patients were 59.5 ± 9.5%, 29.9 ± 6.1%, and 9.4 ± 5.1%, and 3-year estimates of overall survival (OS) were 59.5 ± 9.5%, 34.5 ± 6.3%, and 14.5 ± 10.8%, respectively. Multivariate analysis adjusted for genetic risk, blast cell level, secondary disease, age, sex, and donor relationship pre-HCT, the hazard ratios of abnormal expression of CD7+, CD56+, HLA-DR-, and CD38^- were 6.69 (range 2.08-21.52; p = 0.001) for DFS, 2.24 (range 1.21-4.14; p = 0.010) for OS, and 7.18 (range 2.23-23.10; p = 0.001) for relapse compared with CD7-, CD56-, HLA-DR+, and CD38+ patients. Our finding suggested that abnormal expression of CD7+, CD56+, HLA-DR-, and CD38- is associated with poor outcomes, and the more number of abnormal antigens expression predict worse outcomes.