中国生物工程杂志

Objective: To investigate the characteristics and prognostic significance of Ki-67 antigen expression at diagnosis in adult t(8;21) acute myeloid leukemia (AML).Methods: Bone marrow samples of 57 adult t(8;21) AML patients were collected at diagnosis from July 2012 to February 2019 in our hospital, their frequencies of Ki-67 in CD34 ⁺ cells were detected by flow cytometry method, and the relationships between Ki-67 and the biological characteristics, therapeutic effect and relapse were analyzed. Results: Of all patients tested, the median percentage of CD34 ⁺Ki-67 ⁺ cells were 30.5% (range: 10.0%~65.8%); A receiver operating characteristic (ROC) curve was used to identify the optimal cutoff levels of CD34 ⁺Ki-67 ⁺ cells, higher frequencies of CD34 ⁺Ki-67 ⁺ cells were significantly related to higher rate of c-KIT mutation and lower WT1 transcript level at diagnosis (P=0.001; P=0.042). Of all patients followed up, higher frequency of CD34 ⁺Ki-67 ⁺ cells was significantly related to a higher 1-year cumulative incidence relapse (CIR) rate (P=0.035). In addition, both lower WT1 transcript level at diagnosis and higher level of minimal residual diseases (MRD, < 3-log reduction of the RUNX1-RUNX1T1 transcript level after the second consolidation therapy) were significantly related to a higher 1-year CIR rate (P<0.000 1; P=0.041), and patients with c-KIT mutation and white blood cell count>10×10 ⁹/L at diagnosis tended to have higher 1-year CIR rates, respectively (P=0.091; P=0.054). Patients simultaneously with high frequency of CD34 ⁺Ki-67 ⁺ cells and high MRD levels have a significantly higher 1-year CIR rate than others (P<0.000 1). Conclusion: In adult patients with t(8;21) AML, high frequency of CD34 ⁺Ki-67 ⁺ cells at diagnosis may be a poor prognostic factor, combination of MRD levels and frequency of CD34 ⁺Ki-67 ⁺ cells at diagnosis may better predict relapse than MRD alone.