Objective: Microtransplantation (MST) has been found to enhance clinical outcomes in elderly patients with newly diagnosed acute myeloid leukemia (AML) compared with chemotherapy alone. It is important to investigate clinical effectiveness and mechanisms.
Methods: From January 2012 to December 2022, a total of 40 patients over 60 years with newly diagnosed low - and medium-risk AML were analyzed retrospectively, which was divided into two groups: MST group (chemotherapy combined with donor peripheral blood stem cell [PBSC] injection, n = 20) and control group (chemotherapy alone, n = 20). Flow cytometry and commercial enzyme-linked immunosorbent assay (ELISA) kits were used to measure changes in the percentage of natural killer (NK) cells and the quantity of interferon IFN-γ. The complete remission (CR), 2-year overall survival (OS) and disease-free survival (DFS) were also calculated following therapy.
Results: After induction chemotherapy, the 20 MST patients had a CR rate of 60%, a 2-year OS of 61.8%, and a 2-year DFS of 51.6%.
Conclusion: MST has a faster hematological recovery and a greater CR, both of which can enhance OS and DFS in elderly AML patients. After MST, there is a significant correlation between the percentage of NK cells and the quantity of IFN-γ. This suggests that NK cells and IFN-γ are putative immunologic mechanisms of MST action.
Keywords: Acute myeloid leukemia; elderly patient; interferon-γ; lymphocyte; microtransplantation; natural killer cell.