A novel molecular classification based on efferocytosis-related genes for predicting clinical outcome and treatment response in acute myeloid leukemia.

Background: Previous studies have shown that macrophage-mediated efferocytosis is involved in immunosuppression in acute myeloid leukemia (AML). However, the regulatory role of efferocytosis in AML remains unclear and needs further elucidation.

Methods: We first identified the key efferocytosis-related genes (ERGs) based on the expression matrix. Efferocytosis-related molecular subtypes were obtained by consensus clustering algorithm. Differences in immune landscape and biological processes among molecular subtypes were further evaluated. The efferocytosis score model was constructed to quantify molecular subtypes and evaluate its value in prognosis prediction and treatment decision-making in AML.

Results: Three distinct efferocytosis-related molecular subtypes were identified and divided into immune activation, immune desert, and immunosuppression subtypes based on the characteristics of the immune landscape. We evaluated the differences in clinical and biological features among different molecular subtypes, and the construction of an efferocytosis score model can effectively quantify the subtypes. A low efferocytosis score is associated with immune activation and reduced mutation frequency, and patients have a better prognosis. A high efferocytosis score reflects immune exhaustion, increased activity of tumor marker pathways, and poor prognosis. The prognostic predictive value of the efferocytosis score model was confirmed in six AML cohorts. Patients exhibiting high efferocytosis scores may derive therapeutic benefits from anti-PD-1 immunotherapy, whereas those with low efferocytosis scores tend to exhibit greater sensitivity towards chemotherapy. Analysis of treatment data in ex vivo AML cells revealed a group of drugs with significant differences in sensitivity between different efferocytosis score groups. Finally, we validated model gene expression in a clinical cohort.

Conclusions: This study reveals that efferocytosis plays a non-negligible role in shaping the diversity and complexity of the AML immune microenvironment. Assessing the individual efferocytosis-related molecular subtype in individuals will help to enhance our understanding of the characterization of the AML immune landscape and guide the establishment of more effective clinical treatment strategies.