Comprehensive exploration of tumor mutational burden and immune infiltration in diffuse glioma

Kai Kang1, Fucun Xie2, Yijun Wu1

  • 1Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.

Abstract

Insights

Tumor mutational burden (TMB) correlates negatively with diffuse glioma prognosis. Immune cell infiltration impacts TMB and outcomes, informing immunotherapy selection and target identification.

Area of Science:

  • Neuro-oncology
  • Immunology
  • Genomics

Background:

  • Immune checkpoint inhibitors (ICIs) show variable efficacy in diffuse gliomas.
  • Tumor mutational burden (TMB) and immune infiltration are potential factors influencing ICI response.

Purpose of the Study:

  • To investigate the relationship between TMB and immune infiltration in diffuse gliomas.
  • To explore their combined impact on patient prognosis and potential for predicting ICI efficacy.

Main Methods:

  • Differential gene expression analysis (DESeq2) and construction of a gene risk score model.
  • Development of a nomogram incorporating clinical features.
  • Analysis of TMB and immune infiltration using the CIBERSORT algorithm to build an immune risk score model.
  • Validation of models using TCGA and CGGA datasets.

Main Results:

  • Higher TMB correlated with worse prognosis, older age, higher tumor grade, and increased immune checkpoint expression.
  • A gene risk score model (BIRC5, SAA1, TNFRSF11B) and a nomogram (age, grade) predicted prognosis.
  • Immune risk score model identified M0 macrophages and neutrophils associated with high TMB and poor prognosis, while naïve CD4+ T cells and activated mast cells showed opposite correlations.

Conclusions:

  • TMB is a negative prognostic factor in diffuse gliomas.
  • Specific immune cell types differentially associate with TMB and prognosis.
  • Developed models accurately predict diffuse glioma prognosis, aiding in patient stratification for ICIs and identifying therapeutic targets.

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