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Updated: Feb 25, 2026
Quantitative Immunohistochemistry of the Cellular Microenvironment in Patient Glioblastoma Resections
Published on: July 31, 2017
Tumour-associated microglia/macrophages predict poor prognosis in high-grade gliomas and correlate with an aggressive
M D Sørensen1,2, R H Dahlrot3, H B Boldt1
1Department of Pathology, Odense University Hospital, Odense, Denmark.
Aims:
Glioblastomas are highly aggressive and treatment resistant. Increasing evidence suggests that tumour-associated macrophages/microglia (TAMs) facilitate tumour progression by acquiring a M2-like phenotype. Our objective was to investigate the prognostic value of TAMs in gliomas using automated quantitative double immunofluorescence.
Methods:
Samples from 240 patients with primary glioma were stained with antibodies against ionized calcium-binding adaptor molecule-1 (IBA-1) and cluster of differentiation 204 (CD204) to detect TAMs and M2-like TAMs. The expression levels were quantified by software-based classifiers. The associations between TAMs, gemistocytic cells and glioblastoma subtype were examined with immuno- and haematoxylin-eosin stainings. Three tissue arrays containing glioblastoma specimens were included to study IBA-1/CD204 levels in central tumour and tumour periphery and to characterize CD204+ cells.
Results:
Our data revealed that the amount of especially CD204+ TAMs increases with malignancy grade. In grade III-IV, high CD204 expression was associated with shorter survival, while high IBA-1 intensity correlated with a longer survival. In grade IV, CD204 showed independent prognostic value when adjusting for clinical data and the methylation status of O6-methylguanine-DNA methyltransferase. Our findings were confirmed in two bioinformatics databases. TAMs were more abundant in central tumour tissue, mesenchymal glioblastomas and gliomas with many gemistocytic cells. CD204+ TAMs co-expressed proteins related to tumour aggressiveness including matrix metallopeptidase-14 and hypoxia-inducible factor-1α.
Conclusions:
This is the first study to use automated quantitative immunofluorescence to determine the prognostic impact of TAMs. Our results suggest that M2-like TAMs hold an unfavourable prognostic value in high-grade gliomas and may contribute to a pro-tumourigenic microenvironment.
Insights
Tumor-associated macrophages (TAMs) with an M2-like phenotype, identified by CD204 expression, are linked to poorer outcomes in high-grade gliomas. This study used automated immunofluorescence to assess TAMs
Area of Science:
- Neuro-oncology
- Immunology
- Pathology
Background:
- Glioblastomas are aggressive brain tumors with limited treatment options.
- Tumor-associated macrophages/microglia (TAMs) with an M2-like phenotype are implicated in promoting tumor progression.
Purpose of the Study:
- To investigate the prognostic value of TAMs in gliomas using automated quantitative double immunofluorescence.
- To correlate TAMs and M2-like TAMs with glioma malignancy and patient survival.
Main Methods:
- Analyzed 240 primary glioma samples using double immunofluorescence for IBA-1 and CD204.
- Quantified TAM and M2-like TAM expression via software-based classifiers.
- Examined associations with gemistocytic cells, glioblastoma subtypes, and tumor location.
Main Results:
- CD204+ TAMs increased with glioma malignancy grade.
- High CD204 expression correlated with shorter survival in high-grade gliomas (grades III-IV).
- CD204 demonstrated independent prognostic value in grade IV glioblastoma, and co-expressed with aggressive tumor markers.
Conclusions:
- Automated quantitative immunofluorescence provides prognostic insights into TAMs.
- M2-like TAMs (CD204+) have an unfavorable prognostic value in high-grade gliomas.
- TAMs likely contribute to a pro-tumourigenic microenvironment in gliomas.
