The Diagnostic Significance of CXCL13 in M2 Tumor Immune Microenvironment of Human Astrocytoma

Background: CXCL13 may act as a mediator of tumor-associated macrophage immunity during malignant progression. Objective: The present study clarifies the clinicopathological significances of CXCL13 and its corresponding trend with M2 macrophage in human astrocytoma. Methods: The predictive potential of CXCL13 was performed using 695 glioma samples derived from TCGA lower-grade glioma and glioblastoma (GBMLGG) dataset. CXCL13 and M2 biomarker CD163 were observed by immunohistochemistry in 112 astrocytoma tissues. Results: An in-depth analysis showed that CXCL13 expression was related to the poor prognosis of glioma patients (p = 0.0002) derive from TCGA analysis. High level of CXCL13 was detected in 43 (38.39%) astrocytoma and CXCL13/CD163 coexpression was expressed in 33 (29.46%) cases. The immunoreactivities of CXCL13 and CXCL13/CD163 were found in the malignant lesions, which were both significantly associated with grade, patient survival, and IDH1 mutation. Single CXCL13 and CXCL13/CD163 coexpression predicted poor overall survival in astrocytoma (p = 0.0039 and p = 0.0002, respectively). Multivariate Cox regression analyses manifested CXCL13/CD163 phenotype was a significant independent prognostic indicator of patient outcome in astrocytoma (CXCL13, p = 0.0642; CXCL13/CD163, p = 0.0368). Conclusion: CXCL13 overexpression is strongly linked to CD163+ M2 infiltration in malignant astrocytoma. CXCL13/CD163 coexpression would imply M2c-related aggressive characteristics existing in astrocytoma progression could also provide predictive trends of patient outcomes.