Podoplanin expression is associated with local inflammation and survival in glioma

Glioma subtypes differ in prognosis and treatment strategies. We aimed to determine the correlation of podoplanin (PDPN) expression in glioma subtypes with survival as well as systemic and local inflammation. In a prospective cohort study including 192 patients with glioma, tumor-infiltrating lymphocytes (TILs), programmed cell death ligand 1 (PD-L1) expression and podoplanin (PDPN) expression were analyzed by immunohistochemistry. PDPN and PD-L1 expression were more frequently observed in IDH1 wildtype (wt) compared to IDH1 mutant (mut) glioma (p = 0.015). In IDHwt glioma, overall survival was significantly longer in glioma patients without PDPN expression compared to those with PDPN expression (median 26.3 vs. 12.5 months, log-rank test, p < 0.001). Levels of tumor-infiltrating CD8 + and CD68 + cells were highest in IDH1wt glioma with both PDPN and PD-L1 expression (p < 0.001). IDH1wt, PDPN and non-PD-L1 expressing glioma presented with the highest neutrophil-to-lymphocyte (NLR) ratio in the blood compared to other subtypes (p = 0.023). Gliomas differ in the composition of the inflammatory microenvironment according to the presence of IDH1 mutation. Podoplanin, a marker of innate inflammation, is associated with survival prognosis and systemic inflammation in patients with IDH1wt glioma.