To explore immune cell infiltration and PDL1 expression in the tumor microenvironment (TME) of primary central nervous system lymphoma (PCNSL), we performed immunohistochemical staining on paraffin-embedded tumor tissues from 34 patients diagnosed with PCNSL. CD8 and CD163 positive cells were manually counted, and PDL1 expression was quantified by the H-score scoring method in the tumor center and around the tumor. The Kaplan-Meier method was used to analyze the prognostic value of the TME. We found obvious infiltration of CD8+ CTLs and CD163+ TAMs in the TME of PCNSL patients. And PDL1 was expressed in the tumor center as well as around the tumor. Survival analysis showed that high CD8+ CTLs levels and high intratumoral PDL1 expression were significantly correlated with longer OS. High CD8+ CTLs and CD163+ TAMs levels were associated with longer PFS.
Keywords: CD163+ TAMs; CD8+ CTLs; PDL1; Primary central nervous system lymphoma; tumor microenvironment.