Programmed death ligand 1 and tumor-infiltrating CD8+ T lymphocytes are associated with the clinical features in meningioma

Objective To investigate the expression of programmed death ligand-1 (PD-L1) and the levels of CD8(+) tumor-infiltrating lymphocytes (TILs) in meningioma as well as determine the association between their levels and the clinical outcomes. Methods We performed a retrospective case-control study on 93 patients with meningioma. The patients showed tumor recurrence and were matched with the control patients without recurrence in their age, gender, admission time, tumor sites, tumor volume, peritumoral brain edema (PTBE), Simpson grade resection, WHO grade, postoperative radiotherapy, and the follow-up duration. We reviewed the clinical data of patients and performed immunohistochemistry analysis to investigate the PD-L1 expression and the levels of CD8(+) TILs. Multivariate logistic regression was performed to analyze the association between clinical features and immune markers. The conditional logistic regression models were used to calculate the odds ratios (ORs) with 95% confidence intervals (CIs), and Kaplan-Meier analysis was performed to analyze tumor recurrence. Results Tumor volume was correlated with the PD-L1 expression (P = 0.003, HR = 5.288, 95%CI, 1.786-15.651). PTBE served as an independent predictor of CD8(+) TIL levels (P = 0.001, HR = 0.176, 95%CI 0.065-0.477). The levels of CD8(+) TILs were associated with tumor recurrence (P = 0.020, OR = 0.325, 95%CI, 0.125-0.840). Conclusion Tumor volume was associated with PD-L1 expression, and PTBE was an independent predictor of CD8(+) TIL levels in meningioma. CD8(+) TIL levels correlated with tumor recurrence in meningioma.