Background Glioblastoma is the most aggressive primary malignant brain tumor in adults and is characterized by poor prognosis. Immune evasion occurs via programmed death-ligand 1 (PD-L1)/programmed death receptor 1 (PD-1) interaction. Some malignant tumors have responded to PD-L1/PD-1 blockade treatment strategies, and PD-L1 has been described as a potential predictive biomarker. This study discussed the expression of PD-L1 and CD8 in glioblastomas.
Methods Thirty cases of glioblastoma were stained immunohistochemically for PD-L1 and CD8, where PD-L1 expression in glioblastoma tumor tissue above 1% is considered positive and CD-8 is expressed in tumor infiltrating lymphocytes. The expression of each marker was correlated with clinicopathologic parameters. Survival analysis was conducted to correlate progression-free survival (PFS) and overall survival (OS) with PD-L1 and CD8 expression.
Results Diffuse/fibrillary PD-L1 was expressed in all cases (mean expression, 57.6%), whereas membranous PD-L1 was expressed in six of 30 cases. CD8-positive tumor-infiltrating lymphocytes (CD8+ TILs) had a median expression of 10%. PD-L1 and CD8 were positively correlated (p = .001). High PD-L1 expression was associated with worse PFS and OS (p = .026 and p = .001, respectively). Correlation of CD8+ TILs percentage with age, sex, tumor site, laterality, and outcomes were statistically insignificant. Multivariate analysis revealed that PD-L1 was the only independent factor that affected prognosis.
Conclusions PD-L1 expression in patients with glioblastoma is robust; higher PD-L1 expression is associated with lower CD8+ TIL expression and worse prognosis.
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Analysis of PD-L1 and CD3 Expression in Glioblastoma Patients and Correlation with Outcome: A Single Center Report Navid Sobhani, Victoria Bouchè, Giovanni Aldegheri, Andrea Rocca, Alberto D’Angelo, Fabiola Giudici, Cristina Bottin, Carmine Antonio Donofrio, Maurizio Pinamonti, Benvenuto Ferrari, Stefano Panni, Marika Cominetti, Jahard Aliaga, Marco Ungari, Antonio Fi Biomedicines.2023; 11(2): 311. CrossRef