Investigation of the Status of Immune Checkpoint Molecules in Meningiomas by Immunohistochemistry.

Aim: To investigate the status of immune checkpoint molecules (CTLA-4 and TIM-3) in meningiomas and thus contribute to the development of new personalized treatment strategies.

Material and methods: We utilized 402 cases of meningioma for this study. New blocks were prepared using the tissue microarray method, and sections obtained from these blocks were immunohistochemically stained with CTLA-4 and TIM-3 antibodies. Subsequently, statistical analysis were performed.

Results: Our findings revealed that CTLA-4 expression were observed in 25.1% of meningiomas. CTLA-4 expression and the number of expressing lymphocytes were found to be significantly higher in high-grade tumors and in those with brain invasion. Meningiomas with staining of immune cells with TIM-3 are 3.5%, and the tumor grade was correlated with the number of immune cells expressing TIM-3.

Conclusion: Immune checkpoint molecules (CTLA-4 and TIM-3) with varying levels of expression can serve as prognostic and predictive biomarkers, as well as important targets for therapy. Drugs developed for CTLA-4 and TIM-3 molecules may prove to be more effective in treating meningiomas with high-grade, brain-invading, spontaneous necrosis, and macronucleolus.