CORRELATION BETWEEN PD-L1 PROTEIN AND KI-67 AND CLINICOPATHOLOGICAL FEATURES IN GLIOMA PATIENTS

Wei Du*, Guozheng Xu*, **, #, Bo Diao***, Guojie Yao**, Jian Song**, Ke Wei**, Jie Wu**, Jie Gong**, Ming Yang**

* The First School of Clinical Medicine, Southern Medical University, Guangzhou, PR China - **Department of Neurosurgery, Central Theater General Hospital of PLA, Wuhan, PR China - ***Department of Medical Laboratory Center, Central Theater General Hospital of PLA, Wuhan, PR China

Objective: To analyse the correlation between programmed death receptor-ligand 1 (PD-L1) protein and Ki-67 and clinicopathological features in glioma patients. 

Methods: Sixty cases of glioma resection specimens and 60 cases of adjacent tissue specimens were selected from the tumour center of our hospital from July 2013 to July 2014. The expression of PD-L1 and Ki-67 in glioma tissues was detected by immunohistochemistry to analyse the correlation between the expression of PD-L1 and Ki-67 and clinicopathological features. The relationship between the expression of PD-L1 and Ki-67 and the five-year survival rate of patients was analysed by the Kaplan-Merier survival curve. 

Results: PD-L1 was mainly expressed in the cytoplasm or cell membrane, and yellow and brown particles were positive cells. The positive expression rate of PD-L1 in glioma tissues was 65.00% (39/60), which was significantly higher than that in normal brain tissues at 26.67% (16/60) (P<0.01). Ki-67 was mainly expressed in the nucleus and presented brown-yellow granules as positive cells. The positive expression rate of Ki-67 in glioma tissues was 68.33% (41/60), which was significantly higher than that in normal brain tissues at 30.00% (18/60) (P<0.01). PD-L1 expression in glioma tissues was correlated with necrosis, tumour size and WHO grade (P<0.05). The expression of Ki-67 was correlated with the WHO grade of tumour site (P<0.05). The expression of PD-L1 and Ki-67 was not correlated with age, gender, KPS score or whether there was any invasion of the cerebral lobe (P>0.05). The five-year survival rate of patients with a high expression of PD-L1 and Ki-67 was significantly lower than that of patients with low expression (P<0.05). 

Conclusion: PD-L1 and Ki-67 are highly expressed in glioma tissues, which are related to the WHO grade of glioma and may play a potential role in the occurrence and development of glioma.