Objective: To detect the expression levels of programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) in the peripheral blood of patients with oral squamous cell carcinoma (OSCC) and to discuss their biological and clinical significance.
Methods: PD-1/PD-L1 expression on the surface of T-lymphocytes and the counts of T-lymphocyte subpopulations of peripheral blood in 82 patients with OSCC (OSCC group) and 25 healthy controls (control group) were examined via flow cytometry. The expression levels of soluble PD-1 (sPD-1) and soluble PD-L1 (sPD-L1) in the serum were observed through enzyme-link immunology method. The data were tested and analyzed with SPSS 17.0 software.
Results: The percentage of CD8+ T cells in the OSCC group was significantly higher than that in the control group (P<0.05), whereas the percentages of CD3+ and CD4+ T cells as well as CD4+/CD8+ ratio were significantly lower than those in the control group (P<0.05). The positive rates of PD-1 and PD-L1 in CD3+ and CD4+ T cells in OSCC peripheral blood were remarkably higher than those in the control group (P<0.01). Difference was not observed between the expression levels of sPD-1 in the serum of OSCC group and those in the control group (P>0.05), but the average of sPD-L1 was remarkably higher than that in the control group (P<0.05). sPD-L1 expression was related to clinical stage, tumor cell differentiation, and lymph node status (P<0.05) but not related to sex, age, tumor location, and tumor size.
Conclusion: T-lymphocyte subpopulations in the peripheral blood of patients with OSCC developed immunosuppression with different degrees. PD-1 and PD-L1 expression levels on the surface of CD3+ and CD4+ T cells significantly increased. Abnormal increase in sPD-L1 expression may be associated with OSCC development.
目的: 检测口腔鳞状细胞癌患者外周血中程序性死亡分子1（PD-1）及其配体（PD-L1）的表达水平，探讨其生物学及临床意义。
方法: 选取82例口腔鳞状细胞癌患者（口腔鳞癌组）和25例健康对照者（对照组）为研究对象，收集研究对象的外周血，采用流式细胞术检测外周血T淋巴细胞表面PD-1、PD-L1的表达及T淋巴细胞亚群计数，采用酶联免疫吸附方法检测血清中可溶性PD-1（sPD-1）和可溶性PD-L1（sPD-L1）的表达水平。采用SPSS 17.0软件对数据进行检验和相关性分析。
结果: 口腔鳞癌组外周血CD8+ T淋巴细胞百分数明显高于对照组（P<0.05），而CD3+、CD4+T淋巴细胞百分数及CD4+/CD8+T亚群百分数比值均低于对照组（P<0.05）。口腔鳞癌组外周血CD4+、CD8+ T淋巴细胞表面PD-1、PD-L1的阳性表达率均高于对照组（P<0.01）。口腔鳞癌组血清sPD-L1水平高于对照组（P<0.05），而sPD-1水平二者差异无统计学意义（P>0.05）。sPD-L1的表达与临床分期、肿瘤分化程度及淋巴结转移状态相关（P<0.05），与性别、年龄、肿瘤部位及大小无关。
结论: 口腔鳞状细胞癌患者外周血T淋巴细胞亚群存在不同程度的免疫功能抑制，CD4+和CD8+ T淋巴细胞表面PD-1及PD-L1表达显著升高。异常升高的sPD-L1可能与口腔鳞状细胞癌的发生发展有关。