Lung cancer is the leading cause of cancer death worldwide. We aim here to determine the soluble programmed death ligand-1 (sPD-L1) and soluble programmed death ligand-2 (sPD-L2) levels in the plasma of patients with lung cancer and evaluate the clinical significance. Plasma samples from 95 lung cancer patients and 55 healthy donors were collected, and the sPD-L1 and sPD-L2 levels were measured using the enzyme-linked immunosorbent assay. The correlations of the plasma sPD-L1 and sPD-L2 levels with clinicopathological status and survival of the patients were analyzed. The sPD-L1 and sPD-L2 levels in plasma of lung cancer patients were 713.8 (240.6–3815) pg/ mL and 3233(1122–13955) pg/ mL, respectively, which were significantly higher than those of the health donors 618.6 (189.1–1149) pg/ mL and 2182 (1133–3471) pg/ mL, and the plasma levels of sPD-L1 are correlated with sPD-L2. ROC results showed that both sPD-L1 and sPD-L2 were potential biomarker for lung cancer, and with a higher accuracy level when combined with CEA. Patients with Higher plasma sPD-L1 level (>713.75 pg/ mL) are associated with poor overall survival in advanced lung cancer patients (197 days vs 643 days). The combination of sPD-L1 and sPD-L2 could be used as adjunctive diagnostic, High level of plasma sPD-L1 rather than sPD-L2 is associated with poor prognosis in lung cancer patients.

中文翻译：

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肺癌患者血浆中sPD-L1和sPD-L2的检测及其临床意义

肺癌是全世界癌症死亡的主要原因。我们的目的是测定肺癌患者血浆中可溶性程序性死亡配体-1（sPD-L1）和可溶性程序性死亡配体-2（sPD-L2）的水平并评估其临床意义。收集 95 名肺癌患者和 55 名健康捐献者的血浆样本，并使用酶联免疫吸附测定法测量 sPD-L1 和 sPD-L2 水平。分析血浆sPD-L1、sPD-L2水平与患者临床病理状态及生存率的相关性。肺癌患者血浆中sPD-L1和sPD-L2水平分别为713.8（240.6-3815）pg/mL和3233（1122-13955）pg/mL，显着高于健康献血者618.6（ 189.1-1149)pg/mL和2182(1133-3471)pg/mL，并且sPD-L1的血浆水平与sPD-L2相关。ROC结果显示，sPD-L1和sPD-L2都是肺癌的潜在生物标志物，且与CEA联合时具有更高的准确度。血浆 sPD-L1 水平较高（>713.75 pg/mL）的患者与晚期肺癌患者的总生存期较差相关（197 天 vs 643 天）。sPD-L1和sPD-L2的组合可用作辅助诊断，高水平的血浆sPD-L1而不是sPD-L2与肺癌患者的不良预后相关。