Introduction: Whether immunohistochemical staining of programmed death ligand 1 (PD‐L1) on cells of pleural effusion could be used to predict response to immunotherapy treatment has not been reported. Methods: We retrospectively enrolled patients who had undergone malignant pleural effusion drainage and had effusion cell block specimens from 2014 to 2016. Immunohistochemical staining for PD‐L1 was performed with tumor cells, immune cells, and macrophages of all cell block specimens. Immunoactivity was scored as 0 for absence of staining and 1+ for faint, 2+ for moderate, and 3+ for intense membranous staining. Patients’ clinicopathological characteristics were also collected. Results: PD‐L1 expression of pleural effusion tumor cells was associated with the PD‐L1 expression of macrophages (p = 0.003) and immune cells (p < 0.001). However, the PD‐L1 expression of immune cells was not associated with that of macrophages. The PD‐L1 expression of tumor cells was correlated with sex (p = 0.012), smoking status (p = 0.032), and Eastern Cooperative Oncology Group performance status (p = 0.017). The PD‐L1 expression of immune cells was associated with the overall survival of patients (p = 0.004). Conclusions: These results suggest that there might be an immune interaction between pleural effusion tumor cells and macrophages. The low intensity of PD‐L1 expression in immune cells is associated with the poor survival of patients with lung cancer with malignant pleural effusion.

中文翻译：

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简报：非小细胞肺癌恶性胸腔积液患者肿瘤细胞、巨噬细胞和免疫细胞PD-L1的表达

介绍：胸腔积液细胞上程序性死亡配体1（PD-L1）的免疫组织化学染色是否可用于预测对免疫治疗的反应尚未见报道。方法：我们回顾性纳入了 2014 年至 2016 年接受过恶性胸腔积液引流术并有积液细胞块标本的患者。对所有细胞块标本的肿瘤细胞、免疫细胞和巨噬细胞进行 PD-L1 免疫组化染色。免疫活性评分为 0 表示没有染色，1+ 表示微弱，2+ 表示中度，3+ 表示强膜染色。还收集了患者的临床病理特征。结果：胸腔积液肿瘤细胞的 PD-L1 表达与巨噬细胞 (p = 0.003) 和免疫细胞 (p < 0.001) 的 PD-L1 表达相关。然而，免疫细胞的 PD-L1 表达与巨噬细胞的表达无关。肿瘤细胞的 PD-L1 表达与性别 (p = 0.012)、吸烟状况 (p = 0.032) 和东部肿瘤合作小组的体能状况 (p = 0.017) 相关。免疫细胞的 PD-L1 表达与患者的总生存期相关（p = 0.004）。结论：这些结果表明胸腔积液肿瘤细胞和巨噬细胞之间可能存在免疫相互作用。免疫细胞中 PD-L1 表达的低强度与恶性胸腔积液肺癌患者的不良生存相关。和东部肿瘤合作小组的表现状态（p = 0.017）。免疫细胞的 PD-L1 表达与患者的总生存期相关（p = 0.004）。结论：这些结果表明胸腔积液肿瘤细胞和巨噬细胞之间可能存在免疫相互作用。免疫细胞中 PD-L1 表达的低强度与恶性胸腔积液肺癌患者的不良生存相关。和东部肿瘤合作小组的表现状态（p = 0.017）。免疫细胞的 PD-L1 表达与患者的总生存期相关（p = 0.004）。结论：这些结果表明胸腔积液肿瘤细胞和巨噬细胞之间可能存在免疫相互作用。免疫细胞中 PD-L1 表达的低强度与恶性胸腔积液肺癌患者的不良生存相关。