在肺癌患者的支气管肺泡灌注液（BAL）中，程序化细胞死亡蛋白1（PD-1）的表达明显增加。然而，迄今为止，肺癌患者BAL中PD-1阳性T细胞的比例尚未得到充分评估。在这项前瞻性研究中，通过流式细胞术确定了来自肺癌、哮喘或间质性肺病（ILD）患者BAL样本中PD-1阳性CD4+和PD-1阳性CD8+T细胞的比例，并进行了差异比较。在34名患者中（其中14名肺癌患者，10名哮喘患者，10名ILD患者）进行了支气管肺泡灌注。PD-1阳性CD4+或PD-1阳性CD8+T细胞的中位数比例最高的是ILD患者（83.1％[IQR 72.1; 87.5]和73.8％[IQR 60.3; 86.3]），其次是肺癌患者（66.4％[IQR 59; 69]和77.1％[IQR 35.8; 82.3]）和哮喘患者（61.3％[IQR 57.4; 70.5]和57.3％[IQR 46; 65]）。与哮喘患者相比，ILD患者的PD-1阳性CD3+CD4+ BAL细胞比例差异显著（P = 0.04）。肺癌患者BAL中PD-1阳性CD4+和PD-1阳性CD8+T细胞的比例与良性肺疾病患者没有显著差异。ILD患者观察到最高比例，提示有必要进一步研究PD-1/PD-L1通路在ILD患者中的作用。©2023年。作者。

The expression of the programmed cell death protein 1 (PD-1) has been shown to be markedly increased in tumor-infiltrating lymphocytes. However, the proportion of PD-1 + T cells in the bronchoalveolar lavage (BAL) of lung cancer patients has not been sufficiently evaluated so far. In this prospective study, the proportion of PD-1 + CD4 + as well as PD-1 + CD8 + T cells in BAL samples, isolated from patients with lung cancer, asthma or interstitial lung disease (ILD), were determined via flow cytometry and compared for differences. Bronchoalveolar lavage was performed in 34 patients (14 patients with lung cancer, 10 patients with asthma, 10 patients with ILD). The highest median proportion of PD-1 + CD4 + or PD-1 + CD8 + T cells were found in patients with ILD (83.1% [IQR 72.1; 87.5] and 73.8% [IQR 60.3; 86.3]) followed by patients with lung cancer (66.4% [IQR 59; 69] and 77.1% [IQR 35.8; 82.3]) and patients with asthma (61.3% [IQR 57.4; 70.5] and 57.3% [IQR 46; 65]). Thereby, the difference in the proportion of PD-1 + CD3 + CD4 + BAL cells between ILD patients and asthmatics was significantly different (p = 0.04). The proportion of PD-1 + CD4 + and PD-1 + CD8 + T cells in the BAL of patients with lung cancer did not differ significantly to patients with benign lung diseases. The highest proportion was observed in ILD patients suggesting further research to evaluate the role of the PD-1/PD-L1 pathway in ILD patients.© 2023. The Author(s).