Increased circulating PD-L1 expressing CD14 high CD16 negative classical monocytes correlate with poor prognosis in cancer patients treated with PD-1 blockade therapies (AACR 2022)
As monocytes can be further classified into subsets (classical, intermediate, non-classical), we herein investigated the prognostic factors in peripheral blood mononuclear cell (PBMC) subsets and assessed the clinical significance for the PD-L1-expressing subsets of each of these cells including classical, intermediate and non-classical monocyte subsets in patients with various cancer types, along with their clinical implications in PD-1 blockade therapies.Material and We evaluated 44 patients (20 with gastric cancer, 17 with non-small cell lung carcinoma, and 7 with esophageal cancer) undergoing PD-L1 blockade therapy (pembrolizumab or nivolumab) for PD-L1 expression levels in classical (CD14high, CD16-), intermediate (CD14high, CD16+), and non-classical (CD14low, CD16+) monocytes measured via flow cytometry before ICI treatment. Circulating PD-L1-expressing classical monocytes in the peripheral bloods were associated with poor prognosis in patients treated with PD-1 blockade therapies. Among the monocyte subsets, classical monocyte, especially PD-L1-expressing classical monocytes can be a potential biomarker for prognosis in these patients.