Phenotypic and clinical characterization of low density neutrophils in patients with advanced lung adenocarcinoma

PURPOSE: An immunosuppressive subgroup of neutrophils, low density neutrophils (LDNs) was reported to be closely related to several diseases. This study was designed to explore the association between LDNs and advanced lung adenocarcinoma, as well as potential mechanisms. RESULTS: The expression levels of surface CD molecules on LDNs were different from high density neutrophils (HDNs), consistent with previous studies. The ratio of LDNs/HDNs, rather than the percentage of LDNs in peripheral blood mononuclear cells (PBMCs), was significantly higher in lung adenocarcinoma patients than healthy controls. It was also observed that the ratio decreased when patients received anti-cancer treatments, and increased when disease relapsed. Patients harboring positive epidermal growth factor receptor (EGFR) mutation had significantly higher ratios. Both the ratio and the percentage showed positive correlation with CD8+ T cells. Although significantly increased TGF-β was detected in lung adenocarcinoma patients, relationship between TGF-β and LDNs was not obvious. MATERIALS AND METHODS: LDNs and HDNs levels of peripheral blood from 52 lung adenocarcinoma patients and 13 healthy controls were determined by flow cytometry. Lymphocytes and cytokines were also detected. CONCLUSIONS: Two kinds of neutrophils with different phenotypes were identified in lung adenocarcinoma patients. Besides, we found the existence of high ratio of LDNs/HDNs in these patients, which is related to disease prognosis, EGFR mutation and bad immune status.