Immunophenotype of neutrophils in oral squamous cell carcinoma patients

Abstract

Background: The aim was to explore the immunophenotype of neutrophils and lymphocytes and the inflammatory mediators in patients with oral squamous cell carcinoma, comparing with controls; and to associate with clinicopathological data.

Methods: Blood was collected from 13 patients and 13 controls. The immunophenotype of neutrophils (CD66b, CD16, CD11a, arginase-1), T lymphocytes (CD4, CD8) and the intracellular cytokine production (IL-10, TNF, IFN-γ) was evaluated by flow cytometry. Plasma concentration of sVCAM-1, sTNF-RI, sTNF-RII, and IL-1β was measured by ELISA. MPO, Lipocalin-2/NGAL, sICAM-1, and p-selectin were quantified by Luminex assay. The excised tumors were submitted to immunohistochemistry for neutrophils (CD66b) and lymphocytes (CD3, CD4, CD8). Association with clinical data was explored. P values <.05 were considered significant.

Results: Patients presented higher percentage of neutrophils and lower lymphocytes, resulting a higher neutrophil/lymphocyte ratio than controls. They also presented higher percentage of neutrophils expressing CD66b⁺ , CD66b⁺ Arginase-1⁺ , CD66b⁺ IL10⁺ , CD66b⁺ TNF⁺ , CD66b⁺ Arginase-1⁺ IL-10⁺ , and lower CD66b⁺ CD16⁺ CD11a⁺ and CD66b⁺ Arginase-1⁺ TNF⁺ . CD66b⁺ neutrophils were detected in all tumors, with a CD66b⁺ /CD3⁺ ratio of 0.40. Patients showed higher concentration of plasmatic sVCAM-1 and lower Lipocalin-2/NGAL. Patients with good outcome presented lower percentage of neutrophils, higher percentage of lymphocytes, and lower NLR than patients who died.

Conclusion: The amount and immunophenotype of neutrophils and lymphocytes differ between patients and healthy individuals, with a pro-tumorigenic profile of neutrophils. As these cells also get within tumor microenvironment, they possibly exert systemic and local functions in cancer pathogenesis. The association of neutrophil count with outcome corroborates recent studies and this merits further investigation for applicability as a prognosticator.

Keywords: ELISA; flow cytometry; immunohistochemistry; neutrophils; outcome; squamous cell carcinoma.