Characteristics of Peripheral Blood Lymphocyte Populations in Patients with Locally Advanced Unresectable Non-Small Cell Lung Cancer

Background: The main type of treatment of unresectable NSCLC is chemoradiotherapy, which has a relatively high toxicity. One option allowing to reduce the toxicity of this approach may be immunocorrective therapy. The appointment of this type of treatment should be warranted in terms of patient’s immune system response. This confirms the importance of verifying systemic immune disorders in primary patients with NSCLC. Goal: To assess the features of the population of immune cells in peripheral blood in patients with stage IIIB, IIIC primary NSCLC and to identify any signs of secondary immunodeficiency in this cohort. Methods: We analyzed the frequencies of circulating T cells (CD3+, CD4+, CD8+), B-cells (CD19+), NK-cells (CD3-CD16+CD56+ cell), and NKT-cells (CD3+CD56+ cells) within CD45+ cells (lymphocytes) in 80 patients with stage IIIB-IIIC NSCLC, and in 40 healthy controls using eight-color flow cytometry. Results: In patients with stages IIIB-IIIC primary NSCLC, changes within immunocompetent blood cells were found. Moreover, it was unveiled that quantitative changes affected all major immunocompetent cells. A decrease in the proportion of CD4+ T cells and B lymphocytes and an increase in the number of NK and NKT cells were found. Also, an increase in the number of double-positive CD4+CD8+ T cells was revealed, as well as a significant increase in the proportion of B1a (CD5+CD19+) cells among B lymphocytes (qualitative disorders). Conclusion: The revealed multidirectional changes among immunocompetent peripheral blood cells in patients with locally advanced NSCLC (stages IIIB-IIIC) can be beyond doubt considered as signs of systemic immune disorders in this cohort (secondary immunodeficiency). © 2025 by the authors.