Abstract: Objective To analyze the correlation between FEV₁ level and serum cytokine levels in patients with chronic obstructive pulmonary disease (COPD) complicated with active tuberculosis infection, and to provide theoretical evidence for clinical intervention. Method Patients with COPD combined with active tuberculosis infection admitted to the department of respiratory and critical care medicine of the fourth people's hospital of Shaanxi province from January 2019 to April 2022 were included in the study, and patients with COPD control group, tuberculosis control group and conventional control group were included in the same period. General data such as age, gender and lung function of the four groups were compared. The expression levels of natural killer cells (NK), T lymphocyte subsets and cytokines in peripheral blood of patients were compared and analyzed, and the correlation between lung function and T lymphocyte subsets and cytokine expression levels was analyzed. Result There were statistically significant differences in age, smoking history, lung function, NK expression rate, CD4⁺T lymphocyte level, CD8⁺T lymphocyte level and CD4⁺/CD8⁺ ratio among 4 groups of patients (all P<0.05), the levels of SIL2R, IL-6, IFN-γ and TNF-α were significantly higher in COPD patients with tuberculosis than in COPD patients (P<0.05); The levels of FEV₁ were negatively correlated with the levels of Sil2R, TNF-α and IL-6 (r=-0.476,-0.487,-0.596; P<0.05). Conclusion The levels of SIL-2R, IL-6, IFN-γ and TNF-α in COPD patients with active tuberculosis infection were significantly increased, and the increased levels of SIL-2R, TNF-α and IL-6 were significantly correlated with the deterioration of FEV₁.

Key words: Chronic obstructive pulmonary disease, Active pulmonary tuberculosis, Pulmonary function, T lymphocyte subsets, Cytokines, Correlation