More severe lung lesions in smoker patients with active pulmonary tuberculosis were associated with peripheral NK cell subsets

Background Both pulmonary tuberculosis (PTB) and cigarette smoke (CS) exposure may lead to lung damage. The potential impact of CS exposure on tuberculosis-associated lung damage and the disturbance of immune cells and mediators involved, need to be further elucidated. Methods We firstly evaluated the chest X-ray (CXR) scores of a retrospective cohort of male patients with active PTB, followed for 6 months, and compared the scores between smoker (≥10 pack-years) and non-smoker patients. In a cross-sectional study, we measured the peripheral blood NK cell subsets and plasma inflammatory cytokines in male smoker and non-smoker patients with active PTB before anti-tuberculosis therapy, and the proportions of NK cell subsets and the levels of cytokines were analyzed for correlation with the CXR scores. Results In the retrospective cohort, male smoker patients with active PTB showed a higher CXR score, characterized by more cavitary lesions, enlarged lymph nodes and emphysema, as compared to non-smokers. The cross-sectional study revealed that the CXR score in smoker patients was correlated inversely with the percentages of blood CD107a + , NKP46 + , and TIGIT + NK cells. Conclusion In patients with active PTB, CS exposure was associated with more severe lung lesions, which were correlated with peripheral NK cell subsets.