Assessing the causal relationship between 731 immunophenotypes and the risk of lung cancer: a bidirectional mendelian randomization study

Previous studies have observed a link between immunophenotypes and lung cancer, both of which are closely associated with genetic factors. However, the causal relationship between them remains unclear. Bidirectional Mendelian randomization (MR) was performed on publicly available genome-wide association study (GWAS) summary statistics to analyze the causal relationships between 731 immunophenotypes and lung cancer. Sensitivity analyses were conducted to verify the robustness, heterogeneity, and potential horizontal pleiotropy of our findings. Following Bonferroni adjustment, CD14 CD16 monocyte (OR = 0.930, 95%CI 0.900-0.960, P = 8.648 × 10 , P = 0.006) and CD27 on CD24 CD27 B cells (OR = 1.036, 95%CI 1.020-1.053, P = 1.595 × 10 - 5, P = 0.012) were identified as having a causal role in lung cancer via the inverse variance weighted (IVW) method. At a more relaxed threshold, CD27 on IgD CD24 B cell (OR = 1.035, 95%CI 1.017-1.053, P = 8.666 × 10 , P = 0.063) and CD27 on switched memory B cell (OR = 1.037, 95%CI 1.018-1.056, P = 1.154 × 10 , P = 0.084) were further identified. No statistically significant effects of lung cancer on immunophenotypes were found. The elevated level of CD14 CD16 monocytes was a protective factor against lung cancer. Conversely, CD27 on CD24 CD27 B cell was a risk factor. CD27 on class-switched memory B cells and IgD CD24 B cells were potential risk factors for lung cancer. This research enhanced our comprehension of the interplay between immune responses and lung cancer risk. Additionally, these findings offer valuable perspectives for the development of immunologically oriented therapeutic strategies.