Causal relationship between immune cells and venous thromboembolism: a bidirectional two-sample Mendelian randomization study.

Background: Venous thromboembolism (VTE), which includes Pulmonary embolism (PE) and Deep vein thrombosis (DVT), is a complex vascular disorder with poorly understood pathological mechanisms. Emerging research highlights the potential involvement of immune cells in the pathogenesis of VTE, although their causal relationship remains unproven.

Methods: To systematically assess the causal relationships between 731 immune phenotypic traits and VTE, PE, and DVT, this study employed a bidirectional, two-sample Mendelian randomization (MR) approach. In the forward MR analysis, immune cell characteristics were treated as the exposure, while VTE, DVT, and PE were the outcomes. In the reverse MR analysis, VTE, DVT, and PE were considered exposures, with immune cell characteristics as the outcomes. To ensure the robustness, heterogeneity, and control for potential confounding factors in the study results, we performed a sensitivity analysis. Furthermore, we applied the False discovery rate (FDR) method to account for statistical bias arising from multiple comparisons.

Results: After FDR correction, we identified potential causal associations between four immune cell types and VTE, six types and PE, and three types and DVT.

Conclusion: This study demonstrates that specific immune cell types are causally linked to VTE, DVT, and PE, providing valuable insights for future clinical research.