Causal relationship between immune cells and posttraumatic stress disorder: a bulk two-sample Mendelian randomization study

Background: There is increasing evidence that the immune system is associated with posttraumatic stress disorder (PTSD). However, the causal relationship between immune cells and PTSD and the possible related types of immune cells are still unclear. Aim: To determine the causal relationship between immune cells and PTSD. Two-sample Mendelian randomization (MR) analysis was then performed. Materials and Methods: The exposure and outcome data used in this study were obtained from a GWAS (https://gwas.mrcieu.ac.uk/). Two-sample MR analysis was performed to assess the causal relationships between 731 types of immune cell features and PTSD. We used 731 types of immune cells for exposure and PTSD as the outcome. Our MR analysis uses a variety of methods to ensure the robustness of the experiment. For each immune cell that may be related to PTSD, we adopted a sufficient number of methods to ensure the accuracy and effectiveness of the results. Results: Our study identified potential causal relationships between various immune cells and PTSD. We identified 10 types of immune cells that are potentially causally linked to PTSD. CD33-related cells are the most prominently related immune cells. Conclusions: Our study determined the causal relationship between a variety of immune cells and PTSD via MR, which can provide help for future clinical practice.