Causal Relationship Between Post-Traumatic Stress Disorder and Immune Cell Traits: A Mendelian Randomization Study

Area of Science:

• Immunology
• Psychiatry
• Genetics

Background:

• Post-traumatic stress disorder (PTSD) is a significant mental health condition linked to immune system alterations.
• The precise causal relationship between PTSD and immune function remains unclear, necessitating further investigation.

Purpose of the Study:

• To investigate the bidirectional causal relationship between PTSD and immune cell traits using Mendelian randomization (MR).

Main Methods:

• Conducted forward and backward two-sample Mendelian randomization (MR) analyses.
• Utilized summary-level genome-wide association studies (GWAS) data for PTSD and various immune cell traits.
• Assessed potential pleiotropy to ensure analytical validity.

Main Results:

• Forward MR indicated PTSD causally reduces specific dendritic cell (DC) populations and increases CD28- CD8dim T-cell counts.
• Backward MR revealed causal effects of certain immune traits (CD33, FSC-A, CCR2) on PTSD risk.
• No significant pleiotropy was detected, supporting the robustness of the findings.

Conclusions:

• This MR study establishes a bidirectional causal relationship between immune function, particularly T cells, and PTSD.
• Findings offer novel insights into the interplay between immunity and PTSD, suggesting potential targets for prevention and early intervention.