Causal Characteristics of Immune Cells Associated with Aortic Dissection: A Mendelian Randomisation Analysis

Area of Science:

• Immunology
• Genetics
• Cardiovascular Disease

Background:

• Aortic dissection (AD) is a serious cardiovascular condition with complex etiology.
• Understanding the interplay between immune system function and AD pathogenesis is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the causal relationships between a wide range of immune cell traits and the risk of developing aortic dissection (AD).
• To identify specific immune cell phenotypes and genetic factors that may contribute to AD development.
• To explore the clinical implications of these findings for patient risk stratification and therapeutic interventions.

Main Methods:

• Employed a bivariate Mendelian randomization (MR) framework to analyze causal links between 731 immune cell traits and AD.
• Utilized genome-wide association study summary statistics for immune phenotypes and genetic variants as instrumental variables.
• Performed univariable MR, sensitivity analyses, and assessed horizontal pleiotropy using MR-Egger and MR pleiotropy residual sum and outlier methods.
• Identified cis-expression quantitative trait loci (eQTLs) through the Genotype-Tissue Expression (GTEx) database for tissue-specific expression and pathway analyses.

Main Results:

• Identified five immune cell traits with significant causal effects on AD: four associated with increased risk and one with a protective effect.
• Pathogenic traits included specific B cell and T regulatory cell phenotypes (e.g., CD19, CD39+ CD4+ Treg cells).
• A protective association was found with CD86+ myeloid dendritic cells; key genes SLAMF6 and CD28 were implicated through pathway analysis.

Conclusions:

• Specific immune cell traits may play a causal role in the pathogenesis of aortic dissection.
• The identified immune cell types and genes present potential targets for clinical risk stratification and novel therapeutic strategies for AD.
• Further research is needed to translate these genetic and immunological findings into clinical practice for improved patient outcomes.