Causality of immune cells on primary sclerosing cholangitis: a bidirectional two-sample Mendelian randomization study

Area of Science:

• Immunology
• Genetics
• Gastroenterology

Background:

• Primary sclerosing cholangitis (PSC) is associated with immune dysregulation, particularly involving intestinal immune cells.
• The causal relationship between peripheral blood immune cells and PSC is not well understood.

Purpose of the Study:

• To investigate the causal effects between peripheral blood immune cells and primary sclerosing cholangitis (PSC) using a bidirectional two-sample Mendelian randomization analysis.
• To identify specific immune cell markers that may causally influence PSC risk.

Main Methods:

• A bidirectional two-sample Mendelian randomization (MR) analysis was performed using publicly available genetic data.
• The inverse variance weighted (IVW) method was the primary analysis technique, with heterogeneity and pleiotropy assessed using Cochran's Q statistics and MR-Egger intercept.

Main Results:

• Forward MR analysis revealed that increased expression of CD11c on myeloid dendritic cells (DCs) and CD62L-myeloid DC AC were associated with higher PSC risk.
• Conversely, increased CD28 on resting regulatory T cells (Tregs) and CD3 on secreting Tregs were negatively associated with PSC risk.
• Reverse MR analysis indicated a genetic causal effect of PSC on various CD8+ T cell subsets.

Conclusions:

• This study provides evidence for causal relationships between specific peripheral blood immune cells and primary sclerosing cholangitis (PSC).
• These findings may offer a foundation for developing novel diagnostic and therapeutic strategies for PSC.