Primary biliary cirrhosis and rheumatoid arthritis: a comprehensive study combining genetics and transcriptomics

Area of Science:

• Genetics
• Immunology
• Hepatology

Background:

• Observational studies suggest a correlation between primary biliary cirrhosis (PBC) and rheumatoid arthritis (RA).
• The underlying genetic factors and shared biological pathways contributing to this association remain largely unexplored.
• Understanding this relationship is crucial for patient management and disease prevention.

Purpose of the Study:

• To investigate the bidirectional genetic correlation between PBC and RA using a Mendelian randomization approach.
• To identify specific genes and signaling pathways implicated in the shared disease risk.
• To explore the potential diagnostic utility of identified genes.

Main Methods:

• Acquired genome-wide association studies (GWAS) summary data for PBC and RA.
• Employed a bidirectional two-sample Mendelian randomization (MR) analysis.
• Conducted sensitivity analyses (heterogeneity, pleiotropy, outlier, Leave-One-Out) and ROC curve analysis.
• Performed SNP-associated gene mapping and pathway enrichment analysis.

Main Results:

• MR analysis confirmed a significant positive bidirectional disease risk correlation between PBC and RA (PBC to RA: OR=1.081, P<0.001; RA to PBC: OR=1.702, P<0.001).
• No evidence of heterogeneity, horizontal pleiotropy, or outliers was detected.
• Identified 14 candidate genes, with enrichment in chemokine signaling, JAK-STAT signaling, and Th1/Th2 cell differentiation pathways. IL12RB2, CCR6, and MANBA were highlighted as key mediators.
• MANBA showed potential diagnostic value via ROC curve analysis.

Conclusions:

• PBC and RA exhibit a bidirectional genetic correlation, acting as mutual risk factors.
• Clinical vigilance is recommended for patients with RA regarding PBC development, and vice versa.
• Identified genes and pathways offer insights into shared molecular mechanisms and potential therapeutic targets.