Inflammatory bowel disease and allergic diseases: A Mendelian randomization study

Area of Science:

• Genetics
• Immunology
• Epidemiology

Background:

• Inflammatory bowel disease (IBD) and allergic diseases share similar genetic and pathogenic pathways.
• Observational studies suggest a correlation, but the causal direction is unclear.

Purpose of the Study:

• To investigate the bidirectional causal relationship between IBD and allergic diseases using Mendelian randomization (MR).

Main Methods:

• Bidirectional MR study utilizing genome-wide association study summary data.
• Inverse variance weighted (IVW-RE) and multivariate Mendelian randomization (MVMR) analyses were performed.
• Body mass index (BMI) was adjusted for in MVMR analyses.

Main Results:

• IBD significantly increased the risk of overall allergic disease, allergic conjunctivitis (AC), and atopic dermatitis (AD).
• Crohn's disease (CD) specifically elevated the risk for overall allergic disease, AC, AD, allergic asthma (AAS), and allergic rhinitis (AR).
• Reverse MR analysis showed no significant association between allergic diseases and IBD.

Conclusions:

• IBD, particularly CD, is a significant risk factor for developing allergic diseases.
• The findings highlight a causal link from IBD to allergic conditions like AC, AD, AAS, and AR.
• Further research is warranted to elucidate the complex causal interplay between allergic diseases and IBD.