Inflammatory bowel disease and rheumatoid arthritis share genetic similarities, says recent study!

The latest study featured in the publication 'Frontiers in Immunology' sought to establish the genetic connection between inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) to explain the high rate of coexistence between the two conditions. Guoling Cao and colleagues took data from the genome-wide association study on IBD and RA. They used linkage disequilibrium score regression (LDSC) to assess overall genetic associations, followed by local correlation analysis to estimate heritability in summary statistics. Two-sample Mendelian randomization was employed to analyze causality between the diseases, and genetic overlap was investigated using the conditional/conjoint false discovery rate (cond/conjFDR) method. Additionally, LDSC with gene analysis of specific expression was used to identify related tissues, and a GWAS multi-trait analysis (MTAG) was also conducted.

As revealed, IBD and RA showed genomic correlations both generally and specifically. Findings suggest that IBD can induce RA development. Overall, 20 shared genetic locations between IBD and RA were discovered. Additionally, the spleen and small intestine terminal ileum emerged as common tissues linked to both diseases.

This study confirmed a polygenic overlap in the genetic profiles of IBD and RA, shedding light on their shared genetic architecture and mechanisms contributing to their high co-occurrence.