CD27 and GZMK as Co-Biomarkers in Rheumatoid Arthritis and Crohn's disease and Mediate Immune Imbalance.

Background: Studies have found similar immune responses, genetic susceptibility, and inflammatory mediators between Rheumatoid arthritis (RA) and Crohn's disease (CD), but these findings are controversial.

Methods: The Gene Expression Omnibus (GEO) was utilized to get microarray data. Differentially expressed genes (DEGs) in individuals with CD and RA were identified. Weighted gene co-expression network analysis (WGCNA) was used to identify key modular genes in CD and RA. The least absolute shrinkage and selection operator (LASSO) logistic regression was used to identify hub genes. The correlation between immune cell infiltration and common biomarkers was examined by utilizing the GSEA and ssGSEA.

Results: CD27 and GZMK were recognized as co-biomarkers in RA and CD. The analysis of immune infiltration revealed a significant relationship between a range of immune cells, including CD8 T cell, MDSC, and natural killer T cell, and both RA and CD.

Conclusion: CD27 and GZMK are biomarkers shared by CD and RA and are potential diagnostic and therapeutic targets for them, especially in patients with CD combined with RA. CD and RA are highly associated with dysregulation of the acquired immune response system and imbalance of the innate immune system.